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Model 2182/2182A Nanovoltmeter
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1. seen 9 5 External scanning example with Model 7001 eese 9 11 Waveform to be programmed into Model 2400 esses 9 14 Setup of Model 2182 and Model 2400 seen 9 15 Remote Operation Hiis hhSUDd Ud EE 11 6 IEEE 488 COMMCCHONS cesses acarani eese pe Ms eR PR Re Ea 11 7 IEEE 488 connector location esee eene nnnennne 11 7 Model 2182 status model structure essere 11 14 Standard event status esses eene eene nnne nnne nns entere ena 11 16 Operation event sCatus e e pecie rere rites teri prese Ee ae E Eee HEURE CES E ERR FEE aE TEE 11 16 Measurement event Status ceecceeccsseeeeeceseeeeeeceseeceeeceaeeeeeeceaeeeteeseaeesteeesae 11 17 Questionable event status cccccsssssccecessssseccceessssecceceessseeececessseeeeceessenees 11 17 Status byte and service request nen eee 11 19 RS 232 interface connector eese eee eee eene tn etn nne tne tn nett n ee T ER 11 29 12 Figure 12 1 Figure 12 2 Figure 12 3 Figure 12 4 15 Figure 15 1 Figure 15 2 Figure 15 3 Figure 15 4 Figure 15 5 Figure 15 6 Figure 15 7 Figure 15 8 Figure 15 9 Figure 15 10 C Figure C 1 Figure C 2 Figure C 3 Figure C 4 Figure C 5 F Figure F 1 Figure F 2 Figure F 3 Figure I 1 Figure I 2 Figure I 3 Figure I 4 Figure I 5 Figure I 6 Figure I 7 Common Commands Standard eve
2. 14 4 SCPI Reference Tables Table 14 1 CALCulate command summary cont Default Command Description Parameter Ref SCPI IMMediate Clear limit test results V AUTO lt b gt Enable or disable clearing of limit test results ON v when a new trigger model cycle starts AUTO Query state of auto clear v LIMit2 Limit 2 Testing v UPPer Configure upper limit v DATA n Specify limit 100e6 to 100e6 2 v DATA Query upper limit v LOWer Configure lower limit v DATA n Specify limit 100e6 to 100e6 2 v DATA Query lower limit V STATe lt b gt Enable or disable Limit 2 test OFF v STATe Query state of Limit 2 test v FAIL Return result of Limit 2 test 0 pass or 1 fail V CLEar Clear test results v IMMediate Clear limit test results V AUTO lt b gt Enable or disable clearing of limit test results ON v when a new trigger model cycle starts AUTO Query state of auto clear v QMMediate Recalculate limit tests v Table 14 2 CALibration command summary user accessible Default Command Description Parameter Ref SCPI CALibration See Note UNPRotected Calibration accessible to operator ACALibration ACAL procedure Sec 2 INITiate Prepares 2182 for ACAL STEP1 Performs a full ACAL 100V and 10mV STEP2 Performs a limited ACAL 10mV only DONE Exit ACAL mode TEMPerature Queries the internal temperature at the time of last ACAL If present internal temperature
3. ettet retener tenere 7 9 External triggering with BNC connections eeeeee 7 12 SCPI programming triggering sese nne nnne 7 13 Trigger model remote operation eeeeeeeeeeeeeenrnee 7 13 Trigger model operation 5 rne treten inis 7 15 Triggering commands oi cccss cases ceevesscesda sede coausenseecivsscuctesbevessuuesasesseeveesseaiseey 7 16 Programmmg example e garwasucaissteassieaveasusvasasveadacssevssnaceniesasgiesnsscaaseny 7 17 Limits Latnit operations 2 ctii Perd tr ioo ra re doa sade rep EPA e UR UHR orae 8 3 Setting limit values i ase eeina NEn E Ea eet sp ee uade E gend e ka Rua 8 4 Enabling luis seraient ito ree teen Ope Ce ena 8 4 SCPI programming limits eee ika ecd Sapete 8 5 Application irri eh edt p Ee D PE EOD eb ub LA epa rre Ee bean 8 7 Sorting CE GIC C ES ERROPE D 8 7 10 11 Stepping and Scanning Step Scan OVELVICW T 9 3 Internal Stepping Scanning Channels 1 and 2 esses 9 3 External Stepping Scanning esee eene 9 3 Front panel trigger models sitet reete tera it rere debe ipee tienes 9 4 Internal scanmin Mr 9 4 Other Stepping Scanning operations sese 9 6 Stepping Scanning controls eeseseeseseeeeeeenenee nennen eene nenne 9 6 Step Scan configuration 0 0 ee eeeses
4. sese C 2 Thermoelectric generation essent een rennen nennen nens C 3 Source resistance noise ssesseeseeeseeeeeeeene nennen nennen nennen nen etre C 4 Magnetic fields ete eaeque epe AES C 6 Radio frequency interference essere nennen C 6 Ground loops s t ee eee iii eerte let tiere ania had C 6 shielding 5 retener tro en ere re ete ie teatime ERA C 8 hiodbrna p mm ds C 9 Model 182 Emulation Commands Example Programs Program examples tn tet ie detur do i ovra EU RR erae ete i E 2 Changing function and range eeeeseeseeeseeeeeeeeeenene enne nnne E 2 One Shot fig gerig uis e er irsinin aetas aae eas eei Seen verto ane Sani cb E 4 Generating SRQ on buffer full eese nennen E 5 Storing readings in buffer oo eee eeseeeeceecesseeeeceeeeeeeaeeeseeceaeeeeeeseeeeeeeeeaes E 6 Taking readings using the READ command eee E 7 Controlling the Model 2182 via the RS 232 COM2 port esse E 8 IEEE 488 Bus Overview ice PE H F 2 lic EMITIR F 2 Bus MNES m F 4 Data MMES A F 4 Bus management lines eessesseeeseeeeeeee nennen nnne entente ns F 4 Handshake lines iie rettet eri Ei ria NE F 5 B s conimands sie dii ce rade erre eer Ive ra TA E ded EY a Y Er a dpa F 6 Uniline commands
5. 15 3 SPE XT COMM ANS rd tmt a a a EEEE E A o raie iia 15 3 FORMat subsystem 1 ein eeepc ted ere tte peti ene te E EN iR a aisi 15 4 DATA command PEDE 15 4 BORDer Command sirene a EE R RS Ea 15 6 SELEMents commaltd huerto c rere E aA 15 6 STAT us SubsyStem uie trece tertie Hed ted pei pee Pub d deba d redigere 15 7 EVENt command issenensis rerea aeaa nennen nennen enne enne nnns 15 7 BNABIe command SIG eee es 15 11 CONDition command sess eene eene nnns 15 13 PRESetcoimmatid crei eed dd eate aa RENE CRPe eet 15 14 QUEue commands esses eene nennen nnne nennen 15 14 NBenEDPMDE T 15 16 PRESet coinimalld conet R ta eret aede Ee end 15 16 Performance commands eret tees catur S c a ee a ean 15 16 BEBPer command ceret inerte ttr FAE ERER ES EREE 15 18 KCDLick command eui iride reete store nce Fee ehe pese EXER RSEN EURS 15 18 POSetup name command esee 15 18 SVERSION command eaea EEEE E RR 15 19 SERROG command eerte tette irm cr PER REIR ERR ERE 15 19 CEBar command erret reset Eos a died 15 19 TKEY lt NRf gt command 0 ccccsessesssseeessstecesececsssnceessesecssnsersseneeesenenessnes 15 20 Specifications Status and Error Messages Measurement Considerations Measurement Considerations 0 0 ee eeceseeeeeeseceeeeseeseeeseesseeseeeaeeseeeaeeseeeaecseeeaeenees C 2 Thermoelectric potentials
6. BFL BHF BAV RAV HL2 LL2 HL1 LL1 ROF Measurement Event B15 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 BO Register amp 9 BFL BHF BAV RAV HL2 LL2 HLI LL1 ROF Measurement Event B15 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 BO Enable Register BFL Buffer Full HL High Limit amp Logical AND BHF Buffer Half Full LL Low Limi OR Logical OR BAV Buffer Available ROF Reading Overflow RAV Reading Available R ACAL Cal E Temp E Questionable B15 B14 B10 B9 B8 B7 B5 B4 B3 BO Condition Register 0 JACAL Cal femp 0 Questionable Event B15 B14 B10 B9 BS B7 B5 B4 B3 BO Register 0 amp amp amp 0 ACAL Cal Temp Ee Questionable Event B15 B14 B10 B9 B8 B7 B5 B4 B3 BO Enable Register ACAL ACAL Summary Cal Calibration Summary Temp Temperature Summary amp Logical AND OR Logical OR 11 17 11 18 Remote Operation Queues The Model 2182 uses two queues which are first in first out FIFO registers e Output Queue Used to hold reading and response messages Error Queue Used to hold error and status messages The Model 2182 status model Figure 11 4 shows how the two queues are structured with the other registers Output queue The output queue holds data that pertains
7. 3 4 SCPI programming LANGE 1 n rrt e cr eer eee ape ge riget ui 3 4 Iii e 3 5 SCPIprogrammung digits eei rtr ee tape that asirian aas 3 5 Rafe p 3 6 SCPI programming tate nire reet tpe ch depre ape Re STEE cn 3 7 gli 3 8 nuruig D 3 8 Ibrsirlsil d 3 8 SCPI programming filter tente trend ete teinte 3 12 Relative mX b and Percent 96 ipu M Ra 4 3 REL KEY 4 3 SCPI programming relative soseri nonis nene 4 4 MX b and percent ecesccescccsscceseecscceseeceeceeseecseesseeceaeeeeeeeeaeeeseeeeeeeeeeeeseeeneeees 4 6 ncm M 4 6 Percent Mo 4 7 SCPI programming mX b and percent esee 4 8 Ratio and Delta cun 5 2 Basic procedure 2 rte e EORR EROR TER PAR LES EROR E ERR daa 5 2 Filter Rel and Ranging considerations eeeeee 5 4 Delfa 5 6 Selecting Delta onte riter the te ge ree E ba va de Eee age vans 5 9 Delta measurement procedure using a SourceMeter sess
8. Address Display Request Limit 1 Address Display Limit 1 Request Limit 2 Address Display Limit 2 2182 to talk reading on CRT result of test 2182 to talk result of test result of test 2182 to talk result of test Limits 8 7 Application Sorting resistors Limits can be used to sort resistors Figure 8 2 shows a basic setup to test 10 resistors The Model 220 is used to source a constant 1mA through the resistor and the Model 2182 measures the voltage drop Figure 8 2 Setup to test 10 2 resistors Model 220 Current Source Test Circuit 2182 For this application the idea is to sort a batch of 10 resistors into three bins Bin 1 is for resistors that are within 1 of the nominal value Bin 2 is for resistors that exceed 1 tolerance but are within 5 Bin 3 is for resistors that exceed 5 tolerance Limit 1 will be used to test for the 1 tolerance and Limit 2 will be used to test for the 5 tolerance The Model 2182 does not directly measure resistance so the tolerances have to be converted to voltage values The voltage drop across a nominal 10 resistor is calculated as follows VNOM 102 x ImA 10mV The voltage values for the 1 and 5 tolerances are calculated as follows Vig 10mV x 1 V5 10mV X Vs 10mV x 0 01 10mV x 0 05 0 1mV 0 5mV Finally the high and low limits are calculated as follows HI Limit 10mV
9. e Relative Explains how to null an offset or establish a baseline value Includes the SCPI commands for remote operation mX b and Percent 96 Covers these two basic math operations and includes the SCPI commands for remote operation Relative Relative mX b and Percent 4 3 Relative rel nulls an offset or subtracts a baseline reading from present and future readings When a rel value is established subsequent readings will be the difference between the actual input and the rel value Displayed Rel ed Reading Actual Input Rel Value Once a rel value is established for a measurement function the value is the same for all ranges For example if 5V is set as the rel value on the 10V range for DCV1 the rel value is also 5V on the 100V 1V 100mV and 10mV ranges When a rel value is larger than the selected range the display is formatted to accommodate the rel ed reading However this does not increase the maximum allowable input for that range An over range input signal will still cause the display to overflow For example on the 10V range the Model 2182 still overflows for a 12V input NOTE _ Rel ed readings are used for Ratio and Delta calculations See Section 5 for more information on using Relative with Ratio and Delta For offsets that vary the DC current reversal technique should be used instead of REL This technique uses the Delta measurement mode of the Model 2182 to cancel offsets Se
10. Buffer SCPI programming buffer Buffer commands are summarized in Table 6 1 TRACe subsystem commands are used to store and recall readings in the buffer and CALCulate2 commands are used to obtain statistics from the buffer data Additional information on these commands is provided after the table Table 6 1 SCPI commands buffer Commands Description Default TRACe TRACe Subsystem See Note CLEar Clear readings from buffer FREE Query bytes available and bytes in use POINts lt n gt Specify number of readings to store 2 to 1024 FEED lt name gt Select source of readings SENSe CALCulate or NONE CONTrol lt name gt Select buffer control mode NEVer or NEXT DATA Read all readings in buffer CALCulate2 CALCulate2 Subsystem FORMat lt name gt Select buffer statistic MINimum MAXimum MEAN NONE SDEViation or NONE STATe lt b gt Enable or disable statistic calculation OFF IMMediate Recalculate raw input data in buffer MMediate Perform calculation and read result DATA Read result of statistic calculation Note SYSTem PRESet and RST have no effect on TRACe commands TRACe subsystem The FEED command controls the source of the readings With the SENSe parameter selected raw input readings are stored in the buffer With the CALCulate parameter selected results of the mX b or Percent 96 calculation are stored in the buffer Commands to control and configure the mX b and Percent
11. Up ranging occurs at 120 of range while down ranging occurs at 10 of nominal range To disable autoranging press AUTO the RANGE A or V key Pressing AUTO to disable autoranging leaves the instrument on the present range SCPI programming range Table 3 1 SPCI commands range Commands Description Default SENSe SENSe Subsystem VOLTage Volts function CHANnell Channel 1 DCV1 RANGe Range selection UPPer n Specify expected reading O to 120 volts 120 AUTO lt b gt Enable or disable auto range CHANnel2 Channel 2 DCV2 RANGe Range selection UPPer n Specify expected reading O to 12 volts 12 AUTO b Enable or disable auto range Programming example The following program fragment enables autoranging for DCV1 and sets DCV2 to the 1V range CALL SEND 7 sens volt rang auto on status CALL SEND 7 sens volt chan2 rang 0 5 status Enable autorange for DCV1 Set DCV2 to 1V range Digits Range Digits Rate and Filter 3 5 The DIGITS key sets display resolution for the Model 2182 Display resolution for voltage readings can be set from 34 to 7 digits For temperature readings resolution can be set from 4 to 7 digits You can have a separate digits setting for voltage and temperature functions The digits setting for a voltage function applies to the other voltage function For example if you set DCV1 for 5 digits DCV2 will also be set for 5
12. After sending a query command the response message is placed in the Output Queue When the Model 2182 is addressed to talk the response message is sent from the Output Queue to the computer Multiple response messages If you send more than one query command in the same program message see Multiple command messages the multiple response messages for all the queries is sent to the computer when the Model 2182 is addressed to talk The responses are sent in the order that the query commands were sent and are separated by semicolons Items within the same query are separated by commas The following example shows the response message for a program message that contains four single item query commands 0 1 1 0 Response message terminator RMT Each response is terminated with an LF line feed and EOI end or identify The following example shows how a multiple response message is terminated 0 1 1 0 lt RMT gt Remote Operation 11 27 Message exchange protocol Two rules summarize the message exchange protocol Rule 1 Always tell the Model 2182 what to send to the computer The following two steps must always be performed to send information from the instrument to the computer 1 Send the appropriate query command s in a program message 2 Address the Model 2182 to talk Rule 2 The complete response message must be received by the computer before another program message can be sent to the Model 2182
13. B8 B7 B6 B5 B4 B3 B2 B1 BO Condition Register Idle Filt Trig Meas Cal Operation Event B15 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 BO Register A or T i To Operation Summary Bit OSB of Status N Operation Event Idle Filt Trig Meas Cal Byte Register Enable Register See Figure 11 9 B15 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 BO Idle Idle state of the 2182 amp Logical AND Filt Filter Settle OR Logical OR Trig Trigger Layer Meas Measuring Cal Calibrating Figure 11 7 Measurement event status Remote Operation To Measurement Summary Bit MSB of Status Byte Register See Figure 11 9 Figure 11 8 Questionable event status To Questionable Summary Bit QSB of Status Byte Register See Figure 11 9 lt a BFL BHF BAV RAV HL2 LL2 HL1 LL1 ROF Measurement B15 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 BO Condition Register
14. NOTE Registers not included in the above list are not affected by this command QUEue commands NEXT STATus QUEue NEXT Read Error Queue Description As error and status messages occur they are placed into the Error Queue This query command is used to read those messages The Error Queue is a first in first out FIFO register Each time you read the queue the oldest message is read and that message is then removed from the queue The queue will hold up to ten messages If the queue becomes full the 350 Queue Overflow message will occupy the last memory location in the register On power up the Error Queue is empty When the Error Queue is empty the 0 No error message is placed in the Error Queue The messages in the queue are preceded by a number Negative numbers are used for SCPI defined messages and positive numbers are used for Keithley defined messages The messages are listed in Appendix B After this command is sent and the Model 2182 is addressed to talk the oldest message in the queue is sent to the computer NOTE The STATus QUEue NEXT query command performs the same function as the SYSTem ERRor query command see System subsystem CLEar STATus QUEue CLEar Clear Error Queue Description This action command is used to clear the Error Queue of messages Additional SCP Commands 15 15 ENABle lt list gt STATus QUEue ENABle lt list gt Enable messages for Error Queue
15. amp 4 Wait for Trigger poe Trigger Link l Trigger 35 V i Y Scan l Make 5 Channel l Measurement NZ Oupu Eigg Trigger ouput O Trigger Trigger Scanned Channels Triggering 7 11 A Pressing EX TRIG then STEP or SCAN on the Model 2182 places it at point A in the flowchart where it is waiting for an external trigger B Pressing STEP on the Model 7001 7002 takes it out of the idle state and places operation at point B in the flowchart C For the first pass through the model the scanner does not wait at point B for a trigger Instead it closes the first channel D After the relay settles the Model 7001 7002 outputs a Channel Ready pulse Since the instrument is programmed to scan eight channels operation loops back up to point B where it waits for an input trigger E amp F Model 2182 operation is at point A waiting for a trigger The output Channel Ready pulse from the Model 7001 7002 triggers the nanovoltmeter to measure DUT 1 point E After the measurement is complete the Model 2182 outputs a completion pulse point F and then loops back to point A where it waits for another input trigger The trigger applied to the Model 7001 7002 from the Model 2182 closes the next channel in the scan This triggers the nanovoltmeter to measure the next DUT The process continues until all eight channels are scanned and measured 7 12 Triggering
16. x1 K x1000 and M x1 000 000 With the cursor on the polarity sign the amp and W keys toggle polarity Press ENTER to enter the M value and display the B value B 00 000000 m factory default Key in the offset value Press ENTER to enter the B value and display the two character UNITS designator UNITS MX factory default Use the cursor keys and the amp or W key if you wish to change the units designator Each character can be any letter in the alphabet A through Z the degrees symbol or the ohms symbol Q Press ENTER The MATH annunciator will turn on and the result of the calculation will be displayed Note that the calculation will be applied to all measurement functions To disable mX b again press SHIFT and then MX B The MATH annunciator will turn off mX b does not affect analog output Analog output has its own gain and offset settings see Section 10 for details mX b Relative The mX b function can be used to manually establish a relative rel value To do this set the scale factor M to 1 and set the offset B to the rel value Each subsequent reading will be the difference between the actual input and the rel value offset See Relative for more information Relative mX b and Percent 4 7 Percent 96 This math function determines percent deviation from a specified reference value The percent calculation is performed as follows Input Reference Percent x 100
17. 70 ms ASCII READING TO RS 232 19 2K Baud 40 s 40 5 MAX INTERNAL TRIGGER RATE 120 s 120 s MAX EXTERNAL TRIGGER RATE 120 s 120 s MEASUREMENT CHARACTERISTICS A D LINEARITY 0 8ppm of reading 0 5ppm of range FRONT AUTOZERO OFF ERROR 10mV 10V Add 8ppm of reading 500uV for 10 minutes and 41 C NOTE Offset voltage error does not apply for Delta Mode AUTOZERO OFF ERROR 10mV Add 8ppm of reading 100nV for lt 10 minutes and 41 C 100mV 100V Add 8ppm of reading 10uV for 10 minutes and 1 C NOTE Offset voltage error does not apply for Delta Mode INPUT IMPEDANCE 10mV 10V gt 10GQ in parallel with lt 1 5nF Front Filter ON 10mV 10V gt 10GQ in parallel with 0 5nF Front Filter OFF 100V 10MQ 1 DC INPUT BIAS CURRENT lt 60pA 23 C 10V to 5V lt 120pA 23 C 5 V to 10V COMMON MODE CURRENT 50nA p p at 50Hz or 60Hz INPUT PROTECTION 150V peak to any terminal 70V peak Channel 1 LO to Channel 2 LO CHANNEL ISOLATION gt 10GQ EARTH ISOLATION 350V peak gt 10GQ and 150pF any terminal to earth Add 35pF ft with Model 2107 Low Thermal Input Cable RKN 6 08 04 2182A Nanovoltmeter Specifications ANALOG OUTPUT MAXIMUM OUTPUT 1 2V ACCURACY 0 1 of output ImV OUTPUT RESISTANCE 1kQ 5 GAIN Adjustable from 10 to 10 With gain set to 1 a full range input will produce a 1V output OUTPUT REL Selects the value of input that represents OV at
18. Calculate differential voltage dV using last three A D Rdgs Step Start OVA Step 10A Stop 500A Delta dl 200A Stop SOA Step 4OpA unin Sweep with OpA Delta dl Sweep with 20pA Delta dl Step Y 30pA Step Step Y Start OpA Step 10 A 20pA dV Calculations The following equations are used by the 622x to calculate differential voltage dV dV Calc AD Rdgc OULU LLL LY time A A D Rdg B lt dV Calc 1 Ato C i lt dV Calc 4 D to F gt lt dV Calc 2 B to D gt dV Calc 5 E to G gt dV Calc 3 C to E dV Calc 6 F to H gt To calculate dV points A through H are 2182 2182A voltage measurements A D readings A B 2 C B 2 dV 1 2 e 1 9 av 2 Weoyel D C 2 e 1 dV 3 KC Dy2 E D 21 e 1 2 dG and dR Calculations With dl known dl Delta and dV calculated the 622x can then calculate 2 dv 4 dv 5 dv 6 differential conductance dG or differential resistance dR With G units selected readings are calculated as follows dG dl dV With R units selected readings are calculated as follows dR dV dl D E 2 F E 2 si 2 E F 2 G F 2 2 2 1 e 1 KF GV 2 H621 1 I 15 I 16 Delta Pulse Delta and Differential Conductance Differential Co
19. Key click On Limits Off Beeper Never High limit 1 1 Low limit 1 i High limit 2 2 Low limit 2 2 mX b Off Scale factor M 1 0 Offset B 0 0 Percent Off Reference 1 0 Ratio V1 V2 Off RS 232 Off Baud rate No effect Flow control No effect Terminator Tx No effect Getting Started 1 18 Getting Started Table 1 2 Factory defaults cont Setting Factory Default Scanning Off Type Internal Timer Off Channel 1 count 1 Reading count 2 TEMPI and TEMP2 Digits 6 Filter On Analog filter Off Digital filter On Count 10 Mode Moving average Window 0 0196 Rate 5 PLC Slow Reference junction Internal Relative REL Off Sensor Thermocouple Thermocouple type Type J Units C Triggers Continuous On Delay Auto Control Source Immediate DCV1 and DCV2 Digits 7 5 Filter On Analog filter Off Digital filter On Count 10 Mode Moving average Window 0 0196 Hold Off Count 5 Window 1 Range Auto Rate 5 PLC Slow Relative REL Off Voltage and Temperature Measurements 2 2 Voltage and Temperature Measurements Measurement overview Explains the voltage and temperature measurement capabilities of the Model 2182 Performance considerations Covers various aspects of operation that affect accuracy and speed These include warm up ACAL calibration autozero and LS YNC line cycle synchronization Includes the SCPI commands for remote operation Connections Covers test ci
20. One Pulse Delta Cycle One Pulse Delta Cycle Sweep Delay Sweep Delay Sweep Delay Sweep Delay s Sweep Delay I 14 Delta Pulse Delta and Differential Conductance Differential Conductance process Differential measurements can be used to study the individual slopes of an I V or V I curve By applying a known differential current dI to a device differential voltage dV measurements can be performed With dI and dV known differential conductance dG and differential resistance dR can be calculated This differential measurement process is shown in Figure I 7 The Model 622x is config ured to output a stepped sweep with a specified Delta which is the differential current dI As shown in the illustration Delta is added to and subtracted from each subsequent step in the sweep The solid line in Figure I 7 is the actual output of the Model 622x As shown each differential voltage calculation dV Calc uses the three previous Model 2182 2182A A D measurement conversions Keep in mind that dI Delta is the same for all calculated points With dI known and dV calculated the Model 622x can also calculate display and store the differential conductance dG or differential resistance dR for each calculated point Figure I 7 Delta Pulse Delta and Differential Conductance Differential Conductance measurement process A 7OpA 60pA A D Rdg 2182 2182A voltage measurement conversion dV Calc
21. Pulse Delta Reading Reading Reading i 1st 2nd Nth i 1st Pulse Delta 2nd Pulse Delta gt lt 3rd Pulse Delta Cycle Cycle Cycle C Differential Conductance measurements 622x I Source Start 2nd Diff Cond Cycle i I 3rd Diff Cond Cycle i4 4th Diff Cond Cycle Delta Pulse Delta and Differential Conductance l 5 Test system configurations There are two test system configurations that can be used for Delta Pulse Delta and Differential Conductance measurements and are shown in Figure I 2 One is for front panel stand alone operation and the other is for remote programming PC control system Both systems use serial communications via RS 232 interface between the Model 622x and the Model 2182 2182A The Model 622x sends setup commands to the Model 2182 2182A and the Model 2182 2182A sends Delta Pulse Delta or Differential Conductance readings to the buffer of the Model 622x Once the test is started trigger synchronization between the two instruments is controlled by the Trigger Link Figure I 2 Test system configurations A Stand alone system front panel operation Keithley 622x Keithley ae Cae 2182 2182A t t Trigger Link Current Source Nanovoltmeter B PC control of 6220 21 IEEE 488 or Ethernet 6221 Keithley 622x Keithley null modem 2182 2182A Ch 1 GPIB or Ethernet 6221 Sele
22. TRIGger TIMer DEFault Sets timer to 0 1 sec TRIGger TIMer MINimum Sets timer to 1 msec TRIGger TIMer MAXimum Sets timer to 999999 999 sec List Specifies one or more switching channels ROUTe SCAN 21 10 Specify external scan list 1 10 Angle Brackets lt gt Used to denote a parameter type Do not include the brackets in the program message SENSe HOLD STATe lt b gt The lt b gt indicates that a Boolean type parameter is required Thus to enable the Hold feature you must send the command with the ON or 1 parameter as follows SENSe HOLD STATe ON or 1 Remote Operation 11 23 Query commands The Query command requests the presently programmed status It is identified by the question mark at the end of the fundamental form of the command Most commands have a query form TRIGger TIMer Queries the timer interval Most commands that require a numeric parameter lt n gt can also use the DEFault MINimum and MAXimum parameters for the query form These query forms are used to determine the RST default value and the upper and lower limits for the fundamental command TRIGger TIMer DEFault Queries the RST default value TRIGger TIMer MINimum Queries the lowest allowable value TRIGger TIMer MAXimum Queries the largest allowable value Case sensitivity Common commands and SCPI commands are not case sensitive You can use upper or lower case and any case combination Examples RST
23. User s Manual 2182A 900 01 Rev A Jane 2004 Equipment An Interworld Highway LLC Company A GREATER MEASURE 9 F GON Fl DE N CE WARRANTY Keithley Instruments Inc warrants this product to be free from defects in material and workmanship for a period of 3 years from date of shipment Keithley Instruments Inc warrants the following items for 90 days from the date of shipment probes cables rechargeable batteries diskettes and documentation During the warranty period we will at our option either repair or replace any product that proves to be defective To exercise this warranty write or call your local Keithley representative or contact Keithley headquarters in Cleveland Ohio You will be given prompt assistance and return instructions Send the product transportation prepaid to the indicated service facility Repairs will be made and the product returned transportation prepaid Repaired or replaced products are warranted for the balance of the original warranty period or at least 90 days LIMITATION OF WARRANTY This warranty does not apply to defects resulting from product modification without Keithley s express written consent or misuse of any product or part This warranty also does not apply to fuses software non rechargeable batteries damage from battery leakage or problems arising from normal wear or failure to follow instructions THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES EXPRESSED OR IMP
24. Vi HI Limit2 10mV V5 10mV 0 1mV 10mV 0 5mV 10 1mV 10 5mV LO Limit 1 10mV V q LO Limit2 10mV Vs5q 10mV 0 1mV 10mV 0 5mV 9 9mV 9 5mV The limits are illustrated in Figure 8 3 8 8 Limits Figure 8 3 Limits to sort 10Q resistors 1 5 and gt 5 Beep Beep Beep No Beep low pitch normal pitch low pitch No Beep 9 5mV 9 9mV 0 10 1mV 10 5mV LO2 LOI H HI2 Limit 1 1 Limit 2 596 Beeper Mode INSIDE Front panel operation For front panel operation the INSIDE beeper mode must be used A normal pitch beep and the message IN indicates that the resistor is within the 196 tolerance limit see Figure 8 3 This 1 resistor belongs in Bin 1 A low pitch beep and the HI or LO message indicates that the resistor is gt 1 tolerance but lt 5 tolerance This 5 resistor belongs in Bin 2 For resistors gt 5 no beep will sound Place these resistors in Bin 3 Remote operation For remote operation make sure both Limit 1 and Limit 2 are enabled The following table evaluates the three possible pass fail combinations for this application Limit 1 Limit 2 Resistor Bin Result Result Tolerance Assignment Pass Pass 1 1 Fail Pass 5 2 Fail Fail gt 5 3 Keep in mind that a fail condition must be reset before testing the next resistor Fail can be reset manually or automatically see CLEar command in T
25. status sour curr mode list status init status 2182 System preset defaults 2182 1sec delay 2182 Enable Delta Disable Front Autozero to double Delta speed 2182 External triggering 2182 Buffer size 3 2182 Enable buffer SM RST defaults SM Select trigger link SM Enable source bypass SM Output trigger after source SM Trig count 6 SM Source current SM Measure voltage SM Fast measurements SM Current list values SM Turn output on SM Enable list mode SM Start sweep 5 18 Ratio and Delta Applications Calibrating resistor network dividers Ratio can be used to calibrate resistor network dividers The 1 10 divider network in Figure 5 5 is made up of nominal resistances of 1k 2 and 10kQ The 1kQ resistance is the result of the parallel combination of the 2k 2 pot and the 2kQ resistor The pot provides fine tuning of the network Figure 5 5 Calibrating 1 10 divider Model 220 Current Source The Keithley Model 220 is used to source a constant current of 1mA Channel 1 which is used to measure the 1kQ resistance component of the network should be set to the 1V range 1k 2 x 1mA 1V or autorange Channel 2 which is used to measure the 10kQ resistance component should be set to the 10V range or autorange When Ratio is enabled the Model 2182 will display the result of V1 1V divided by V2 10V FiltVl _ IV Ratio
26. 10 TCONtrol lt name gt Select filter type MOVing or REPeat MOVing STATe lt b gt Enable or disable digital filter ON For TEMP2 SENSe SENSe Subsystem TEMPerature Temperature function CHANnel2 Channel 2 TEMP2 LPASs lt b gt Enable or disable analog filter OFF DFILter Configure and control digital filter WINDow n Specify filter window in 0 to 10 0 01 COUNt lt n gt Specify filter count 1 to 100 10 TCONtrol lt name gt Select filter type MOVing or REPeat MOVing STATe lt b gt Enable or disable digital filter ON Programming example Range Digits Rate and Filter 3 13 The following program fragment configures the Filter for Channel 2 voltage DCV2 It disables the analog filter and enables the digital filter 5 window count 10 moving Analog Filter CALL SEND 7 Sens Digital Filter CALL SEND 7 CALL SEND 7 CALL SEND 7 CALL SEND 7 Sens Sens Sens Sens volt volt volt volt volt chan2 chan2 chan2 chan2 chan2 lpas dfil dfils off status wind 5 status dfil dfil coun 10 status tcon mov status stat on status Disable analog filter Set window to 5 Set count to 10 Select filter Enable filter moving digital 3 14 Range Digits Rate and Filter Relative mX b and Percent 4 2 Relative mX b and Percent
27. 2182 1 CH 1 x0 1009 HI SourceMeter 2182 2 Thermal Source l D CH 1 EMFs 30 Cables LO y DUT 000 Cryostat The readings in the buffer of Model 2182 1 correspond to the current sweep values You can then use the buffer location numbers to reference DUT readings to current amplitudes Model 2182 1 Buffer Model 2182 2 Buffer RDG NO 1 imV 10pA RDG NO 1 DUT measurement RDG NO 2 2mV 20nA RDG NO 2 DUT measurement RDG NO 3 5mV 50pA RDG NO 3 DUT measurement Delta measurements As previously explained the DC current reversal measurement technique must be used to cancel the effects of thermal EMFs in the test leads By configuring a custom sweep the SourceMeter can function as a bipolar growing amplitude source For example if the test requires current steps of 10uA 20pA and 50pA the 6 point custom sweep would be configured as follows P0000 10pA P0001 10pA P0002 20nA P0003 200A P0004 50pA P0005 50pA By enabling Delta measurements on the Model 2182 the effects of thermal EMFs in the test leads will automatically be canceled during the source measure process 5 24 Ratio and Delta To check measurement repeatability you may wish to perform more than one Delta measurement at each current amplitude In Figure 5 11 the SourceMeter outputs five bipolar steps for each amplitude The result will be five Delta measurements for each amplitude When con
28. C F or K C Note Channel 0 is the internal temperature sensor With a temperature function selected reading Channel 0 returns the inter nal temperature reading With a voltage function selected reading Channel 0 returns the voltage reading of the internal temperature sensor Voltage and Temperature Measurements 2 21 Programming Example measure voltage and temperature The following program fragments will measure voltage on Channel and temperature on Channel 2 Temperature is configured using a simulated reference junction i e ice bath and a type K thermocouple Configure Temperature CALL SEND 7 sens temp trans tc status Select thermocouple sensor CALL SEND 7 sens temp rjun rsel sim status Select simulated reference CALL SEND 7 sens temp rjun rsel sim 0 status Set reference to 70 C CALL SEND 7 sens temp TC K status Set for type K thermocouple CALL SEND 7 unit temp F status Read in F Measure voltage on Channel 1 CALL SEND 7 sens chan 1 status Select Channel 1 CALL SEND 7 sens func volt status Select DCV1 CALL SEND 7 sens data fres status Request a fresh reading reading SPACES 80 CALL ENTER reading length 7 status Address 2182 to talk PRINT reading Display reading on CRT Measure temperature on Channel 2 CALL SEND 7 sens chan 2 status Select Channel 2 CALL SEND 7 sens func t
29. External triggering with BNC connections An adapter cable is available to connect the micro DIN Trigger Link of the Model 2182 to instruments with BNC trigger connections The Model 8503 DIN to BNC Trigger Cable has a micro DIN connector at one end and two BNC connectors at the other end The BNC cables are labeled VMC trigger line 1 and EXT TRIG trigger line 2 Figure 7 9 shows how a Keithley Model 220 Current Source can be connected to the Trigger Link of the Model 2182 using the adapter cable When used with the STEP mode of the Model 220 you can perform synchronized source measure operations without the use of a computer Whenever the Model 220 receives a trigger from the Model 2182 it will step to the next current source value Figure 7 9 DIN to BNC trigger cable 2182 Nanovoltmeter External 5 Trigger 9 8503 DIN to BNC Trigger Cable 220 Current Source Tigger Link NOTE Ifthe Model 2182 trigger line configuration has been changed from the factory setting the Model 8502 Trigger Link Adapter must be used to interface with instruments having BNC trigger connections It has two micro DIN connectors and six BNC connectors one for each trigger line SCPI programming triggering Trigger model remote operation Triggering 7 13 The following paragraphs describe how the Model 2182 operates for remote operation The flowchart in Figure 7 10 summarizes operation over the bus The flowchart is c
30. H that surrounds it is held constant For the following two applications the Model 2182 is used to measure voltage and a Keithley SourceMeter Model 2400 2410 or 2420 is used to source a known current s Therefore whether varying the magnetic field or varying the current the actual resistance of the DUT can be calculated using Ohm s Law R V I Thermal EMFs Test leads that connect the Model 2182 to the superconductor sample DUT in a cryostat are typically 30 feet or longer The test lead connections and the wide temperature range from OK at the DUT to the ambient temperature of the lab create substantial thermal EMFs in the test leads The effects of these thermal EMFs must be canceled to achieve accurate voltage measurements To cancel the effects of thermal EMFs the DC current reversal measurement technique must be used This measurement technique requires a source that can provide a bipolar output When using a SourceMeter a custom sweep can be configured to provide a bipolar output By enabling Delta measurements on the Model 2182 the effects of thermal EMFs in the test leads will automatically be canceled during the source measure process For details on the DC current reversal technique see Delta 5 20 Ratio and Delta Superconductor Application 1 fixed current A typical test on a superconductor sample DUT is to vary the magnetic field H while maintaining a fixed current I through the DUT S
31. NONE MXB or PERCent NONE KMATh Path to configure mX b and Percent MMFactor lt NRf gt Specify scale factor M for mX b 100e6 to 100e6 1 MBFactor lt NRf gt Specify offset B for mX b 100e6 to 100e6 0 MUNIits lt name gt Specify units for mX b see Setting mX b units MX PERCent lt NRf gt Specify reference value for Percent 100e6 to 100e6 1 ACQuire Use input signal as reference value STATe lt b gt Enable or disable the selected calculation OFF DATA LATest Query last calculation result FRESh Trigger a reading and query the calculation result Setting mX b units The lt name gt parameter for CALCulate KMATh MUNIts can be one or two characters enclosed in single or double quotes A character can be any letter of the alphabet the degrees symbol or the ohms symbol Q The ohms symbol and the degrees symbol are not ASCII characters and therefore must be substituted with the and V characters as follows CALCulate KMAth MUNits CALCulate KMAth MUNits v Programming examples mX b and percent Use ohms symbol Q as units designator Use degrees symbol as units designator Program Example 1 This program fragment shows how to configure and enable the mX b calculation CALL SEND 7 CALL SEND 7 CALL SEND 7 CALL SEND 7 CALL SEND 7 calc form mxb status Selects mX b calculation calc kmat mmf 2 status Sets scale factor M
32. Parameter lt list gt numlist where numlist is a specified list of messages that you wish to enable for the Error Queue Description On power up all error messages are enabled and will go into the Error Queue as they occur Status messages are not enabled and will not go into the queue This command is used to specify which messages you want enabled Messages not specified will be disabled and prevented from entering the queue When this command is sent all messages will first be disabled then the messages specified in the list will be enabled Thus the returned list ENABle will contain all the enabled messages Messages are specified by numbers see Appendix B The following examples show various forms for expressing a message numlist Numlist 110 Single message 110 140 22 Messages separated by commas 110 222 Range of messages 110 through 222 110 222 230 Range entry and single entry separated by a comma NOTE To disable all messages from entering the Error Queue send the following command stat que enab DISable lt list gt STATus QUEue DISable lt list gt Disable messages for Error Queue Parameter lt list gt numlist where numlist is a specified list of messages that you wish to disable for the Error Queue Description On power up all error messages are enabled and will go into the Error Queue as they occur Status messages are not enabled and will not go into the
33. Reference where Input is the normal display reading Reference is the user entered constant Percent is the displayed result To configure and control the percent calculation perform the following steps 1 Press SHIFT and then to display the present reference value REF 1 000000 factory default 2 Key ina reference value The lt q and gt keys control cursor position and the amp and V range keys increment and decrement the digit value To change range place the cursor on the multiplier and use the and W keys m x0 001 x1 K x1000 and M x1 000 000 With the cursor on the polarity sign the amp and W keys toggle polarity 3 Press ENTER The MATH annunciator will turn on and the result of the calculation will be displayed Note that the calculation will be applied to all measurement functions 4 To disable percent again press SHIFT and then The MATH annunciator will turn off NOTES The result of the percent calculation is positive when the input exceeds the reference and negative when the input is less than the reference The result of the percent calculation may be displayed in exponential notation For example a displayed reading of 2 500E 03 is equivalent to 250096 2 5K 4 8 Relative mX b and Percent SCPI programming mX b and percent Table 4 2 SCPI commands mX b and percent Commands Description Default CALCulate FORMat name Select calculation
34. SENSe command summary Default Command Description Parameter Ref SCPI SENSe 1 FUNCton lt name gt Select function VOLTage DC or TEMPerature VOLT Sec 2 V FUNCtion Query measurement function V DATA Path to return instrument readings Sec 2 V LATest Return the last instrument reading V FRESh Return a new fresh reading V CHANnel n Select channel to measure 0 1 or 2 0 internal 1 See 2 temperature sensor CHANnel Query selected channel HOLD Path to configure and control Hold Sec 7 WINDow n Set Hold window 0 01 to 20 96 1 WINDow Query Hold window COUNt n Set Hold count 2 to 100 5 COUNt Query Hold count STATe lt b gt Enable or disable Hold OFF STATe Query state of Hold VOLTage DC Path to configure DC volts v NPLCycles n Set integration rate in line cycles PLC 0 01 to 60 5 Sec 3 V 60Hz or 0 01 to 50 50Hz NPLCycles Query NPLC v APERture n Set integration rate in seconds 166 67e 6 to 1 83 33 60Hz or 200e 6 to 1 50Hz APERture Query Aperture DIGits n Set display resolution 4 to 8 8 Sec 3 DIGits Query display resolution RATio lt b gt Enable or disable Ratio V1 V2 OFF Sec 5 RATio Query state of Ratio DELTa lt b gt Enable or disable Delta V1t1 V1t2 2 OFF Sec 5 DELTa Query state of Delta CHANnell Channel 1 voltage commands RANGe Configure measurement range Sec3 V UPPer n Select range
35. Select buffer control mode TRACe FEED CONTrol NEVer immediately stop storing readings TRACe FEED CONTrol NEXT start now stop when buffer is full The following example program sets up the Model 2182 to take 20 readings as fast as it can into the buffer and then reads the data back after the buffer has filled Example program to demonstrate the reading buffer For QuickBASIC 4 5 and CEC PC488 interface card Edit the following line to where the QuickBASIC libraries are on your computer SINCLUDE c Nqb45Nieeeqb bi Initialize the CEC interface as address 21 CALL initialize 21 0 Reset controls and put trigger model in IDLE state CALL SEND 7 rst status Reset STATus subsystem not affected by RST CALL SEND 7 stat pres cls status CALL SEND 7 stat meas enab 512 status enable BFL CALL SEND 7 sre 1 status enable MSB CALL SEND 7 trig coun 20 status TRACe subsystem is not affected by RST CALL SEND 7 trac poin 20 status CALL SEND 7 trac feed sensl feed cont next status Start everything CALL SEND 7 init statuss Initialize reading while the 2182 is busy taking readings reading SPACES 4000 WaitSRQ IF NOT srq THEN GOTO WaitSRQ CALL SPOLL 7 poll status IF poll AND 64 0 THEN GOTO WaitSRQ CALL SEND 7 stat meas status CALL ENTER S length 16 status CALL SEND 7 form elem read unit status CALL SEND 7 trac data status CALL EN
36. and measure events for the Trigger Model By sending the WAI command after the TRG command subsequent commands will not be executed until the pointer for the Trigger Model has finished moving in response to TRG and has settled at its next state Program fragment CALL SEND 7 syst pres staus CALL SEND 7 init cont off abort status Place 2182 in idle CALL SEND 7 trig coun 1 sour tim status CALL SEND 7 samp coun 30 status Program for 30 measurements then stop CALL SEND 7 init wai status Start measurements and send WAI CALL SEND 7 data status Query a reading reading SPACES 80 CALL ENTER reading length 7 status Get a response when 2182 goes into idle PRINT reading Display the reading 13 SCPI Signal Oriented Measurement Commands 13 2 SCPI Signal Oriented Measurement Commands The signal oriented measurement commands are used to acquire readings You can use these high level instructions to control the measurement process These commands are summarized in Table 13 1 Table 13 1 Signal oriented measurement command summary Command Description CONFigure lt function gt Places the Model 2182 in a one shot measurement mode for the specified function FETCh Requests the latest reading READ Performs an ABORt INITiate and a FETCh MEASure lt function gt Performs an ABORt CONFigure lt function g
37. and buffer statistics For any of the buffer statistics maximum minimum peak to peak average standard deviation the STAT annunciator is on 3 To return to the normal display press EXIT Figure 6 1 Buffer locations RDG NO 10 Reading Value RDG NO 9 Reading Value RDG NO 8 Reading Value RDG NO 7 Reading Value RDG NO 6 Reading Value RDG NO 5 Reading Value RDG NO 4 Reading Value a RDG NO 3 Reading Value RDG NO 2 Reading Value RANGE RDG NO 1 Reading Value RANGE STD DEV Standard Deviation Value v Average Average Value Peak toPeak Peak to Peak Value Min At XX Minimum Value Max At XX Maximum Value CED 6 4 Buffer Buffer statistics e MIN and MAX provides the minimum and maximum readings stored in the buffer It also indicates the buffer location of these readings The Peak to Peak reading is the absolute value of the difference between the MAX and MIN readings It is calculated as follows Peak to Peak IMAX MINI e Average is the mean of the buffer readings Mean is calculated as follows where Xj is a stored reading nis the number of stored readings The STD DEV value is the standard deviation of the buffered readings The equation used to calculate the standard deviation is n 2 1 2 Pu i y jfi l 2 5 1 1 n 1 where Xj is a stored reading n is the number of stored readings NOTE The Model 2182 uses IEEE 754 floating point format for math calculations
38. and press the or W key to display the desired units 3 Press ENTER The present sensor selection TCOUPLE or INTERNL is displayed The internal INTERNL sensor is used for measuring internal temperature 4 Tochange the sensor selection press the fe key to place the blinking cursor on TCOUPLE and press the amp or V key to display INTERNL 5 Press ENTER to return to the normal display state 6 Press TEMPI or TEMP2 to measure and display the internal temperature of the Model 2182 Note that when displaying the internal temperature both the CH1 and CH2 annunciators are off NOTE As long as the INTERNL sensor is selected TEMP1 and TEMP2 will only measure and display the internal temperature of the Model 2182 Checking TCAL temperature Perform the following steps to determine the internal temperature at the time of the last ACAL 1 Press SHIFT and then CAL to access the calibration menu 2 Use A or V key to display CAL TEMP 3 Press ENTER The temperature in C at the time of the last ACAL is displayed 4 Use the EXIT key to back out of the menu structure Autozeroing modes An A D measurement cycle measures the input signal and will periodically measure internal voltages that correspond to offsets zero and amplifier gains and the internal reference temperature These measurements help maintain stability and accuracy over time and changes in temperature The signal offset gain and temperature measureme
39. are optional and need not be included in the program message Program messages A program message is made up of one or more command words sent by the computer to the instrument Each common command is simply a three letter acronym preceded by an asterisk SCPI commands are categorized in the STATus subsystem and are used to help explain how command words are structured to formulate program messages Command structure STATus Path Root OPERation Path ENABle lt NRf gt Command and parameter ENABle Query command PRESet Command Remote Operation 11 25 Single command messages The above command structure has three levels The first level is made up of the root command STATus and serves as a path The second level is made up of another path OPERation and a command PRESet The third path is made up of one command for the OPERation path The three commands in this structure can be executed by sending three separate program messages as follows stat oper enab lt NRf gt stat oper enab stat pres In each of the above program messages the path pointer starts at the root command stat and moves down the command levels until the command is executed Multiple command messages You can send multiple command messages in the same program message as long as they are separated by semicolons The following is an example showing two commands in one program message stat oper stat oper enab lt NRf gt
40. corresponding bus line true REN Remote Enable REN is sent to set up instruments on the bus for remote operation When REN is true devices will be removed from the local mode Depending on device configuration all front panel controls except the LOCAL button if the device is so equipped may be locked out when REN is true Generally REN should be sent before attempting to program instruments over the bus EOI End or Identify EOI is used to positively identify the last byte in a multi byte transfer sequence thus allowing data words of various lengths to be transmitted easily IFC Interface Clear IFC is used to clear the interface and return all devices to the talker and listener idle states IEEE 488 Bus Overview F 8 a129 1 U0q X 8OIG d LOIA C 91oN 81 9powW Aq pejueureduir Jou TOYLNOD 3DIVI LOL pue AUNDIANODNN 110d T3T1v3lvd Add GANDIANOD 110d T3T1V3lvd Ddd Das DOd dnOND5 dNOYXD GNVWWOD CNVWWOD AYVGNODAS ANVWINd OVD Dv ON DOV dNOUND dnouo dNOND dNOND ssaudav ssIAAAY GNVWWOD QNVWWOO XTVL Nasi TWSYIAINN Gassasaav ad o INN SI Oo INN SI sn IS SI LLL 1 u 0 U vl N 0 lt Vl SM OS Vl en ee ee ul 6c l Ww 6c I 5 S XD L Ew b E 9c N e 1 9c gt e Sd dd 4 0 0 L I J LT LL LT LL 2S3 l LL L L 0 L z f 97 Z OL f 9c OL ans 11 OL 0 L1 0 I SC A 6 l SC 6 6 dds Wa LOL 1H 6
41. digits Similarly the digits setting for a temperature function applies to the other temperature function Setting TEMPI for 6 digits also sets TEMP2 for 6 digits Digits has no effect on the remote reading format The number of displayed digits does not affect accuracy or speed Those parameters are controlled by the RATE setting Perform the following steps to set display resolution 1 Select the desired function 2 Press the DIGITS key until the desired number of digits is displayed SCPI programming digits Table 3 2 SPCI commands digits Commands Description Default SENSe SENSe Subsystem VOLTage DCV1 and DCV2 DIGits n Specify display resolution 4 to 8 8 TEMPerature TEMPI and TEMP2 DIGits n Specify display resolution 4 to 7 6 Programming example digits The following program fragment selects 3 4 digit resolution for voltage readings and 5 4 digit resolution for temperature readings CALL SEND 7 sens volt digits 4 status CALL SEND 7 sens temp digits 5 status Set volts for 3 digits Set temp for 5 digits 3 6 Rate Range Digits Rate and Filter The RATE key selects the integration time of the A D converter This is the period of time the input signal is measured also known as aperture The integration time affects the amount of reading noise as well as the ultimate reading rate of the instrument The integration time is specified in paramete
42. ess F 10 Typical addressed bus sequence eese F 11 Typical addressed common command sequence esee F 11 IEEE command groups eeseeeeeeeeeeeeeee nnne nrten nnne nnnen F 12 Model 2182 interface function codes 00 eee eeeeeseceseceseeceneeeeeeceaceeteeceaeeetaeeeaeens F 13 IEEE 488 and SCPI Conformance Information IEEE 488 documentation requirements esee G 2 Coupled commands tinc e e ee rere ep be ae Fe ete e et E Rad G 3 1 Getting Started 1 2 Getting Started NOTE This User s Manual supports both the Models 2182 and 2182A References to the Model 2182 apply to both the Models 2182 and 2182A References to the Model 2182 2182A apply to the Model 2182 with firmaware ver sion A10 or higher and the Model 2182A with firmware version C01 or higher References to the Model 2182A applies to the Model 2182A with firmware version C01 or higher General information Covers general information that includes warranty information contact information safety symbols and terms inspection and available options and accessories Nanovoltmeter features Summarizes the features of the Model 2182 Front and rear panel familiarization Summarizes the controls and connectors of the instrument Cleaning input connector terminals Explains how to clean the contacts of the input LEMO connectors Power Up Covers line power connection line vol
43. ger is received or the TRIG key is pressed After the trigger occurs operation drops down to the Delay block Delay If a delay auto or manual is being used operation will hold up at this block until the delay period expires Device action Measurements are performed at this block The first measurement is performed on Channel 2 of the Model 2182 Subsequent measurements are performed on Channel 1 Note that every reading is automatically stored in the buffer Sample counter For each scan cycle Channel 2 is measured once and Channel 1 is measured a specified number of times Therefore the sample count is the sum of those two values CH1 COUNT 1 Operation will continue to loop back to Delay and Device Action until all the sample readings are taken Output trigger After the last Channel 1 measurement is performed an output trigger is applied to the rear panel Trigger Link connector Trigger counter The value of this counter determines how many scan cycles will be performed If configured for another scan operation will loop back to the control source for another pass through the trigger model Figure 9 1 Front panel triggering internal scanning Control Source Immediate External Timer Figure 9 2 Stepping and Scanning Event Detection Yes Delay Device Action Front panel triggering other step scan oper
44. sese 1 7 Front panel SUDIIBAE 1a eec e re a b ee tie eter epo espe ten penes 1 7 Rear panel SUMIMALY 2 2 2 e tete b i tb eere ta deua AER a 1 11 Cleaning input connectors issirsiisisiriar osoari insasi een eene nennen rennen 1 13 PowerUp Me M 1 14 Line power Connection ce teret rr rre tp epe Re e PE ee AR aE 1 14 Setting line voltage and replacing fuse sse 1 15 Power up SEQUENCE 2 eee eerte deeper tre tein LR RE Hg ER HER GR Eia 1 15 Line frequency M J 1 16 Display M es 1 16 Status and error messages ssssseseeeeeeereenen rennen een em ren enne 1 16 Default SCH SS i etn itt i titt i Ene p p E Eae ei Fer rey Cre eaae 1 16 2 Voltage and Temperature Measurements Measurement Overview P 2 3 Voltage measurements essesseeseeseeeeeeeneee nennen entem enne nennen enne 2 3 Temperature measurements seen enne nre rennen 2 3 Performance considerations sse nne en nennen nennen 2 5 Eod E C ETRE 2 5 ACAL calibration cccccccccccesssscccccesssssceccesessseeecccessnsuececeessnseeeceesessaeeeeeeesnes 2 5 AXutozeromg modes deter tenete ree PER OG vede 2 6 LSYNC line cycle synchronization eese 2 8 Pumpout current low charge injection mode eee 2 9 SCPI programm
45. 1 5 etit ero ehe tei eere IEEE EER ia F 7 Universal multiline commands esses eene enn F 8 Addressed multiline commands sse F 9 Address commands ccscccsssecessseeeseseeeesseeeessseecseseeessseeeessaeecssneeesseeeeseneeesages F 9 Unaddr ss commands 2 ier tenete iro e ESER ERE rolg F 9 Common commands ssssssseesseeee eene eene nennen nnne rennen nennen nens F 10 SCPIcomimatids etnies eee rc rie REI rai edens F 10 Command codes esses nennen nennen EEs r rE nnne nennen nens F 10 Typical command sequences essen enne nennen nnne F 11 IEEE command groups essen nene nnne nneennnen F 12 Interface function codes eee eerie tete eere dedi dd ER needs F 13 IEEE 488 and SCPI Conformance Information NY 1707010 615 0 1 ER NR G 2 Measurement Queries FETON aeron e nai DU IM E OM tes H 2 What it does M H 2 Limitations iret eiit EE e Xe Pert ove Peer o E Ee EE ae Eara EEA PERPE Se RETE FE oe H 2 Where Appropriate sien veseiarsevvacesscietecastacgucecades oE EE EE EREEE REPE NERE H 2 JI DERE H 2 What it COGS occ H 2 D amittatlons 3 2 cesses ee erede re erre eoe rere tre LY Esa e etes da E H 3 MEASure functioti 1 cr E eee Rees H 3 brum c H R H 3 Limitations e H 3 When appropriate rediere
46. 120V MAX LIMITS VALUE ON OFF 12V MAX CATI 350V PEAK ANY TERMINAL TO CHASSIS V 17 26 19 28 21 30 23 32 15 13 18 27 20 29 22 31 24 14 12 15 21 15 22 Additional SCP Commands Specifications 2182A Nanovoltmeter Specifications VOLTS SPECIFICATIONS 20 OVER RANGE CONDITIONS 1PLC with 10 reading digital filter or SPLC with 2 reading digital filter ACCURACY ppm of reading ppm of range ppm parts per million e g 10ppm 0 001 CHANNEL 1 24 Hour 90 Day 1 Year 2 Year RANGE RESOLUTION INPUT RESISTANCE Tea C Tear 5 C Tear 5 C Tear 5 C 10 000000 mV I nV gt 10 GQ 20 4 40 4 50 4 60 4 100 00000 mV 10 nV gt 10 GQ 10 3 2543 3044 4045 1 0000000 V 100 nV gt 10 GQ 742 1842 2542 3243 10 000000 V 1V gt 10 GQ 2415 1842 2542 3243 100 00000 v 10 pV 10 MQ 1 1043 2543 3544 5245 CHANNEL 2 100 00000 mV 10 nV gt 10 GQ 10 6 2546 3047 4047 1 0000000 V 100 nV gt 10 GQ 742 1842 2542 3243 10 000000 V 1V gt 10 GQ 2415 1842 2542 3243 CHANNEL 1 CHANNEL 2 RATIO Ratio accuracy channel 2 reading accuracy channel 1 range channel 1 reading accuracy channel 2 range channel 2 reading TEMPERATURE COEFFICIENT 0 18 C amp 28 50 C 1 0 5 C 1 0 2 C 1 0 D C 1 0 D C 1 0 5 C D C 1 0 5 C 1 0 5 C DELTA hardware triggered coordination with 24XX series or 622X series current sources for low noise
47. 2 Set bit BI 512 Set bit B9 4 Set bit B2 1024 Set bit B10 16 Set bit B4 16384 Set bit B14 32 Set bit B5 65535 Set all bits 64 Set bit B6 Description These commands are used to set the contents of the event enable registers see Figure 15 7 Figure 15 8 and Figure 15 9 An ENABle command is sent with the decimal equivalent of the binary value that determines the desired state 0 or 1 of each bit in the appropriate register Each event enable register is used as a mask for events see EVENt for descriptions of events When a bit in an event enable register is cleared 0 the corresponding bit in the event register is masked and thus cannot set the corresponding summary bit of the next register set in the status structure Conversely when a bit in an event enable register is set 1 the correspond ing bit in the event register is unmasked When the unmasked bit in the event register sets the summary bit of the next register set in the status structure will set The decimal weighting of the bits for each event enable register are included in Figure 15 7 Figure 15 8 and Figure 15 9 The sum of the decimal weights of the bits that you wish to set is sent as the parameter lt NRf gt for the appropriate ENABle command For example to set the BFL and RAV bits of the Measurement Event Enable Register send the following command stat meas enab 544 where BFL bit B9 Decimal 512 RAV bit B5 Decimal 32 lt NRf gt 544 15 12
48. Additional SCP Commands Figure 15 7 Measurement event enable register Bit Position B15 B10 nm B7 B6 B5 B4 B3 B2 B1 BO BFL BHF BAV RAV HL2 LL2 HL1 LL1 ROF Event 512 256 128 32 16 8 4 2 1 Decimal Weightin 8 29 28 27 25 24 23 22 21 20 Value O 1 O 1 O 1 O 1 O 1 O 1 O 1 O 1 0 1 Value 1 2 Measurement Event Set Events BFL Buffer Full 0 Measurement Event Cleared BHF Buffer Half Full BAV Buffer Available RAV Reading Available HL2 High Limit 2 LL2 Low Limit 2 HL1 High Limit 1 LL1 Low Limit 1 ROF Reading Overflow Figure 15 8 Questionable event enable register Bit Position B15 B10 B7 B5 B4 B3 BO Event ACAL Cal Temp Decimal Weighting 512 256 16 29 28 24 Value L 0 1 0 1 0 1 Value 1 Operation Event Set Events ACAL ACAL Summary 0 Operation Event Cleared Cal Calibration Summary Temp Temperature Summary Additional SCPI Commands 15 13 Figure 15 9 Operation event enable register Bit Position B15 B11 B9 B8 B7 B6 B3 B1 i BO Event Idle Filt Trig Meas Cal Decimal Weighting 1024 256 32 16 1 210 28 25 24 20 Value E Ool 1 m 0 1 0 1 x 0 1 Value 1 Enable Operation Event Events Idle Idle state of the 2182 0 Disable Mask Operation Event Fi
49. CALL SEND 7 trig del 0 5 status Set delay for 0 5sec CALL SEND 7 samp coun 10 status Set sample count to 10 CALL SEND 7 read status Trigger and request readings reading SPACES 80 CALL ENTER reading length 7 status Address 2182 to talk PRINT reading Display the 10 readings on the CRT 7 18 Triggering Limits 8 2 Limits Limit operations Explains Limit 1 and Limit 2 testing operations SCPI programming Covers the SCPI commands for remote operation Application Provides an application that sorts resistors by tolerances Limits 8 3 Limit operations Limit operations set and control the values that determine the HI IN LO status of subsequent measurements The limit test is performed on the result of an enabled Rel mX b or Percent operation There are two sets of limits Limit 1 uses high and low limits HI1 and LO1 as does Limit 2 HI2 and LO2 However the HI IN LO status message only applies to Limit 1 Figure 8 1 illustrates the following limits which are the factory defaults Limit 1 HI 1V and LOI 1V Limit 2 HI2 2V and LO2 2V Figure 8 1 Default limits LO X IN xX HI gt e 2V 1V 0 1V 2V LO2 LO1 HI1 HI2 Limit 1 Limit 2 For the limits shown in Figure 8 1 a reading of 1 5V is outside Limit 1 which is the primary limit Therefore the message HI will be displayed A beeper is also avai
50. Differential Conductance Overview NOTE With the use ofa bi polar current source the Model 2182 can perform basic Delta measurements See Section 5 of this manual for details on basic Delta measure ments This appendix summarizes the enhanced Delta Pulse Delta and Differential Conductance measurement processes that can be performed with the use of the Keithley Model 622x Current Source It does NOT provide the procedures to con figure and perform these measurements Detailed information on all aspects of Delta Pulse Delta and Differential Con ductance operation are provided in the Model 622x Reference Manual Section 5 An abbreviated version of this information is provided in the Model 622x User s Manual Section 5 You can use supplied example software that is available on the Keithley website www keithley com as a learning tool to configure and run Delta Pulse Delta and Differential Conductance With the use of any PC simple mouse clicks on a virtual front panel of the Model 622x are used to control operation For details see Using the example software in Section 10 of the Model 622x Reference Manual Keithley instrumentation requirements Keithley instrumentation requirements for Delta Pulse Delta and Differential Conduc tance are as follows Models 6220 and 2182 Delta and Differential Conductance measurements Models 6220 and 2182A Delta and Differential Conductance measurements Models 6221
51. F 12 IEEE 488 Bus Overview IEEE command groups Command groups supported by the Model 2182 are listed in Table F 5 Common commands and SCPI commands are not included in this list Table F 5 IEEE command groups HANDSHAKE COMMAND GROUP NDAC NOT DATA ACCEPTED NRFD NOT READY FOR DATA DAV DATA VALID UNIVERSAL COMMAND GROUP ATN ATTENTION DCL DEVICE CLEAR IFC INTERFACE CLEAR REN REMOTE ENABLE SPD SERIAL POLL DISABLE SPE SERIAL POLL ENABLE ADDRESS COMMAND GROUP LISTEN LAG LISTEN ADDRESS GROUP MLA MY LISTEN ADDRESS UNL UNLISTEN TALK TAG TALK ADDRESS GROUP MTA MY TALK ADDRESS UNT UNTALK OTA OTHER TALK ADDRESS ADDRESSED COMMAND GROUP ACG ADDRESSED COMMAND GROUP GTL GO TO LOCAL SDC SELECTIVE DEVICE CLEAR STATUS COMMAND GROUP RQS REQUEST SERVICE SRQ SERIAL POLL REQUEST STB STATUS BYTE EOI END IEEE 488 Bus Overview F 13 Interface function codes The interface function codes which are part of the IEEE 488 standards define an instrument s ability to support various interface functions and should not be confused with programming commands found elsewhere in this manual The interface function codes for the Model 2182 are listed in Table F 6 Table F 6 Model 2182 interface function codes Code Interface function SHI Source Handshake capability AH Acceptor Handshake capability T5 Talker basic talker talk only serial poll u
52. Figure 7 1 Figure 7 2 Figure 7 3 Figure 7 4 Figure 7 5 Figure 7 6 Figure 7 7 Figure 7 8 Figure 7 9 Figure 7 10 8 Figure 8 1 Figure 8 2 Figure 8 3 9 Figure 9 1 Figure 9 2 Figure 9 3 Figure 9 4 Figure 9 5 11 Figure 11 1 Figure 11 2 Figure 11 3 Figure 11 4 Figure 11 5 Figure 11 6 Figure 11 7 Figure 11 8 Figure 11 9 Figure 11 10 Buffer B ffer locations 25 2 ecce enero see eo eere ee eec ieve ete e ees E edere elena 6 3 Triggering Front panel trigger model without Stepping Scanning ssss 7 3 pup EM 7 5 Rear panel pinout T E 7 7 Trigger link input pulse specifications EXT TRIG eee 7 8 Trigger link output pulse specifications VMC sse 7 8 DUT vic E PRRM 7 9 Trigger link Connections 2 e isse cisseceeeses tne tanen oc ci nean toes Re sd odas 7 9 Operation model for triggering example esee 7 10 DIN to BNC trigger cable eiecti eere o Eee Een 7 12 Trigger model remote operation eese 7 13 Limits Default linats 2 rrr e OUR EORR REESE Re EE RR UNE NAP E ER reu 8 3 Setup to test 10 resistOrs eese neret ennn enne 8 7 Limits to sort 10 resistors 196 596 and 2596 esee 8 8 Stepping and Scanning Front panel triggering internal scanning esee 9 5 Front panel triggering other step scan operations
53. GPIB is the IEEE 488 interface The Model 2182 must be assigned to a unique address At the factory the address is set to 07 but can be set to any value from 0 to 30 However the address must not conflict with the address assigned to other instruments in the system You can use either the SCPI or 182 language to program the instrument RS 232 interface When using the RS 232 interface you must select baud rate terminator and flow control For the RS 232 interface you can only use the SCPI language to program the instrument NOTE When changing the interface GPIB to RS 232 or vice versa all data in the buffer clears Languages For the GPIB interface there are two programming languages to choose from SCPI Language 182 Language NOTE For the RS 232 interface only the SCPI language can be used to program the instrument When the RS 232 interface is selected it automatically defaults to SCPI SCPI language Standard Commands for Programmable Instrument SCPI is fully supported by the GPIB and RS 232 interfaces Always calibrate the Model 2182 using the SCPI language 182 Language The Model 2182 implements most commands DDCs available in the Keithley Model 182 Sensitive Digital Voltmeter The commands along with programming limitations are provided in Appendix D See the Model 182 Instruction Manual NOTE The 182 Language is intended to be used only over the IEEE 488 bus Using front panel controls in conjunction
54. Invalid character data EE 140 Character data error EE 128 Numeric data not allowed EE 124 Too many digits EE 123 Exponent too large EE 121 Invalid character in number EE 120 Numeric data error EE 114 Header suffix out of range EE 113 Undefined header EE 112 Program mnemonic too long EE 111 Header separator error EE 110 Command header error EE 109 Missing parameter EE 108 Parameter not allowed EE 105 GET not allowed EE 104 Data type error EE 103 Invalid separator EE 102 Syntax error EE 101 Invalid character EE 100 Command error EE 000 No error SE 101 Operation complete SE 121 Device calibrating SE 125 Device measuring SE 171 Waiting in trigger layer SE 174 Re entering the idle layer SE 180 Filter settled SE 301 Reading overflow SE 302 Low limit 1 event SE 303 High limit 1 event SE 304 Low limit 2 event SE 305 High limit 2 event SE 306 Reading available SE B 3 B 4 Status and Error Messages Table B 1 cont Status and error messages Number Description Event 308 Buffer available SE 309 Buffer half full SE 310 Buffer full SE Calibration messages 400 10m vde zero error EE 401 1 vdc zero error EE 402 10 vdc zero error EE 403 100 vdc zero error EE 404 10 vdc full scale error EE 405 10 vdc full scale error EE 406 100 vdc full scale error EE 408 10 vde ch2 high zero error EE 409 10 vdc ch2 low zero error EE 1410 B 7 div100 ACAL error EE 411 B 0
55. Japan Tokyo 81 3 5733 7555 Fax 81 3 5733 7556 www keithley jp Korea Seoul 82 2 574 7778 Fax 82 2 574 7838 www keithley com Netherlands Gorinchem 0183 635333 Fax 0183 630821 www keithley nl Singapore Singapore 65 6747 9077 Fax 65 6747 2991 www keithley com Sweden Solna 08 509 04 600 Fax 08 655 26 10 www keithley com Taiwan Hsinchu 886 3 572 9077 Fax 886 3 572 9031 www keithley com tw 3 04 Model 2182 and 2182A Nanovoltmeter User s Manual This User s Manual supports both the Models 2182 and 2182A References to the Model 2182 apply to both the Models 2182 and 2182A References to the Model 2182 2182A apply to the Model 2182 with firmaware version A10 or higher and the Model 2182A with firmware version C01 or higher References to the Model 2182A applies to the Model 2182A with firmware version C01 or higher 2004 Keithley Instruments Inc All rights reserved Cleveland Ohio U S A First Printing June 2004 Document Number 2182A 900 01 Rev A Manual Print History The print history shown below lists the printing dates of all Revisions and Addenda created for this manual The Revision Level letter increases alphabetically as the manual undergoes subsequent updates Addenda which are released between Revisions contain important change information that the user should incorporate immediately into the manual Addenda are numbered sequentially When a new Revision is created all
56. L054 T o TE x u vc X 9 H vc 8 9 dd NYO 13D sg 9 0 0 0 I M 3 EZ M Z D c n n 813 qq Z L L 1 0 J cc 9 E 44 9 9 NAS OV 9 O0 L1 1 0 n IZ n S 3 LZ S S dd VN odd ONI S L Ol Lj oO0 1 p oz l v a 0z Y Y 10d vod Das 103 Y 0 0 1 0 E 5 61 S 2 61 od X13 L L 0 0 J q 91 M A g 91 c c coa XLS c 0 1 0 0 b e ZL o L v ZL L L i OT Da ILD HOS L Liol o o d 91 d 0 2 91 0 0 dS qa NN 0 0 0 0 0 f moy 1 1 1 f a Z W Z 09 9 s WS r Wr 9 WE az c 1 WL a 0 0 uunjb q a a fa sug gt gt gt 27 gt gt gt gt o L 0 amp 3 L amp 3 0 amp 3 I amp 3 0 S L Q 0 a L LISD o 3 8 0 6 8 l 6 L 5 0 3 0 a L I 5 53 j 53 o 43 o 8 o 0 q 5 x x x x x x x amp x za Figure F 3 Command codes IEEE 488 Bus Overview F 9 Addressed multiline commands Addressed commands are multiline commands that must be preceded by the device listen address before that instrument will respond to the command in question Note that only the addressed device will respond to these commands Both the commands and the address preceding it are sent with ATN true SDC Selective Device Clear The SDC command performs essentially the same function as the DCL command except that only the addressed device responds Generally instruments return to their power up default conditions when resp
57. Note 2 ENABle lt NRf gt Program the enable register Note 3 ENABle Read the enable register CONDition Read the condition register PRESet Return status registers to default states QUEue Path to access Error Queue NEXT Read the most recent message Note 4 ENABle lt list gt Specify error and status messages for Error Queue Note 5 ENABle Read the enabled messages DISable lt list gt Specify messages not to be placed in queue Note 5 DISable Read the disabled messages CLEar Clears all messages from Error Queue Notes 1 Commands in this subsystem are not affected by RST or SYSTem PRESet The effects of cycling power CLS and STATus PRESet are explained by the following notes 2 Event Registers Power up and CLS clears all bits STATus PRESet has no effect 3 Enable Registers Power up and STATus PRESet clears all bits CLS has no effect 4 Error Queue Power up and CLS clears all bits of the registers 5 Error Queue Messages Power up clears list of messages CLS and STATus PRESet have no effect 14 12 SCPI Reference Tables Table 14 9 SYSTem command summary Default Command Description Parameter Ref SCPI SYSTem Sec 15 PRESet Return to SYSTem PRESet defaults FAZero Path to control Front Autozero STATe lt b gt Enable or disable Front Autozero ON STATe Query state of Front Autozero AZERo Path to control Autozero STATe lt b gt Enable or disable Au
58. Press ENTER The present digital filter count 1 to 100 will be displayed If you wish to change the digital filter count use the cursor keys and the RANGE A or W keys to display the desired count Press ENTER The present digital filter type moving average or repeat will be displayed If you wish to change the digital filter type place the cursor on the type name and press the RANGE A or V key Press ENTER The instrument returns to the normal measurement display state NOTES While the Filter is enabled FILT annunciator on changes to the configuration take effect as soon as they are made With Filter disabled FILT annunciator off changes to the configuration take place when the Filter is enabled If both the analog and digital filters are configured to be off the digital filter will automatically turn on if or when the Filter is enabled FILT annunciator on This ensures that filtering analog andlor digital is being applied whenever the FILT annunciator is on While the filtering operation is in progress the FILT annunciator blinks Readings will continue to be processed i e displayed stored sent over the bus sent to analog output but they could be questionable When the FILT annunciator stops blinking the filter has settled Changing function or range causes the Filter to reset The Filter then assumes the state enabled or disabled and configuration for that function or range When both channels are b
59. R measurement accuracy accuracy of selected Channel range plus accuracy of I source range DELTA measurement noise with 6220 or 6221 Typical 3nVRMS VHz 10mV range 1 Hz achieved with IPLC delay Ims RPT filter 23 20 if 50Hz PULSE MODE with 6221 line synchronized voltage measurements within current pulses from 50us to 12ms pulse repetition rate up to 12 Hz Pulse measurement noise typical RMS noise Rpur lt 10 ohms 0 009ppm of range meas time Npulse avg count 3nV 2 meas time pulse avg count for 10mV range 0 0028ppm for the 100mV range 0 0016ppm for ranges 1V and above 8nV NHz for ranges above 10mV meas time sec pulsewidth pulse meas delay in 33us incr DC NOISE PERFORMANCE DC NOISE EXPRESSED IN VOLTS PEAK TO PEAK Response time time required for reading to be settled within noise levels from a stepped input 60Hz operation CHANNEL 1 RANGE RESPONSE TIME NPLC FILTER 10mV 100mV 1V 10V 100V 25 0s 5 73 6nV 20 nV 75nV 750 nV 75 uV 40s 5 10 15nV 50 nV 150 nV 1 5 pV 75 uV 1 0s 1 18 25 nV 175 nV 600 nV 2 5uV 100 uV 667 ms 1 10 or 5 2 35 nV 250 nV 650 nV 3 3 WV 150 pV 60 ms 1 Off 70 nV 300 nV 700 nV 6 6 uV 300 uV CHANNEL 2 25 0 s 53 150 nV 200 nV 750 nV 40s 5 10 150 nV 200 nV 1 5 pV 1 0s 1 10 or 5 2 175 nV 400 nV 2 5 uV 85 ms 1 Off 425 nV 1 uV 9 5 uV VOLTAGE NOISE VS SOURCE RESISTANCE DC NOISE EXPRESSED IN VOLTS PEAK TO PEAK SOURCE RESISTANCE NOISE ANALO
60. Rer ripeto Cre Rr HE rH npe HAIR qa dE Ira ena st H 3 SENSe TIEDACEA ERESDR iiie prre denen ein eee H 4 What 1t dO6S 5 rcr etr RR C DH RE e e e E Re ER Ee LATE GER H 4 Limitations pe H 4 When Appropriate nre rem bate RR isr rat le eene EE ORUM RIPE E AET etae de EAS H 4 SENSe TEDATA EATest cnisia H 4 breui TETEE REES H 4 Limitations p H 4 When appropriate siisi seier enearo Ene iren rh t eor eae trie nan eoe toes E e i REE i H 4 locu qr H 5 One shot reading DC volts no trigger fastest rate sss H 5 One shot reading DC volts bus trigger auto ranging esee H 5 One shot reading external trigger auto delay enabled H 5 Delta Pulse Delta and Differential Conductance OVerVIeW discesa ce etie ier ise aree e FR EU dee en ru S I 2 Keithley instrumentation requirements essere nennen I 2 Op ration OVerVieW AP I 3 Test system configurations eeesseeseeeeeeeeeee enne enne nnne nentes ennt tennis enne ennn enn I 5 Delta measurement process ierit eene eerte eiei a i EE HEURE ERES I 6 PulsePDelta Proces P PE I 9 Pulse Delta measurements enn ones ti teet erri rise Ee E I 9 Pulse Delta outputs esses nennen enne nnne enne tentent ennn enne I 11 Differential Conductance process essent enne nennen I
61. TRIG COUN 1 SAMP COUN 5 INIT OPC Returns 2182 to default setup Disables continuous initiation Aborts operation Places 2182 in idle These two commands configure the 2182 to perform five measurements Starts measurement process Sends the OPC command After all five measurements are performed and the instrument returns to idle state an ASCII T will be placed in the Output Queue After addressing the Model 2182 to talk the 1 from the Output Queue is sent to the computer SYST PRES Returns 2182 to default setup Common Commands 12 11 NOTE The following commands take a long time to process and may benefit from using OPC or OPC RST and SYST PRES RCL and SAV CALC2 IMM and CALC2 IMM Only when performing the standard deviation cal culation on a large buffer RS 232 operation can also benefit from OPC Comments 1 Resets the Model 2182 to default operating conditions 2 Disables continuous initiation and aborts operation Places 2182 in the idle state 3 Configures the Model 2182 to perform five measurements 4 Performs an immediate initiation INITiate to restart the measurement process and sends the OPC command After all five measurements are performed and the instrument has returned to the idle state an ASCII 1 will be placed in the Output Queue 5 Addresses the Model 2182 to talk This sends the 1 from the Output Queue to the computer 6 Displays the
62. This bit only sets in response to the OPC query command Bit B1 Not used Bit B2 Query Error QYE A set bit indicates that you attempted to read data from an empty Output Queue Bit B3 Device Dependent Error DDE A set bit indicates that an instrument operation did not execute properly due to some internal condition Bit B4 Execution Error EXE A set bit indicates that the Model 2182 detected an error while trying to execute a command Bit B5 Command Error CME A set bit indicates that a command error has occurred Command errors include EEE 488 syntax error Model 2182 received a message that does not follow the defined syntax of the IEEE 488 2 standard Semantic error Model 2182 received a command that was misspelled or received an optional IEEE 488 2 command that is not implemented The instrument received a Group Execute Trigger GET inside a program message Common Commands 12 7 Bit B6 User Request URQ A set bit indicates that the LOCAL key on the Model 2182 front panel was pressed Bit B7 Power ON PON A set bit indicates that the Model 2182 has been turned off and turned back on since the last time this register has been read Figure 12 2 Standard event status register Bit Position B7 B6 B5 B4 B3 B2 B1 BO Decimal Weighting 128 64 32 16 8 4 27 2 2 24 23 Q2 Value O 1 O 1 O 1 0 1 O 1 0 1 Note Bits B8 throug
63. When the above is sent the first command word is recognized as the root command stat When the next colon is detected the path pointer moves down to the next command level and executes the command When the path pointer sees the colon after the semicolon it resets back to the root level and starts over Commands that are on the same command level can be executed without having to retype the entire command path Example stat oper enab lt NRf gt enab After the first command enab is executed the path pointer is at the third command level in the structure Since enab is also on the third level it can be entered without repeating the entire path name Notice that the leading colon for enab is not included in the program message If a colon were included the path pointer would reset to the root level and expect a root command Since enab is not a root command an error would occur Command path rules Each new program message must begin with the root command unless it is optional e g SENSe If the root is optional simply treat a command word on the next level as the root The colon at the beginning of a program message is optional and need not be used s stat pres stat pres When the path pointer detects a colon it moves down to the next command level An exception is when the path pointer detects a semicolon which is used to separate commands within the program message When the path p
64. a GPIB trigger the following program fragment will provide the GET Program fragment CALL TRANSMIT UNL LISTEN 7 GET status Trigger 2182 from over the bus When the command is executed the trigger event for the 2182 occurs Any other listeners ignore the trigger 11 12 Remote Operation SPE SPD serial polling Use the serial polling sequence to obtain the Model 2182 serial poll byte The serial poll byte contains important information about internal functions Generally the serial polling sequence is used by the controller to determine which of several instruments has requested service with the SRQ line However the serial polling sequence may be performed at any time to obtain the status byte from the Model 2182 Program Fragment WaitSRQ CALL SPOLL 7 poll status Serial poll the 2182 IF poll AND 64 0 THEN GOTO WaitSRQ Loop back if no SRQ Front panel GPIB operation The following paragraphs describe aspects of the front panel that are part of GPIB operation including messages status indicators and the LOCAL key Error and status messages See Appendix B for a list of error and status messages associated with IEEE 488 programming The instrument can be programmed to generate an SRQ and command queries can be performed to check for specific error conditions GPIB status indicators The REM remote TALK talk LSTN listen and SRQ service request annunciators show the GPIB bus stat
65. bit in the Status Byte Register will set When used with the Initiate Immediately command INITiate a 1 will not be placed into the Output Queue until the Model 2182 goes back into the idle state The INIT command operation is not considered finished until the Model 2182 goes back into the idle state See the description for WAI for more information on command execution The execution of OPC is not completed until it has placed the 1 in the Output Queue To use OPC exclusively with the TRG command first force the completion of the initiate command so that only the TRG command is pending To do this send the ABORt command to place the instrument in idle which by definition completes the initiate command Since continuous initiation is on operation continues on into the Trigger Model After sending the TRG command an ASCII 1 is placed in the Output Queue and the MAV bit sets when the TRG command is finished After OPC is executed additional commands cannot be sent to the Model 2182 until the pending overlapped commands are finished For example INITiate CONTinuous ON followed by OPC locks up the instrument and requires a device clear DCL or SDC before it will accept any more commands NOTE See OPC TRG and WAI for more information Programming example The following command sequence demonstrates how to use OPC to signal the end of a measurement process SYST PRES INIT CONT OFF ABORt
66. by pressing the OUTPUT ON OFF key ARM annunciator turns on B Reset the trigger model as follows 1 Press CONFIG and then TRIG to access the trigger configuration menu 2 Select HALT to place the SourceMeter in the idle state ARM annunciator turns off 3 Press EXIT to return to the normal display Step9 Set up the Model 2182 to store readings in the buffer optional On the Model 2182 press STORE and set the number of Delta readings to store in the buffer Press ENTER to enable the buffer Step 10 Start the sweep from the SourceMeter A To arm the sweep press SWEEP B To start the sweep press TRIG At the end of each 2 point sweep a Delta reading will be calculated and displayed and stored in the buffer if it is enabled NOTES A sweep in progress can be aborted by pressing EXIT on the SourceMeter f you are done sweeping turn off the source by pressing the ON OFF OUTPUT key on the SourceMeter Turning the source off prevents heat from building up in the DUT Delta readings stored in the buffer can be accessed by pressing RECALL on the Model 2182 Step 11 Repeating the sweep A On the Model 2182 press EX TRIG twice to disable and then re enable external triggering The TRIG annunciator indicates that the Model 2182 is in the external triggering mode B Repeat Steps 8 9 and 10 However if the SourceMeter output is already on skip Step 8A 5 14 Ratio and Delta Model 218
67. calculations are summarized in Table 4 2 in Section 4 FEED CONTrol is used to control the storage process NEXT starts the storage process and NEVer stops it After storage is completed buffer control automatically returns to NEVer CALCulate2 subsystem After the selected statistic is enabled IMMediate or IMMediate must be sent to calculate the statistic from the data in the buffer The DATA command does not initiate a calculate operation It simply returns the result of the last calculation If new data is stored in the buffer you must again send the IMMediate or IMMediate to recalculate the statistic from that new data There is no SCPI command to obtain the Peak to Peak statistic To get the Peak to Peak statistic your program will have to calculate it from the MAX and MIN statistics NOTE Since CALC2 IMM and CALC2 IMM are slow responding when performing the standard deviation calculation on large buffers OPC or OPC should be used with them Details on OPC and OPC are provided in Section 12 6 5 6 6 Buffer Programming example The following program fragment stores 20 readings into the buffer and then calculates the mean average on the buffer readings Store Readings CALL SEND 7 trac poin 20 status CALL SEND 7 trac feed sens status CALL SEND 7 trac feed cont next CALL SEND 7 trac data status reading SPACES 80 CALL ENTER reading PRINT reading Calculat
68. command CLEar SYSTem CLEar Clear Error Queue Description This action command is used to clear the Error Queue of messages 15 20 Additional SCP Commands KEY lt NRf gt command KEY SSYSTem KEY lt NRf gt Simulate key press Parameters lt NRf 1 SHIFT key lt NRf gt 17 LOCAL key 2 DCV key 18 EX TRIG key 3 DCV2 key 19 TRIG key 4 RATIO key 20 STORE key 5 ACAL key 21 RECALL key 6 FILT key 22 VALUE key 7 RELkey 23 ON OFF key 8 TEMPI key 24 left arrow key gt 25 10 26 STEP key 11 up arrow key 27 SCAN key 12 AUTO key 28 SAVE 13 down arrow key 29 RESTORE key 14 ENTER key 30 DIGITS key 15 right arrow key 31 RATE key 16 TEMP2 key 32 EXIT key Description This command is used to simulate front panel key presses For example to select RATIO you can send the following command to simulate pressing the RATIO key isyst key 4 The parameter listing provides the key press code in numeric order Figure 15 10 also illustrates the key press codes The queue for the KEY query command can only hold one key press When KEY is sent over the bus and the Model 2182 is addressed to talk the key press code number for the last key pressed either physically or with KEY is sent to the computer NOTE SYST KEY should not be used to put the Model 2182 into the local mode use GTL instead Additional SCP Commands Figure 15 10 Key press codes KEITHILEY NNAL A CHANNEL 2
69. differs from the last ACAL temperature by more than 1 C perform another ACAL Note The above table only provides the commands to perform ACAL which is a procedure to be performed by the operator The formal calibration is to be performed by qualified service personnel and is provided in the Model 2182 Service Manual SCPI Reference Tables 14 5 Table 14 3 DISPlay command summary Default Command Description Parameter Ref SCPI DISPlay Sec 15 ENABle lt b gt Turn front panel display on or off Note 1 v ENABle Query display state v WINDow 1 Path to control user test messages V TEXT Note 2 Vv DATA lt a gt Define ASCII message a up to 12 characters v DATA Read text message v STATe lt b gt Enable or disable text message mode Note 3 Vv STATe Query state of text message mode v Notes 1 RST and SYSTem PRESet have no effect on the display circuitry Pressing LOCAL or cycling power enables ON the display circuit 2 RST and SYSTem PRESet have no effect on a user defined message Pressing LOCAL or cycling power can cels all user defined messages 3 RST and SYSTem PRESet have no effect on the state of the message mode Pressing LOCAL or cycling power disables OFF the message mode Table 14 4 FORMat command summary Default Command Description Parameter Ref SCPI FORMat 5ec 15 DATA lt type gt lt length gt
70. enables autorange CALL SEND 7 fetch status Fetches Channel 1 offset reading SPACES 80 CALL ENTER reading length 7 status Gets offset reading CALL SEND 7 sens volt ref acq status Acquires Rel Value CALL SEND 7 sens volt ref stat on status Enables relative for DCVl Program Example 2 This program fragment shows how to establish a 1V baseline for the DCV1 function For this baseline value a 1V input will be displayed as OV CALL SEND 7 syst pres status Selects DCVI function and enables autorange CALL SEND 7 sens volt ref 1 status Sets a 1V rel value CALL SEND 7 sens volt ref stat on status Enables relative for DCVl 4 6 Relative mX b and Percent mX b and percent mX b This math operation manipulates normal display readings X mathematically according to the following calculation Y mX b where X is the normal display reading m and b are user entered constants for scale factor and offset Y is the displayed result To configure and control the mX b calculation perform the following steps 1 NOTE Press SHIFT and then MX B to display the present scale factor M 1 0000000 factory default Key in a scale factor value The lt q and gt keys control cursor position and the A and W range keys increment and decrement the digit value To change range place the cursor on the multiplier and use the and W keys m x0 001
71. even if reasonable precautions are taken Figure C 1 Thermal EMF generation 2182 Er Qas Ty 7 T A HI O CH1 LO O T C4 Measurement Considerations Minimizing thermal EMFs To minimize thermal EMFs use only copper wires lugs and test leads for the entire test setup Also it is imperative that all connecting surfaces are kept clean and free of oxides As noted in Table C 1 copper to copper oxide junctions can result in thermal EMFs as high as ImV C Even when low thermal cables and connections are used thermal EMFs can still be a problem in some cases It is especially important to keep the two materials forming the junction at the same temperature Keeping the two junctions close together is one way to minimize such thermal problems Also keep all junctions away from air currents in some cases it may be necessary to thermally insulate sensitive junctions to minimize temperature variations When a Cu Cu connection is made sufficient pressure must be applied to ensure the connection is gas tight to prevent future oxidation In some cases connecting the two thermal junctions together with good thermal contact to a common heat sink may be required Unfortunately most good electrical insulators are poor conductors of heat In cases where such low thermal conductivity may be a problem special insulators that combine high electrical insulating properties with high thermal conductivity may be used Some examples of these mate
72. factory default settings listed in Table 1 2 The Model 2182 can instead be set to power up to a user default setup The power on default setup will be the last configuration you saved The SAVE key saves the present configuration as the USER power on setup The RESTR key restores the instrument to the factory defaults or the user saved defaults Perform the following steps to save the present setup as the power on default configuration Configure the instrument for your measurement application Press SAVE 1 2 3 Use the A and keys to display YES or NO 4 Press ENTER The instrument will power on to this USER default setup NOTE Toassure that the proper filter state is recalled set the analog and digital filters before saving the user setup See Section 3 To restore factory or user settings 1 Press RESTR 2 Use the A and keys to display FACT factory or USER defaults 3 Press ENTER NOTE The basic measurement procedure in the next section Section 2 assumes factory defaults Table 1 2 Reset the instrument to the factory default settings when following that step by step procedure Table 1 2 Factory defaults Setting Factory Default Analog output On Gain M 1 0 Offset B 0 Relative REL Off Autozeroing modes Front Autozero On Autozero On LSYNC Off Buffer No effect Delta Off Function DCVI GPIB No effect On at factory Address No effect 7 at factory Language No effect SCPI at factory
73. in case the transfer sequence stops for any reason Figure F 2 IEEE 488 handshake sequence DATA SOURCE DAV SOURCE VALID ALL READY ACCEPTOR NRFD a ALL ACCEPTED NDAC ACCEPTOR F 6 IEEE 488 Bus Overview Once all NDAC and NRFD are properly set the source sets DAV low indicating to accepting devices that the byte on the data lines is now valid NRFD will then go low and NDAC will go high once all devices have accepted the data Each device will release NDAC at its own rate but NDAC will not be released to go high until all devices have accepted the data byte The previous sequence is used to transfer both data talk and listen addresses as well as multiline commands The state of the ATN line determines whether the data bus contains data addresses or commands as described in the following paragraphs Bus commands The instrument may be given a number of special bus commands through the IEEE 488 interface The following paragraphs briefly describe the purpose of the bus commands which are grouped into the following three categories 1 Uniline commands Sent by setting the associated bus lines true For example to assert REN Remote Enable the REN line would be set low true 2 Multiline commands General bus commands which are sent over the data lines with the ATN line true low 3 Common commands Commands that are common to all devices on the bus sent with ATN high false 4 SCPIcommands
74. in process will be aborted e Autozero is set to the RST default value All operations associated with stepping or scanning are disabled This command is automatically asserted when the MEASure command is sent Program fragment CALL SEND 7 conf volt CALL SEND 7 trig del 0 5 CALL SEND 7 samp coun 10 CALL SEND 7 read reading SPACES 80 CALL ENTER reading PRINT reading FETCh Description length status status3 status3 status 7 status 4 4 4 Perform CONFigure operations Set delay for 0 5sec Set sample count to 10 Trigger and request readings Address 2182 to talk Display the 10 readings on the CRT This command requests the latest post processed reading After sending this command and addressing the Model 2182 to talk the reading is sent to the computer This command does not affect the instrument setup This command does not trigger a measurement The command simply requests the last available reading Note that this command can repeatedly return the same reading Until there is new reading this command continues to return the old reading If your application requires a fresh reading use the DATA FRESh command see the SENSe Subsystem command This command is automatically asserted when the READ or MEASure command is sent READ Description This command is typically used with the instrument in the one shot measure
75. in the display sending this command will cause a 230 Data corrupt or stale error This query will not cause the box to trigger a reading nor will it wait for a result if a reading is in progress It is possible to get the same reading over and over using this query It will continue to give the same result until one of two things has happened Anew reading has been triggered The old reading has been invalidated by changing ranges or by changing function Where appropriate Since this query does not trigger a reading and can give duplicate results there are not many cases where this command should be used The DATA FRESh query see page H 4 is often a better choice If this query is used the following conditions should be met e A reading has been triggered either by free running INIT CONT ON and TRIG SOUR IMM by some event such as a bus trigger TRG or by an external trigger TRIG SOUR EXT tis confirmed that the reading is completed either by the setting of the RAV bit in the status model or by allowing sufficient time to pass for the reading to complete READ What it does This command performs three actions It will reset the trigger model to the idle layer equivalent to the ABORt command take the trigger model out of idle equivalent to the INIT command and return a reading equivalent to a FETCh query This command will always return a new reading since aborting the trig
76. instrument returns to the normal display state RS 232 interface The RS 232 interface is selected and configured from the RS 232 menu structure From this menu you can enable or disable the RS 232 interface and check or change the following settings Baud rate 19 2k 9600 4800 2400 1200 600 or 300 Flow control none or XonXoff Terminator CR LF CRLF or LFCR NOTE See RS 232 interface reference located at the end of this section for information on the these settings and connections to the computer Remote Operation 11 5 Perform the following steps to select and configure the RS 232 interface NOTE To retain a present RS 232 setting press ENTER with the setting displayed You can exit from the menu structure at any time by pressing EXIT 1 Press SHIFT and then RS232 to access the RS 232 menu The present state on or off of the RS 232 is displayed 2 To enable the RS 232 interface A Place the cursor on the on off selection by pressing the gt key B Press the or V key to toggle the selection to ON C Press ENTER The present baud rate is displayed 3 To change baud rate A Place the cursor on the baud rate value B Use the A and keys to display the desired baud rate value C Press ENTER The present flow control setting is displayed 4 To change flow control A Place the cursor on the present flow control selection B Press the or V key to toggle the selection C Press
77. into Ratio For more information see Ranging considerations for Ratio NOTE After Ratio is enabled next step pressing the AUTO range key will either enable autorange for both channels or disable autorange for both channels Step5 Enable Ratio To enable Ratio press the V1 V2 key The CH1 CH2 message will be displayed briefly While in Ratio the RA message is displayed and both the CH1 and CH2 annunciators are on NOTE Ifan overflow condition OVRFLW occurs the range that overflowed will format the display Step6 Take Ratio readings from display 5 4 Ratio and Delta Filter Rel and Ranging considerations Filter considerations As explained in Section 3 a unique Filter configuration can be established for each voltage channel However the Filter configuration for Channel 1 is applied to both channels when Ratio is enabled The Filter state and configuration for Channel 2 are ignored Channel 1 Filter has priority because it has the most sensitive measurement range 10mV and may therefore be configured to provide more filtering than Channel 2 When the FILT annunciator is on while in Ratio the Channel 1 DCV1 Filter settings are applied to both input channels When the FILT annunciator is off filtering is not used When using Filter Ratio is calculated as follows Ratio Filt V1 Filt V2 where Filt V1 is the filtered reading for Channel 1 voltage input Filt V2 is the filtered r
78. lt item list FORMat ELEMents lt item list Specify elements to include in data string Parameters lt item list READing Includes reading in data string CHANnel Includes channel number UNITs Includes units NOTE Each item in the list must be separated by a comma Description This command is used to specify the elements to be included in the data string for each measurement conversion You can specify from one to all three elements Each element in the list must be separated by a comma These elements shown in Figure 15 1 are explained in the following paragraphs READing Instrument reading The resolution of this reading tracks the display resolution of the instrument An overflow reading reads as 9 9e37 with no units Additional SCPI Commands 15 7 CHANnel Corresponds the instrument reading to the channel number Channel 0 corresponds to the sensor used to measure the internal temperature of the Model 2182 Channel 1 and Channel 2 corresponds to the two input channels of the instrument For external scanning the number corresponds to the channel number of the switching card UNITs This element attaches the function unit to the reading and the channel unit internal or external to the channel number An external channel refers to the channel for an external switch system This element is not available for the binary formats The ASCII format in Figure 15 1 shows the byte order of the data string Remember that th
79. one point Shielding also helps minimize AC interference The metal shield should enclose the test circuit and be connected to Channel 1 LO or to the chassis ground screw on the rear panel Voltage and Temperature Measurements 2 23 Applications Low resistance measurements The Model 2182 can be used with a current source to measure resistances at levels well below the capabilities of most conventional instruments The following paragraphs discuss low resistance measurement techniques and include some applications to test switches Measurement techniques Techniques used to measure resistances in the normal range are not generally suitable for making low resistance measurements because of errors caused by voltage drops across the test leads To overcome these limitations low resistance measurements are usually made using the 4 wire Kelvin connections shown in Figure 2 10 A current source forces the current I through an unknown resistance developing a voltage across that device Even though the test lead resistance Ry gap is present it does not affect the current through Rpyr because I is assumed to be a constant current source with high output impedance Also since the voltmeter has a very high input resistance very low leakage current the current through the sense leads will be negligible and the voltage drop across Ry gap will be essentially zero Thus the voltage measured by the meter will be essentially the same as the vo
80. operation can be resumed by using the ENABle command to enable the display or by putting the Model 2182 into local mode press LOCAL TEXT commands DATA lt a gt DISPlay WINDow 1 TEXT DATA lt a gt Define message for display Parameter lt a gt ASCII characters for the message maximum of 12 characters The characters ee 99 must be enclosed in either double quotes or single quotes Description These commands define the text message for display A message can be as long as 12 characters space counts as a character Excess message characters results in an error STATe lt b gt DISPlay WINDow 1 TEXT STATe lt b gt Control on off message Parameters lt b gt 0 or OFF Disable text message 1 or ON Enable text message Description This command enables and disables the text message mode When enabled a defined message is displayed When disabled the message is removed from the display A user defined text message remains displayed only as long as the instrument is in remote Taking the instrument out of remote by pressing the LOCAL key or sending GTL cancels the message and disables the text message mode 15 4 Additional SCPI Commands FORMat subsystem The commands in this subsystem are used to select the data format for transferring instrument readings over the bus The BORDer command and DATA command only affect readings transferred from the buffer 1 e SENSE DATA or CALC D
81. output The reference value can be either programmed value or the value of the previous input TRIGGERING AND MEMORY WINDOW FILTER SENSITIVITY 0 01 0 1 1 10 or full scale range none READING HOLD SENSITIVITY 0 01 0 1 1 or 10 of reading TRIGGER DELAY 0 to 99 hours 1ms step size EXTERNAL TRIGGER DELAY 2ms lt 1 ms jitter with auto zero off trigger delay 0 MEMORY SIZE 1024 readings MATH FUNCTIONS Rel Min Max Average Std Dev Peak to Peak of stored reading Limit Test and mX b with user defined units displayed REMOTE INTERFACE Keithley 182 emulation GPIB IEEE 488 2 and RS 232C SCPI Standard Commands for Programmable Instruments GENERAL SPECIFICATIONS POWER SUPPLY 100V 120V 220V 240V LINE FREQUENCY 50Hz 60Hz and 400Hz automatically sensed at power up POWER CONSUMPTION 22VA OPERATING ENVIRONMENT Specified for 0 to 50 C Specified to 80 RH at 35 C MAGNETIC FIELD DENSITY 10mV range 4 0s response noise tested to 500 gauss STORAGE ENVIRONMENT 40 to 70 C WARRANTY 3 years SAFETY Complies with European Union Directive 73 23 EEC low voltage directive meets EN61010 1 safety standard Installation category I EMC Complies with European Union Directive 89 336 EEC CE marking requirement FCC part 15 class B CISPR 11 IEC 801 2 IEC 801 3 IEC 801 4 VIBRATION MIL PRF 28800E Type III Class 5 WARM UP 2 5 hours to rated accuracy DIMENSIONS Rack Mounting 89m
82. output to a specific value such as zero For example assume you are measuring 100mV on the 1V range With gain set to 1 the analog output would be 100mV You can increase analog output sensitivity by setting gain to 10 This increases the analog output to 1V You can then set Offset to 1V to reference the 1V analog output to zero The Analog Output calculation looks like this Analog Output 10 x 100mV 1V 1V 0V NOTE Analog Output Rel can be used to automatically reference the analog output voltage to zero See Analog output rel The factory default for Gain is 1 and the factory default for Offset is 0 Therefore when using the factory defaults Gain and Offset drop out of the equation Analog Output Rdg Rng Table 10 1 shows analog output examples with Gain set to 1 and Offset set to 0 Table 10 1 Analog output examples Analog Output Reading Range Voltage 1V 1V 1V 1V 1V 1V 1V 10V 0 1V 12V 10 1 2V 50mV 100mV 0 5V lmV 1V mV Gain 1 Offset 0 10 4 Analog Output Temperature The analog output voltage for temperature measurements depends on thermocouple type and the selected units C F or K The 1 2V analog output is scaled to the maximum positive temperature reading For example the measurement range for the Type J thermocouple is 200 C to 760 C For a 760 C reading the analog output voltage will be 1 2V and for a 200 C reading the analog outpu
83. power is applied to the device under test Safe operation requires the use of a lid interlock Ifa screw is present connect it to safety earth ground using the wire recommended in the user documentation The IN symbol on an instrument indicates that the user should refer to the operating instructions located in the manual The A symbol on an instrument shows that it can source or measure 1000 volts or more including the combined effect of normal and common mode voltages Use standard safety precautions to avoid personal contact with these voltages The Al symbol indicates a connection terminal to the equipment frame The WARNING heading in a manual explains dangers that might result in personal injury or death Always read the associated information very carefully before performing the indicated procedure The CAUTION heading in a manual explains hazards that could damage the instrument Such damage may invalidate the war ranty Instrumentation and accessories shall not be connected to humans Before performing any maintenance disconnect the line cord and all test cables To maintain protection from electric shock and fire replacement components in mains circuits including the power transformer test leads and input jacks must be purchased from Keithley Instruments Standard fuses with applicable national safety ap provals may be used if the rating and type are the same Other components that are not safety related may be purchased
84. pulse is specified by the user The high pulse levels for this output are ImA 2mA 4mA 8mA and 16mA The low pulse level for this sweep is OmA Delta Pulse Delta and Differential Conductance I 13 Figure I 6 Pulse sweep output examples A Staircase sweep pulse train 2 to 10mA in 2mA steps Linear Scale Step 2mA set by the user A Stop710mA 10mA Step OmA LO HI LO LO HI LO LO HI LO LO Hi LO LO HI LO lt gt i lt gt q gt One Pulse Delta Cycle One Pulse Delta Cycle One Pulse Delta Cycle One Pulse Delta Cycle One Pulse Delta Cycle r Sweep Delay Sweep Delay i Sweep Delay Sweep Delay Sweep Delay B Logarithmic sweep pulse train 1 to 10mA using 5 logarithmic Logrithmic Scale Log Step is calculated and set by the 622x A 10mA Stop110mA 5 6234mA Log Step 3 1623mA Log Step 17783mA L09 step Log Step T Start Low OmA LO HI LO LO HI LO LO HI LO LO HI LO LO HI LO i gt lt bie P One Pulse Delta Cycle One Pulse Delta Cycle One Pulse Delta Cycle One Pulse Delta Cycle One Pulse Delta Cycle Sweep Delay d Sweep Delay i Sweep Delay i Sweep Delay Sweep Delay C Custom sweep pulse train 1mA 2mA 4mA 8mA and 16mA 5 points Linear Scale i 16mA 16mAT 8mA 4mA 1mA ems Low OmA LO HI LO LO HI LO LO HI LO LO HI LO LO HI LO lt gt 4 pi lt bi gt One Pulse Delta Cycle One Pulse Delta Cycle One Pulse Delta Cycle
85. queue This command is used to specify which messages you want disabled Disabled messages are prevented from going into the Error Queue Messages are specified by numbers see Appendix B See QUEue ENABle for examples to express a numlist 15 16 Additional SCP Commands CLEar STATus QUEue CLEar Clears all messages from Error Queue Description This command is used to clear the Error Queue of all messages SYSTem subsystem The SYSTem subsystem commands are summarized in Table 14 9 PRESet command PRESet SYSTem PRESet Return to SYSTem PRESet defaults Description This command returns the instrument to states optimized for front panel operation SYSTem PRESet defaults are listed in the SCPI tables Table 14 1 through Table 14 12 Performance commands FAZero STATe lt b gt SYSTem FAZero STATe b Control Front Autozero Parameters lt b gt 0 or OFF Disable Front Autozero 1 or ON Enable Front Autozero Description With Front Autozero enabled which is the default setting the instrument performs two A D measurement cycles for each reading The first one is a normal measurement cycle The second measurement cycle is performed with the polarity of the front end amplifier reversed This current reversal measurement technique is used to cancel internal offsets in the amplifier With Front Autozero disabled the second measurement cycle is not performed The speed for Delta measurements can be doubled by di
86. read status To display the response message on the CRT the computer has to read the message and then print it to the computer display as follows reading SPACES 80 CALL ENTER reading length 7 status PRINT reading The following programming example shows how all the above statements are used together SINCLUDE c Nqb45Nieeeqb bi Include QuickBASIC libraries CALL INITIALIZE 21 0 Initialize card as address 21 CALL SEND 7 rst status Restore 2182 to RST defaults CALL SEND 7 read status Trigger and request a reading reading SPACES 80 Allocate room for data CALL ENTER reading length 7 status Address 2182 to talk PRINT reading Display reading on CRT General bus commands Commands and associated statements General commands are those commands such as DCL that have the same general meaning regardless of the instrument Table 11 1 lists the general bus commands along with the programming statement for each command Table 11 1 General bus commands and associated statements Command Programming Statement Effect On Model 2182 REN REN Goes into remote when next addressed to listen IFC CALL INITIALIZE Reset interface all devices go into talker and listener idle states LLO LLO LOCAL key locked out GTL GTL Cancel remote restore front panel operation for the 2182 DCL DCL Return all devices to known conditions SDC SDC Returns Model 2182 to known cond
87. restores front panel key operation Program Fragment CALL TRANSMIT MTA LISTEN 7 REN status Place 2182 in remote CALL TRANSMIT UNL LISTEN 7 GTL status Place 2182 in local mode DCL device clear Use the DCL command to clear the GPIB interface and return it to a known state Note that the DCL command is not an addressed command so all instruments equipped to implement DCL will do so simultaneously When the Model 2182 receives a DCL command it clears the Input Buffer and Output Queue cancels deferred commands and clears any command that prevents the processing of any other device command A DCL does not affect instrument settings and stored data Program fragment CALL TRANSMIT DCL status Clears all devices SDC selective device clear The SDC command is an addressed command that performs essentially the same function as the DCL command However since each device must be individually addressed the SDC command provides a method to clear only selected instruments instead of clearing all instruments simultaneously as is the case with DCL Program fragment CALL TRANSMIT UNL LISTEN 7 SDC status Clears 2182 GET group execute trigger GET is a GPIB trigger that is used as an event to control operation The Model 2182 reacts to this trigger if it is the programmed control source The control source is programmed from the SCPI TRIGger subsystem With the instrument programmed and waiting for
88. set bit indicates that one or more enabled Status Byte conditions have occurred Read the MSS bit by using the STB query command or perform a serial poll to detect the occurrence of a service request RQS bit set Bit 7 Operation Summary OSB A set bit indicates that an enabled operation event has occurred The event can be identified by reading the Operation Event Status Register using the STATus OPERation query command see Section 15 for details Common Commands 12 15 Figure 12 4 Status byte register Bit Position B7 B6 B5 B4 B3 B2 B1 BO Event MSB P REM l 1 Decimal Weighting 20 Value 0 1 Value 1 Event Bit Set Events OSB Operation Summary Bit 0 Event Bit Cleared MSS Master Summary Status RQS Request Service ESB Event Summary Bit MAV Message Available QSB Questionable Summary Bit EAV Error Available MSB Measurement Summary Bit TRG Trigger Send bus trigger to 2182 Description Use the TRG command to issue a GPIB trigger to the Model 2182 It has the same effect as a group execute trigger GET Use the TRG command as an event to control operation The Model 2182 reacts to this trigger if BUS is the programmed control source The control source is programmed from the TRIGger subsystem see Section 14 TST Self Test Query Run self test and read result Description Use this query command to perform a checksum test on ROM The command
89. simulated reference junction ice bath is used Figure 2 9 Connections voltage and temperature simulated reference Cable to copper 2107 wire connection Input Cable one of two Thermocouple DCV1 DUT m black green TEMP2 Test Circuit white Ice Bath Cable to thermocouple wire connection one of two Cleaning test circuit connectors Wherever possible copper to copper connections should be used throughout your test circuit s to minimize thermal EMFs However exposed copper is susceptible to oxidation which could corrupt the measurement Make sure that the copper contact surfaces are free of oxidation before making the connection DeoxIT can be used to clean copper connectors A small bottle of DeoxIT is supplied with the Model 2182 The Model 2107 Input Cable is terminated with copper lugs and the connection terminals of a LEMO connector are copper Perform the following steps to clean the copper connectors used in your test circuit 1 Using a lint free foam swab or other applicator soak up a small amount of DeoxIT 2 Apply the DeoxIT sparingly to connector contact Only a thin coating is required NOTE After cleaning make your test circuit connections in a timely manner to prevent oxidation from forming on exposed connector surfaces 2 18 Voltage and Temperature Measurements Temperature configuration If you are going to perform temperature measurements you hav
90. speed of bus information transfer since the task of listening takes up bus time Through the use of control lines a handshake sequence takes place in the transfer process of information from a talker to a listener This handshake sequence helps ensure the credibility of the information transfer The basic handshake sequence between an active controller talker and a listener is as follows 1 The listener indicates that it is ready to listen The talker places the byte of data on the bus and indicates that the data is available to the listener 3 The listener aware that the data is available accepts the data and then indicates that the data has been accepted 4 The talker aware that the data has been accepted stops sending data and indicates that data is not being sent 5 The listener aware that there is no data on the bus indicates that it is ready for the next byte of data Bus description The IEEE 488 bus which is also referred to as the GPIB General Purpose Interface Bus was designed as a parallel transfer medium to optimize data transfer without using an excessive number of bus lines In keeping with this goal the bus has only eight data lines that are used for both data and with most commands Five bus management lines and three handshake lines round out the complement of bus signal lines A typical setup for controlled operation is shown in Figure F 1 Generally a system will contain one controller and a number of ot
91. time and Channel 1 is again measured four times After the last measurement is performed the instrument goes into idle 9 10 Stepping and Scanning External scanning Figure 9 3 summarizes the front panel operations to configure a scan for the External triggering example provided in Section 7 In that example the Model 2182 is used to scan and measure eight DUTs switched by a Model 7168 Nanovolt Scanner card installed in a Model 7001 7002 Switch System Figure 7 6 and Figure 7 7 show the signal and trigger connections while Figure 7 8 shows trigger model operation for the test Both instrument setups assume factory defaults Note that Channel 1 of the Model 2182 must be used for external scanning 1 Bo D On the Model 7001 Switch System enter a scan list of channels 1 to 8 on card 1 Also on the Model 7001 configure the instrument for Trigger Link triggers and one scan of eight channels On the Model 2182 configure an external scan of the first eight channels Set the Model 2182 for external triggers by pressing EX TRIG Press STEP or SCAN on the Model 2182 The asterisk and STEP or SCAN annunciator will light Press STEP on the Model 7001 to start channel closures After the scan you can recall eight readings from the Model 2182 buffer Figure 9 3 External scanning example with Model 7001 Model 7001 from reset setup SCAN CHANNELS 1 1 1 8 CONFIGURE SCAN CHAN CONTROL CHANNE
92. to 2 calc kmat mbf 0 5 status Sets offset B to 0 5 calc kmat mun cd status Sets units to CD calc stat on status Enables calculation Program Example 2 This program fragment shows how to configure and enable the Percent calculation CALL SEND 7 CALL SEND 7 CALL SEND 7 calc form perc status Selects percent calculation calc kmat perc acq status Uses input signal as reference calc stat on status Enables calculation Ratio and Delta 5 2 Ratio and Delta NOTE When using the Model 2182 2182A with the Model 6220 or 6221 Current Source enhanced Delta and Differential Conductance measurements can be performed When using the Model 2182A with the Model 6220 Current Source Pulsed Delta measurements can be performed See Section I for details on enhanced Delta Pulsed Delta and Differential Con ductance Ratio Covers the Ratio calculation and the effects of Filter Rel and Ranging Delta Explains how to perform Delta measurements which are used to cancel the effects of thermal EMFs in the test leads Features the use of a Keithley SourceMeter with the Model 2182 to perform Delta measurements Includes the effects of Filter on Delta measurements SCPI programming Covers the SCPI commands used to control Ratio and Delta and includes programming examples Applications Provides applications that use Ratio and Delta Ratio Ratio V1 V2 display
93. to respond to triggers is implicit in the non SCPI voltmeters Sending a command to a non SCPI voltmeter to change any of the trigger controls causes the instrument to arm itself for triggers The SCPI trigger model implemented in the Model 2182 gives Explicit control over the trigger source the TRIGger subsystem A way for completely disabling triggers Changing any of the settings in the TRIGger subsystem does not automatically arm the Model 2182 for triggers The following program sets up the Model 2182 to take one reading each time it receives an external trigger pulse Example program to demonstrate one shot external triggering For QuickBASIC 4 5 and CEC PC488 interface card Edit the following line to where the QuickBASIC libraries are on your computer SINCLUDE c Nqb45Nieeeqb bi Initialize the CEC interface as address 21 CALL initialize 21 0 Reset controls and put trigger model in IDLE state CALL SEND 7 rst status CALL SEND 7 trig sour ext coun inf status start everything CALL SEND 7 init status After the Model 2182 receives the INITiate command it stops at the control source in the trigger model waiting for a trigger pulse Each time a pulse arrives at the Trigger Link connector the Model 2182 takes one reading Because TRIGger COUNt has been set to INFinity the instrument never enters the idle state You can send the ABORt command to put the instrument in the idle state disabling
94. triggers until another INITiate command is sent Example Programs E 5 Generating SRQ on buffer full When your program must wait until the Model 2182 has completed an operation it is more efficient to program the Model 2182 to assert the IEEE 488 SRQ line when it is finished rather than repeatedly serial polling the instrument An IEEE 488 controller will typically address the instrument to talk and then unaddress it each time it performs a serial poll Repeated polling of the Model 2182 will generally reduce its overall reading throughput Therefore use the srq function call The Model 2182 provides a status bit for almost every operation it performs It can be programmed to assert the IEEE 488 SRQ line whenever a status bit becomes true or false The IEEE 488 controller your computer can examine the state of the SRQ line without performing a serial poll thereby detecting when the Model 2182 has completed its task without interrupting it in the process The following example program segment sets up the Model 2182 to assert SRQ when the reading buffer has completely filled and then arms the reading buffer initiates readings and waits for the Model 2182 to indicate that the buffer is full This is not a complete program The commands to configure the trigger model and the reading buffer see the next example are not shown The example shown here can be modified for any event in the Model 2182 status reporting system Reset STAT
95. up at this block until the delay period expires Device action Measurements are performed at this block For internal stepping the first measurement is performed on Channel 2 of the Model 2182 Subsequent measurements are performed on Channel 1 For internal scanning and external scanning each measurement corresponds to a channel in the step scan list All readings are automatically stored in the buffer Output trigger After each measurement is performed an output trigger is applied to the rear panel Trigger Link connector Trigger counter Reading Count specifies the total number of measurements to perform If another measurement is to be performed operation loops back to the control source Stepping Scanning controls SHIFT CONFIG Selects and configures internal or external scanning See Step Scan configuration for details EX TRIG Selects the External Trigger control source TRIG Satisfies event detection for the External Trigger control source STEP and SCAN Enables a stepping or scanning operation of consecutive channels SHIFT HALT Stops stepping or scanning and restores the trigger model to a non stepping scanning mode Stepping and Scanning 9 7 Step Scan configuration Internal Stepping Scanning The settings for internal stepping and scanning are explained as follows Timer The maximum timer interval is 99H 99M 99 999S Hour Minute Second format Channel 1 Count Th
96. value bits B5 and B9 of the Measurement Event Register are set 15 8 Additional SCPI Commands Measurement Event Register Bit B0 Reading Overflow ROF Set bit indicates that the reading exceeds the measure ment range of the instrument Bit B1 Low Limit1 LL1 Set bit indicates that the reading is less than the Low Limit 1 setting Bit B2 High Limit1 HL1 Set bit indicates that the reading is greater than the High Limit 1 setting Bit B3 Low Limit 2 LL2 Set bit indicates that the reading is less than the Low Limit 2 setting Bit B4 High Limit 2 HL2 Set bit indicates that the reading is greater than the High Limit 2 setting Bit B5 Reading Available RAV Set bit indicates that a reading was taken and processed Bit B6 Not used Bit B7 Buffer Available BAV Set bit indicates that there are at least two readings in the trace buffer Bit B8 Buffer Half Full BHF Set bit indicates that the trace buffer is half full Bit B9 Buffer Full BFL Set bit indicates that the trace buffer is full Bits B10 through B15 Not used Figure 15 4 Measurement event register Bit Position B15 B10 Event BFL BHF BAV RAV HL2 LL2 HL1 LL1 ROF i iohti 512 256 128 32 16 8 4 2 1 Decima Weighting 29 28 27 25 24 23 22 Q1 20 Value 2 3 0 1 0 1 o 1 0 0 1 0 1 0 1 0 1 0 1 Value 1 Measurement E
97. when Rel is enabled The Model 2182 is optimized to provide low noise readings when measurement speed is set from 1 to 5 PLC At 1 PLC current can be reversed after 100msec At 5 PLC current can be reversed after 333msec At these reading rates noise induced by the power line should be insignificant Filtering can be used to reduce peak to peak reading variations For more information on Filter in regard to Delta measurements see Filter considerations in this section The following example shows how a bipolar current source and Delta can be used to cancel the effects of thermal EMFs In Figure 5 1A a constant 1mA is being sourced to a 0 1 2 DUT Under ideal conditions the Model 2182 would measure 100uV across the DUT 1mA x 0 1Q 100uV However connection points and temperature fluctuations may generate thermal EMFS in the test leads Note that the thermal EMFs drift with temperature Figure 5 1 shows 10uV of thermal EMF Vq4gggw Therefore the Model 2182 will measure 110uV instead of 100pV V282 Vruerm Vpur 10nV 100uV 110pV Ratio and Delta 5 7 Figure 5 1 Test circuit using constant current source Vout 100uV Voig2 10uV 100uV 110uV A Positive Current Source VTHERM Vpur 7 100uV Vo1g2 10uV 100uV 90uV B Negative Current Source Figure 5 1B shows what happens when the current is reversed The measurement by the Model 2182 still includes the 10uV of thermal EMF but
98. with this language may cause erratic operation In this case results cannot be guaranteed 11 4 Remote Operation Interface selection and configuration procedures When you select enable the GPIB interface the RS 232 interface disables Conversely selecting enabling the RS 232 interface disables the GPIB interface GPIB interface The GPIB interface is selected and configured from the GPIB menu structure From this menu you can enable or disable the GPIB interface and check or change the following settings Primary address 0 to 30 Language SCPI or 182 Perform the following steps to select and configure the GPIB interface NOTE Toretaina present GPIB setting press ENTER with the setting displayed You can exit from the menu structure at any time by pressing EXIT 1 Press SHIFT and then GPIB to access the GPIB menu The present state on or off of the GPIB is displayed 2 To enable the GPIB interface A Place the cursor on the on off selection by pressing the gt key B Press the or V key to toggle the selection to ON C Press ENTER The present GPIB address is displayed 3 To change the GPIB address A Use the lt q P gt A and keys to display a valid address value B Press ENTER The present language selection is displayed 4 To change the programming language A Place the cursor on the present language selection B Press the or V key to toggle the selection C Press ENTER The
99. 0 to 120 volts 120 V UPPer Query range value v AUTO lt b gt Enable or disable autorange ON v AUTO Query state of autorange V REFerence n Specify reference Rel value for Channel 1 0 Sec 4 V 120 to 120 volts STATe lt b gt Enable or disable Rel OFF v STATe Query state of Rel v ACQuire Use input signal as Rel 14 8 SCPI Reference Tables Table 14 7 SENSe command summary cont Default Command Description Parameter Ref SCPI REFerence Query Rel value v LPASs Control analog filter for DCV1 Sec 3 STATe lt b gt Enable or disable analog filter OFF STATe Query state of analog filter DFILter Configure and control digital filter Sec 3 WINDow n Specify filter window in 26 0 to 10 0 01 WINDow Query filter window COUNt n Specify filter count 1 to 100 10 COUNt Query filter count TCONtrol lt name gt Select filter type MOVing or REPeat MOVing TCONtrol Query filter type STATe lt b gt Enable or disable digital filter ON STATe Query state of digital filter CHANneD Channel 2 voltage commands OFF LOMode lt b gt Enable or disable low charge injection mode Sec2 LOMode Query state of low charge injection mode RANGe Configure channel 2 measurement range Sec 3 V UPPer lt n gt Select range 0 to 12 volts 12 V UPPer Query range value v AUTO b Enable or disable autorange ON v AUTO Query state of au
100. 1 on the monitor 7 Resets the Model 2182 to default operating conditions RCL Recall Return to setup stored in memory Parameters lt NRf gt 0 Description Use this command to return the Model 2182 to the configuration stored in memory The SAV command is used to store the setup configuration in memory location Only one setup configuration can be saved and recalled The Model 2182 ships from the factory with SYSTen PRESet defaults loaded into the available setup memory If a recall error occurs the setup memory defaults to the SYSTem PRESet values NOTE For RS 232 operation and in some cases GPIB operation OPC or OPC should be used with RCL which is a slow responding command Details on OPC and OPC are provided in Section 12 12 12 Common Commands RST Reset Return 2182 to RST defaults Description When the RST command is sent the Model 2182 performs the following operations 1 Returns the Model 2182 to the RST default conditions see SCPI tables 2 Cancels all pending commands 3 Cancels response to any previously received OPC and OPC commands NOTE For RS 232 operation and in some cases GPIB operation OPC or OPC should be used with RST which is a slow responding command Details on OPC and OPC are provided in Section 12 SAV Save Save present setup in memory Parameters lt NRf gt 0 Description Use the SAVE command to save the present instrument setup
101. 1 PLC reading rate selected Indicates that Analog Output is on Relative enabled for present measurement function Instrument in GPIB remote mode Scan mode selected Accessing a shifted key Slow 5 PLC reading rate selected Service request over GPIB Displaying buffer statistics Step mode selected Instrument addressed to talk over GPIB bus Timer controlled scans in use External triggering front panel bus or trigger link selected Measure voltage or temperature Volts Ranges 10mV 100mV 1V 10V and 100V Measure voltage or temperature Volts Ranges 100mV 1V and 10V Pull out and rotate to desired position Getting Started 1 11 Rear panel summary The rear panel of the Model 2182 is shown in Figure 1 2 This figure includes important abbreviated information that should be reviewed before operating the instrument Figure 1 2 Model 2182 rear panel WARNI ANALOG oUTPUT 1KQ OPTPUT RESISTANCE TRIGGER LINK KEITHLEY A WrTHANALOG OUTPUT GAIN SET TO 1 Pins 7 and 8 DIGITAL COMMON o0 Pin 2 Pin 1 EXTERNAL TRIGGER INPUT VOLTMETER COMPLETE OUTPUT Trigger Reading Reading Complete TTL HI TTL HI 22 gt 10 K cap ga TILLO IPSE TTL LO 1 12 Getting Started 1 ANALOG OUTPUT Provides a scaled non inverting DC voltage With analog output gain set to one a full range input will result in a 1V analo
102. 14 Differential Conductance calculations eese I 16 List of Illustrations 1 Figure 1 1 Figure 1 2 Figure 1 3 2 Figure 2 1 Figure 2 2 Figure 2 3 Figure 2 4 Figure 2 5 Figure 2 6 Figure 2 7 Figure 2 8 Figure 2 9 Figure 2 10 Figure 2 11 Figure 2 12 Figure 2 13 Figure 2 14 3 Figure 3 1 Figure 3 2 5 Figure 5 1 Figure 5 2 Figure 5 3 Figure 5 4 Figure 5 5 Figure 5 6 Figure 5 7 Figure 5 8 Figure 5 9 Figure 5 10 Figure 5 11 Figure 5 12 Getting Started Model 2182 front panel 2 enirere aa E Eo oia 1 7 Model 2182 rear panel esses eene nnnen 1 11 Power module nes eenean i iin des ERR es eee aan 1 14 Voltage and Temperature Measurements Line cycle synchronization sissi enesenn e aN 2 8 Model 2107 input Cable 6 dome 2 13 LEMO connector terminal identification eee 2 13 Connections single channel voltage eene 2 14 Connections dual channel voltage esee 2 15 Connections temperature internal reference eee 2 15 Connections temperature simulated reference sees 2 16 Connections voltage and temperature internal reference 2 16 Connections voltage and temperature simulated reference 2 17 4 Wire low resistance measurement technique see 2 23 Measuring swit
103. 19 25 LAG 20 3F 32 63 TAG 40 5F 64 95 SCG 60 7F 96 127 UNL 3F 63 UNT SF 95 IEEE 488 Bus Overview Typical command sequences For the various multiline commands a specific bus sequence must take place to properly send the command In particular the correct listen address must be sent to the instrument before it will respond to addressed commands Table F 3 lists a typical bus sequence for sending the addressed multiline commands In this instance the SDC command is being sent to the instrument UNL is generally sent as part of the sequence to ensure that no other active listeners are present Note that ATN is true for both the listen command and the SDC command byte itself Table F 3 Typical addressed bus sequence Data bus Step Command ATN state ASCII Hex Decimal 1 UNL Set low 3F 63 2 LAG Stays low 27 39 3 SDC Stays low EOT 04 4 4 Returns high Assumes primary address 7 Table F 4 gives a typical common command sequence In this instance ATN is true while the instrument is being addressed but it is set high while sending the common command string Table F 4 Typical addressed common command sequence Data bus Step Command ATN state ASCII Hex Decimal 1 UNL Set low 2 3F 63 2 LAG Stays low 27 39 3 Data Set high t 2A 42 4 Data Stays high R 52 82 5 Data Stays high S 53 83 6 Data Stays high T 54 84 Assumes primary address 7
104. 2 Measuring switch contact resistance and temperature Thermocouple 10A p uro Constant Current Source Test Circuit 2182 The Model 2182 measures both the voltage across the switch contact and the temperature These measurements allow you to develop a resistance vs temperature profile With current known and voltage measured resistance can be calculated using Ohms Law R V I 2 26 Voltage and Temperature Measurements Standard cell comparisons Standard cell comparisons are conducted by measuring the potential difference between a reference and an unknown standard cell All cell differences are determined in series opposition configuration The positive terminals of the standard cells V1 and V2 are connected to the HI and LO inputs of the nanovoltmeter as shown in Figure 2 13A The Model 2107 Input Cable supplied with the Model 2182 should be used to connect the cells to the nanovoltmeter in order to minimize errors caused by thermal EMFs Vgypr Figure 2 13 Standard cell comparison measurements Thermal EMFs VEMF DCV1 VIO zum Standard Cells V2 Reading 1 2 V1 V2 Vener A Reading 1 Thermal EMFs qs a DCVi VEMF Standard Cells 2182 Reading 2 Vg V5 Vi B Reading 2 Once the measurement connections have been made care must be taken to avoid errors from thermally generated potentials To minimize the effects of thermal EMFS a s
105. 2 and SourceMeter trigger synchronization The timing diagram in Figure 5 4 shows trigger synchronization between the SourceMeter and the Model 2182 for a 2 point custom sweep As shown in the timing diagram the SourceMeter will output a trigger after every source sweep point and the Model 2182 will output a trigger after every A D conversion Figure 5 4 Triggering timing diagram One Delta Measurement _ 1mA P0000 P0000 SourceMeter Output P0001 1mA SourceMeter TRIG OUT Press TRIG Ignored by 2182 Ignored by 2182 2182 Delta Measurements Delay A D Conversion Delay A D Conversion Delay A D Conversion vit VIO vit 2182 VMC AMA uH iid Delta reading available on second VMC When the TRIG key on the SourceMeter is pressed it starts the sweep outputs 1mA and triggers the Model 2182 to start a Delta measurement After the delay period the Model 2182 performs an A D conversion for the V1t1 phase of the Delta measurement and then triggers the SourceMeter to output the second point of the sweep mA At this point the Model 2182 does not wait for the return trigger from the SourceMeter to perform the V1t2 phase of the Delta measurement That second trigger from the SourceMeter is ignored After the A D conversion for the V1t2 phase the Delta reading is calculated and displayed If programmed for another sweep the trigger from the Model 2182 to the SourceMeter will again start the sweep to perform an
106. 2 detects the line power frequency and automatically selects the proper line frequency setting The line frequency setting can be checked using this command The response message will be 50 or 60 The value 50 indicates that the line frequency is set for 50Hz or 400Hz while 60 indicates that it is set for 60Hz 15 18 Additional SCP Commands BEEPer command SSTATe b SYSTem BEEPer STATe b Enable or disable beeper Parameters b 1 or ON Enable beeper 0 or OFF Disable beeper Description This command is used to enable or disable the beeper for limit tests and HOLD KCLick command KCLick lt b gt SYSTem KCLick lt b gt Enable or disable keyclick Parameters lt b gt 1orON Enable keyclick 0 or OFF Disable keyclick Description This command is used to enable or disable the keyclick The keyclick can also be enabled or disabled from the front panel by pressing SHIFT then LOCAL POSetup name command POSetup name SYSTem POSetup lt name gt Program power on defaults Parameters lt name gt RST Select RST defaults on power up PRESet Select SYSTem PRESet defaults on power up SAVO Select saved defaults on power up Description This command is used to select the power on defaults With RST selected the instrument powers up to the RST default conditions With PRES selected the instrument powers up to the SYStem PRESet default conditions Default conditions are listed in the SCPI tables
107. 2 require the use of an alternating polarity source The source must have external triggering capabilities that are compatible with the external triggering capabilities of the Model 2182 The following procedure shows how to use a Keithley SourceMeter with the Model 2182 to perform Delta measurements Delta measurement procedure using a SourceMeter A Keithley SourceMeter Model 2400 2410 or 2420 can be used as a bipolar source by configuring it to perform a custom sweep In general a custom sweep is made up of number of specified source points To provide current reversal the positive current value s are assigned to the even numbered points and the negative current value s are assigned to the odd numbered points For details on custom sweep see the User s Manual for the SourceMeter Applications that use Delta measurements require either a fixed current or a growing amplitude current When a fixed current is required the SourceMeter can be configured to output a bipolar 2 point custom sweep That sweep can be run a specified number of times or it can run continuously For example if a fixed current of 1mA is required for the test the two bipolar sweep points for the custom sweep would be 1mA and 1mA 5 10 Ratio and Delta When a growing amplitude current is required the custom sweep can be configured to include all the current values required for the test For example assume the test requires two Delta measurements at each of thre
108. 32 error messages Common Commands 12 2 Common Commands Common commands summarized in Table 12 1 are device commands that are common to all devices on the bus These commands are designated and defined by the IEEE 488 2 standard Table 12 1 IEEE 488 2 common commands and queries Mnemonic Name Description CLS Clear status Clears all event registers and Error Queue ESE lt NRf gt Event enable command Program the Standard Event Enable Register ESE Event enable query Read the Standard Event Enable Register ESR Event status register query Read the Standard Event Enable Register and clear it IDN Identification query Returns the manufacturer model number serial number and firmware revision levels of the unit OPC Operation complete command Set the Operation Complete bit in the Standard Event Status Register after all pending commands have been executed OPC Operation complete query Places an ASCII 1 into the output queue when all pend ing selected device operations have been completed RCL lt NRf gt Recall command Returns the 2182 to the user saved setup RST Reset command Returns the 2182 to the RST default conditions SAV lt NRf gt Save command Saves the present setup as the user saved setup SRE lt NRf gt Service request enable command Programs the Service Request Enable Register SRE Service request enable query Reads the Service Request Enable Register STB Status byte que
109. 5 9 Falter considerations 1 eerte torre EE eda ee ON ee Eee EE 5 15 SCPI programming ratio and delta essere 5 16 Programming examples 11 tte a e pe ier on ERRARE en 5 16 Applications MN 5 18 Testing superconductor materials esee 5 19 Buffer Butter operations eite ree erret ee Ree e re PEE T Ca te rupes 6 2 jj eT 6 2 hoc 6 3 Buller statistics x E Aaa NiE 6 4 SCPI programming buffer i nne rera pete teta er cR een ges 6 5 Programmmg example esce see cette isio iina 6 6 Triggering Trigger model C 7 3 i H R U 7 3 Control source and event detection seen 7 4 DCL AY sen leeaeveens 7 4 Device ACTION x 7 5 Ou tp t TAS BOR susicsscesvesensertaisrsspeses eran an EAE EE ENE ENEE E NE EEEa Sa 7 5 Reading hold autosettle eese E R i iE i 7 6 Hold example 5 geis rore td tee tr E EUR He EEE ERTE 7 6 Extetnal triggering i3 taie ard ete pete ERR e ri reside de eee RR ed Von boa e e Re Ege TELLS 7 7 External tS Or 1 rm or pe Ce a re E eee LS Do SEDE engen 7 8 Voltmeter Complete ene eee tege ci pe e ubere te ace aeg 7 8 External triggering example
110. 5 PLC Pulse Low High Low 7L JL e es 4 One Line Cycle One Line Cycle One Line Cycle gt lt gt lt Dit One Line Cycle One Line Cycle CEP es DOMIN Voltage 1 I High can be set from 105mA to 105mA default is 1mA 2 l Low can be set from 105mA to 105mA default is OmA 3 Pulse Width can be set from 50us to 12ms default is 110ys 4 One 60Hz power line cycle 16 667ms 1 60 One 50Hz power line cylce 20ms 1 50 5 With Interval set to 5 PLC power line cycles 60Hz One Pulse Delta cycle 83 33ms 5 60 50Hz One Pulse Delta cycle 100ms 5 50 6 Interval can be set from 5 to 999999 PLC default is 5 PLC The three available sweeps include 1 staircase sweep 2 logarithmic sweep and 3 cus tom sweep Examples of these Sweep outputs are shown in Figure I 6 Staircase sweep Figure I 6A shows an example of a staircase Sweep output The sweep is configured to start high pulses at 2mA and staircase to 10mA in 2mA steps The low pulse level for this sweep is OmA Logarithmic sweep Figure I 6B shows an example of a logarithmic Sweep output The sweep is configured to output five high pulses points The first high pulse starts at 1mA and logarithmically steps to 10mA The low pulse level for this sweep is OmA Custom sweep Figure I 6C shows an example of a custom Sweep output The sweep is configured to output five high pulses points The level for each high
111. 82 is 2 while the minimum buffer size for the Model 182 is 1 Therefore to set minimum buffer size 11 0 is valid for the Model 182 and I1 2 is valid for the Model 2182 The I2 command circular buffer is not supported 6 J Commands For the Model 2182 J1 uses the last reading as the Rel value whereas the J1 command for the Model 182 uses the next reading as the Rel value The J3 command simply enables analog output relative and uses the present Rel value 7 S Commands The S3 command has been added to include a 1 second integration 8 period 8 T Commands The front panel TRIG key is always operational even when T10X is sent to disable all triggers 9 U Commands e U1 For the Model 2182 the U1 error status word only supports the IDDC Invalid Device Dependent Command error bit 0 the IDDCO Invalid Device Dependent Command Option error bit 2 and the Uncalibrated Error bit 8 All other bits remain at zero e U2 The Model 2182 uses two processors while the Model 182 uses three processors Therefore the U2 command will be formatted to only provide revision levels for the Front Panel Processor and the Main Processor 10 U11 and U14 Not supported 11 V Commands The V1 command is not supported 12 Z Commands For the Model 2182 Z1 uses the last reading as the Rel value whereas the Z1 command for the Model 182 uses the next reading as the Rel value The Z3 command simpl
112. ABORt INITiate and a FETch E TRIGger Trigger commands SOURce lt name gt Select control source IMMediate TIMer F IMMediate MANual BUS or EXTernal TIMer n Set timer interval 0 to 999999 999 sec 0 1 COUNt lt n gt Set trigger count 1 to 9999 or INF Note 2 DELay lt n gt Set delay 0 to 999999 999 sec 0 AUTO lt b gt Enable or disable auto delay G SIGNal Loop around control source H SAMPle Sample counter COUNt n Set sample count 1 to 1024 I 1 SENSe SENSe Subsystem HOLD Reading Hold commands J WINDow n Set Hold window in 46 0 01 to 20 1 COUNt n Set Hold count 2 to 100 5 STATe lt b gt Enable or disable Hold OFF SYSTem SYSTem Subsystem BEEPer Beeper control STATe lt b gt Enable or disable the beeper ON RST Restore RST defaults see Default column of this table Places 2182 in the idle state Notes 1 Defaults for continuous initiation SYSTem PRESet enables continuous initiation RST disables continuous initiation 2 Defaults for trigger count SYSTem PRESet sets the count to INF infinite RST sets the count to 1 Triggering 7 17 Reference A ABORt With continuous initiation disabled the 2182 goes into the idle state With continuous initiation enabled operation continues at the top of the trigger model B INITiate Whenever the instrument is operating within the trigger model sending this command causes an error and will be i
113. ACAL options FULL ACAL calibrates the 10mV and 100V ranges while LOW LVL low level ACAL only calibrates the 10mV range If you are not going to use the 100V range it is recommended that you only perform LOW LVL ACAL NOTES FULL ACAL requires that there not be any connectors or cables connected to the LEMO input connector of the Model 2182 Whenever LEMO connections are broken for an extended period of time the contacts must be cleaned before reconnecting See Cleaning input connectors in Section 1 Getting Started For LOW LVL ACAL you do not need to remove the input cable break any connections or remove power ACAL procedure Perform the following steps to perform LOW LVL or FULL ACAL 1 Press the ACAL key to access the menu 2 Use A or V key to display desired ACAL LOW LVL or FULL 2 6 Voltage and Temperature Measurements 3 Press ENTER The message ACAL will be displayed while calibration is in process It takes around five minutes to complete LOW LVL ACAL and a little more than five minutes to complete FULL ACAL When finished the instrument returns to the normal display state Measuring internal temperature Perform the following steps to measure the internal temperature of the Model 2182 1 Press SHIFT and then TCOUPL to display the present units designator C F or K for temperature measurements 2 To change the units designator press the fj key to place the blinking cursor on the units designator
114. ACAL procedure in this section for details In order to make accurate temperature measurements the thermocouple connections reference junction have to be maintained at a known temperature You have the option to use the internal reference junction or an external simulated reference junction These reference junctions are discussed as follows Internal Reference Junction The internal reference junction of the Model 2182 is the input connector A temperature sensor is located inside the unit adjacent to the input connector The sensor is measured continuously to maintain accuracy Thermocouple connections reference junction have to be made at the input connector of the Model 2182 To utilize the internal reference junction the thermocouple wires must be soldered directly to a LEMO connector that mates to the input connector A disadvantage of using the internal reference junction is the connection requirements You cannot use the supplied input cable as is You will have to modify the cable or use a separate LEMO connector Model 2182 KIT Simulated Reference Junction An external apparatus such as an ice bath can instead be used for the reference junction The thermocouple wires are connected to the copper lugs of the supplied input cable The connection points are then immersed in the ice bath The temperature of the ice bath must be entered into the Model 2182 as the simulated reference temperature Voltage and Temperatur
115. AIN MENU gt SAVESETUP gt GLOBAL gt RESET gt BENCH Ratio and Delta 5 11 Figure 5 3 Delta measurement connections 8501 Trigger Link Cable SourceMeter Step 3 Configure the trigger model of the SourceMeter The menu structure to configure triggers is accessed by pressing CONFIG and then TRIG Configure the trigger model as follows Arm Layer Arm In Event Arm Out TLink Line Arm Out Events Arm Count Trig Layer Trigger In Trigger In Source Trig In TLink Line Event Detect Bypass Trigger In Events Trigger Out Trig Out TLink Line Trigger Out Events Delay Trig Count IMMEDIATE 3 OFF INFINITE TRIGGER LINK 1 NEVER SOURCE ON DELAY OFF MEAS OFF 2 SOURCE ON DELAY OFF MEAS OFF 000 0000 s 0002 trigger count must equal the number of sweep points 5 12 Ratio and Delta Step 4 Set up the SourceMeter to source current and measure voltage A On the SourceMeter select Source I and Measure V B Select an appropriate current source range For example if your current reversal values are going to 1mA select the 1mA source range C Press SPEED and select FAST SourceMeter measurements are not used in this test but it must run as fast as possible to avoid synchronization problems with the Model 2182 Step5 Configure the SourceMeter to perform a 2 point custom sweep A The menu to configure a sweep is accessed by pressing CONFIG and then SWEEP From the menu select TYPE and then sele
116. ALCulate 1 or NONE CONTrol lt name gt Select buffer control mode NEXT or NEVer Vv CONTrol Query buffer control mode Vv FEED Query source of readings for buffer v Note SYSTem PRESet and RST have no effect on the commands in this subsystem SCPI Reference Tables 14 13 Table 14 11 Trigger command summary Default Command Description Parameter Ref SCPI Sec 7 INITiate Path to Initiate measurement cycle s Vv IMMediate Initiate one cycle V CONTinuous lt b gt Enable or disable continuous initiation see Note 1 V CONTinuous Query state of continuous initiation V ABORt Reset trigger system goes to idle state v TRIGger Path to configure Trigger Layer v SEQuence 1 V SOURce name Select control source IMMediate TIMer MANual IMMediate V BUS or EXTernal SOURce Query control source v SIGNal Loop around control source v COUNt n Set measure count 1 to 9999 or INF see Note 2 V COUNt Query measure count v DELay n Set trigger delay 0 to 999999 999 sec 0 v AUTO lt b gt Enable or disable auto delay ON v AUTO Query state of auto delay v DELay Query delay value v TIMer n Set timer interval for TIMer control source 0 to 0 1 V 999999 999 sec TIMer Query timer interval V SAMPle Sample Counter COUNt n Specify sample count 1 to 1024 1 COUNt Query sample count Notes 1 Defaults for continuous ini
117. ATA are always sent in ASCII These commands are summarized in Table 14 4 DATA command DATA type FORMat DATA type Specify data format Parameters type ASCii ASCII format SREal IEEE754 single precision format DREal IEEE754 double precision format Description This command is used to select the data format for transferring readings over the bus For every reading conversion the data string sent over the bus contains the elements specified by the ELEMents command The specified elements are sent in a particular order The ASCII data format is in a direct readable form for the operator Most BASIC languages easily convert ASCII mantissa and exponent to other formats However some speed is compromised to accommodate the conversion Figure 15 1 shows the ASCII format that includes all the data elements Figure 15 1 ASCII data format Reading Channel Number 1 23456789E 00VDC OINTCHAN Mantissa Exponent Units INTCHAN Internal Channel L EXTCHAN External Channel Units VDC DC Volts C Temperature in C F Temperature in F K Temperature in K 0 Internal Temperature Sensor 1 Channel 1 2 Channel 2 1 to 80 External Channel Number An overflow reading is displayed as 9 9E37 with no units normal byte order format for each data element For example if three valid elements are Additional SCPI Commands 15 5 SREal will select the binary IEEE754 singl
118. Addenda associated with the previous Revision of the manual are incorporated into the new Revision of the manual Each new Revision includes a revised copy of this print history page Revision A Document Number 2182A 900 01 sess June 2004 All Keithley product names are trademarks or registered trademarks of Keithley Instruments Inc Other brand names are trademarks or registered trademarks of their respective holders KEGU Safety Precautions The following safety precautions should be observed before using this product and any associated instrumentation Although some instruments and accessories would normally be used with non hazardous voltages there are situations where hazardous conditions may be present This product is intended for use by qualified personnel who recognize shock hazards and are familiar with the safety precautions required to avoid possible injury Read and follow all installation operation and maintenance information carefully before us ing the product Refer to the manual for complete product specifications If the product is used in a manner not specified the protection provided by the product may be impaired The types of product users are Responsible body is the individual or group responsible for the use and maintenance of equipment for ensuring that the equip ment is operated within its specifications and operating limits and for ensuring that operators are adequately trained Operators us
119. B4 Meas of the Operation Condition Register is set When the measurement is completed bit B4 clears Use the CONDition query commands in the STATus Subsystem to read the condition registers See Section 14 for more information Event registers As Figure 11 4 shows each status register set has an event register An event register is a latched read only register whose bits are set by the corresponding condition register Once a bit in an event register is set it remains set latched until the register is cleared by a specific clearing operation The bits of an event register are logically ANDed with the bits of the corresponding enable register and applied to an OR gate The output of the OR gate is applied to the Status Byte Register Use the ESR Common Command to read the Standard Event Register All other event registers are read using the EVENt query commands in the STATus Subsystem See Section 14 for more information An event register is cleared when it is read The following operations clear all event registers Cycling power Sending CLS Enable registers As Figure 11 4 shows each status register set has an enable register An enable register is programmed by you and serves as a mask for the corresponding event register An event bit is masked when the corresponding bit in the enable register is cleared 0 When masked a set bit in an event register cannot set a bit in the Status Byte Register 1 AND 0 0 To
120. C Sends the OPC command ESR Reads the Standard Event Status Register After addressing the Model 2182 to talk the returned value of 0 denotes that the bit bit 0 is not set indicating that the INITiate operation is not complete ABORt Aborts operation Places 2182 in idle ESR Reads the Standard Event Status Register After addressing the Model 2182 to talk the returned value of 1 denotes that the bit bit 1 is set indicating that the INITiate operation is now complete SYST PRES Returns 2182 to default setup NOTE The following commands take a long time to process and may benefit from using OPC or OPC RST and SYST PRES RCL and SAV CALC2 IMM and CALC2 IMM Only when performing the standard deviation calculation on a large buffer RS 232 operation can also benefit from OPC 12 10 Common Commands OPC Operation Complete Query Place a 1 in the output queue after all pending operations are completed Description When this common command is sent an ASCII 1 will be placed in the Output Queue after the last pending operation is completed When the Model 2182 is then addressed to talk the 1 in the Output Queue will be sent to the computer The 1 in the Output Queue will set the MAV Message Available bit B4 of the Status Byte Register If the corresponding bit B4 in the Service Request Enable Register is set the RQS MSS Request for Service Master Summary Status
121. CAL key or send LOCAL 7 over the bus to remove the instrument from the remote mode TIMer Event detection is immediately satisfied on the initial pass through the loop Each subsequent detection is satisfied when the programmed timer interval 0 to 999999 999 sec elapses The timer source is only available during step scan operation The timer resets to its initial state when the instrument goes into the normal mode of operation or into the idle state EXTernal Event detection is satisfied when an input trigger via the TRIGGER LINK connector is received by the Model 2182 BUS Event detection is satisfied when a bus trigger GET or TRG is received by the Model 2182 Delay and device action These blocks of the trigger model operate the same for both front panel and GPIB operation See the front panel Trigger model located at the beginning of this section for operating information on these trigger model blocks Also see Reading hold autosettle for details on Hold Counters Programmable counters are used to repeat operations within the trigger model For example if performing a 10 channel scan the sample counter would be set to 10 Operation will continue until all 10 channels are scanned and measured If you wanted to repeat the scan three times you would set the trigger counter to three For a sample count value gt 1 the sample readings will automatically be stored in the buffer For example with sa
122. Commands Signal oriented measurement command summary eee 13 2 SCPI Reference Tables CALCulate command summary eese ene ene 14 3 CALibration command summary user accessible sess 14 4 DISPlay command summary eese ene nnne 14 5 FORMat command summary eese ener ener 14 5 OUTPut command summary eeeeeseeeeenenee rennen ene 14 6 ROUTe command summary eese rennen en een ener 14 6 SENSe command summary sese eene menn nennen rennes 14 7 STATus command summary eseeseeeeeeeen rennen emere en renneens 14 11 SYSTem command summary eene eene eere 14 12 TRACe command summary esee nen eem ene eee 14 12 Trigger command summary eese eene em ene nere 14 13 UNIT command summary esee nennen nem enne 14 14 Status and Error Messages Status and error messages cen renci it e EE E i e aiiis B 2 Measurement Considerations Material thermoelectric Coefficients esee C 2 Model 182 Emulation Commands Model 182 device dependent command summary eese D 2 F Table F 1 Table F 2 Table F 3 Table F 4 Table F 5 Table F 6 G Table G 1 Table G 2 IEEE 488 Bus Overview IEEE 488 bus command summary esses eere nennen eene nennen F 7 Hexadecimal and decimal command codes
123. Commands that are particular to each device on the bus sent with ATN false These bus commands and their general purpose are summarized in Table F 1 IEEE 488 Bus Overview Table F 1 IEEE 488 bus command summary Command State of type Command ATN line Comments Uniline REN Remote Enable X Set up devices for remote operation EOI X Marks end of transmission IFC Interface Clear x Clears interface ATN Attention Low Defines data bus contents SRQ X Controlled by external device Multiline LLO Local Lockout Low Locks out local operation Universal DCL Device Clear Low Returns device to default conditions SPE Serial Enable Low Enables serial polling SPD Serial Poll Disable Low Disables serial polling Addressed SDC Selective Device Clear Low Returns unit to default conditions GTL Go To Local Low Returns device to local Unaddressed UNL Unlisten Low Removes all listeners from the bus UNT Untalk Low Removes any talkers from the bus Common High Programs IEEE 488 2 compatible instruments for common operations SCPI mz High Programs SCPI compatible instruments for particular operations Uniline commands ATN IFC and REN are asserted only by the controller SRQ is asserted by an external device EOI may be asserted either by the controller or other devices depending on the direction of data transfer The following is a description of each command Each command is sent by setting the
124. Connections WARNING A hazardous voltage condition exists at or above 42V peak To prevent electric shock that could result in injury or death NEVER make or break connections while hazardous voltage is present CAUTION Exceeding the following limits may cause instrument damage not covered by the warranty Channel 1 HI and LO terminals have a maximum measurement capability of 120V peak These inputs are protected to 150V peak to any terminal or 350V peak to chassis Channel 2 HI and LO terminals have a maximum measurement capability of 12V peak to Channel 1 LO Channel 2 HI is protected to 150V peak to any terminal Channel 2 LO is protected to 70V peak to Channel 1 LO Both inputs are protected to 350V peak to chassis Step2 Configure Channel 1 and Channel 2 for voltage measurements Configure each channel DCV1 and DCV2 for the desired voltage measurement Unique settings for each channel include Range Filter and Rel Step3 Verify on scale readings for DCV1 and DCV2 Verify that DCV1 and DCV2 are displaying on scale readings If an OVRFLW message is displayed for any channel select a higher range until an on scale reading is displayed or press AUTO to enable autoranging Step4 Select the range control channel If you want the manual range keys to control Channel 1 ranges select press DCV1 just before going into Ratio If you want the manual range keys to control Channel 2 ranges select DCV2 just before going
125. Delta Pulse Delta and Differential Conductance l 9 Pulse Delta process Pulse Delta measurements For Pulse Delta the Model 6221 outputs current pulses Current pulses that have a short pulse width are ideal to test a low power DUT that is heat sensitive By default Pulse Delta uses a 3 point repeating average algorithm to calculate readings Each Pulse Delta reading is calculated using A D measurements for a low pulse a high pulse and another low pulse The Model 6221 outputs the pulses and the Model 2182A performs the A D measurements As shown in Figure I 4 every three pulses yields a single Pulse Delta voltage reading Figure I 4 Pulse Delta 3 point measurement technique 2182A 2182A 2182A A D A D A D B E Y FHigh 332 Pulse Delta Pulse Delta Pulse Delta Reading Reading Reading ist 2nd Nth 62xx l Source 2182A 2182A 2182A 2182A 2182A 2182A A D A D A D A D A D A D A C D F X Z I Low Low High Low Low High Low i Low High Low i rae JTL 2n EJ oes i prc Jb 2 1st Pulse Delta 2nd Pulse Delta Nth Pulse Delta l Interval Interval Interval BAS 2Y X Z ist Pulse Delta Reading 28 9 Nth Pulse Delta Reading Where 2nd Pulse Delta Reading D F X Y and Z are the A Ds for the first low high and 2 second low pulses for the Pulse Delta cycle In cases where the high pulse will cause heating of the DUT the measurement at the sec ond lo
126. ENTER The present terminator is displayed 5 To change the terminator A Place the cursor on the present terminator selection B Press the or V key to display the desired terminator C Press ENTER The instrument returns to the normal display NOTE Only the SCPI language can be used with the RS 232 interface The instrument defaults to the SCPI language when the RS 232 interface is selected enabled 11 6 Remote Operation GPIB operation and reference GPIB bus standards The GPIB bus is the IEEE 488 instrumentation data bus with hardware and programming standards originally adopted by the IEEE Institute of Electrical and Electronic Engineers in 1975 The Model 2182 conforms to these standards TEEE 488 1987 1 JEEE 488 1987 2 This standard defines a syntax for sending data to and from instruments how an instrument interprets this data what registers should exist to record the state of the instrument and a group of common commands e SCPI 1991 Standard Commands for Programmable Instruments This standard defines a command language protocol It goes one step farther than IEEE 488 1987 2 and defines a standard set of commands to control every programmable aspect of an instrument GPIB bus connections To connect the Model 2182 to the GPIB bus use a cable equipped with standard IEEE 488 connectors as shown in Figure 11 1 Figure 11 1 IEEE 488 connector To allow many parallel connections to one instrume
127. FT and then OUTPUT a second time The message AOUT REL OFF will be displayed briefly NOTE Anew Rel value for analog output can be established at any time by first disabling Analog Output Rel and then re enabling it 10 6 Analog Output SCPI programming analog output Commands for analog output are summarized in Table 10 2 Additional information on these commands follows the table The Ref column in the table provides reference for this information Table 10 2 SCPI commands analog output OFFSet lt NRf gt Specify offset B 1 2 to 1 2 STATe lt b gt RELative lt b gt Enable or disable Analog Output Enable or disable Analog Output Relative Commands Description Ref Default OUTPut OUTPut Subsystem GAIN lt NRf gt Specify gain factor M 1e 9 to 1e6 OU SSos Reference A GAIN and OFFSet Gain and offset changes do not take affect until the next reading is triggered B STATe OFF 0 forces analog output to OV immediately ON 1 does not take effect until next reading is triggered C RELative Sending ON 1 while Rel is enabled acquires a new Rel value Programming example The following program fragment assumes that you are using analog output to monitor a lmV signal on the 10mV range Analog output gain is set to 10 to increase sensitivity Therefore ImV will result in a 1V analog output Finally Analog Output Rel is enabled to reference the 1V anal
128. G FILTER DIGITAL FILTER 00 6nV Off 100 100 Q 8nV Off 100 1kQ 15 nV Off 100 10 KQ 35 nV Off 100 100 kQ 100 nV On 100 1 MQ 350 nV On 100 NMRR 110 dB 100 dB 95 dB 90 dB 60 dB 110 dB 100 dB 90 dB 60 dB CMR 140d 140d 140 140 140 140d 140 d 140 d R B B B B B 140 d B B B B RKN 6 08 04 Rev A Page 1 of 3 2182A Nanovoltmeter Specifications Temperature Thermocouples DISPLAYED IN C F OR K ACCURACY BASED ON ITS 90 EXCLUSIVE OF THERMOCOUPLE ERRORS ACCURACY 90 Day 1 Year 23 5 C Relative to Simulated TYPE RANGE RESOLUTION Reference Junction J 200 to 760 C 0 001 C 0 2 C K 200 to 1372 C 0 001 C 0 2 C N 200 to 1300 C 0 001 C 0 2 C T 200 to 400 C 0 001 C 0 2 C E 200 to 1000 C 0 001 C 0 2 C R 0 to 1768 C 0 1 C 0 2 C S 0 to 1768 C 0 1 C 0 2 C B 350 to 1820 C 0 1 C 0 2 C OPERATING CHARACTERISTICS 60HZ 50HZ OPERATION FUNCTION DIGITS READINGS s PLCs DCV Channel 1 75 3 1 2 5 Channel 2 7 5118 6 1 7 5 Thermocouple 6 5199 18 5 5 1 6 518 1920 45 7 2 1 5 51119 80 20 9 0 1 4 516179 115 28 0 0 01 Channel 1 Channel 2 TS 1 5 1 2 5 Ratio 75 519 2 3 1 7 5 Delta with 24XX 6 55 8 5 5 5 1 Scan 6 51820 20 7 2 1 5 57 30 20 9 0 1 4 57 41 28 0 0 01 Delta with 622X 6 5 47 40 1 SYSTEM SPEEDS RANGE CHANGE TIME 40 ms 50 ms FUNCTION CHANGE TIME 45 ms 55 ms AUTORANGE TIME 60 ms
129. ING type INTernal or EXTernal Press the amp or W key to display EXT and press ENTER The minimum channel MIN CHAN to step scan is displayed Use the edit keys lt q gt A and WV to specify the Min channel and press ENTER The maximum channel MAX CHAN is then displayed Use the edit keys to specify the Max channel and press ENTER The present state of the timer is displayed OFF or ON Press amp or to display the desired timer state and press ENTER If you turned the timer on the timer interval will be displayed Use the edit keys lt q P gt A and W to set the timer interval and press ENTER The Present Reading Count RNG CNT is displayed It will be Max Min 1 If you wish to increase the Reading Count use the edit keys to display the value and press ENTER to return to the normal display state Stepping Scanning examples Internal scanning Settings Control Source Immediate timer off Delay Auto Channel 1 Count 4 Reading Count 10 Overview With Channel 1 count set to 4 each scan cycle will measure Channel 2 once and Channel 1 four times for a total of five measurements This sets the Sample Counter in Figure 9 1 to 5 The Reading Count 10 indicates that the five measurement scan will be performed twice This sets the Trigger Counter to 2 A total of 10 measurements will be performed All ten readings will be stored in the buffer Stepping and Scanning 9 9 Operation Int
130. L SPACING Model 2182 from factory setup TRIGLINK ASYNCHRONOUS CHAN COUNT 8 SCAN CONTROL SCAN COUNT 1 SHIFT CONFIG TYPE EXT MIN CHAN 001 MAX CHAN 008 TIMER OFF RDG CNT 0008 ENTER Y Q2 Ex TRIG Y STEP or SCAN Y Y RECALL 8 readings 4 2 EXIT Stepping and Scanning 9 11 9 12 Stepping and Scanning SCPI programming stepping and scanning Commands to scan are listed in Table 9 1 Notice that many commands from the TRIGger Subsystem are used for scanning See Section 7 for details on triggering Table 9 1 SCPI commands stepping and scanning Commands Description Default For ROUTe Subsystem ROUTe ROUTe Subsystem SCAN Scanning INTernal Internal Scan CCOunt lt n gt Specify number of Channel 1 readings 1 to 1 1023 EXTernal lt list gt Specify external scan list 2 to 800 see note 1 1 10 LSELect lt name gt Select scan operation NONE INTernal or NONE EXTernal see Note 2 For TRIGger Subsystem TRIGger Trigger commands SOURce lt name gt Select control source IMMediate TIMer MANual IMMediate BUS or EXTernal TIMer lt n gt Set timer interval 0 to 999999 999 sec 0 1 COUNt lt n gt Set trigger count 1 to 9999 or INF see Note 3 DELay lt n gt Set delay 0 to 999999 999 sec 0 AUTO lt b gt Enable or disable auto delay SAMPle Sample C
131. LIED INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE THE REMEDIES PROVIDED HEREIN ARE BUYER S SOLE AND EXCLUSIVE REMEDIES NEITHER KEITHLEY INSTRUMENTS INC NOR ANY OF ITS EMPLOYEES SHALL BE LIABLE FOR ANY DIRECT INDIRECT SPECIAL INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OF ITS INSTRUMENTS AND SOFTWARE EVEN IF KEITHLEY INSTRUMENTS INC HAS BEEN ADVISED IN ADVANCE OF THE POSSIBILITY OF SUCH DAMAGES SUCH EXCLUDED DAM AGES SHALL INCLUDE BUT ARE NOT LIMITED TO COSTS OF REMOVAL AND INSTALLATION LOSSES SUSTAINED AS THE RESULT OF INJURY TO ANY PERSON OR DAMAGE TO PROPERTY KEITHLEY A GREATER MEASURE OF CONFIDENCE Keithley Instruments Inc Corporate Headquarters 28775 Aurora Road Cleveland Ohio 44139 440 248 0400 Fax 440 248 6168 1 888 KEITHLEY 534 8453 www keithley com Belgium Sint Pieters Leeuw 02 363 00 40 Fax 02 363 00 64 www keithley nl China Beijing 8610 82251886 Fax 8610 82251892 www keithley com cn Finland Helsinki 09 5306 6560 Fax 09 5306 6565 www keithley com France Saint Aubin 01 64 53 20 20 Fax 01 60 11 77 26 wwwkeithley fr Germany Germering 089 84 93 07 40 Fax 089 84 93 07 34 www keithley de Great Britain Theale 0118 929 7500 Fax 0118 929 7519 www keithley co uk India Bangalore 91 80 2212 8027 Fax 91 80 2212 8005 www keithley com Italy Milano 02 48 39 16 01 Fax 02 48 39 16 28 wwwkeithley it
132. MM Immediate trigger PRINT Z1 DISP ENAB OFF No display PRINT 1 INIT Send init SLEEP 1 Wait one second PRINT 1 FETCH Read query LINE INPUT 1 RD Get data PRINT RD Display data PRINT 1 DISP ENAB ON Turn on display PRINT 1 SYST AZER STAT ON Auto zero on Clean up and quit finish CLOSE 1 Close file CLEAR Interface clear END F IEEE 488 Bus Overview F 2 IEEE 488 Bus Overview Introduction The IEEE 488 bus is a communication system between two or more electronic devices A device can be either an instrument or a computer When a computer is used on the bus it serves as a supervisor of the communication exchange between all the devices and is known as the controller Supervision by the controller consists of determining which device will talk and which device will listen As a talker a device will output information and as a listener a device will receive information To simplify the task of keeping track of the devices a unique address number is assigned to each On the bus only one device can talk at a time and is addressed to talk by the controller The device that is talking is known as the active talker The devices that need to listen to the talker are addressed to listen by the controller Each listener is then referred to as an active listener Devices that do not need to listen are instructed to unlisten The reason for the unlisten instruction is to optimize the
133. Mediate These brackets indicate that IMMediate is implied optional and does not have to used Thus the above command can be sent in one of two ways NITiate or INITiate IMMediate Notice that the optional command is used without the brackets When using optional command words in your program do not include the brackets 11 22 Remote Operation e Parameter types The following are some of the common parameter types lt b gt lt name gt lt name gt lt NRf gt lt n gt lt list gt Boolean Used to enable or disable an instrument operation 0 or OFF disables the operation and 1 or ON enables the operation OUTPut RELative ON Enable Analog Output Rel Name Parameter Select a parameter name from a listed group NEVer NEXT CALCulate FORMat MXB Select Mx B calculation Numeric Representation Format A number that can be expressed as an integer e g 8 a real number e g 23 6 or an exponent 2 3E6 TRACe POINts 20 Set buffer size to 20 Numeric Value Can consist of an NRf number or one of the following name parameters DEFault MINimum or MAXimum When the DEFault parameter is used the instrument is programmed to the RST default value When the MINimum parameter is used the instrument is programmed to the lowest allowable value When the MAXimum parameter is used the instrument is programmed to the largest allowable value TRIGger TIMer 0 1 Sets timer to 100 msec
134. Model 7001 7002 Note that with the default trigger settings on the Model 7001 7002 line 1 is an input and line 2 is an output This complements the trigger lines on the Model 2182 Figure 7 7 Trigger link connections 7001 or 7002 Switch System 2182 Nanovoltmeter i K Trigger Trigger T Link Trigger Link Link Cable 8501 7 10 Triggering For this example the Models 2182 and 7001 7002 are configured as follows Model 2182 Factory defaults restored accessed from SHIFT SETUP External scanning channels 8 no timer 8 readings accessed from SHIFT CONFIG External triggers accessed from EX TRIG Model 7001 or 7002 Factory defaults restored Scan list 1 1 1 8 Number of scans 1 Channel spacing TrigLink To run the test and store readings in the Model 2182 with the unit set for external triggers press STEP or SCAN The Model 2182 waits with the asterisk annunciator lit for an external trigger from the Model 7001 7002 Press STEP on the Model 7001 7002 to take it out of idle and start the scan The scanner s output pulse triggers the Model 2182 to take a reading store it and send a trigger pulse The following explanation on operation is referenced to the operation model shown in Figure 7 8 Figure 7 8 Operation model for triggering example 7001or 7002 Press STEP to start scan 2182 Idle Idle n a Bypass Wait for 2 Trigger Link
135. NL command UNT Untalk Any previously commanded talkers will be placed in the talker idle state by the UNT command F 10 IEEE 488 Bus Overview Common commands Common commands are commands that are common to all devices on the bus These commands are designated and defined by the IEEE 488 2 standard Generally these commands are sent as one or more ASCII characters that tell the device to perform a common operation such as reset The IEEE 488 bus treats these commands as data in that ATN is false when the commands are transmitted SCPI commands SCPI commands are commands that are particular to each device on the bus These commands are designated by the instrument manufacturer and are based on the instrument model defined by the Standard Commands for Programmable Instruments SCPI Consortium s SCPI standard Generally these commands are sent as one or more ASCII characters that tell the device to perform a particular operation such as setting a range or closing a relay The IEEE 488 bus treats these commands as data in that ATN is false when the commands are transmitted Command codes Command codes for the various commands that use the data lines are summarized in Figure F 3 Hexadecimal and the decimal values for the various commands are listed in Table F 2 Table F 2 Hexadecimal and decimal command codes Command Hex value Decimal value GTL 01 1 SDC 04 4 GET 08 8 LLO 11 17 DCL 14 20 SPE 18 24 SPD
136. OTE Most keys provide a dual function or operation The nomenclature on a key indicates its unshifted functionloperation which is selected by pressing the key Nomenclature in blue above a key indicates its shifted function A shifted function is selected by pressing the SHIFT key and then the functionloperation key 1 Special keys and power switch SHIFT Use to select a shifted function or operation LOCAL Cancels GPIB remote mode POWER Power switch In position turns 2182 on 1 out position turns it off 0 1 8 Getting Started 2 Function and operation keys Top Row Un shifted DCVI DCV2 V1 V2 ACAL FILT REL TEMPI TEMP2 Shifted MX B V1 V2 LSYNC TYPE OUTPUT AOUT TCOUPL Middle Row Un shifted EX TRIG TRIG STORE RECALL VALUE ON OFF and gt Shifted DELAY HOLD Selects Channel 1 voltage measurement function Selects Channel 2 voltage measurement function Selects Ratio Channel 1 voltage reading Channel 2 voltage reading Selects automatic gain calibration Enables disables filter for selected measurement function Enables disables relative for selected measurement function Selects Channel 1 temperature measurement function Selects Channel 2 temperature measurement function Multiplies a scale factor M to the reading X and then adds an offset B Calculates percent deviation from a specified reference Selects Delta V1tl V1t2 2 Enables disables line cycle synchr
137. Percent SCPI programming relative Table 4 1 SCPI commands relative Commands Description Default For DCVI and DCV2 SENSe SENSe Subsystem VOLTage Volts function CHANnel1 Channel 1 DCV1 REFerence n Specify rel value 120 to 120 volts 0 STATe lt b gt Enable or disable relative OFF ACQuire Use input signal as rel value CHANnel2 Channel 2 DCV2 REFerence n Specify rel value 12 to 12 volts 0 STATe lt b gt Enable or disable relative OFF ACQuire Use input signal as rel value For TEMP1 and TEMP2 SENSe SENSe Subsystem TEMPerature Temperature function CHANnel1 Channel 1 TEMP1 REFerence n Specify rel value 273 to 1800 0 STATe lt b gt Enable or disable relative OFF ACQuire Use input signal as rel value CHANnel2 Channel 2 TEMP2 REFerence n Specify rel value 273 to 1800 0 STATe lt b gt Enable or disable relative OFF ACQuire Use input signal as rel value For Analog Output OUTPut OUTPut Subsystem RELative b Enabling ON relative uses the analog output voltage as OFF the rel value Sending ON with rel already enabled acquires a new rel value Relative mX b and Percent 4 5 Programming examples relative Program Example 1 This program fragment shows how to null out zero offset for the DCV 1 function Be sure to short the Channel 1 input CALL SEND 7 syst pres status Selects DCV1 and
138. RS 232 interface reference Sending and receiving data The RS 232 interface transfers data using eight data bits one stop bit and no parity Make sure the controller you connect to the Model 2182 also uses these settings You can break data transmissions by sending a C or X character string to the controller This clears any pending operation and discards any pending output Baud rate flow control and terminator NOTE The procedure to select and configure the RS 232 interface is provided in Selecting and configuring an interface located at the beginning of this section Baud rate The baud rate is the rate at which the Model 2182 and the programming terminal communicate Choose one of the following available rates 19 2k e 9600 4800 e 2400 1200 e 600 e 300 The factory selected baud rate is 9600 Make sure that the programming terminal that you are connecting to the Model 2182 can support the baud rate you selected Both the Model 2182 and the other device must be configured for the same baud rate To select a baud rate follow these steps 11 28 Remote Operation Flow control signal handshaking Signal handshaking between the controller and the instrument allows the two devices to communicate to each other regarding being ready or not ready to receive data The Model 2182 does not support hardware handshaking flow control Software flow control is in the form of X__ON and X__ OFF characters and i
139. Ratio reading on CRT Ratio and Delta 5 17 Delta programming example The following program fragment uses a SourceMeter SM with the Model 2182 to perform Delta measurements External triggering via Trigger Link is used to synchronize the source measure operations between the two instruments Also Front Autozero is disabled to double the speed of Delta Three Delta measurements will be performed one at a source value of 10pA one at 20nA and one at 50uA The three readings will be stored in the buffer of the Model 2182 CALL CALL CALL CALL CALL CALL CALL CALL CALL CALL CALL CALL CALL CALL CALL CALL SEND SEND SEND SEND SEND SEND SEND SEND SEND SEND SEND SEND SEND SEND SEND SEND 20e 6 CALL CALL CALL SEND SEND SEND 7 3 7 7 3 7 3 Cie T n O 24 24 24 24 24 u 24 24 24 24 20e 6 24 24 24 Syst pres status a trig del 1 status 2 sens volt delta on status Syst faz off status 5 trig sour ext status 1 trac poin 3 status strac feed cont next status rst statust trig sour tlin status trig dir sour status i trig outp sour status f trig coun 6 status 4 sour func curr status j func volt status 3 volt nplc 0 01 status j sour list curr 10e 6 10e 6 50e 6 50e 6 status s soutp on
140. Register is shown in Figure 12 3 Notice that the decimal weight of each bit is included in the illustration The sum of the decimal weights of the bits that you wish to set is the value that is sent with the SRE command For example to set the ESB and MAV bits of the Service Request Enable Register send the following command SRE 48 Where ESB bit B5 2 Decimal 32 MAV bit B4 2 Decimal 16 lt NRf gt 48 The contents of the Service Request Enable Register can be read using the SRE query command Figure 12 3 Service request enable register Bit Position B7 B6 BS B4 B3 B2 B1 BO Event OSB ESB MAV QSB EAV MSB oh 128 32 16 8 4 1 Decimal Weighting 7 a ea a3 o3 Q9 PM ud M Value 1 Enable Service Events OSB Operation Summary Bit Request Event ESB Event Summary Bit O Disable Mask MAV Message Available Service Request Event QSB Questionable Summary Bit EAV Error Available MSB Measurement Summary Bit 12 14 Common Commands STB Status Byte Query Read status byte register Description Use the STB query command to acquire the value in decimal of the Status Byte Register The Status Byte Register is shown in Figure 12 4 The binary equivalent of the decimal value determines which bits in the register are set All bits except Bit B6 in this register are set by other event registers and queues Bit 6 sets when one or m
141. S 1 OPEN chan2 xls FOR OUTPUT AS 2 FOR i 1 TO CalcReadings NEXT i CLOSE 1 CLOSE 2 CHlpos CHl1neg NumRdgsPerStep 1 CHlneg Reading k i NumRdgsPerStep 2 this will place current working this will place current working chanl xls in your directory chan2 xls in your directory PRINT 2 DataCH2 i PRINT 1 DataCH1 i close the chanl xls file close the chan2 xls file 9 19 9 20 Stepping and Scanning 10 Analog Output 10 2 Analog Output e Overview Covers the capabilities of the Analog Output Operation Explains how to configure and control the Analog Output SCPI programming Covers the SCPI commands associated with the Analog Output Analog Output 10 3 Overview The ANALOG OUTPUT provides a scaled non inverting voltage output up to 1 2V It is typically used to drive a chart recorder The Analog Output voltage is calculated as follows Analog Output Gain x Rdg Rng Offset where Gain is the user entered gain factor Rdg is the reading on the Model 2182 Rng is the measurement range Offset is the user entered offset value NOTE Gain and offset for Analog Output are not related to gain and offset for the mX b calculation see Section 4 Gain provides amplification for small analog output voltage signals while offset allows you to adjust the analog output to keep it between 1 2V maximum output or reference the voltage
142. SYNc STATe ON Enable 2182 Line Synchronization SYSTem AZERo STATe OFF Disable 2182 Autozero Autozero should only be disabled for short periods of time After performing a sweep re enable Autozero For details on Autozero see Section 2 InStep 9 set the buffers of both Model 2182s to store the Delta readings If performing a 30 point sweep set both buffers to store 30 Delta readings Log sweep If your test requires currents that span two or more decades you can configure the SourceMeter to output a log sweep The 30 point sweep in Figure 5 11 is confined to the 10uA 100uA decade If for example you want to expand the sweep to span three current decades the next 30 sweep points would be used for the 100nA 200pA and the 5000A amplitudes The last 30 sweep points would be used for the ImA 2mA and 5mA amplitudes The I V data points can then be graphed using a logarithmic linear scale Ratio and Delta 5 25 Figure 5 11 SourceMeter output 30 point custom sweep 2 508A P20 P22 P24 P26 P28 2 20uA P10 P12 P14 P16 P18 a10uA PO P2 P4 P6 P8 10uA P1 P3 P5 P7 P9 20uA Pli P113 P15 P17 P19 50uA P21 P23 P25 P27 P29 5 26 Ratio and Delta Trigger link connections External triggering is used to synchronize source measure operations among the instruments The SourceMeter must trigger both Model 2182s to achieve simultaneous measurements In turn only one of the Model 2182s must trigger the SourceMe
143. Scanning 9 17 A loop program can be written to extract the data as follows This is for Channel 2 Data Let NumRdgsPerStep 4 1 Ch2 and 3 Chl readings stored in the buffer 2400 current level Let CalcRdgs 6 Total number of positive or negative current levels out of the 2400 Let k 1 For j 1 to CalcRdgs CH2 Rdg j Buffer Rdg k Buffer Rdg k NumRdgsPerStep CH2 Rdg j CH2 Rdg k 2 k k NumRdgsPerStep 2 Next j This for For Channel 1 Data Let NumRdgsPerStep 4 Let CalcRdgs 6 Let k 1 For j 1 to CalcRdgs Let CH1 Rdg _pos 0 Let CH1 Rdg neg 0 For m 1 to NumRdgsPerStep 1 CH1 Rdg pos CH1 Rdg pos Buffer Rdg k m CH1 Rdg neg CH1 Rdg neg Buffer Rdg k m NumRdgsPerStep Next m CH1 Rdg j CH1 Rdg _pos CH1 Rdg neg NumRdgsPerStep 1 2 Next j An example program using QBASIC was written that sets up an Array for all the data out of the 2182 buffer parses the comma separated data into the array and calculates the DC current reversal data for both Channel 1 and Channel 2 CONST Addr 7 Represents the address of the 2182 CONST NumRdgsPerStep 4 Represents the total number of CH1 amp CH2 readings at each positive or negative current step CONST CalcReadings 6 Represents number of paired positive amp negative steps in 2400 CONST NumRdgs NumRdgsPerStep 2 CalcReadings NumRdgs represents the number o
144. Specify data format ASCii SREal or DREal ASCii v DATA Query data format V BORDer name Specify byte order NORMal or SWAPped SWAPped v BORDer Query byte order v ELEMents name Specify data elements READing CHANnel READing v and UNITS ELEMents Query data format elements v 14 6 SCPI Reference Tables Table 14 5 OUTPut command summary Default Command Description Parameter Ref SCPI OUTPut Sec 10 GAIN lt NRf gt Set analog output gain M 100e6 to 100e6 1 GAIN Query analog output gain OFFSet lt NRf gt Set analog output offset B 1 2 to 1 2 0 OFFSet Query analog output offset STATe lt b gt Enable or disable analog output OFF forces OV ON STATe Query state of analog output RELative lt b gt ON uses the present analog output voltage as the Rel value OFF OFF disables analog output Rel RELative Query state of Rel Table 14 6 ROUTe command summary Default Command Description Parameter Ref SCPI ROUTe Sec 9 SCAN Path to configure and control scanning v INTernal Internal scanning CCOunt lt n gt Specify number of readings on Channel 1 1 to 1023 CCOunt Query Channel 1 count EXTernal lt list gt Specify external scan list 1 10 LSELect name Select and enable scan operation INTernal EXTernal or NONE LSELect Query selected scan operation SCPI Reference Tables 14 7 Table 14 7
145. TER MEASURE OF CONFIDENCE Keithley Instruments Inc Corporate Headquarters 28775 Aurora Road Cleveland Ohio 44139 440 248 0400 Fax 440 248 6168 1 888 KEITHLEY 534 8453 e www keithley com Belgium Sint Pieters Leeuw 02 363 00 40 Fax 02 363 00 64 www keithley nl China Beijing 8610 82251886 Fax 8610 82251892 www keithley com cn Finland Helsinki e 09 5306 6560 Fax 09 5306 6565 www keithley com France Saint Aubin 01 64 53 20 20 Fax 01 60 11 77 26 www keithley fr Germany Germering 089 84 93 07 40 Fax 089 84 93 07 34 www keithley de Great Britain Theale 0118 929 7500 Fax 0118 929 7519 www keithley co uk India Bangalore 91 80 2212 8027 Fax 91 80 2212 8005 www keithley com Italy Milano 02 48 39 16 01 Fax 02 48 39 16 28 www keithley it Japan Tokyo 81 3 5733 7555 Fax 81 3 5733 7556 www keithley jp Korea Seoul 82 2 574 7778 Fax 82 2 574 7838 www keithley com Netherlands Gorinchem 0183 635333 Fax 0183 630821 www keithley nl Singapore Singapore 65 6747 9077 Fax 65 6747 2991 www keithley com Sweden Solna 08 509 04 600 Fax 08 655 26 10 www keithley com Taiwan Hsinchu 886 3 572 9077 Fax 886 3 572 9031 www keithley com tw Copyright 2003 Keithley Instruments Inc Printed in the U S A 3 04
146. TER reading lengths 16 status PRINT reading NOTE To repeat buffer storage send the following command and then repeat the steps following the Start everything comment in the previous example CALL SEND 7 feed cont next status Example Programs E 7 Taking readings using the READ command This programming example demonstrates a simple method for taking and displaying on the computer CRT a specified number of readings The number of readings is specified by the SAMPle COUNt command When READ is asserted the specified number of readings is taken After all the readings are taken they are sent to the computer Note that these readings are also stored in the buffer The following program takes 10 readings on the DCV1 function and displays them on the computer CRT For QuickBASIC 4 5 and CEC PC488 interface card edit the following line to where the QuickBASIC libraries are on your computer SINCLUDE c Nqb45Nieeeqb bi Initialize the CEC interface as address 21 CALL initialize 21 0 Reset controls clear buffer and place 2182 in idle CALL SEND 7 rst status CALL SEND 7 trac cle status CALL SEND 7 sample coun 10 status CALL SEND 7 form elem read unit status CALL SEND 7 read status reading SPACES 300 CALL ENTER reading length 16 status PRINT reading E 8 Example Programs Controlling the Model 2182 via the RS 232 COM2 port This example progra
147. Table 14 1 through Table 14 12 With the SAVO parameter selected the instrument powers on to the setup that is saved in the specified location using the SAV command Additional SCP Commands 15 19 VERSion command VERSion 2 SYSTem VERSion Read SCPI version Description This query command is used to read the version of the SCPI standard being used by the Model 2182 Example code 1991 0 The above response message indicates the version of the SCPI standard ERRor command E RRor SYSTem ERRor Read Error Queue Description As error and status messages occur they are placed in the Error Queue This query command is used to read those messages The Error Queue is a first in first out FIFO register that can hold up to ten messages Each time you read the queue the oldest message is read and that message is then removed from the queue If the queue becomes full the 350 Queue Overflow message occupies the last memory location in the register On power up the queue is empty When the Error Queue is empty the 0 No error message is placed in the Error Queue The messages in the queue are preceded by a number Negative numbers are used for SCPI defined messages and positive numbers are used for Keithley defined messages Appendix B lists the messages NOTE The SYSTem ERRor query command performs the same function as the STATus QUEue query command see STATus subsystem CLEar
148. able 8 1 Nulling thermal EMFs To maximize handling speed quick disconnect test clips are typically used for the resistor connections Unfortunately these connections may contribute enough thermal EMFs to corrupt the measurement The Relative feature of the Model 2182 can be used to null out this offset as follows 1 Connect the test circuit shown in Figure 8 1 but leave the current source disconnected 2 Using the lowest possible range or autorange measure the offset voltage 3 Press REL to zero the display of the Model 2182 4 Connect the current source and test the resistors NOTE As long as all the resistor leads in the batch are made of the same metal the Rel value obtained for the first resistor should be satisfactory for each subsequent resistor Stepping and Scanning 9 2 Stepping and Scanning e Step Scan overview Summarizes the stepping and scanning operations Front panel trigger models Uses the trigger model to illustrate how stepping and scanning operates Stepping Scanning controls Covers the front panel keys used to configure and control stepping scanning Stepping Scanning examples Provides examples for internal stepping and scanning and external scanning SCPI programming Covers the SCPI commands used for stepping and scanning Application Uses internal scanning to produce an I V curve for a DUT Stepping and Scanning 9 3 Step Scan overview The Model 2182 ca
149. able at the rear panel Trigger Link connector This trigger can be used to trigger another instrument to perform an operation e g select the next channel for an external scan 7 6 Triggering Reading hold autosettle With hold enabled HOLD annunciator on the first processed reading becomes the seed reading and operation loops back within the device action block After the next reading is processed it is checked to see if it is within the selected hold window 0 01 0 1 1 10 of the seed reading If the reading is within the window operation again loops back within the device action block This looping continues until the specified number 2 to 100 of consecutive readings are within the window If one of the readings is not within the window the instrument acquires a new seed reading and the hold process continues When a hold reading is acquired an audible beep is sounded if enabled and the reading is considered a true measurement The reading is held on the display until an out of window reading occurs to restart the hold process For remote operation or when scanning the hold process seeks a new seed once it has been satisfied and the readings have been released For basic front panel operation the hold process does not seek a new seed until the held condition is removed NOTE Hold can only be used with Channel 1 Whenever Hold is enabled Channel 2 becomes inoperative H
150. al poll is performed If an SRQ does occur bit B6 of the Status Byte Register will set and the program can branch to a service subroutine when the SRQ is detected by the serial poll Remote Operation 11 21 The serial poll automatically resets RQS of the Status Byte Register This allows subsequent serial polls to monitor bit B6 for an SRQ occurrence generated by other event types After a serial poll the same event can cause another SRQ even if the event register that caused the first SRQ has not been cleared A serial poll clears RQS but does not clear MSS The MSS bit stays set until all Status Byte event summary bits are cleared Programming syntax The following paragraphs cover syntax for both common commands and SCPI commands For more information see the IEEE 488 2 and SCPI standards Command words Program messages are made up of one or more command words Commands and command parameters Common commands and SCPI commands may or may not use a parameter The following are some examples SAV lt NRf gt Parameter NRf required RST No parameter used SINITiate CONTinuous lt b gt Parameter lt b gt required SYSTem PRESet No parameter used Put at least one space between the command word and the parameter e Brackets Some command words are enclosed in brackets These brackets are used to denote an optional command word that does not need to be included in the program message For example NITiate IM
151. alled the trigger model because operation is controlled by SCPI commands from the Trigger subsystem Key SCPI commands are included in the trigger model Figure 7 10 Trigger model remote operation ABOrt RCL 0 START O SYST PRES RST Idle and Initiate No Yes INIT IMM or INIT CONT ON Trigger Signal Another wv Control Source Event Detection Trigger Source Immediate Trigger Source External Trigger Source Timer Trigger Source Manual Trigger Source BUS K Trigger Delay n Trigger Delay AUTO lt b gt Delay Trigger 2 Trigger Count n Infinite Output Trigger Device Action Another Sample 2 Sample Count n 7 14 Triggering Idle and initiate The instrument is considered to be in the idle state whenever operation is at the top of the trigger model As shown in Figure 7 10 initiation needs to be satisfied to take the instrument out of idle While in the idle state the instrument cannot perform any measure or step scan operations The following commands will return operation to the top of the trigger model idle at the START point of the trigger model e ABORt RCLO e SYSTem PREset e RST What happens next depends on the state of initiation If continuous initiation is already enabl
152. and 2182 Delta and Differential Conductance measurements Models 6221 and 2182A Delta Pulse Delta and Differential Conductance measure ments NOTE The firmware version of the Model 2182 must be A10 or higher The firmware version of the Model 2182A must be C01 or higher Delta Pulse Delta and Differential Conductance l 3 Operation overview The Model 6220 or 6221 Current Source can be used with a Model 2182 2182A Nanovolt meter to perform Delta and Differential Conductance The Model 2182A 6221 combina tion can also perform Pulse Delta These operations use a delta current reversal technique to cancel the effects of thermal EMFs The Model 622x provides a bipolar output current and the Model 2182 2182A performs A D conversions measurements at source high and source low points An averaging algo rithm is then used to calculate the delta reading Delta The Model 622x provides a square wave current output and the Model 2182 2182A performs A D conversions measurements at each high and low output level A 3 point moving average algorithm is used to calculate Delta readings As shown in Figure I 1A the first three Model 2182 2182A A D conversions measure ments yields the first Delta reading Each subsequent Model 2182 2182A A D conversion then yields a single Delta reading Every Delta reading uses the three previous A Ds to cal culate Delta Pulse Delta The Model 6221 outputs pulses and uses 3 point repea
153. ands filter iue iret e e Pete irent ipta 3 12 Relative mX b and Percent 96 SCPI commands relative esses eene eene eene nennen 4 4 SCPI commands mX b and percent sse 4 8 Ratio and Delta SCPI commands ratio and delta enne 5 16 Buffer SCPI commands buffer essessssesseeseeeeee nennen eene nnnne 6 5 Triggering Auto delay HIMES eei rage iai nep d E e Ede a E RR ER ER IHRE ERR due 7 4 SCPI commands triggering essere rennen nen emen 7 16 Limits SCPEcommiands mits e oet Bee tae eee e oec PEN ER 8 5 Stepping and Scanning SCPI commands stepping and scanning eese 9 12 10 Table 10 1 Table 10 2 11 Table 11 1 Table 11 2 Table 11 3 12 Table 12 1 13 Table 13 1 14 Table 14 1 Table 14 2 Table 14 3 Table 14 4 Table 14 5 Table 14 6 Table 14 7 Table 14 8 Table 14 9 Table 14 10 Table 14 11 Table 14 12 B Table B 1 C Table C 1 D Table D 1 Analog Output Analog output examples cossiros 10 3 SCPI commands analog output eese enne 10 6 Remote Operation General bus commands and associated statements esses 11 9 RS 232 connector pinout seen nen enne eere nenne 11 29 PC serial port pinoul e ee ERR EIER ERE E HEISE HENRI 11 30 Common Commands IEEE 488 2 common commands and queries eee 12 2 SCPI Signal Oriented Measurement
154. ardous voltage condition exists at or above 42V peak To prevent electric shock that could result in injury or death NEVER make or break connections while hazardous voltage is present CAUTION Exceeding the following limits may cause instrument damage not covered by the warranty Channel 1 HI and LO inputs have a maximum measurement capability of 120V peak These inputs are protected to 150V peak to any terminal or 350V peak to chassis Channel 2 HI and LO inputs have a maximum measurement capability of 12V peak Channel 2 HI is protected to 150V peak to any terminal and Channel 2 LO is protected to 70V peak to Channel 1 LO Both inputs are protected to 350V peak to chassis NOTE Asa general rule use Channel 1 whenever possible to measure voltage below IV If using Channel 2 to measure 1V and the impedance between Channel 2 LO and Channel I LO is gt 100kQ pumpout current may be high enough to corrupt measurements In this case the Low Charge Injection mode can be enabled to reduce pumpout current at the expense of increased measurement noise See Performance considerations Pumpout current low charge injection mode for details Connection techniques Copper to copper connections should be used wherever possible in the test circuit to minimize thermal EMFs that could corrupt measurements see Measurement error external causes for information on thermal EMFs Any solder connections to your test circuit require the use
155. are appropriate and speed is not a requirement H 4 Measurement Queries SENSe 1 DATA FRESh What it does This query is similar to the FETCh in that it returns the latest reading from the instrument but has the advantage of making sure that it does not return the same reading twice Limitations Like the FETCh query this command does not trigger a reading When appropriate This is a much better choice than the FETCh query because it can t return the same reading twice This would be a good query to use when triggering by BUS or EXTERNAL because it will wait for a reading to complete if a reading is in progress The CALC DATA FRESh query is similar to the DATA FRESh query but applies to readings which have math applied to them e g MX B scaling SENSe 1 DATA LATest What it does This query will return the last reading the instrument had regardless of what may have invalidated that reading such as changing ranges or functions Limitations This query is fully capable of returning meaningless old data When appropriate If for some reason the user wanted the last completed reading even after changing ranges or other measurement settings which would invalidate the old reading The CALC DATA LATest query is similar to the DATA LAT query but applies to readings which have math applied to them e g MX B scaling Measurement Queries H 5 Examples On
156. ategories data lines management lines and handshake lines The data lines handle bus data and commands while the management and handshake lines ensure that proper data transfer and operation takes place Each bus line is active low with approximately zero volts representing a logic 1 true The following paragraphs describe the operation of these lines Data lines The IEEE 488 bus uses eight data lines that transfer data one byte at a time DIO1 Data Input Output through DIO8 Data Input Output are the eight data lines used to transmit both data and multiline commands and are bi directional The data lines operate with low true logic Bus management lines The five bus management lines help to ensure proper interface control and management These lines are used to send the uniline commands ATN Attention The ATN state determines how information on the data bus is to be interpreted IFC Interface Clear The IFC line controls clearing of instruments from the bus REN Remote Enable The REN line is used to place the instrument on the bus in the remote mode IEEE 488 Bus Overview F 5 EOI End or Identify The EOI line is used to mark the end of a multi byte data transfer sequence SRQ Service Request The SRQ line is used by devices when they require service from the controller Handshake lines The bus handshake lines operate in an interlocked sequence This method ensures reliable data transmissio
157. ation time Selecting 5 PLC slow provides better noise performance at the expense of speed Range Digits Rate and Filter 3 7 NOTE For remote operation the integration time can be set from 0 01 PLC to 60 PLC 50 PLC for 50Hz line power Integration time can instead be set as an aperture time from 166 67usec 200usec for 50Hz to 1 second Perform the following steps to set the integration rate 1 Select the desired function 2 Press the RATE key until the desired number of power line cycles PLC is displayed The appropriate annunciator will turn on FAST MED or SLOW NOTE Pressing the front panel RATE key will enable Autozero if it was off For remote programming the rate commands have no effect on the state of Autozero For details see Autozeroing modes in Section 2 SCPI programming rate Table 3 3 SCPI commands rate Commands Description Default SENSe SENSe Subsystem VOLTage DCV1 and DCV2 NPLCycles n Specify integration rate in PLCs 0 01 to 60 60Hz 5 0 01 to 50 S0Hz APERture lt n gt Specify integration rate in seconds 166 67psec to 1 sec 60Hz 83 33msec 200ysec to 1 sec 50Hz TEMPerature TEMP and TEMP2 NPLCycles n Specify integration rate in PLCs 0 01 to 60 60Hz 3 0 01 to 50 50Hz APERture lt n gt Specify integration rate in seconds 166 67usec to 1 sec 60Hz 83 33msec 200ysec to 1 sec 50Hz Programming example rate The following program frag
158. ations Control Source Immediate External Timer Idle b lt Yes AA Event Detection Device Action Another Trigger Scan Counter Output Trigger m Another Sample Reading Counter Another Trigger Counter Reading Reading Count Output Trigger 9 5 9 6 Stepping and Scanning Other Stepping Scanning operations Control source Immediate With immediate triggering event detection occurs immediately allowing operation to drop down to the next trigger model block Delay Timer The timer is used to set a time interval between channels in a step scan cycle When STEP or SCAN is pressed the timer starts and event detection occurs immediately allowing operation to drop down to Delay When operation later loops back to this control source it waits until the timer interval expires If the timer interval is already expired event detection will be satisfied immediately External trigger After the stepping or scanning operation is configured pressing the EX TRIG key places the instrument in the external trigger mode When STEP or SCAN key is pressed the step scan is enabled However it doesn t start until an external trigger is received or the TRIG key is pressed After the trigger occurs operation drops down to the Delay block Delay If a delay auto or manual is being used operation will hold
159. calculation would instead be 9 5mV This results in 5 mea surement error due to heating The affects of heating can be eliminated by not performing the measurement at point C low pulse For this 2 point measurement technique Pulse Delta is calculated as follows PulseDelta 5 1 _ 2 10 01 2 0 01 2 20mV 2 10mV Delta Pulse Delta and Differential Conductance I 11 Measurement units The fundamental Pulse Delta measurement explained on the previous page is in volts The reading can instead be converted into an Ohms W Siemens S or Power W reading by the Model 622x With Power W units selected a Pulse Delta reading can be expressed and displayed as a Peak power reading or an Average power reading W peak power I x V W Average power I x V x Duty Cycle Pulse Delta outputs Pulse Delta output is made up of one or more Pulse Delta cycles Each cycle is made up of three output pulses low high and low The time period for a cycle is adjustable and is the same for all cycles The output pulses have an adjustable pulse width which is the same for all pulses There are two basic Pulse Delta output types Fixed output and Sweep output For Fixed output all high and low pulses are fixed for all Pulse Delta cycles in the test For Sweep output the sweep SWP function of the Model 6221 is used to output a staircased loga rithmic or user specified custom pulse sweep Fixed output Figur
160. ce 1 15 Primary address selection 11 8 Program examples E 2 Pulse Delta I 3 Fixed output I 11 Measurement units I 11 Pumpout current low charge injection mode 2 9 QuickBASIC programming 11 8 Rack mount kits 1 5 Radio frequency interference C 6 Range 3 3 Range Digits Rate and Filter 3 1 Rate 3 6 Ratio 5 2 Ratio and Delta 5 1 Ratio programming example 5 16 Reading hold autosettle 7 6 Rear panel summary 1 11 Recall 6 3 REL Key 4 3 Relative 4 3 Relative mX b and Percent 4 1 Remote Operation 11 1 ROUTe command summary 14 6 RS 232 connections 11 29 RS 232 interface reference 11 27 Safety symbols and terms 1 3 SCPI commands F 10 SCPI programming ACAL Front Autozero Autozero LSYNC and Low Charge Injection 2 10 SCPI programming analog output 10 6 SCPI programming buffer 6 5 SCPI programming digits 3 5 SCPI programming filter 3 12 SCPI programming limits 8 5 SCPI programming mX b and percent 4 8 SCPI programming range 3 4 SCPI programming rate 3 7 SCPI programming ratio and delta 5 16 SCPI programming relative 4 4 SCPI programming stepping and scanning 9 12 SCPI programming triggering 7 13 SCPI programming voltage and temperature measurements 2 20 SCPI Reference Tables 14 1 SCPI Signal Oriented Measurement Commands 13 1 Selecting and configuring an interface 11 3 Selecting Delta 5 9 Sending and receiving data 11 27 SENSe command summary 14 7 Settin
161. ce Function Codes See Appendix F 2 Behavior of 2182 when the address is set outside Cannot enter an invalid address the range 0 30 3 Behavior of 2182 when valid address is entered Address changes and bus resets 4 Power On Setup Conditions Determine by SYSTem POSetup Section 15 5 Message Exchange Options a Input buffer size 256 bytes b Queries that return more than one response None message unit c Queries that generate a response when parsed All queries Common Commands and SCPI d Queries that generate a response when read None e Coupled commands See Table G 2 6 Functional elements required for SCPI commands Contained in SCPI command subsystems tables see Table 14 1 through Table 14 12 7 Buffer size limitations for block data Block display messages 12 characters max 8 Syntax restrictions See Programming syntax in Section 11 9 Response syntax for every query command See Programming syntax in Section 11 10 Device to device message transfer that does not None follow rules of the standard 11 Block data response size See DISPlay subsystem in Section 15 12 Common Commands implemented by 2182 See Common Commands in Section 12 13 Calibration query information 14 Trigger macro for DDT Not applicable Table G 1 cont IEEE 488 documentation requirements Requirements IEEE 488 and SCPI Conformance Information Descriptio
162. ce with an input resistance of 1OMQ the error due to loading will be approximately 0 01 Configure and control analog output 1 Press SHIFT and then AOUT to display the Gain M factor M 1 0000000 factory default 2 Gain can be set from 100e6 to 100e6 The lt q and gt keys control cursor position and the amp and range keys increment and decrement the digit value To change range place the cursor on the multiplier and use the amp and W keys m x0 001 x1 K x1000 and M x1 000 000 With the cursor on the polarity sign the and W keys toggle polarity 3 Press ENTER to enter the Gain value and display the Offset value B 00 000000 factory default 4 Key in the Offset value 5 Press ENTER to enter the Offset value and enable Analog Output The instrument returns to the normal display state 6 To disable Analog Output press SHIFT and then AOUT Analog output rel With analog output enabled Analog Output Rel is used to automatically reference the analog output voltage to zero When Analog Output Rel is turned ON the present analog output voltage is used as the Rel value This sets the analog output voltage to zero Subsequent analog output readings will be the difference between the actual analog output and the Rel value To enable Analog Output Rel press SHIFT and then OUTPUT The message AOUT REL ON will be displayed briefly to indicate that it is enabled To disable Analog Output REL press SHI
163. ch contact resistance 0 0 eeeeseeseeeseesecseeeseeeceeaeeeseesesenesaeenseeaes 2 24 Measuring switch contact resistance and temperature sees 2 25 Standard cell comparison measurements see 2 26 Heated Zener characterization seen een em nee en 2 27 Range Digits Rate and Filter Speed vs noise characteristics esses eeseeseceseesecsseeseeesesseesseeseesseeseeeseeseeeaeesaeens 3 6 Moving and repeating filters esses eem eem 3 10 Ratio and Delta Test circuit using constant current source oo eee eeeeseceeeeeeeeseceeeesecseeeseeneeeaees 5 7 Delta measurement using bipolar source eee 5 8 Delta measurement connections sese eene 5 11 Triggering timing diagram sessi eere enne nnne entente 5 14 Calibrating 1 10 divider i uie teet irre reor Ee 5 18 Test circuit Fixed I Vary H eeeeeseeeeeeeeeeeeeenee ennt nnne nene 5 20 H V C tve Fixed D 14e ttr rire a ea oce rarae aU 5 21 SourceMeter output 2 point custom SWEEP seseeeeeeeeneneeem eem 5 21 I V Curve Fixed H eeeeeeeeeeeeeeeeeee eene eene nnne ette ennt tnn ns estne 5 22 Test circuit Pixed H Vary D 4 eec ettet ertet eng evan e EE Pe rna ngo 5 23 SourceMeter output 30 point custom sweep seseeeeeeee 5 25 Trigger link connections using two Model 2182s eese 5 26 6 Figure 6 1 7
164. ck mounting a separate main input pow er disconnect device must be provided in close proximity to the equipment and within easy reach of the operator For maximum safety do not touch the product test cables or any other instruments while power is applied to the circuit under test ALWAYS remove power from the entire test system and discharge any capacitors before connecting or disconnecting ca 5 03 bles or jumpers installing or removing switching cards or making internal changes such as installing or removing jumpers Do not touch any object that could provide a current path to the common side of the circuit under test or power line earth ground Al ways make measurements with dry hands while standing on a dry insulated surface capable of withstanding the voltage being measured The instrument and accessories must be used in accordance with its specifications and operating instructions or the safety of the equipment may be impaired Do not exceed the maximum signal levels of the instruments and accessories as defined in the specifications and operating in formation and as shown on the instrument or test fixture panels or switching card When fuses are used in a product replace with same type and rating for continued protection against fire hazard Chassis connections must only be used as shield connections for measuring circuits NOT as safety earth ground connections If you are using a test fixture keep the lid closed while
165. configuration in memory for later recall Any control affected by RST can be saved by the SAV command The RCL command is used to restore the instrument to the saved setup configuration Only one setup configuration can be saved and recalled NOTE For RS 232 operation and in some cases GPIB operation OPC or OPC should be used with SAV which is a slow responding command Details on OPC and OPC are provided in Section 12 SRE lt NRf gt Service Request Enable Program service request enable register SRE Service Request Enable Query Read service request enable register Parameters lt NR 0 Clears enable register 1 Set MSB bit Bit 0 4 Set EAV bit Bit 2 8 Set QSB bit Bit 3 16 Set MAV bit Bit 4 32 Set ESB Bit 5 128 Set OSB Bit 7 255 Set all bits Common Commands 12 13 Description Use the SRE command to program the Service Request Enable Register Send this command with the decimal equivalent of the binary value that determines the desired state 0 or 1 of each bit in the register This register is cleared on power up This enable register is used along with the Status Byte Register to generate service requests SRQ With a bit in the Service Request Enable Register set an SRQ occurs when the corresponding bit in the Status Byte Register is set by an appropriate event For more information on register structure see the information presented earlier in this section The Service Request Enable
166. cross the DUT I is the known current that flows through the DUT Figure 5 9 I V Curve Fixed H Fixed H Measure V Source Such a test system is shown in Figure 5 10 A Keithley SourceMeter Model 2400 2410 or 2420 is used to source current through the DUT and two Model 2182s are used to provide simultaneous voltage measurements Model 2182 1 measures the voltage across a precision reference resistor Rggp and stores the readings in its buffer These stored readings allow you to reference current amplitudes to the voltage measurements of the DUT Model 2182 2 measures voltage across the DUT and stores the readings in its buffer For example assume you want to measure DUT voltage at current sweep values of 10pA 20uA and 50nA When the sweep is started 10pA output Model 2182 1 measures ImV 10uA x 100 1mV and stores the reading in its buffer at location 1 At the same time Model 2182 2 measures the DUT and stores that reading in its buffer at location 1 At the next sweep point 201A Model 2182 1 measures 2mV and stores the reading in its buffer at location 2 and Model 2182 2 measures the DUT and stores the reading in its buffer at location 2 At the last sweep point 500A Model 2182 1 measures 5mV and stores the reading in its buffer at location 3 and Model 2182 2 measures the DUT and stores the reading in its buffer at location 3 Ratio and Delta 5 23 Figure 5 10 Test circuit Fixed H Vary I
167. ct CUSTOM Set the POINTS to two and set ADJUST POINTS P0000 and P0001 to the positive and negative current source values For example if the test requires lmA set P0000 to 1mA and set P0001 to 1mA B Also from the sweep configuration menu specify the number of 2 point sweeps to perform Selecting INFINITE allows the SourceMeter to continuously source the current reversal sweep Select FINITE if you wish to perform a specific number of 2 point sweeps Step6 Return the Model 2182 to FACTory defaults Return the nanovoltmeter to its factory default conditions by pressing RESTR and selecting FACT Step7 Configure the Model 2182 for Delta measurements A Press RATE to select 1 PLC MED annunciator on or 5 PLC SLOW annunciator on B Enable Delta measurements by pressing SHIFT and then V1 V2 NOTE For fast Delta measurements 2x speed disable Front Autozero SHIFT gt CONFIG gt FRONT AUTOZERO N C Press EX TRIG to place the instrument in the external trigger mode This will halt measurements D Ifa longer settling time is required before performing each measurement set a manual delay from the Model 2182 Press SHIFT and then DELAY to select and set delay NOTE Do not set a delay on the SourceMeter as this may adversely affect trigger synchronization between the SourceMeter and the Model 2182 Ratio and Delta 5 13 Step 8 Turn on the SourceMeter output and reset the trigger model A Turn on the output
168. cted RS 232 On Trigger Link Current Source Nanovoltmeter l 6 Delta Pulse Delta and Differential Conductance Delta measurement process The Delta process is shown in Figure I 3 As shown three Model 2182 2182A A D conversions are performed to yield a single Delta reading When Delta starts three Model 2182 2182A A Ds A B and C are performed and the Delta reading is calculated After the 1st Delta cycle the moving average technique is then used As shown a Delta reading is yielded for every subsequent Model 2182 2182A A D The new A D replaces the oldest A D in the Delta calculation Figure I 3 Delta measurement technique 2182 2182A 2182 2182A 2182 2182A A D A A DC A D E I High 622x I Source 4 1st Delta Cycle 4 2nd Delta Cycle Low rm Jerem 2182 2182 2182 2182A i 2182A 2182A ADB ADD ADF 3rd Delta Cycle 1 4th Delta Cycle 1st Delta Reading Goes e 1 3rd Delta Reading C2 8 e 1 4 4 2nd Delta Reading D e 1 4th Delta Reading e 4 Delta Pulse Delta and Differential Conductance l 7 The following equation can be used to calculate any Delta reading Delta e 1 Where X Y and Z are the three A D measurements for a Delta reading n Delta Cycle Number 1 Example Calculate the 21st Delta reading X Y and Z are the
169. cy and RF fields can seriously corrupt measurements rendering experimental data virtually useless In order to minimize noise a closed metal shield surrounding the source may be necessary as shown in the example of Figure C 4 This shield should be connected to input LO in most cases although better noise performance may result with the shield connected to chassis ground in some situations WARNING Do not float input LO more than 30V rms 424V peak above earth ground with an exposed shield connected to input LO To avoid a possible shock hazard surround the LO shield with a second safety shield that is insulated from the inner shield Connect this safety shield to safety earth ground using 18 AWG minimum wire before use Figure C 4 Shielding example 2182 Noise Shield Safety Shield Connect noise shield to LO Connect safety shield to a known safety earth ground using 18 AWG wire or higher WARNING Safety shield required when floating noise shield gt 30V rms above chassis ground Measurement Considerations C 9 Meter loading Loading of the voltage source by the Model 2182 becomes a consideration for high source resistance values As the source resistance increases the error caused by meter loading increases Figure C 5 shows the method used to determine the percent error due to meter loading The voltage source Vs has a source resistance Rs while the input resistance of the Model 2182 is Ry and
170. d a o o P g og bor o o Pg bor o g gg Lor o p gd gd 3ogog og og Ofr a or or O aoa oar oa or 10 7i oa or or 1 10 m m S e f Bytes 3 4 5 and 6 not shown s sign bit 0 positive 1 negative e exponent bits 11 f fraction bits 52 Normal byte order shown For swapped byte order bytes sent in reverse order Header Byte 8 Byte 7 Byte 1 The Header is only sent once for each measurement conversion 15 6 Additional SCPI Commands BORDer command BORDer name FORMat BORDer lt name gt Specify binary byte order Parameters name NORMal Normal byte order for binary formats SWAPped Reverse byte order for binary formats Description This command is used to control the byte order for the IEEE754 binary formats For normal byte order the data format for each element is sent as follows Byte 1 Byte 2 Byte 3 Byte4 Single precision Byte 1 Byte 2 m Byte8 Double precision For reverse byte order the data format for each element is sent as follows Byte 4 Byte 3 Byte 2 Byte 1 Single precision Byte 8 Byte 7 m Byte 1 Double precision The 0 Header is not affected by this command The Header is always sent at the beginning of the data string for each measurement conversion The ASCII data format can only be sent in the normal byte order The SWAPped selection is ignored when the ASCII format is selected ELEMents command ELEMents
171. d If on DCV1 when Ratio is enabled the state of the REL annunciator on or off will indicate the state enabled or disabled of Rel for DCV1 If on DCV2 when Ratio is enabled the state if the REL annunciator will indicate the state of Rel for DC V2 The REL key is operational while in Ratio Pressing REL will either disable Rel for both channels or enable Rel for both channels REL annunciator turns on When Rel is enabled the instrument acquires the input signal from each of the two channels as Rel values Each Rel value is then applied to the respective channel Keep in mind that the Rel operations are performed on the input channels not on the result of Ratio Ranging considerations As explained in Section 3 a separate range setting fixed or AUTO can be used for each voltage channel When Ratio is enabled the range setting for each channel is retained For example Channel 1 could be set for autoranging and Channel 2 could be fixed on the 10V range Range control The manual range keys can only control one of the two channels If the instrument is on DCV1 TEMPI or TEMP2 when Ratio is enabled the manual range keys will control Channel 1 DCV 1 The manual range keys will have no effect on Channel 2 DCV2 If on DCV2 Channel 2 when Ratio is enabled range control will apply to Channel 2 DCV2 The manual range keys will have no effect on Channel 1 DCV1 NOTES When Ratio is selected the range control channel will be disp
172. d TEMP2 measurements Temperature measurements are performed on a single fixed range The DIGITS key sets reading resolution Maximum readings The full scale readings for every voltage range are 20 over range For example on the 10V range the maximum input voltage is 12V Depending on which type of thermocouple is being used the maximum temperature readings range from 200 C to 1820 C The Specifications Appendix A list the reading range for each thermocouple type Input values that exceed the maximum readings cause the overflow message COVRFLW to be displayed Manual ranging To select a range press the RANGE A or key The instrument changes one range per key press The selected range is displayed for one second Note that the manual range keys have no effect on temperature TEMPI and TEMP2 If the instrument displays the OVRFLW message on a particular range select a higher range until an on range reading is displayed Use the lowest range possible without causing an overflow to ensure best accuracy and resolution 3 4 Range Digits Rate and Filter Autoranging To enable autoranging press the AUTO key The AUTO annunciator turns on when autoranging is selected While autoranging is enabled the instrument automatically selects the best range to measure the applied signal Autoranging should not be used when optimum speed is required Note that the AUTO key has no effect on temperature TEMP1 and TEMP2
173. d in the table Table C 1 Table C 2Material thermoelectric coefficients Material Thermoelectric Potential Copper Copper 0 2nV C Copper Silver 0 3nV C Copper Gold 0 3nV C Copper Cadmium Tin 0 30 VC Copper Lead Tin 1 30 V PC Copper Kovar 40g V C Copper Silicon 4000 V C Copper Copper Oxide 10000 V C Measurement Considerations C 3 Thermoelectric generation Figure C 1 shows a representation of how thermal EMFs are generated The test leads are made of the A material while the source under test is the B material The temperatures between the junctions are shown as T and T5 To determine the thermal EMF generated the following relationship may be used Ep Qap T T7 where Ey Generated thermal EMF Qag Thermoelectric coefficient of material A with respect to material B uV C T Temperature of B junction C or K T5 Temperature of A junction C or K In the unlikely event that the two junction temperatures are identical no thermal EMFs will be generated More often the two junction temperatures will differ and considerable thermal EMFs will be generated A typical test setup will probably have several copper to copper junctions As pointed out earlier each junction can have a thermoelectric coefficient as high as 0 20 V C Since the two materials will frequently have a several degree temperature differential it is easy to see how thermal potentials of several microvolts can be generated
174. death Always read the associated information very carefully before performing the indicated procedure The CAUTION heading used in this manual explains hazards that could damage the instrument Such damage may invalidate the warranty Inspection The Model 2182 was carefully inspected electrically and mechanically before shipment After unpacking all items from the shipping carton check for any obvious signs of physical damage that may have occurred during transit There may be a protective film over the display lens which can be removed Report any damage to the shipping agent immediately Save the original packing carton for possible future shipment The following items are included with every Model 2182 order e Model 2182 Nanovoltmeter with line cord Model 2107 4 Input Cable Four alligator clips that attach to the copper lugs of the Model 2107 Input Cable Deoxlt copper cleaning solution Accessories as ordered Certificate of calibration e Model 2182 User s Manual P N 2182 900 00 e Model 2182 Service Manual P N 2182 902 00 Manual Addenda pertains to any improvements or changes concerning the instrument or manual 1 4 Getting Started If an additional manual is required order the appropriate manual package The manual packages include a manual and any pertinent addenda Options and accessories The following options and accessories are available from Keithley for use with the Model 2182 Cab
175. display of readings 1 16 Getting Started Line frequency Display On power up the Model 2182 detects the line power frequency and automatically selects the proper line frequency setting The line frequency setting can be checked using the following command SYSTem LFRequency The response message will be 50 or 60 The value 50 indicates that the line frequency is set for 50Hz or 400Hz while 60 indicates that it is set for 60Hz The display of the Model 2182 is primarily used to display readings along with the units and type of measurement Annunciators are located at the top bottom left and right of the reading or display message The annunciators indicate various states of operation See Front panel sum mary presented earlier in this section for a complete listing of display annunciators NOTE The Display and Keys Test allows you to test display digit segments and annunciators and check the functionality of front panel keys These tests are accessed by pressing SHIFT and then TEST Refer to the Model 2182 Service Manual for details Status and error messages Status and error messages are displayed momentarily During operation and programming you will encounter a number of front panel messages Typical messages are either of status or error variety as listed in Appendix B Default settings There are two default setup configurations factory and user As shipped from the factory the Model 2182 powers up to the
176. div100 ACAL error EE 412 B_7_1 ACAL error EE 413 B_0_1 ACAL error EE 414 B_1_1 ACAL error EE 415 B 1 10 ACAL error EE 416 B_0_10 ACAL error EE 417 B PI 10 ACAL error EE 418 B_P1_100 ACAL error EE 419 B_0_10 ACAL error EE 420 Analog output zero error EE 421 Analog positive gain error EE 422 Analog negative gain error EE 423 B_0_100 ACAL error EE 430 Precal selection error EE 432 ACAL Temperature Error EE 438 Date of calibration not set EE 439 Next date of calibration not set EE 440 Gain aperture correction error EE 449 10 vdc ch2 Low Q zero error EE 500 Calibration data invalid EE 510 Reading buffer data lost EE 511 GPIB address lost EE 512 Power on state lost EE 514 DC calibration data lost EE 515 Calibration dates lost EE 516 Linearity precal lost EE 522 GPIB communication language lost EE Table B 1 cont Status and error messages Status and Error Messages Number Description Event 610 Questionable Calibration EE 611 Questionable Temperature Measurement EE 612 Questionable ACAL SE 800 RS 232 Framing Error detected EE 802 RS 232 Overrun detected EE 803 RS 232 Break detected EE 805 Invalid system communication EE 806 RS 232 Settings Lost EE 807 RS 232 OFLO Characters Lost EE 808 ASCII only with RS 232 EE 900 Internal System Error EE 953 DDC Uncalibrated Error EE DDC Status Model 960 DDC Mode IDDC Error EE 961 DDC Mode IDDCO Error EE Keithley 182 Serial Poll Byte Event
177. e Delta in Section 5 for details REL Key The REL key sets a rel value for the selected function DCV1 DCV1 TEMPI and TEMP2 Note that a unique rel value can be established for each measurement function Perform the following steps to set a rel value 1 Display the reading you want as the rel value This could be a zero offset reading that you want to null out or it could be an applied level that you want to use as a baseline 2 Press REL The REL annunciator turns on and subsequent readings will be the difference between the actual input and the rel value 3 To disable REL press the REL key a second time The REL annunciator turns off NOTE You can manually set a rel value using the mX b function Set M for 1 and B for the desired rel value See mX b for more information Analog Output Rel A rel value can also be established for analog output When Analog Output Rel is turned ON the present analog output voltage is used as the rel value Subsequent analog output readings will be the difference between the actual analog output and the rel value To enable Analog Output Rel press SHIFT and then OUTPUT The message AOUT REL ON will be displayed briefly to indicate that it is enabled To disable Analog Output REL press SHIFT and then OUTPUT a second time The message AOUT REL OFF will be displayed briefly See Section 10 Analog Output for more information on Analog Output 4 4 Relative mX b and
178. e byte order can only be reversed for the binary formats When using this command to add an element you must include all elements that you want in the format For example if the reading is already specified and you want to add the channel you must include the READing parameter form elem chan read Data elements for the item list can be listed in any order but they are always sent in the order shown in Figure 15 1 STATus subsystem The STATus subsystem is used to control the status registers of the Model 2182 The commands in this subsystem are summarized in Table 14 8 NOTE The status structure of Model 2182 is explained in Section 12 EVENt command EVENt STATus MEASurement EVENt Read Measurement Event Register STATus OPERation EVENt Read Operation Event Register STATus QUEStionable EVENt Read Questionable Event Register Description These query commands are used to read the event registers After sending one of these commands and addressing the Model 2182 to talk a decimal value is sent to the computer The binary equivalent of this value determines which bits in the appropriate register are set The event registers are shown in Figure 15 4 Figure 15 5 and Figure 15 6 Note that reading an event register clears the bits in that register For example assume that reading the Measurement Event Register results in an acquired decimal value of 544 The binary equivalent is 0000001000100000 For this binary
179. e I 5 shows one Pulse Delta cycle for a Fixed output As shown the Model 6221 out puts a low pulse a high pulse and then another low pulse during every Pulse Delta cycle The pulse width is adjustable and is the same for all high and low pulses The cycle inter val is also adjustable and is based on the set number of power line cycles The Pulse Delta interval shown in Figure I 5 is set for 5 PLC power line cycles which is the default set ting After the set interval expires the next Pulse Delta cycle starts if pulse count is gt 1 Pulses are synchronized to the frequency of the power line voltage When Pulse Delta is started the three pulses low high and low are generated on the positive going edges of the first three power line cycles For the remaining power line cycles in the interval the output remains at the I Low level Sweep output The sweep feature of the Model 6221 can be used to output a series of pulses that allow the use of different levels for the high pulses Each high pulse returns to the programmed low pulse level The low level is the same for all pulses Like the Fixed output shown in Figure I 5 a Sweep output is synchronized to the fre quency of the power line voltage and the pulse width is adjustable and is the same for all pulses I 12 Delta Pulse Delta and Differential Conductance Figure I 5 Pulse timing I High I Low Power Line One Pulse Delta Cycle 5 8 Interval
180. e Mean of Buffer Readings status status CALL SEND 7 calc2 form mean status CALL SEND 7 calc2 stat on status CALL SEND 7 calc2 imm status reading SPACES 80 CALL ENTER reading PRINT reading 7 status Set buffer size to 20 Store raw input readings Start storing readings Request all stored readings Address 2182 to talk Display all buffer readings on CRT Select mean calculation Enable mean calculation Perform calculation and request result Address 2182 to talk Display all buffer readings on CRT Triggering 7 2 Triggering Trigger model Explains the various components of the front panel trigger model which controls the triggering operations of the instrument Reading hold Explains the Reading Hold feature which is used to screen out readings that are not within a specified reading window External triggering Explains external triggering which allows the Model 2182 to trigger other instruments and be triggered by other instruments SCPI programming Covers remote operation for triggering including the GPIB trigger model and the SCPI commands Triggering 7 3 Trigger model NOTE Additional information on measurement query commands to trigger and or return readings are provided in Section 13 and Appendix H The flowchart in Figure 7 1 summarizes triggering as viewed from the front panel It is called a trig
181. e Measurements 2 5 Performance considerations The following aspects of operation affect accuracy and speed Warm up After the Model 2182 is turned on it must be allowed to warm up for at least 2 hours to allow the internal temperature to stabilize After the warm up period an ACAL must be performed if the present internal temperature and TCAL differ by more than 1 C TCAL is the internal temperature reading stored for the last ACAL see ACAL ACAL calibration ACAL is a special front end gain calibration for the 10mV and 100V ranges It needs to be performed whenever the internal temperature and TCAL vary by more than 1 C TCAL is the internal temperature reading at the time of the last ACAL For example if ACAL was performed at 28 C and the internal temperature changes to 29 1 C another ACAL will be required to main tain specified accuracy The procedures to measure internal temperature and TCAL are located after the ACAL Procedure When the internal temperature and TCAL differ by more than 1 C Bit 9 in the Questionable Event Condition Register will set to indicate a questionable ACAL See Status structure in Section 11 for more information NOTE Do not confuse this partial calibration to be performed by the user with the com plete instrument calibration that is to be performed by a qualified service technician The complete calibration procedure is located in the Model 2182 Service Manual There are two
182. e current levels ImA 2mA and 5mA That test would require the following 12 point custom sweep to produce the six Delta measurements P0000 1mA P0001 1mA P0002 1mA P0003 1mA P0004 2mA P0005 2mA P0006 2mA P0007 2mA P0008 5mA P0009 5mA P0010 5mA P0011 mA The following procedure uses the SourceMeter as a bipolar fixed amplitude current source It outputs a 2 point custom sweep to provide current reversal that is required for Delta measurements by the Model 2182 NOTES When using the Model 2182 to perform Delta measurements RATE must be set to 1 PLC or 5 PLC to optimize measurement performance At 1 PLC or 5 PLC Delta measurements will cancel thermal EMFs to a 50nV level The SourceMeter SPEED must be set to FAST 0 01 PLC Using a slower speed will result in trigger synchronization problems with the Model 2182 The following procedure assumes SourceMeter firmware version C11 or later Step 1 Connect the Delta measurement test circuit Connect the SourceMeter and Model 2182 to the DUT as shown in Figure 5 3 Also connect a trigger link cable Model 8501 from the Model 2182 to the SourceMeter NOTE This procedure assumes that the Model 2182 is using the factory default Trigger Link line configuration Line 1 is VMC output Line 2 is EXT TRIG input Step2 Return the SourceMeter to BENCH defaults BENCH defaults are restored from the Main Menu which is accessed by pressing MENU M
183. e precision data format Figure 15 2 shows the specified the data string for each reading conversion is made up of three 32 bit data blocks Note that the data string for each reading conversion is preceded by a 2 byte header that is the binary equivalent of an ASCII sign and 0 Figure 15 2 IEE754 single precision data format 32 data bits Header Byte 1 Byte 2 Byte 3 Byte 4 bor od gd d d bor o d od d d bor o Pd ord J d Lor od od d Lor o d od d d bor od od id bor o od d bor od od gd EU ug ga seek dr Y tb Ebor ora ca FOE d d d 1430 7 d d d g bt 140 70 P d tet 0 130 70 rat tr I0 s sign bit 0 positive 1 negative e exponent bits 8 f fraction bits 23 Normal byte order shown For swapped byte order bytes sent in reverse order Header Byte 4 Byte 3 Byte 2 Byte 1 The Header is only sent once for each measurement conversion DREal selects the binary IEEE754 double precision data format and is shown in Figure 15 3 normal byte order shown This format is similar to the single precision format except that it is 64 bits long Figure 15 3 IEEE754 double precision data format 64 data bits Header Byte 1 Byte 2 i Byte 7 Byte 8 a o pP g og g bor o d Pg For o o gg bor o p Pg bog o og og bog d od J god Log og gg Lor o gd d gd 0 bog gd og gd bor o d od gd Lo gd og gg Lor o gd gg g
184. e shot reading DC volts no trigger fastest rate RST INITiate CONTinuous OFF ABORt SENSe FUNCtion VOLTage DC SENSe VOLTage DC RANGe 10 Use fixed range for fastest readings SENSe VOLTage DC NPLC 0 01 Use lowest NPLC setting for fastest readings DISPlay ENABle OFF Turn off display to increase speed SYSTem AZERO STATe OFF Disable autozero to increase speed but may cause drift over time SENSe VOLTage DC LPASs OFF Turn off analog filter for speed SENSe VOLTage DC DFILter OFF Turn off digital filter for speed TRIGger COUNt 1 READ Enter reading One shot reading DC volts bus trigger auto ranging RST INITiate CONTinuous OFF ABORt TRIGger SOURCe BUS SENSe FUNCtion VOLTage DC SENSe VOLTage DC RANGe AUTO ON TRIGger COUNt 1 INITiate TRG or GPIB GET command Triggers reading SENSe DATA FRESh Enter reading One shot reading external trigger auto delay enabled RST INITiate CONTinuous OFF ABORt TRIGger SOURce EXTernal TRIGger DELay AUTO ON Note Auto trigger delay only takes effect with trigger source set for BUS or EXTernal SENSe FUNCtion VOLTage DC SENSe VOLTage DC RANGe AUTO ON INITiate external trigger SENSe DATA FRESh Enter reading This step will time out if the trigger hasn t occurred H 6 Measurement Queries I Delta Pulse Delta and Differential Conductance l 2 Delta Pulse Delta and
185. e synchronization OFF For Low Charge Injection SENSe VOLTage SENSe Subsystem CHANnel2 LOMode lt b gt Enable or disable Low Charge Injection Mode for OFF Channel 2 see Pumpout current low charge injection mode for details Note After sending DONE the 2182 goes into the idle state An INITiate command is needed to trigger readings see Program Example 1 Voltage and Temperature Measurements 2 11 Programming examples ACAL Autozero and LSYNC Program Example 1 This program fragment performs low level ACAL NOTE After sending the following commands the DONE and INIT commands will not execute until calibration is completed CALL SEND 7 cal unpr acal init status Prepares 2182 for ACAL CALL SEND 7 cal unpr acal step2 status Performs low level ACAL CALL SEND 7 cal unpr acal done status Exits ACAL mode CALL SEND 7 init cont on status Starts continuous triggering Program Example 2 This program fragment disables autozero CALL SEND 7 syst azer off status Disables autozero Program Example 3 This program fragment enables line cycle synchronization CALL SEND 7 syst lsync on status Enables LSYNC Program Example 4 This program fragment enables low charge injection for Channel 2 CALL SEND 7 sens volt chan2 1qm on status Enables low charge injection 2 12 Voltage and Temperature Measurements Connections WARNING A haz
186. e the product for its intended function They must be trained in electrical safety procedures and proper use of the instrument They must be protected from electric shock and contact with hazardous live circuits Maintenance personnel perform routine procedures on the product to keep it operating properly for example setting the line voltage or replacing consumable materials Maintenance procedures are described in the manual The procedures explicitly state if the operator may perform them Otherwise they should be performed only by service personnel Service personnel are trained to work on live circuits and perform safe installations and repairs of products Only properly trained service personnel may perform installation and service procedures Keithley products are designed for use with electrical signals that are rated Measurement Category I and Measurement Category II as described in the International Electrotechnical Commission IEC Standard IEC 60664 Most measurement control and data I O signals are Measurement Category I and must not be directly connected to mains voltage or to voltage sources with high transient over voltages Measurement Category II connections require protection for high transient over voltages often as sociated with local AC mains connections Assume all measurement control and data I O connections are for connection to Category I sources unless otherwise marked or described in the Manual Exercise extreme cautio
187. e to configure the Model 2182 appropriately from the temperature configuration menu Temperature configuration menu The items of the temperature configuration menu are explained as follows UNITS Select the desired units designator for temperature readings C E or K SENS Select the thermocouple TCOUPLE to perform temperature measurements at the thermocouple The internal INTERNL sensor is used to measure the internal temperature of the Model 2182 TYPE Select the thermocouple type that you are using to measure temperature J K T E R S B or N JUNC Select INTRNL to reference measurements to the internal reference junction Select SIM to reference measurements to an external simulated reference After selecting SIM you will be prompted to enter the simulated reference temperature After pressing SHIFT and then TCOUP to access the menu use the following rules to configure temperature There are four menu items UNITS SENS TYPE and JUNC Along with each menu item the present option is displayed For example if C is the present units option then UNITS C is displayed Blinking characters indicate cursor position The cursor can be on a menu item name i e UNITS blinking or on an menu item option i e C blinking Cursor position is controlled by the lt q and f keys With the cursor on a menu item name you can use the amp or key to scroll through the other menu items Pressin
188. e with the type and rating listed If the instrument repeatedly blows fuses locate and correct the cause of the trouble before replacing the fuse See the Model 2182 Service Manual for troubleshooting information 3 Ifconfiguring the instrument for a different line voltage remove the line voltage selector from the assembly and rotate it to the proper position When the selector is installed into the fuse holder assembly the correct line voltage appears inverted in the window 4 Install the fuse holder assembly into the power module by pushing it in until it locks in place Table 1 1 Fuse ratings Line Voltage Fuse Rating Keithley P N 100 120V 220 240V 0 25A slow blow 5x20mm 0 125A slow blow 5x20mm FU 96 4 FU 91 Power up sequence On power up the Model 2182 performs self tests on its EPROM and RAM and momentarily lights all digit segments and annunciators If a failure is detected the instrument momentarily displays an error message and the ERR annunciator turns on Error messages are listed in Appendix B NOTE Ifa problem develops while the instrument is under warranty return it to Keithley Instruments Inc for repair If the instrument passes the self tests the firmware revision levels are displayed For example REV A01 A02 where AOI is the main board ROM revision A02 is the display board ROM revision After the power up sequence the instrument begins its normal
189. eading for Channel 2 voltage input Keep in mind that the Filter settings are applied to the input channels not on the result of Ratio The FILT key is operational while in Ratio Pressing FILT will either disable Filter for both channels or enable Filter for both channels FILT annunciator turns on However remember that even though Filter can be enabled for both channels only the Channel 1 Filter settings are used NOTE The filter configuration menu cannot be accessed while in Ratio To make filter configuration changes you must first disable Ratio This can be done by returning to Channel 1 press DCV1 Rel Relative considerations As explained in Section 3 a separate Rel value can be established for each voltage channel When Ratio is enabled any established Rel values are applied to the respective channels before the calculation is performed Ratio is calculated as follows Ratio Filt V1 V1 Rel Filt V2 V2 Rel where Filt V1 is the filtered reading for Channel 1 voltage input V1 Rel is the Rel value established for Channel 1 Filt V2 is the filtered reading for Channel 2 voltage input V2 Rel is the Rel value established for Channel 2 Ratio and Delta 5 5 NOTE The previous calculation shows Filter enabled If Filter is not used remove the Filt component from the calculation When Ratio is enabled the state on or off of the REL annunciator depends on which measurement function was last selecte
190. econd measurement is taken with the nanovoltmeter leads reversed as shown in Figure 2 13B The small voltage difference is calculated by averaging the absolute values of the two readings Calculation of standard deviation across several redundant readings will help provide this assurance Once stability has been achieved the actual voltage difference between the cells is measured For each comparison several readings are usually averaged This process of comparing is then repeated each week month or year depending upon the standards laboratory The results can then be plotted and compared over time Voltage and Temperature Measurements 2 27 Heated Zener Reference and Josephson Junction Array comparisons The performance of a Heated Zener Reference can be analyzed by comparing it to a Josephson Junction JJ Array using both channels of the Model 2182 In a cryogenic environment the JJ Array provides an output voltage in precise stable 175uV steps The test circuit for this application is shown in Figure 2 14 The JJ Array is adjusted until Channel 1 of the Model 2182 measures OV 10pV The null condition indicates that the Heated Zener Reference voltage is the same as the JJ Array voltage Channel 2 of the Model 2182 is used to determine the exact step that the JJ Array is on Channel 1 can then be monitored to study noise and drift characteristics of the Heated Zener Reference Figure 2 14 Heated Zener characterization Ee Jos
191. ections single channel voltage Cable to copper Cable to copper 2107 wire connection 2107 wire connection Input Cable one of two Input Cable one of three red HI 95 CH 1 ReaD loo black gt HI ar green CH2 DUT DCV2 LO T white 2182 Test Circuit 2182 Test Circuit A Channel 1 Measurements B Channel 2 Measurements Dual Channel Measurement Connections The dual channel feature of the Model 2182 allows you to make comparison measurements within a test circuit Figure 2 5A shows typical connections to make comparison measurements of two devices in a test circuit For this measurement configuration there is no voltage differential between the two measurement channels Channel 2 HI is connected directly to Channel 1 LO Figure 2 5B shows a measurement configuration that has a voltage differential between two channels The differential is the 2V drop across R Channel 1 measures voltage across DUT 1 and Channel 2 measures voltage across DUT 2 Internally the A D converter references Channel 2 measurements to Channel 1 LO For example if 1V is being input to Channel 2 and there is a 2V differential between the two channels 3V will be applied to the A D converter Therefore if Channel 2 is on the 1V range the 3V applied to the A D converter will cause it to overflow The 1V measurement on Channel 2 can only be performed on the 10V range Voltage and Temperature Measurements 2 15 Al
192. ed the instrument will leave the idle state SYSTem PRESet enables continuous initiation Therefore operation will immediately leave the idle state when it is sent The RCL 0 command will do the same if INITiation CONTInuous ON is a user saved default RST disables continuous initiation Therefore the instrument will remain in the idle state Either of the following two initiate commands will take the instrument out of the idle state INITiate NITiate CONTinuous ON NOTES While in remote pressing the LOCAL key restores continuous front panel operation When switching from the 152 language to the SCPI language the instrument will go into the idle state and stay there You can take the instrument out of idle by pressing the TRIG key or by sending an initiate command Triggering 7 15 Trigger model operation Once the instrument is taken out of idle operation proceeds through the trigger model down to the device action In general the device action includes a measurement and when stepping scanning closes the next channel Control source As shown in Figure 7 10 a control source is used to hold up operation until the programmed event occurs The control source options are as follows IMMediate Event detection is immediately satisfied allowing operation to continue MANual Event detection is satisfied by pressing the TRIG key The Model 2182 must be in LOCAL mode for it to respond to the TRIG key Press the LO
193. eese nene enne nennen COMMANG COGES PERRO Delta Pulse Delta and Differential Conductance Delta Pulse Delta and Differential Conductance measurements Test system configurations ciee ciiir rente da e ILI ene td Vega sna aedes Lan cu Delta measurement technique eese eee Pulse Delta 3 point measurement technique eee Pulse timing 1 ete ieri Ea ei EEA d Lo eo e Ma pd Pulse sweep output examples sees enne Differential Conductance measurement process esseeeee List of Tables 1 Table 1 1 Table 1 2 2 Table 2 1 Table 2 2 Table 2 3 3 Table 3 1 Table 3 2 Table 3 3 Table 3 4 4 Table 4 1 Table 4 2 5 Table 5 1 6 Table 6 1 7 Table 7 1 Table 7 2 8 Table 8 1 9 Table 9 1 Getting Started Da tating p 1 15 Factory derantis pee RX 1 17 Voltage and Temperature Measurements Measurement channels esses ener enne nnne nennen 2 3 SCPI commands ACAL Front Autozero Autozero LSYNC and Low Charge Injection essere nennen nnne nennen nnne 2 10 SCPI commands voltage and temperature measurements 2 20 Range Digits Rate and Filter SPCI commands Tan Be i es cientes near aiia pue aae 3 4 SPCIcommands digits 1 2 ern re eie tre RA 3 5 SCPI Commands fate iisisti e an vit oege Me cede pedi eda pepe us 3 7 SCPI comm
194. eing measured for Ratio the Filter state enabled or disabled and configuration for channel I DCV1 is used 3 12 Range Digits Rate and Filter SCPI programming filter NOTE All the filter commands are part of the SENSe Subsystem Table 3 4 SCPI commands filter Commands Description Default For DCV1 SENSe SENSe Subsystem VOLTage Volts function CHANnel1 Channel 1 DCV1 LPASs lt b gt Enable or disable analog filter OFF DFILter Configure and control digital filter WINDow n Specify filter window in 0 to 10 0 01 COUNt n Specify filter count 1 to 100 10 TCONtrol lt name gt Select filter type MOVing or REPeat MOVing STATe lt b gt Enable or disable digital filter ON For DCV2 SENSe SENSe Subsystem VOLTage Volts function CHANnel2 Channel 2 DCV2 LPASs lt b gt Enable or disable analog filter OFF DFILter Configure and control digital filter WINDow n Specify filter window in 0 to 10 0 01 COUNt n Specify filter count 1 to 100 10 TCONtrol lt name gt Select filter type MOVing or REPeat MOVing STATe lt b gt Enable or disable digital filter ON For TEMPI SENSe SENSe Subsystem TEMPerature Temperature function CHANnell Channel 1 TEMPI LPASs lt b gt Enable or disable analog filter OFF DFILter Configure and control digital filter WINDow n Specify filter window in 0 to 10 0 01 COUNt n Specify filter count 1 to 100
195. emp status Select TEMP2 CALL SEND 7 sens data fres status Request a fresh reading reading SPACES 80 CALL ENTER reading length 7 status Address 2182 to talk PRINT reading Display reading on CRT 2 22 Voltage and Temperature Measurements Low level considerations For sensitive measurements external considerations beyond the Model 2182 affect accuracy Effects not noticeable when working with higher voltages are significant in nanovolt signals The Model 2182 reads only the signal received at its input therefore it is important that this signal be properly transmitted from the source Two principal factors that can corrupt measurements are thermal EMFs and noise induced by AC interference NOTE More detailed information on thermal EMFs and other factors that affect low level measurements are explained in Appendix C Also for comprehensive information on low level measurements see the Low level measurements handbook which is available from Keithley Thermal EMFs Thermal EMFs thermoelectric potentials are generated by thermal differences between the junctions of dissimilar metals These voltages can be large compared to the signal that the Model 2182 is trying to measure Thermal EMFs can cause the following conditions Instability or zero offset that is above acceptable levels The reading is sensitive to and responds to temperature changes This effect can be demonstrated by touch
196. en the measurement process starts with the positive going zero crossing Figure 2 1 Line cycle synchronization 1 PLC Reading Reading Trigger Done Trigger Done 1 2 A D A D A D A D Conversion Conversion Conversion Conversion Phase A Phase B Phase A Phase B Voltage and Temperature Measurements 2 9 Perform the following steps to enable or disable line cycle synchronization 1 Press SHIFT and then LSYNC to display the present state of line synchronization OFF or ON 2 Use A or V key to display ON or OFF 3 Press ENTER The instrument returns to the normal display state NOTE Line cycle synchronization is not available for integration rates 1 PLC regardless of the LSYNC setting Pumpout current low charge injection mode Pumpout current for Channel 1 is very low 0 5uA peak to peak and therefore does not adversely affect instrument performance Channel 2 can make the same claim as long as Channel 2 LO is connected to Channel 1 LO This pumpout current is due to internal switch transitions and occurs between A D conversions Settling for the transition occurs on the next A D conversion Whenever the impedance between Channel 2 LO and Channel 1 LO is gt 100kQ pumpout current could be high enough to corrupt measurements below 1V Above 1V measurements pumpout current is not significant Low Charge Injection Mode If you must use Channel 2 for measurements below 1V and the impedance be
197. ephson Junction Array 2 28 Voltage and Temperature Measurements 3 Range Digits Rate and Filter 3 2 Range Digits Rate and Filter Range Provides details on measurement range selection for DCV1 and DCV2 Includes the SCPI commands for remote operation Digits Provides details on selecting display resolution for voltage and temperature measurements Includes the SCPI commands for remote operation e Rate Provides details on reading rate selection Includes the SCPI commands for remote operation Filter Provides details on Filter configuration and control Includes the SCPI commands for remote operation Range Range Digits Rate and Filter 3 3 The selected range affects both accuracy of the voltage measurement as well as the maximum voltage that can be measured The DCV1 function has five measurement ranges 10mV 100mV 1V 10V and 100V The DCV2 function has three measurement ranges 100mV 1V and 10V The range setting fixed or AUTO is remembered by each voltage function NOTE The available voltage ranges for Ratio VI V2 depend on which channel is presently selected when Ratio is enabled If Channel 1 is presently selected DCVI ranges will be available when Ratio is enabled If Channel 2 is presently selected DCV2 ranges will be available when Ratio is enabled Complete information on ranging for Ratio is provided in Section 5 There is no range selection for temperature TEMP1 an
198. erage Voltage and Power Average Voltage calculation Average Voltage is the average bias voltage that was present across the device when the corresponding Differential Conductance reading was taken For remote operation the Average Voltage reading for Differential Conductance can be included in the returned data string Average Voltage is calculated as follows X Y Z Y M AvgVolt a 2 AvgVolt MILL Where AvgVolt is the Average Voltage corresponding to a given the differential voltage dV reading X Y and Z are the three A D measurements for the dV reading I 18 Delta Pulse Delta and Differential Conductance Power calculation With WATTS power measurement units selected power for Differential Conductance is calculated using Average Voltage see Average Voltage calculation and Average Cur rent Average Current is calculated by the Model 622x as follows X Y Z Y a R AvgCurr E NEUE P 5 2 AvgCurr mre TRE Where AvgCurr is the Average Current corresponding to a given Differential Conductance reading X Y and Z are the three current levels for the Differential Conductance reading With Average Voltage and Average Current known calculated by the Model 622x power is then calculated as follows Power AvgVolt x AvgCurr Index Symbols CLS Clear Status 12 3 ESE Event Enable 12 4 ESE Event Enable Query 12 4 ESR Event Status Reg
199. ered in Section 5 Autozero When Autozero for the second amplifier is disabled the offset gain and internal reference temperature measurements are not performed This increases measurement speed a few at 1 PLC However the zero gain and temperature reference points will eventually drift resulting in inaccurate readings for the input signal It is recommended that Autozero only be disabled for short periods of time When Autozero is enabled after being off for a long period of time the internal reference points will not be updated immediately This will initially result in inaccurate measurements especially if the ambient temperature has changed by several degrees A faster update of reference points can be forced by setting a faster integration rate Rate With Autozero disabled pressing the front panel RATE key will change the speed setting and will also enable Autozero Rate changes using remote programming have no effect on the state of Autozero To force a single rapid update of the internal reference points when Autozero is enabled set the integration rate to FAST or 0 01 PLC for remote programming and then back to the desired rate 1 e MED 1 0 PLC Details on Rate are covered in Section 3 2 8 Voltage and Temperature Measurements Controlling autozeroing modes For front panel operation the two autozeroing modes are controlled from the SHIFT gt CONFIG menu as follows NOTE For remote programming the co
200. ernal stepping Settings Overview Operation When the SCAN key is pressed operation proceeds to Device Action where a measurement on Channel 2 is performed The sample counter is decremented to 4 causing operation to loop back to Device Action for a measurement on Channel 1 Operation loops back to Device Action three more times to complete the scan cycle After the scan cycle the trigger counter is decremented to 1 and an output trigger is sent Operation loops back to the control source where it immediately falls through and repeats the five measurement scan An output trigger is again sent and the instrument then goes into the idle state Control Source Immediate timer off Delay Auto Channel 1 Count 4 Reading Count 10 A Reading Count of ten sets the Trigger Counter in Figure 9 2 to 10 A total of ten measurements will be performed and stored in the buffer The 1st and 6th measurements will be performed on Channel 2 and the rest will be performed on Channel 1 When the STEP key is pressed operation proceeds to Device Action where a measurement on Channel 2 is performed An output trigger is sent and the Trigger Counter is decremented to 9 Operation then loops back to Device Action four more times to perform four measurements on Channel 1 Note that an output trigger is sent after every measurement At this point the Trigger Counter is set to 5 Operation continues to loop until Channel 2 is again measured one
201. ersely when unmasked a set summary bit in the Status Byte Register sets bit B6 A Status Summary Message bit in the Status Byte Register is masked when the corresponding bit in the Service Request Enable Register is cleared 0 When the masked summary bit in the Status Byte Register sets it is ANDed with the corresponding cleared bit in the Service Request Enable Register The logic 616 output of the AND gate is applied to the input of the OR gate and thus sets the MSS RQS bit in the Status Byte Register The individual bits of the Service Request Enable Register can be set or cleared by using the SRE NRf common command To read the Service Request Enable Register use the SRE query command The Service Request Enable Register clears when power is cycled or a parameter n value of zero is sent with the SRE command SRE 0 Serial poll and SRQ Any enabled event summary bit that goes from 0 to 1 will set RQS and generate a service request SRQ In your test program you can periodically read the Status Byte Register to check if a service request SRQ has occurred and what caused it If an SRQ occurs the program can for example branch to an appropriate subroutine that will service the request Typically service requests SRQs are managed by the serial poll sequence of the Model 2182 If an SRQ does not occur bit B6 RQS of the Status Byte Register will remain cleared and the program will simply proceed normally after the seri
202. esponse to the STB command indicates the status of any set bits with corresponding enable bits set The Request for Service RQS bit sent in response to a serial poll indicates which device was requesting service by polling on the SRQ line For a description of the other bits in the Status Byte Register see Section 12 Common Commands 11 20 Remote Operation The IEEE 488 2 standard uses the STB common query command to read the Status Byte Register When reading the Status Byte Register using the STB command bit B6 is called the MSS bit None of the bits in the Status Byte Register are cleared when using the STB command to read it The IEEE 488 1 standard has a serial poll sequence that also reads the Status Byte Register and is better suited to detect a service request SRQ When using the serial poll bit B6 is called the RQS bit Serial polling causes bit B6 RQS to reset Serial polling is discussed in more detail later in this section Any of the following operations clear all bits of the Status Byte Register Cycling power Sending the CLS common command NOTE The MAV bit may or may not be cleared Service request enable register This register is programmed by you and serves as a mask for the Status Summary Message bits BO B2 B3 B4 B5 and B7 of the Status Byte Register When masked a set summary bit in the Status Byte Register cannot set bit B6 MSS RQS of the Status Byte Register Conv
203. f readings to store in 2182 s buffer The 2 accounts for positive and negative steps DIM DataCH2 CalcReadings array represents total number of channel 2 readings DIM DataCH1 CalcReadings array represents total number of channel 1 readings FOR i 1 TO CalcReadings allocates space for each channel reading DataCH2 i SPACES 18 DataCH1 i SPACE 18 NEXT i CODE for Parsing single string of buffer response into 48 individual readings OneReading SPACES 20 represents 1 reading from buffer string response OneCharacter SPACES 2 represents 1 character from buffer string response 9 18 Stepping and Scanning AsciiRdgsBuf SPACE 18 NumRdgs represents the string of buffer response DIM Readings 1 TO NumRdgs array of the 48 individual readings in numerical representation form converted from ASCII CALL send Addr TRACE DATA status ask 2182 for the buffer response CALL enter AsciiRdgsBuf length Addr status read in buffer response Start Parsing the data readings ParseLength 1 represents how many characters to extract from response string CurrentPosition 1 represents which character on in response string OneReading clear out string contents ReadingOn 1 represents the individual reading on DO OneCharacter MID AsciiRdgsBuf CurrentPosition ParseLength above line reads in the next character for the buffer response IF OneCha
204. f these registers Figure 11 9 Status byte and service request Status Summary Messages 7 Read by Serial Poll Service ROS Request STB OSB B6 ESB MAV QSB EAV MSB Status Byte Generation Serial Poll B7 We B5 BO Register A 7 Read by STB 6 amp La amp OR a lt SRE OSB ESB MAVIQSB EAV MSB Service SRE B7 B6 B5 B4 B3 B2 BD BO Request Enable Register OSB Operation Summary Bit amp Logical AND MSS Master Summary Status OR Logical OR RQS Request for Service ESB Event Summary Bit MAV Message Available QSB Questionable Summary Bit EAV Error Available MSB Measurement Summary Bit Status byte register The summary messages from the status registers and queues are used to set or clear the appropriate bits BO B2 B3 B4 B5 and B7 of the Status Byte Register These bits do not latch and their states 0 or 1 are solely dependent on the summary messages 0 or 1 For example if the Standard Event Status Register is read its register will clear As a result its summary message will reset to 0 which in turn will clear the ESB bit in the Status Byte Register Bit B6 in the Status Byte Register is one of the following The Master Summary Status MSS bit sent in r
205. figuration menu cannot be accessed while in Delta To make filter configuration changes you must first disable Delta This can be done by selecting Channel 1 press Delta 5 16 Ratio and Delta SCPI programming ratio and delta Table 5 1 SCPI commands ratio and delta Commands Description Default SENSe 1 SENSe Subsystem FUNCtion lt name gt Select voltage function VOLTage VOLT CHANnel chan Select range control channel 1 or 2 VOLTage DC Path to configure DC volts RATio lt b gt Enable or disable Ratio V1 V2 OFF DELTa lt b gt Enable or disable Delta Not valid with OFF TEMP or TEMP selected SYSTem FAZero STATe lt b gt Enable or disable Front Autozero To double ON the speed of Delta disable Front Autozero Note Enabling Ratio disables Delta and conversely enabling Delta disables Ratio Programming examples Ratio programming example The following program fragment enables Ratio and displays the result on the computer CRT CALL SEND 7 CALL SEND 7 CALL SEND 7 CALL SEND 7 r reading SPAC u u u u sens volt func volt status sens volt chan 1 status sens volt ratio status sens data fresh status ES 80 CALL ENTER reading length 7 status PRINT reading Select voltage function Select Channel 1 DCV1 for range control Enable Ratio Request a fresh reading Address 2182 to talk Display
206. figuring the custom sweep 10nA would be assigned to the first 10 points of the sweep 20uA would be assigned to the next 10 points and 50uA would be assigned to the last 10 points Therefore the custom sweep in Figure 5 11 would be made up of 30 points PO through P29 The procedure to use the SourceMeter and Model 2182 to perform Delta measurements is provided in Delta measurement procedure using a SourceMeter That procedure presented earlier in this section under Delta uses a 2 point custom sweep and will have to be modified for this application as follows This application uses two Model 2182s Therefore both nanovoltmeters must be configured exactly the same InStep 3 ofthe procedure change the Trigger Count to equal the number of points in the custom sweep For example if using the 30 point custom sweep in Figure 5 11 set the Trigger Count to 30 InStep 5 assign current values to the sweep points For the example 30 point sweep the current values for points PO through P29 are shown in Figure 5 11 InStep 7 enable line synchronization on both Model 2182s To access control press SHIFT and then LSYNC NOTE Optimum synchronization among all instruments is achieved when Model 2182 line synchronization is enabled and autozero is disabled Autozero cannot be disabled from the front panel of the Model 2182 When controlling this application over the bus use the following commands for the Model 2182s SYSTem L
207. filter The digital filter is used to stabilize noisy measurements The displayed stored or transmitted reading is a windowed average of a number of reading conversions from 1 to 100 Digital filter characteristics In general the digital filter places a specified number of A D conversions Filter Count into a memory stack These A D conversions must occur consecutively within a selected reading window Filter Window The readings in the stack are then averaged to yield a single filtered reading The stack can be filled in two ways Filter Type moving or repeating The moving filter keeps adding and removing a single A D conversion from the stack before taking the average while the repeating filter only averages a stack that is filled with new A D conversions Details on digital filter characteristics are provided as follow Filter count The filter count specifies how many consecutive A D conversions within the filter window to place in the memory stack When the stack is full the A D conversions are averaged to calculate the final filtered reading The filter count can be set from 1 to 100 Note that with a filter count of 1 no averaging is done However only readings within the filter window will be displayed stored or transmitted Range Digits Rate and Filter 3 9 Filter window The digital filter uses a window to control filter threshold As long as the input signal remains within the selected window A D conversion
208. from other suppliers as long as they are equivalent to the original component Note that selected parts should be purchased only through Keithley Instruments to maintain accuracy and functionality of the product If you are unsure about the applicability of a replacement component call a Keithley Instruments office for information To clean an instrument use a damp cloth or mild water based cleaner Clean the exterior of the instrument only Do not apply cleaner directly to the instrument or allow liquids to enter or spill on the instrument Products that consist of a circuit board with no case or chassis e g data acquisition board for installation into a computer should never require cleaning if handled accord ing to instructions If the board becomes contaminated and operation is affected the board should be returned to the factory for proper cleaning servicing Table of Contents 1 Getting Started General 1Dformatlon eete re tette ore a d er er PPP ERES RR Cade aep te e raras 1 3 Warranty information eee tette a iiiad tee ka snae ena nun 1 3 Contact Informati e 1 3 Safety symbols and terms 1 aset eeepc nde eaae neben us 1 3 Incun m 1 3 Options and ACCESSOTIES 1 accepi ettet e ed cte dd eaae epe iaa espe etae n 1 4 Nanovoltmeter feat res 1 2 etre etie t perte ie He aeei eN ii ER UHR cea d ud 1 6 Front and rear panel familiarization
209. g ENTER will select the displayed option and move on to the next menu item or exit if at end of menu With the cursor on a menu item option you can use the amp or W key to display one of the other options for that menu item Pressing ENTER will select the displayed option and move on to the next menu item or exit if at end of menu An exception is the SIM menu item After selecting SIM you will be prompted to enter the simulated temperature Use the arrow keys to display the value and press ENTER Pressing EXIT leaves the menu and returns to the normal display state Voltage and Temperature Measurements 2 19 Measuring voltage and temperature NOTES The following procedure assumes factory default conditions see Table 1 2 in Section 1 Details on using other settings and front panel operations are provided in Section 3 through Section 8 of this manual Any time the internal temperature of the Model 2182 changes by 1 C or more the 10mV and 100V ranges will need to be calibrated see Performance considerations ACAL procedure for details Whenever the LEMO connector of the Model 2107 Input Cable or customized cable is disconnected from the input of the Model 2182 for a long period of time the input connectors will have to be cleaned to remove oxidation see Cleaning input connectors in Section 1 Do not use both channels to measure temperature The electrical connection between the two thermocouples will cause erratic tempera
210. g limit values 8 4 Setting line voltage and replacing fuse 1 15 Shielding C 8 Sorting resistors 8 7 Source resistance noise C 4 SourceMeter 5 10 5 14 9 14 Specifications A 1 Speed vs noise characteristics 3 6 Standard cell comparisons 2 26 Status and Error Messages B 1 Status and error messages 1 16 STATus command summary 14 11 Status structure 11 13 STATus subsystem 15 7 Step Scan configuration 9 7 Step Scan overview 9 3 Stepping and Scanning 9 1 Stepping Scanning controls 9 6 Stepping Scanning examples 9 8 Store 6 2 Storing readings in buffer E 6 SYSTem command summary 14 12 Taking readings using the READ command E 7 Temperature configuration 2 18 Temperature configuration menu 2 18 Temperature only connections 2 15 Test systems I 5 Testing superconductor materials 5 19 Testing switch contacts 2 24 Thermal EMFs 2 22 Thermoelectric generation C 3 Thermoelectric potentials C 2 TRACe command summary 14 12 Trigger command summary 14 13 Trigger model 7 3 Trigger model remote operation 7 13 Trigger model operation 7 15 trigger synchronization 5 14 Triggering 7 1 Triggering commands 7 16 Typical command sequences F 11 Unaddress commands F 9 UNIT command summary 14 14 Voltage and temperature connections 2 16 Voltage and Temperature Measurements 2 1 Voltage measurements 2 3 Voltage only connections 2 14 Voltmeter complete 7 8 Warm up 2 5 Warranty information 1 3 Service Form Mode
211. g output 2 TRIGGER LINK Eight pin micro DIN connector for sending and receiving trigger pulses among connected instruments Use a trigger link cable or adapter such as Models 8501 1 8501 2 8502 and 8503 3 RS 232 Connector for RS 232 operation Use a straight through not null modem DB 9 shielded cable 4 IEEE 488 Connector for IEEE 488 GPIB operation Use a shielded cable such as the Models 7007 1 and 7007 2 5 Power Module Contains the AC line receptacle power line fuse and line voltage setting The instrument can be configured for line voltages of 100V 120V 220V 240VAC at line frequencies of 45Hz to 66Hz or 360Hz to 440Hz Getting Started 1 13 Cleaning input connectors The two channel LEMO connector on the front panel is used to connect the Model 2182 to external test circuits This connector mates to the LEMO connector on the Model 2107 input cable or to the LEMO connector that is included with the Model 2182 KIT The contacts of the LEMO connectors are made of copper These copper to copper connections minimize thermal EMFs However exposed copper is susceptible to oxidation which could cause measurement errors A small bottle of DeoxIT is supplied with the Model 2182 This fluid is used to remove oxidation from copper Before connecting a LEMO connector to the LEMO input connector on the instrument clean the copper contacts of the connectors as follows 1 Turn off the Model 2182 and at the rear pane
212. ger model because it is modeled after the SCPI commands used to control triggering Note that for stepping and scanning the trigger model has additional control blocks These are described in Section 9 NOTE The complete trigger model which is based on bus operation is shown and discussed later in this section see SCPI programming triggering Keep in mind that there is only one trigger model The ones shown Figure 7 1 and in Section 9 are abbreviated versions to illustrate front panel operation Figure 7 1 Front panel trigger model without Stepping Scanning C ue D Y Control Event Source Detection Immediate External y Output Delay Trigger Device Action Idle The instrument is considered to be in the idle state whenever it is not performing any measurements or scanning operations From the front panel the unit is considered idle at the end of a step or scan operation when the reading for the last channel remains displayed To restore triggers press SHIFT and then HALT Once the Model 2182 is taken out of idle operation proceeds through the trigger model 7 4 Triggering Control source and event detection The control source holds up operation until the programmed event occurs and is detected The control sources are described as follows Immediate With this control source event detection is immediately satisfied allowing operation to conti
213. ger model will invalidate any old readings and trigger a new one This query will wait for a new reading to become available before the instrument sends a result back Measurement Queries H 3 Limitations This command won t work if the trigger source is set for BUS or EXTERNAL This will cause a 214 Trigger deadlock error Under this condition one should use a FETCh query or a DATA FRESh query see page H 4 If the trigger model is continuously initiating CINIT CONT ON sending this query may cause a 213 Init ignored error but will still give a new reading When appropriate If the Model 2182 receives a RST command then it defaults to INIT CONT OFF TRIG SOUR IMM and TRIG COUNT 1 Sending a READ query under these conditions will trigger a new reading MEASure function What it does This query will reconfigure the instrument to the function specified in the query set the trigger source for immediate set the trigger count to 1 and configure the measurement parameters to RST defaults It will then trigger a single reading and return the result Limitations This query is much slower than a READ or FETCh query because it has to reconfigure the instrument each time it is sent It will reset the NPLC autoranging and averaging to default settings When appropriate This is an ideal command for taking one shot measurements if the default settings for a measurement
214. gnored C INITiate CONTinuous With continuous initiation enabled you cannot use the READ command or set sample count SAMPle COUNTt greater than one D FETch See Section 13 for details on this Signal Oriented Measurement Command E READ Use this one query command to perform the tasks of the three commands See Section 13 for details on this Signal Oriented Measurement Command F TRIGger SOURce With the timer control source selected use the TRIGger TIMer command to set the interval G DELay AUTO Auto delay period is 5msec for the 100V range and 1msec for all other voltage ranges Disabling auto delay sets the delay time to 0 H TRIGger SIGNal Send this action command to bypass the control source when you do not wish to wait for the programmed event to occur The instrument must be waiting at the control source for the event when this command is sent Otherwise an error occurs and the command is ignored I SAMPle COUNt A sample count gt 1 specifies how many readings will automatically be stored in the buffer However with continuous initiation enabled you cannot set the sample count greater than one J SENSe HOLD See Reading hold autosettle located in this section for details on using Hold Programming example The following program fragment triggers and stores in the buffer 10 readings which are then displayed on the computer CRT CALL SEND 7 rst status Restore RST defaults
215. h B15 are not shown since they are not used ent Bit Set Events PON Power On ent Bit Cleared URQ User Request CME Command Error EXE Execution Error DDE Device Dependent Error QYE Query Error OPC Operation Complete Value 1 Ev 0 2 Ev IDN Identification Query Read the identification code Description The identification code includes the manufacturer model number serial number and firmware revision levels and is sent in the following format KEITHLEY INSTRUMENTS INC MODEL 2182 xxxxxxx yyyyy zzzzz Where xxxxxxx is the serial number yyyyy zzzzz is the firmware revision levels of the digital board ROM and display board ROM 12 8 Common Commands OPC Operation Complete Set the OPC bit in the standard event register after all pending commands are complete Description After the OPC command is sent the Operation Complete bit bit BO of the Standard Event Status Register will set immediately after the last pending command is completed If the corresponding bit bit BO in the Standard Event Enable Register and Bit 5 Event Summary Bit of the Service Request Enable Register is set the ROS MSS Request for Service Master Summary Status bit in the Status Byte Register will set When used with the immediate initiation command INITiate the OPC bit in the Standard Event Status Register will not set until the Model 2182 goes back into the idle state The INIT command operation is not con
216. he Event Summary Bit ESB in the Status Byte Register Conversely when a standard event is unmasked enabled the occurrence of that event sets the ESB bit For information on the Standard Event Register and descriptions of the standard event bits see the following section A cleared bit 0 in the enabled register prevents masks the ESB bit in the Status Byte Register from setting when the corresponding standard event occurs A set bit 1 in the enable register allows enables the ESB bit to set when the corresponding standard event occurs The Standard Event Enable Register is shown in Figure 12 1 and includes the decimal weight of each bit The sum of the decimal weights of the bits that you wish to be set is the parameter value that is sent with the ESE command For example to set the CME and QYE bits of the Standard Event Enable Register send the following command ESE 36 Where CME bit B5 Decimal 32 QYE bit B2 Decimal _4 lt NRf gt 36 ll Il Common Commands 12 5 If a command error CME occurs bit B5 of the Standard Event Status Register sets If a query error QYE occurs bit B2 of the Standard Event Status Register sets Since both of these events are unmasked enabled the occurrence of any of them causes the ESB bit in the Status Byte Register to set Read the Standard Event Status Register using the ESE query command Figure 12 1 Standard event enable register Bit Position Event Decima
217. he reduction is related to the square root of the change in temperature For example to cut the noise in half the temperature must be decreased from 293K to 73 25K a four fold decrease C 6 Measurement Considerations Magnetic fields When a conductor loop cuts through magnetic lines of force a very small current is generated This phenomenon will frequently cause unwanted signals to occur in the test leads of a test system If the conductor has sufficient length or cross sectional area even weak magnetic fields such as those of the earth can create sufficient signals to affect low level measurements Three ways to reduce these effects are 1 reduce the lengths of the connecting cables 2 minimize the exposed circuit area and 3 change the orientation of the leads or cables In extreme cases magnetic shielding may be required Special metal with high permeability at low flux densities such as mu metal are effective at reducing these effects Even when the conductor is stationary magnetically induced signals may still be a problem Fields can be produced by various sources such as the AC power line voltage Large inductors such as power transformers can generate substantial magnetic fields so care must be taken to keep the Model 2182 voltage source and connecting cables a good distance away from these potential noise sources Radio frequency interference RFI Radio Frequency Interference is a general term used to describe e
218. he serial poll byte is read or all the conditions that caused SRQ have ceased to exist Remote Operation 11 13 LOCAL key The LOCAL key cancels the remote state and restores local operation of the instrument Pressing the LOCAL key also turns off the REM indicator and returns the display to normal if a user defined message was displayed If the LLO Local Lockout command is in effect the LOCAL key is also inoperative Status structure See Figure 11 4 for the Model 2182 s status structure Instrument events such as errors are monitored and manipulated by four status register sets Notice that these status register sets feed directly into the Status Byte Register More detailed illustrations of these register sets are provided in Figure 11 5 through Figure 11 9 NOTE The status structures registers are configured and controlled by STATus Subsystem commands see Section 15 and Common Commands see ESE ESR SRE and STB in Section 12 11 14 Remote Operation Figure 11 4 Model 2182 status model structure Questionable Condition Register Questionable Questionable Event Event Enable Register Register 1 e 6660 o000 Always Zero Standard Event Status Register Operation Complete Output Queue Standard Event Status Enable Register Query Error Device Specific Error Execution Error Command Error User Request Powe
219. her instruments to which the commands are given Device operation is categorized into three operators controller talker and listener The controller controls the instruments on the bus The talker sends data while a listener receives data Depending on the type of instrument any particular device can be a talker only a listener only or both a talker and listener Figure F 1 IEEE 486 bus configuration DEVICE 1 ABLE TO TALK LISTEN AND CONTROL COMPUTER DEVICE 2 ABLE TO TALK AND LISTEN 2182 DEVICE 3 ONLY ABLE TO LISTEN PRINTER DEVICE 4 ONLY ABLE TO TALK IEEE 488 Bus Overview F 3 TO OTHER DEVICES DATA BUS DATA BYTE TRANSFER CONTROL GENERAL INTERFACE MANAGEMENT DIO 1 8 DATA 8 LINES DAV NRFD HANDSHAKE NDAC IFC ATN RUS SRQ MANAGEMENT REN EOI There are two categories of controllers system controller and basic controller Both are able to control other instruments but only the system controller has the absolute authority in the system In a system with more than one controller only one controller may be active at any given time Certain protocol is used to pass control from one controller to another The IEEE 488 bus is limited to 15 devices including the controller Thus any number of talkers and listeners up to that limit may be present on the bus at one time Although several devices may be commanded to listen simultaneously the bus can have only o
220. hms Q symbol MUNits Query units PERCent lt NRf gt Set target value for PERcent math calculation 1 ACQuire Use input signal as target value PERCent Query target value for PERcent math calculation STATe lt b gt Enable or disable KMATh calculation OFF v STATe Query state of KMATh calculation V DATA Path to acquire calculation result v LATest Return last calculation result V FRESh Trigger a reading and return the calculation result v CALCulate2 Path to configure and control math calculations on Sec 6 V buffer data FORMat lt name gt Select math calculation MEAN SDEViation NONE V MAXimum MINimum or NONE FORMat Query math calculation V STATe lt b gt Enable or disable math calculation OFF v STATe Query state of math calculation V DATA Read result of Calc2 v QMMediate Recalculate using raw input data in buffer v MMediate Recalculate and return result of Calc2 v CALCulate3 Path to configure and control limit testing Sec8 V LIMit 1 Limit 1 Testing v UPPer Configure upper limit v DATA n Specify limit 100e6 to 100e6 1 v DATA Query upper limit v LOWer Configure lower limit v DATA n Specify limit 100e6 to 100e6 1 v DATA Query lower limit V STATe lt b gt Enable or disable Limit test OFF v STATe Query state of Limit 1 test v FAIL Return result of Limit 1 test 0 pass or 1 fail V v CLEar Clear test results
221. ices Internal Scanning Scan the two input channels of the Model 2182 External Scanning Scan the channels or matrix points of Keithley Model 7001 7002 switching cards Setup Storage Two instrument setups user and factory defaults can be saved and recalled Analog Output With analog output gain set to one a full range input will result in a 1V analog output Remote Interface The Model 2182 can be controlled using the IEEE 488 interface GPIB or the RS 232 interface GPIB Programming Language When using the GPIB the instrument can be programmed using the SCPI or Model 182 DDCs programming language Closed cover Calibration The Model 2182 can be calibrated from either the front panel or the GPIB Getting Started 1 7 Front and rear panel familiarization Front panel summary The front panel of the Model 2182 is shown in Figure 1 1 This figure includes important abbreviated information that should be reviewed before operating the instrument Figure 1 1 Model 2182 front panel KEITHLEY CHANNEL 1 CHANNEL 2 2182 NANOVOLTMETER 120V MAX MX B VrV LSYNC TYPE OUTPUT Agut TCOUPL 00000000 2 DELAY HOLD GRE i AUTO Ex TRIG TRIG STORE neca RECALL VALUE ON OFR Gis E HALT E 232 ca TEST RANGE PIB RS step SCAN Gaia bum pies RATE CEXiT_j ENTER D G G 12V MAX 350V PEAK ANY TERMINAL TO CHASSIS N
222. ickBASIC 4 5 and CEC PC488 interface card Edit the following line to where the QuickBASIC libraries are on your computer SINCLUDE c qb45 ieeeqb bi Initialize the CEC interface as address 21 CALL initialize 21 0 Reset the SENSel subsystem settings along with the trigger model each READ will cause one trigger CALL SEND rst status Set DCV1 for 100V range and DCV2 for 10Vrange CALL SEND 7 sens volt chanl rang 100 status CALL SEND 7 sens volt chan2 rang 10 status Switch to DCV2 Channel 2 volts and take reading CALL SEND 7 sens func volt status CALL SEND 7 sens chan 2 read status reading SPACES 80 CALL ENTER reading length 7 status PRINT reading Switch to DCV1 Channel 1 volts and take reading CALL SEND 7 sens func volt status CALL SEND 7 sens chan 1 read status reading SPACES 80 CALL ENTER reading length 7 status PRINT reading E 4 Example Programs One shot triggering Other voltmeters generally have two types of triggering one shot and continuous In one shot each activation of the selected trigger source causes one reading In continuous the voltmeter is idle until the trigger source is activated at which time it begins taking readings at a specified rate Typical trigger sources are EEE 488 talk JEEE 488 Group Execute Trigger GET X command External trigger rear panel BNC Arming the instrument
223. ify reference Rel value for Channel 2 0 Sec 4 328 to 3310 STATe lt b gt Enable or disable Rel OFF STATe Query state of Rel ACQuire Use the voltage on Channel 2 as Rel REFerence Query Rel value LPASs Control analog filter for TEMP2 Sec 3 STATe lt b gt Enable or disable analog filter OFF STATe Query state of analog filter DFILter Configure and control digital filter Sec 3 WINDow lt n gt Specify filter window in 0 to 10 0 01 WINDow Query filter window COUNt lt n gt Specify filter count 1 to 100 10 COUNt Query filter count TCONtrol lt name gt Select filter type MOVing or REPeat MOVing TCONtrol Query filter type STATe b Enable or disable digital filter ON STATe Query state of digital filter SCPI Reference Tables 14 11 Table 14 8 STATus command summary Default Command Description Parameter Ref SCPI STATus Note 1 Sec 15 MEASurement Measurement event registers EVENt Read the event register Note 2 ENABle lt NRf gt Program the enable register Note 3 ENABle Read the enable register CONDition Read the condition register OPERation Operation event registers EVENt Read the event register Note 2 ENABle lt NRf gt Program the enable register Note 3 ENABle Read the enable register CONDition Read the condition register QUEStionable Questionable event registers EVENt Read the event register
224. ill be loaded with that same reading Each subsequent valid reading will then displace one of the loaded readings in the stack The FILT annunciator will flash until 10 new readings fill the stack NOTE _ Bit 8 of the Operation Event Status Register sets when the filter window has properly settled See Status structure in Section 11 for details Range Digits Rate and Filter 3 11 Filter control and configuration The FILT key toggles the state of the Filter When the Filter is enabled the FILT annunciator is on When disabled the FILT annunciator is off The analog and digital filters can be configured while the Filter is enabled or disabled Perform the following steps to configure the Filter 1 oa 10 11 12 Select the desired function DCV1 DCV2 TEMPI or TEMP2 Press SHIFT and then TYPE The present state of the analog filter on or off is dis played If you wish to change the state of the analog filter place the cursor on ON or OFF and press the RANGE A or key Note that the cursor is controlled by the lt q and p gt keys Press ENTER The present state of the digital filter on or off is displayed If you wish to change the state of the digital filter place the cursor on ON or OFF and press the RANGE A or V key Press ENTER The present digital filter window 0 01 0 1 1 10 or NONE will be displayed Use the RANGE A or keys to display the desired window
225. ing ACAL Front Autozero Autozero LSYNC and Low Charge Inject On 2 3 3 reete eee ener eerie reet eben 2 10 eue m 2 12 Connection techniques orent teret peer EAEE A e pee RE Ree eee eas 2 12 Voltage only connections 0 0 cee eececesceeseececeeseeceaeeeseeceseeececeaeeeeeseaeessaeeeaeens 2 14 Temperature only connections eeeeseeseeeeeeeen rennen nennen nennen 2 15 Voltage and temperature connections 00 le eee ese eeeeeseeeeeeeeeseeseeeseeeeeaeees 2 16 Cleaning test circuit connectors eeessseeseeeeeeeeee enne nne enne nnne 2 17 Temperature Configuration cece essere ene m eene nennen rennes 2 18 Measuring voltage and temperature essere eee 2 19 SCPI programming voltage and temperature measurements 2 20 Low level considerations peciit tem Ee ir t rentra TESNE aE E aina edi in 2 22 Thermal EMFS E 2 22 or e E 2 22 Applications E EE 2 23 Low resistance measurements eseeseeeeeeeeen eene een ene ene nee 2 23 Standard cell comparisons essere rennen eene 2 26 Heated Zener Reference and Josephson Junction Array comparisons 2 27 Range Digits Rate and Filter cup m 3 3 Maximum readings C 3 3 M EnUrIBcuPD DR 3 3 Elec
226. ing the circuit by placing a heat source near the circuit or by a regular pattern of instability corresponding to changes in sunlight or the activation of heating and air conditioning systems To minimize thermal EMFs use clean copper to copper connections wherever possible in the test circuit See Connections for details on connection techniques and cleaning Widely varying temperatures within the circuit can also create thermal EMFs Therefore maintain constant temperatures to minimize these thermal EMFs A shielded enclosure around the circuit under test also helps by minimizing air currents The REL Relative control can be used to null out constant offset voltage The basic procedure to use REL is found in Measuring voltage and temperature and details on Relative are provided in Section 4 AC voltages that are extremely large compared with the DC signal to be measured may be induced into the input of the Model 2182 and corrupt the measurement AC interference can cause the Model 2182 to behave in one or more of the following ways Unexpected offset voltages Inconsistent readings between ranges Sudden shifts in a reading To minimize AC pick up keep the test circuit source and the Model 2182 away from strong AC magnetic sources The voltage induced due to magnetic flux is proportional to the area of the loop formed by the input leads Therefore minimize the loop area of the input leads and connect each signal at only
227. ion between the source and the Model 2182 is explained in Model 2182 and SourceMeter trigger synchronization which follows the Delta measurement procedure using a SourceMeter Figure 5 2 Delta measurement using bipolar source VTHERM SourceMeter 2182 Source 1mA C Delta Vout 100uV CH 1 At 1mA At 1mA V1tl 10uV 100uV V1t2 10uV 100uV 110uV 90uV Vi V1t2 110uV 90nV VbeLTA 100uV 2 2 Voeuta Vout Ratio and Delta 5 9 Selecting Delta Delta is selected by pressing the SHIFT key and then the V1 V2 key The Vt1 Vt2 2 message appears briefly before displaying the result of the calculation Delta is disabled by selecting a single measurement function DCV1 DCV2 TEMPI or TEMP2 or by selecting Ratio NOTES To double the speed of Delta measurements disable Front Autozero as follows Press SHIFT Press CONFIG Set FRONT AUTOZERO to N Press ENTER For details on Front Autozero see Autozeroing modes in Section 2 Delta reading is indicated by a small d on the display after the reading Delta performs voltage measurements on Channel 1 If on Channel 2 the Model 2182 will automatically go to Channel 1 when Delta is selected Delta readings can be stored in the buffer See Section 6 for details on using the buffer Delta cannot be selected if stepping or scanning Reading HOLD cannot be used with Delta Delta measurements by the Model 218
228. ional SCP Commands Operation Event Register Bit B0 Calibrating Cal Set bit indicates that the instrument is calibrating Bits B1 through B3 Not used Bit B4 Measuring Meas Set bit indicates that the instrument is performing a measurement Bit B5 Trigger Layer Trig Set bit indicates that the instrument is waiting in the Trigger Layer of the Trigger Model Bits B6 and B7 Not used Bit B8 Filter Settled Filt Set bit indicates that the filter has settled Bit B9 Not used Bit B10 Idle Set bit indicates that the instrument is in the idle state Bits B11 through B15 Not used Figure 15 6 Operation event register Bit Position B15 B11 B10 B9 B8 B7 B6 B5 B4 B3 B1 BO Event EE Idle Decimal 1024 Weighting 210 Value a 0A of ELT 0 1 0 1 RN 0 1 Value 1 Operation Event Set Events Idle Idle state of the 2182 0 Operation Event Cleared Filt Filter Settled Trig Trigger Layer Meas Measuring Cal Calibrating Additional SCP Commands 15 11 ENABle command ENABle lt NRf gt STATus MEASurement ENABle lt NRf gt Program Measurement Event Enable Register STATus QUEStionable ENABle lt NRf gt Program Questionable Event Enable Register STATus OPERation ENABle lt NRf gt Program Operation Event Enable Register Parameters lt NRf 0 Clear register lt NRf gt 128 Set bit B7 1 Set bit BO 256 Set bit B8
229. is specifies the number of measurements to be performed while on Channel 1 Keep in mind that for each step scan cycle only one measurement is performed on Channel 2 Channel 1 Count can be set from 1 to 1023 Reading Count This indicates the total number of measurements that will to be performed for each step scan cycle For example if Channel 1 Count is set to 3 the Reading Count will initially set to 4 the extra reading is for Channel 2 For each additional step scan cycle simply add 4 to the Reading Count Therefore to perform three step scan cycles set the Reading Count to 12 Reading Count can be set from 2 to 1024 NOTES If you change the Reading Count it must be a multiple of the initial count val ue For example if the initial Reading Count is 3 you can change it to 6 or 9 or 12 etc If you enter a non multiple value the instrument will select the next lower value that is a multiple Reading Count can be set to a value gt 1024 or INFinite but only the first 1024 readings will be stored in the buffer Perform the following steps to configure internal stepping or scanning 1 Press SHIFT and then CONFIG Use the gt key to display the present SCANNING type INTernal or EXTernal 2 Press the or V key to display INT and press ENTER 3 The present state of the timer is displayed OFF or ON Press amp or to display the desired timer state and press ENTER 4 Ifyou turned the timer on the timer inter
230. ister Query 12 6 DN Identification Query 12 7 OPC Operation Complete 12 8 OPC Operation Complete Query 12 10 RCL Recall 12 11 RST Reset 12 12 SAV Save 12 12 SRE Service Request Enable 12 12 SRE Service Request Enable Query 12 12 STB Status Byte Query 12 14 RG Trigger 12 15 TST Self Test Query 12 15 WAI Wait to Continue 12 16 Numerics A 4 Wire low resistance measurement 2 23 ACAL calibration 2 5 Additional SCPI Commands 15 1 Address commands F 9 Addressed multiline commands F 9 Analog filter 3 8 Analog Output 10 1 Analog output connections 10 5 Analog output rel 10 5 Application I V curves using internal scan 9 14 Applications 2 23 Autoranging 3 4 Autozeroing modes 2 6 Baud rate flow control and terminator 11 27 Bipolar source 5 8 Buffer 6 1 Buffer operations 6 2 Buffer statistics 6 4 Bus commands F 6 Bus description F 2 Buslines F 4 Bus management lines F 4 Cables connectors and adapters 1 4 CALCulate command summary 14 3 Calibrating resistor network dividers 5 18 CALibration command summary user accessible 14 4 Carrying case 1 5 Changing function and range E 2 Cleaning input connectors 1 13 Cleaning test circuit connectors 2 17 Command codes F 10 Common Commands 12 1 Common commands F 10 Configure and control analog output 10 5 Connection techniques 2 12 Connections 2 12 Contact information 1 3 Control so
231. ition and use the Aand W keys to move the decimal point Note that with the cursor on the polarity sign pressing Aor W toggles the polarity of the value 3 Press ENTER to view the present LOI limit value LO1 1 000000 default 4 Enter the desired value for this low limit 5 Press ENTER to view the present HI2 limit value HI2 2 000000 default 6 Enter the desired value for this high limit 7 Press ENTER to view the present LO2 limit value LO2 2 000000 default 8 Enter the desired value for this low limit and press ENTER to return to the normal display Enabling limits Use the following procedure to turn on the limits operation 1 Press the Limits ON OFF key to view the present beeper status BEEP NEVER default 2 To change the beeper setting use the Aand W keys to display NEVER OUTSIDE or INSIDE 3 Press ENTER to return to the normal display The HI IN LO status is displayed along with the reading 4 To disable Limits press the ON OFF key Limits 8 5 SCPI programming limits For remote operation the testing capabilities of Limit 1 and Limit 2 are the same Limit 1 and or Limit 2 can be enabled The commands to configure and control limit testing are listed in Table 8 1 NOTE When testing limits remotely keep in mind that the front panel HI IN LO status messages only apply to Limit 1 Also if the front panel beeper is set for OUTSIDE or INSIDE it will operate according to its front pa
232. itions GET GET Initiates a trigger SPE SPD SPOLL Serial Polls the Model 2182 11 10 Remote Operation Transmit A transmit routine is used to send General Bus Commands It contains a series of GPIB commands to be carried out In addition to the commands listed in Table 11 1 there are other commands used in the transmit command string Some of the more frequently used ones are explained as follows refer to the User s Manual for the interface card for details on all the commands UNL Unlisten Disables any listeners that may exist UNT Untalk Disables the current talker if any LISTEN 7 Listen Assigns the device at address 7 2182 to be a listener MTA My Talk Address Assigns the computer as the talker The General Bus Commands are explained as follows REN remote enable The remote enable command is sent to the Model 2182 by the controller to set up the instrument for remote operation Generally the instrument should be placed in the remote mode before you attempt to program it over the bus Simply setting REN true does not actually place the instrument in the remote state You must address the instrument to listen after setting REN true before it goes into remote Note that the instrument does not have to be in remote to be a talker Program Fragment CALL TRANSMIT MTA LISTEN 7 REN status Place Model 2182 in remote turn on REM annunciator Note that all front panel c
233. k Cable 2400 9 16 Stepping and Scanning Set up 2400 Menu Savesetup Global Reset Bench Meas V Source Config Trig ARM LAYER ARM IN IMMEDIATE ARM OUT LINE 3 EVENTS TRIG LAYER DONE OFF TRIG LAYER TRIGGER IN TRIGGER LINK 1 EVENT DETECT BYPASS NEVER TRIGGER IN EVENTS SOURCE ON all others off TRIG LAYER TRIGGER OUT LINE 2 EVENTS TRIGGER OUT EVENTS SOURCE ON all others off COUNT 12 Config Sweep TYPE CUSTOM POINTS 12 ADJUST POINTS see waveform COUNT INFINITE Speed 0 01plc Turn output On SWEEP exit TRIG HALT ON the 2182 enable SCAN Note Memory buffer annunciator comes on ON the 2400 enable SWEEP Note Arm annunciator comes on Press Trig on 2400 After completion of the sweep recall the data from the 2182 using the TRACe command To remove thermal EMFs from the readings do the following math on the recalled data CH2 Rdg 1 Buffer Rdg 1 Buffer Rdg 5 2 CH2 Rdg 2 Buffer Rdg 9 Buffer Rdg 13 2 repeat CHI Rdg Pos 1 Buffer Rdg 2 Buffer Rdg 3 Buffer Rdg 4 3 CHI Rdg Neg 1 Buffer Rdg 6 Buffer Rdg 7 Buffer Rdg 8 3 CHI Rdg 1 CH1 Rdg Pos 1 CH1 Rdg Neg 1 2 CHI Rdg Pos 2 Buffer Rdg 10 Buffer Rdg 11 Buffer Rdg 12 3 CHI Rdg Neg 2 Buffer Rdg 14 Buffer Rdg 15 Buffer Rdg 16 3 CHI Rdg 2 CH1 Rdg Pos 2 CH1 Rdg Neg 2 2 repeat Stepping and
234. l disconnect the line cord and any other cables or wires connected to the instrument 2 Stand the Model 2182 on end such that the front panel is facing up 3 Apply one drop of DeoxIT to each of the four contacts of the LEMO input connector on the Model 2182 You can use a clean wire such as a resistor lead to carry a drop of the solution from the bottle of DeoxIT to the connector 4 Wipe off any excess DeoxIT using a clean cloth 5 To clean the contacts of the mating LEMO connector connect and disconnect it to the Model 2182 several times to spread the DeoxIT around NOTE To minimize the accumulation of oxides on LEMO contacts always keep the LEMO input connectors mated whenever possible However cleaning should still be performed after an extended period of time 1 14 Getting Started Power Up Line power connection Perform the following procedure to connect the Model 2182 to line power and turn on the instrument 1 Check to be sure the line voltage setting on the power module see Figure 1 3 is correct for the operating voltage in your area If not refer to the next procedure Setting line voltage and replacing fuse on page 1 15 CAUTION Operating the instrument on an incorrect line voltage may cause damage to the instrument possibly voiding the warranty 2 Before plugging in the power cord make sure the front panel power switch is in the off 0 position 3 Connect the female end of the supplied power cord
235. l No Serial No Date Company List all control settings describe problem and check boxes that apply to problem Q Intermittent C Analog output follows display C Particular range or function bad specify C IEEE failure CJ Obvious problem on power up CJ Batteries and fuses are OK C Front panel operational U All ranges or functions are bad C Checked all cables Display or output check one C Drifts C Unable to zero C Unstable C Overload C Will not read applied input C Calibration only CJ Certificate of calibration required C Data required attach any additional sheets as necessary Show a block diagram of your measurement including all instruments connected whether power is turned on or not Also describe signal source Where is the measurement being performed factory controlled laboratory out of doors etc What power line voltage is used Ambient temperature F Relative humidity Other Any additional information If special modifications have been made by the user please describe Be sure to include your name and phone number on this service form aa USA TEquip pment NET An Interworld Highway LLC Company Specifications are subject to change without notice All Keithley trademarks and trade names are the property of Keithley Instruments Inc All other trademarks and trade names are the property of their respective companies KEITHLEY A GREA
236. l Weighting Value B7 B6 B5 BA B3 B2 B1 BO PON URQ CME EXE DDE QYE OPC 128 64 32 16 8 4 1 27 2 2 24 23 22 29 on O 1 O 1 on jon O 1 of Note Bits B8 through B15 are not shown since they are not used Value 1 Ev 0 Ev ent Bit Set ent Bit Cleared Events PON Power On URQ User Request CME Command Error EXE Execution Error DDE Device Dependent Error QYE Query Error OPC Operation Complete 12 6 Common Commands ESR Event Status Register Query Read register and clear it Description Use this command to acquire the value in decimal of the Standard Event Register see Figure 12 2 The binary equivalent of the returned decimal value determines which bits in the register are set The register is cleared on power up or when CLS is sent A set bit in this register indicates that a particular event has occurred For example for an acquired decimal value of 48 the binary equivalent is 00110000 From this binary value bits B4 and B5 of the Standard Event Status Register are set These bits indicate that a device dependent error and command error have occurred The bits of the Standard Event Status Register are described as follows Bit BO Operation Complete A set bit indicates that all pending selected device operations are completed and the Model 2182 is ready to accept new commands
237. lable for limit testing There are three beeper options NEVER OUTSIDE and INSIDE These options are explained as follows NEVER With this option the beeper is disabled Only the HI IN LO status message is used for the Limit 1 test OUTSIDE With this option the beeper sounds when the reading is outside HI or LO of Limit 1 Again referring to Figure 8 1 a 1 5V reading is outside HI Limit 1 Therefore the beeper will sound INSIDE With this option the beeper sounds when the reading is inside Limit 1 and or Limit 2 If the reading is inside Limit 1 the beeper will sound at its normal pitch If the reading is outside Limit 1 but inside Limit 2 the beeper will sound at a lower pitch The beeper will not sound for readings outside Limit 2 For the limits shown in Figure 8 1 a 0 5V reading will sound the beeper at its normal pitch a 1 5V reading will sound the beeper at a lower pitch and for a 2 5V reading the beeper will not sound NOTE To use the Limit 2 test the INSIDE beeper mode must be selected With NEVER or OUTSIDE selected Limit 2 is in effect disabled 8 4 Limits Setting limit values Use the following steps to enter high and low limit values 1 Press the Limits VALUE key to view the present HII limit value HI1 1 000000 default 2 To change the HII limit use the cursor keys lt and P gt and the manual range keys Aand WV to display the desired value Move the cursor to the rightmost pos
238. layed while the CHI CH2 message is being displayed When a range key is pressed the channel number annunciator for the range controlled channel remains on The other channel annunciator turns off for a brief moment The state on or off of the AUTO range annunciator indicates the state enabled or disabled of autorange for the voltage channel that is under range control With Ratio already enabled pressing the AUTO range key will either disable autorange for both channels or enable autorange for both channels AUTO annunciator turns on 5 6 Ratio and Delta Delta Delta provides the measurements and calculation for the DC current reversal technique to cancel the effects of thermal EMFs in the test leads Each Delta reading is calculated from two voltage measurements on Channel 1 one on the positive phase of an alternating current source and one on the negative phase Basic Delta Calculation Delta VIt1 VIt2 2 where V 1t1 is the voltage measurement on the positive phase of the current source V112 is the voltage measurement on the negative phase of the current source Delta Calculation using Filter and Rel Delta FiltV1tl 3 FiltV1t2 _ RelV1 where Filt VItl and Filt V1t2 are filtered voltage measurements on the positive and negative phases of the current source The FILT annunciator will be on when Filter is enabled e Rel V1 is the Rel value established for DCV1 The REL annunciator will be on
239. le DB 9 connector on the other end It is wired as a straight through not null modem cable Models 8501 1 and 8501 2 Trigger Link Cables Connect the Model 2182 to other instruments with Trigger Link connectors e g Model 7001 Switch System The Model 8501 1 is 1m long the Model 8501 2 is 2m long Model 8502 Trigger Link Adapter Lets you connect any of the six Trigger Link lines of the Model 2182 to instruments that use the standard BNC trigger connectors Model 8503 DIN to BNC Trigger Cable Lets you connect Trigger Link lines one Voltmeter Complete and two External Trigger of the Model 2182 to instruments that use BNC trigger connectors The Model 8503 is 1m long Silver solder 2182 325A Use this Keithley part number to order a 20 foot length of silver solder Also included is an MSDS sheet listing the solder chemical contents Getting Started 1 5 Rack mount kits Model 4288 1 Single Fixed Rack Mount Kit Mounts a single Model 2182 in a standard 19 inch rack Model 4288 2 Side by Side Rack Mount Kit Mounts two instruments Models 182 428 486 487 2000 2001 2002 2010 2182 2400 2410 2420 6517 7001 side by side in a standard 19 inch rack Model 4288 4 Side by Side Rack Mount Kit Mounts a Model 2182 and a 5 25 inch instrument Models 195A 196 220 224 230 263 595 614 617 705 740 775 etc side by side in a standard 19 inch rack Carrying case Model 1050 Padded Carrying Ca
240. lectromagnetic interference over a wide range of frequencies across the spectrum Such RFI can be particularly troublesome at low signal levels but it can also affect measurements at high levels if the fields are of sufficient magnitude RFI can be caused by steady state sources such as radio or TV signals or some types of electronic equipment microprocessors high speed digital circuits etc or it can result from impulse sources as in the case of arcing in high voltage environments In either case the effect on the measurement can be considerable if enough of the unwanted signal is present RFI can be minimized in several ways The most obvious method is to keep the Model 2182 voltage source and signal leads as far away from the RFI source as possible Additional shielding of the instrument signal leads sources and other measuring instruments will often reduce RFI to an acceptable level In extreme cases a specially constructed screen room may be required to sufficiently attenuate the troublesome signal The Model 2182 digital filter may help to reduce RFI effects in some situations In some cases additional external filtering may also be required Keep in mind however that filtering may have detrimental effects such as increased settling time on the desired signal Ground loops When two or more instruments are connected together care must be taken to avoid unwanted signals caused by ground loops Ground loops usually occur when se
241. les connectors and adapters Models 2107 4 and 2107 30 Input Cable Connect the Model 2182 Nanovoltmeter to DUT using one of these input cables The input cable is terminated with a LEMO connector for connection to the Model 2182 on one end and four copper spade lugs for connection to DUT on the other The Model 2107 4 which is a supplied accessory to the Model 2182 is 1 2m 4 ft in length and the Model 2107 30 is 9m 30 ft in length Also included are four copper alligator clips that attach to the copper lugs of the cable and DeoxIt copper cleaning solution Model 2182 KIT Low Thermal Connector Consists of a low thermal LEMO connector and strain relief Includes all the connector parts required to build a custom input cable for the Model 2182 Nanovoltmeter Model 2187 4 Input Cable Low thermal input cable for the Model 2182 2182A Termi nated with a LEMO connector on one end and four banana plugs on the other The cable is 4 ft 1 2m in length Model 2188 Low Thermal Calibration Shorting Plug This input shorting plug is required to calibrate the Model 2182 Nanovoltmeter Models 7007 1 and 7007 2 Shielded GPIB Cables Connect the Model 2182 to the GPIB bus using shielded cables and connectors to reduce electromagnetic interference EMI The Model 7007 1 is 1m long the Model 7007 2 is 2m long Model 7009 5 Shielded RS 232 Cable 1 5m 5 ft RS 232 cable terminated with a male DB 9 connector on one end and a fema
242. lt 2 Filter Settled Trig Trigger Layer Meas Measuring Cal Calibrating CONDiition command CONDiition STATus MEASurement CONDition Read Measurement Condition Register STATus QUEStionable CONDition Read Questionable Condition Register STATus OPERation CONDition Read Operation Condition Register Description These query commands are used to read the contents of the condition registers Each set of event registers except the Standard Event register set has a condition register A condition register is similar to its corresponding event register except that it is a real time register that constantly updates to reflect the present operating status of the instrument See EVENt for register bit descriptions After sending one of these commands and addressing the Model 2182 to talk a decimal value is sent to the computer The binary equivalent of this decimal value indicates which bits in the register are set For example if sending stat meas cond returns a decimal value of 512 binary 0000001000000000 bit B9 of the Measurement Condition Register is set indicating that the trace buffer is full 15 14 Additional SCP Commands PRESet command PRESet STATus PRESet Return registers to default conditions Description When this command is sent all bits of the following registers are cleared to zero 0 e Questionable Event Enable Register e Measurement Event Enable Register e Operation Event Enable Register
243. lt function gt READ When ABORt is executed the instrument goes into the idle state if continuous initiation is disabled If continuous initiation is enabled the operation re starts at the beginning of the Trigger Model When CONFigure is executed the instrument goes into a one shot measurement mode See CONFigure for more details When READ is executed its operations will then be performed In general another ABORt is performed then an INITiate and finally a FETCh to acquire the reading See READ for more details 14 SCPI Reference Tables 14 2 SCPI Reference Tables Table 14 1 CALCulate command summary Table 14 2 CALibrate command summary Table 14 3 DISPlay command summary Table 14 4 FORMat command summary Table 14 5 OUTPut command summary Table 14 6 ROUTe command summary Table 14 7 SENSe command summary Table 14 8 STATus command summary Table 14 9 SYSTem command summary Table 14 10 TRACe command summary Table 14 11 Trigger command summary Table 14 12 UNIT command summary General notes Brackets are used to denote optional character sets These optional characters do not have to be included in the program message Do not use brackets in the program message Angle brackets gt are used to indicate parameter type Do not use angle brackets in the program message The Boolean parameter lt b gt is used to enable or disable an instrumen
244. ltage across the unknown resistance Rpur Figure 2 10 4 Wire low resistance measurement technique R R V OFFSET Current Source Voltmeter Since the current through the measured resistance and the voltage across the device are both known the value of that resistance can easily be determined from Ohm s law Rput Vm 2 24 Voltage and Temperature Measurements Compensating for thermal EMFs Although the 4 wire measurement method minimizes the effects of lead resistances other factors can affect low resistance measurement accuracy Thermal EMFs and other effects can add an extraneous DC offset voltage Vorrspr in Figure 2 10 to the measured voltage The Relative feature of the Model 2182 can be used to null out the offset voltage In general this is done by disconnecting the current source and zeroing the reading on the Model 2182 by pressing the REL key see Measuring voltage and temperature Nulling thermal EMFs The DC offset voltage is effectively cancelled as long as it remains comparatively steady If the offset voltage varies the DC current reversal technique should instead be used The DC current reversal technique to cancel the effects of thermal EMFs requires a source that can output currents equal in magnitude but opposite in polarity In general a voltage measurement is performed on both the positive and negative alternations of the current source The averaged difference of those two readings cancels ou
245. m high x 213mm wide x 370mm deep 3 5in x 8 375in x 14 563in Bench Configuration with handles and feet 104mm high x 238mm wide x 370mm deep 4 125 in x 9 375 in x 14 563 in SHIPPING WEIGHT 5kg 11 Ibs ACCESSORIES SUPPLIED 2107 4 Low Thermal Input Cable with spade lugs 1 2m 4 ft User manual service manual contact cleaner line cord alligator clips ACCESSORIES AVAILABLE 2107 30 Low Thermal Input Cable with spade lugs 9 1m 30 ft 2182 KIT Low Thermal Connector with strain relief 2188 Low Thermal Calibration Shorting Plug 2187 4 Input Cable with safety banana plugs 4288 1 Single Fixed Rack Mount Kit 4288 2 Dual Fixed Rack Mount Kit 7007 1 Shielded GPIB Cable 1m 3 2 ft 7007 2 Shielded GPIB Cable 2m 6 5 ft 7009 5 Shielded RS 232 Cable 1 5m 5 ft 8501 1 Trigger Link Cable 1m 3 2 ft 8501 2 Trigger Link Cable 2m 6 5 ft 8502 Trigger Link Adapter to 6 female BNC connectors 8503 Trigger Link Cable to 2 male BNC connectors Notes 1 Relative to calibration accuracy 2 With Analog Filter on add 20ppm of reading to listed specification 3 When properly zeroed using REL function If REL is not used add 100nV to the range accuracy 4 Specifications include the use of ACAL function If ACAL is not used add 9ppm of reading C from Tc to the listed specification Tea is the internal temperature stored during ACAL 5 For 5PLC with 2 reading Digital Filter Use 4ppm of reading 2p
246. m illustrates the use of the Keithley Model 2182 interfaced to the RS 232 COM2 port The Model 2182 is set up to take 100 readings at the fastest possible rate 2000 per second The readings are taken sent across the serial port and displayed on the screen Example program controlling the Model 2182 via the RS 232 COM2 port For QuickBASIC 4 5 and CEC PC488 interface card RD SPACES 1500 Set string space CLS CLear screen PRINT Set COM2 baud rate to 19200 PRINT Set no flow control and CR as Terminator Configure serial port parameters ComOpen COM2 19200 N 8 1 ASC CD0 CSO DSO LF OPO RS TB8192 RB8192 OPEN ComOpen FOR RANDOM AS 1 1 Model 2182 setup commands Note Serial communications only operate with SCPI mode 1 PRINT 1 RST Clear registers PRINT 1 CLS Clear Model 2182 PRINT 1 INIT CONT OFF ABORT Init off PRINT 1 SENS FUNC VOLT DC DCV PRINT 1 SENS CHAN 1 Channel 1 PRINT 1 SYST AZER STAT OFF Auto zero off PRINT 1 SENS VOLT CHAN1 LPAS STAT OFF Analog filter off PRINT 1 SENS VOLT CHAN1 DFIL STAT OFF Digital filter off PRINT 1 SENS VOLT DC NPLC 0 01 NPLC 0 1 PRINT 1 SENS VOLT CHAN1 RANG 10 10V range PRINT 1 SENS VOLT DC DIG 4 4 digit PRINT 1 FORM ELEM READ Reading only PRINT 1 TRIG COUN 1 Trig count 1 PRINT Z1 SAMP COUN 100 Sample count 100 PRINT 1 TRIG DEL 0 No trigger delay PRINT 1 TRIG SOUR I
247. mation on thermal EMFs see Low level considerations Thermal EMFs Details on Relative are provided in Section 4 1 Connect the test circuit but leave the source voltage or current disconnected or in stand by 2 Select the appropriate voltage function DCV1 or DCV2 3 If not using AUTO range select the lowest possible measurement range to display the voltage offset 4 Onthe Model 2182 press the REL key to zero the display 5 If applicable repeat steps 2 through 4 for the other channel 6 Connect the source Subsequent readings will not include the thermal EMFs that were nulled out SCPI programming voltage and temperature measurements Table 2 3 SCPI commands voltage and temperature measurements Commands Description Default SENSe FUNCtion lt name gt Select function VOLTage or TEMPerature VOLT CHANnel chan Select measurement channel 0 1 or 2 see Note 1 DATA Return 2182 readings LATest Return the last reading FRESh Return a new fresh reading TEMPerature Configure temperature measurements TRANsducer lt name gt Select sensor TCouple or INTernal TCouple RJUNCtion Configure reference junction RSELect name Select reference SIMulated or INTernal INTernal SIMulated n Specify simulated reference temperature in C 0 to 60 23 TCouple type Specify thermocouple type J K T E R S B or N J UNIT TEMPerature lt name gt Select units designator
248. ment mode to trigger and acquire a specified number of readings The SAMPle COUNt command is used to specify the number of readings see Trigger Subsystem Note that the readings are stored in the buffer When this command is sent the following commands execute in the order they are presented ABORt INITiate FETCh When ABORt is executed the instrument goes into the idle state if continuous initiation is disabled If continuous initiation is enabled the operation re starts at the beginning of the Trigger Model 13 4 SCPI Signal Oriented Measurement Commands If the instrument is in the idle state INITiate takes the instrument out of the idle state If continuous initiation is enabled INITiate CONTinuous ON then the INITiate command generates an error and ignores the command NOTE You cannot use the READ command if sample count 1 see Trigger subsystem and there are readings stored in the buffer error 225 out of memory Either set sample count to one or clear the buffer See Appendix C for an example program using the READ command MEASure function Parameters function VOLTage DC Voltage TEMPerature Temperature Description This command combines all of the other signal oriented measurement commands to perform a one shot measurement and acquire the reading When this command is sent the following commands execute in the order that they are presented ABORt CONFigure
249. ment sets the voltage reading rate to 2 PLC and the temperature reading rate to 5 PLC CALL SEND 7 sens volt nplc 2 status Set volts for 2 PLC CALL SEND 7 sens temp nplc 5 status Set temp for 5 PLC 3 8 Range Digits Rate and Filter Filter The Model 2182 has an analog filter and a digital filter When Filter is enabled by pressing the FILT key FILT annunciator on it assumes the combination of analog and digital filter configuration for the present measurement function DCV1 DCV2 TEMP TEMP2 Filter state enabled or disabled and configuration is saved by each function Analog filter With the low pass Analog Filter ON the normal mode noise rejection ratio of the instrument is increased at 60Hz This filters out noise induced by the power line The Analog Filter attenuates frequency at 20dB decade starting at 18Hz A primary use of the Analog Filter is to keep the high gain input stage of the Model 2182 from saturating due to the presence of high AC and DC voltage Note however that the filter only attenuates AC voltages for the 10mV range of the Model 2182 The Analog Filter adds approximately 125msec of settling between A D conversions The additional settling time may be required when using a high impedance z100kQ source in the test circuit The increased settling time causes the reading rate of the Model 2182 to be greatly reduced Therefore if the Analog Filter is not needed turn it OFF Digital
250. ming Programming examples used throughout this manual presume Microsoft QuickBASIC version 4 5 or higher and a Keithley KPC 488 2 or Capital Equipment Corporation IEEE interface with CEC driver 2 11 or higher The Model 2182 must be set to address 07 for the IEEE 488 bus About program fragments Program fragments are used to demonstrate proper programming syntax Only a fragment of the whole program is used to avoid redundancy At the beginning of each program you will have to edit the following line to include the QuickBASIC libraries on your computer SINCLUDE c qb45 ieeeqb bi Remote Operation 11 9 Then initialize the interface card as address 21 CALL INITIALIZE 21 0 Initialize also sends out an interface clear IFC to the entire GPIB system to initialize the other devices see General bus commands IFC interface clear A typical program fragment includes a CALL SEND command and a CALL ENTER command The CALL SEND command sends a program message command string to the Model 2182 If the program message includes a query command then the CALL ENTER command is required to get the response message from the Model 2182 The CALL ENTER command addresses the Model 2182 to talk The following example program fragment demonstrates how CALL SEND and CALL ENTER commands are used Note that the commands assume address 07 which is the factory set address of the Model 2182 CALL SEND 7 rst status CALL SEND 7
251. mmands to control the two autozeroing modes are listed in Table 2 2 1 Press SHIFT and then CONFIG to display the present state of Front Autozero Y yes enabled N no disabled 2 To change the FRONT AZERO setting use the amp or W key to display Y or N 3 If you do not wish to view or change the Autozero setting jump to step 6 Otherwise proceed to the next step 4 Press the gt key to display the present state of Autozero YES enabled NO disabled To change the AUTOZERO setting use the A or V key to display YES or NO 6 Press ENTER to enter the setting s and exit from the menu structure h NOTE The factory default setting for Front Autozero and Autozero in ON enabled The set tings can be saved in the user default setup see Default settings in Section 1 LSYNC line cycle synchronization Synchronizing A D conversions with the frequency of the power line increases common mode and normal mode noise rejection When line cycle synchronization is enabled the measurement is initiated at the first positive or negative going zero crossing of the power line cycle after the trigger Figure 2 1 shows the measurement process that consists of two A D conversions If the trigger occurs during the positive cycle of the power line as shown in Figure 2 1 the first A D conversion starts with the negative going zero crossing of the power line cycle If the next trigger Trigger 2 occurs during the negative cycle th
252. mmyo 7 10v 779 The above calculation includes Channel 1 Filter If Filter is not used remove the Filt component from the calculation The network can then be calibrated by adjusting the network pot until a reading of 0 10000 is displayed Ratio and Delta 5 19 For even greater precision the Relative feature of the Model 2182 can be used to null out thermal EMFs which can corrupt low voltage measurements Use Rel as follows 1 While displaying the Ratio result disconnect the current source from the network Press the REL key on the Model 2182 The voltages at each input which are thermal EMBs are nulled out 3 Reconnect the current source and take the result of Ratio from the display When using Rel Ratio is calculated as follows Filt V1 V1 Rel Ratio Fit V2 V2 Rel The above calculation includes Channel 1 Filter If Filter is not used remove the Filt component from the calculation Testing superconductor materials A superconductor sample is typically tested by either varying the current through it or varying the magnetic field that surrounds it NOTE The following applications use H magnetic field as one of the test parameters The applications can easily be modified to substitute temperature T for H as a test parameter When varying the magnetic field H the current I that flows through the DUT is fixed When varying the current I through the superconductor material DUT the magnetic field
253. mple count set to 5 the five measured readings will be stored in the buffer If the trigger model is configured to repeat the sample readings i e trigger count 2 those five new readings will overwrite the original five readings in the buffer Output trigger The Model 2182 will send one or more output triggers The output trigger is applied to the Trigger Link connector on the rear panel It can be used to trigger an external instrument to perform an operation The trigger model can be configured to output a trigger after the completion of a series of measurements or after every measurement For example with the sample counter set to 10 and the trigger counter set to one a trigger will be sent after the 10 measurements are performed If instead the trigger counter is set to 10 and the sample counter is set to 1 a trigger will be sent after each measurement 7 16 Triggering Triggering commands Commands for triggering are summarized in Table 7 2 Information not covered in the table or in Trigger model GPIB operation is provided after the table The Ref column provides reference for this information Table 7 2 SCPI commands triggering Commands Description Ref Default ABORt Reset trigger system A INITiate Initiation IMMediate Initiate one trigger cycle B CONTinuous lt b gt Enable or disable continuous initiation C Note 1 FETch Request the last reading s D READ Perform an
254. n or reference 15 Macro information Not applicable 16 Response to IDN identification See Common Commands in Section 12 17 Storage area for PUD and PUD Not applicable 18 Resource description for RDT and RDT Not applicable 19 Effects of RST RCL and SAV See Common Commands in Section 12 20 TST information See Common Commands in Section 12 21 Status register structure See Status Structure in Section 11 22 Sequential or overlapped commands All are sequential except INIT and INIT CONT ON which are overlapped 23 Operation complete messages OPC OPC and WAE see Common Commands in Section 12 Table G 2 Coupled commands Command Also changes To TRAC POIN TRAC FEED CONT NEV TRAC CLE TRAC FEED CONT NEV Sense Subsystem Commands RANG UPP RANG AUTO OFF IREF ACQ REF presently displayed reading SENS VOLT DC RAT ON SENS VOLT DC DELT OFF SENS HOLD STAT OFF SENS VOLT DC DELT ON SENS VOLT DC RAT OFF SENS HOLD STAT OFF SENS VOLT DC CHAN1 DFILT TCON REP MOV Valid function command words i e WOLT DC VOLT AC etc G 4 IEEE 488 and SCPI Conformance Information H Measurement Queries H 2 Measurement Queries TETCh What it does This command will simply return the latest available reading from an instrument Limitations If the instrument does not have a reading available indicated by dashes
255. n regardless of the transfer rate Generally data transfer will occur at a rate determined by the slowest active device on the bus One of the three handshake lines is controlled by the source the talker sending information while the remaining two lines are controlled by accepting devices the listener or listeners receiving the information The three handshake lines are DAV DATA VALID The source controls the state of the DAV line to indicate to any listening devices whether or not data bus information is valid NRFD Not Ready For Data The acceptor controls the state of NRFD It is used to signal to the transmitting device to hold off the byte transfer sequence until the accepting device is ready NDAC Not Data Accepted NDAC is also controlled by the accepting device The state of NDAC tells the source whether or not the device has accepted the data byte The complete handshake sequence for one data byte is shown in Figure F 2 Once data is placed on the data lines the source checks to see that NRFD is high indicating that all active devices are ready At the same time NDAC should be low from the previous byte transfer If these conditions are not met the source must wait until NDAC and NRFD have the correct status If the source is a controller NRFD and NDAC must be stable for at least 100ns after ATN is set true Because of the possibility of a bus hang up many controllers have time out routines that display messages
256. n step or scan its two input channels or be used with external scanner cards installed in switching mainframes such as Models 707 7001 and 7002 The following paragraphs summarize the various aspects of stepping scanning using the Model 2182 NOTE Step and Scan operations are illustrated by trigger models see Front panel trigger models in this section Internal Stepping Scanning Channels 1 and 2 When stepping or scanning the two input channels of the Model 2182 Channel 2 is selected measured first and then Channel is selected measured For every step scan cycle Channel 2 is measured once and Channel 1 can be measured from 1 to 1023 times Measured readings are automatically stored in the buffer External Stepping Scanning When using external switching cards the switching mainframe controls the opening and closing of individual channels Up to 800 external channels can be stepped scanned and measured by Channel 1 of the Model 2182 Channel 2 cannot be used for external stepping or scanning Measured readings are automatically stored in the buffer To synchronize Model 2182 measurements with external channel closures connect the Trigger Link lines of the nanovoltmeter and switching mainframe Refer to Section 7 Triggering for details and an example on using external triggering NOTE Channel annunciators do not turn on during an external step or scan 9 4 Stepping and Scanning Front panel trigger models The fron
257. n when a shock hazard is present Lethal voltage may be present on cable connector jacks or test fixtures The American National Standards Institute ANSI states that a shock hazard exists when voltage levels greater than 30V RMS 42 4V peak or 60VDC are present A good safety practice is to expect that hazardous voltage is present in any unknown circuit before measuring Operators of this product must be protected from electric shock at all times The responsible body must ensure that operators are prevented access and or insulated from every connection point In some cases connections must be exposed to potential human contact Product operators in these circumstances must be trained to protect themselves from the risk of electric shock If the circuit is capable of operating at or above 1000 volts no conductive part of the circuit may be exposed Do not connect switching cards directly to unlimited power circuits They are intended to be used with impedance limited sourc es NEVER connect switching cards directly to AC mains When connecting sources to switching cards install protective de vices to limit fault current and voltage to the card Before operating an instrument make sure the line cord is connected to a properly grounded power receptacle Inspect the con necting cables test leads and jumpers for possible wear cracks or breaks before each use When installing equipment where access to the main power cord is restricted such as ra
258. naddressed to talk on LAG LA Listener basic listener unaddressed to listen on TAG SRI Service Request capability RLI Remote Local capability PPO No Parallel Poll capability DC1 Device Clear capability DTI Device Trigger capability CO No Controller capability El Open collector bus drivers TEO No Extended Talker capability LEO No Extended Listener capability The codes define Model 2182 capabilities as follows SH Source Handshake Function SH1 defines the ability of the instrument to initiate the transfer of message data over the data bus AH Acceptor Handshake Function AHI defines the ability of the instrument to guarantee proper reception of message data transmitted over the data bus T Talker Function The ability of the instrument to send data over the bus to other devices is provided by the T function Instrument talker capabilities T5 exist only after the instrument has been addressed to talk L Listener Function The ability for the instrument to receive device dependent data over the bus from other devices is provided by the L function Listener capabilities L4 of the instrument exist only after it has been addressed to listen SR Service Request Function SR1 defines the ability of the instrument to request service from the controller RL Remote Local Function RL1 defines the ability of the instrument to be placed in the remote or local modes F 14 IEEE 488 Bus Overvie
259. nductance calculations dV calculations While the dV calculations for the first six dV readings are shown in Figure I 7 the follow ing formula can be used to calculate any dV reading in the test Where X Y and Z are the three A D measurements for a dV reading n Reading Number 1 Example Calculate the 21st dV reading X Y and Z are the three A D measurements for the 21st dV reading n Reading Number 1 21 1 20 Therefore X Y Z Y ee A ee dV e 1 X Y Z Y 2 2 2 The 1 term in the dV calculation is used for polarity reversal of every other calculated dV reading This makes all calculated dV readings in the test the same polarity Simplified dV calculation The above dV calculation can be simplified as follows X Y Z Y 2 n m w dV 5 1 dV ZIER y Delta Pulse Delta and Differential Conductance I 17 Measurement units The fundamental measurement for Differential Conductance is differential voltage dV However the dV reading can be converted into a differential conductance dG differen tial resistance dR or power Watts reading by the Model 622x With Ohms dR or Siemens dG measurement units selected the reading is calculated as follows dR dV dI dG dI dV With Power measurement units selected power is calculated using Average Voltage and Average Current and is explained in the following paragraphs Av
260. ne active talker or communications would be scrambled F 4 IEEE 488 Bus Overview A device is placed in the talk or listen state by sending an appropriate talk or listen command These talk and listen commands are derived from an instrument s primary address The primary address may have any value between 0 and 31 and is generally set by rear panel DIP switches or programmed in from the front panel of the instrument The actual listen address value sent out over the bus is obtained by ORing the primary address with 20 For example if the primary address is 7 the actual listen address is 27 27 7 20 In a similar manner the talk address is obtained by ORing the primary address with 40 With the present example the talk address derived from a primary address of 7 would be 47 47 7 40 The IEEE 488 standards also include another addressing mode called secondary addressing Secondary addresses lie in the range of 60 7F Note however that many devices including the Model 2182 do not use secondary addressing Once a device is addressed to talk or listen the appropriate bus transactions take place For example if the instrument is addressed to talk it places its data string on the bus one byte at a time The controller reads the information and the appropriate software can be used to direct the information to the desired location Bus lines The signal lines on the IEEE 488 bus are grouped into three different c
261. necessary you can cut the copper lugs off the Model 2107 Input Cable and connect the wires directly to your test circuit If soldering use silver solder to minimize thermal EMFs Temperature Simulated Reference Connections For temperature measurements using an external simulated reference junction simply wrap or clamp the thermocouple wires around the copper lugs or bare wires of the input cable Customized connections Temperature measurements using the internal reference junction require that the thermocouple wires be soldered directly to a LEMO connector that mates to the input of the Model 2182 Silver solder should be used to minimize thermal EMFs Figure 2 3 shows terminal identification for a LEMO connector Figure 2 3 LEMO connector terminal identification Channel 1 HI Channel 1 LO Channel 2 HI Channel 2 LO Rear View 2 14 Voltage and Temperature Measurements To make these customized connections you can modify the supplied input cable or you can use the LEMO connector that is included with the optional Model 2182 KIT CAUTION Silver solder has a high temperature melting point Take care not to damage the LEMO connector by applying excessive heat Voltage only connections Single Channel Measurement Connections Figure 2 4 shows typical connections to measure a DUT using a single channel When using Channel 2 its inputs must be referenced to Channel 1 LO as shown in FFigure 2 4B Figure 2 4 Conn
262. nel definition as previously explained Table 8 1 SCPI commands limits Commands Description Default Note CALCulate3 CALCulate3 Subsystem LIMit Configure and control Limit 1 UPPer n Set upper HI1 limit 100e6 to 100e6 1 LOWer n Set lower LO1 limit 100e6 to 100e6 i STATe lt b gt Enable or disable Limit 1 test OFF FAIL Query test result 0 pass 1 fail 1 CLEar Path to clear fail indication 2 IMMediate Clear fail indication AUTO lt b gt Enable or disable auto clear ON LIMit2 Configure and control Limit 2 UPPer n Set upper HI2 limit 100e6 to 100e6 2 LOWer n Set lower LO2 limit 100e6 to 100e6 2 STATe lt b gt Enable or disable Limit 2 test OFF FAIL Query test result 0 pass 1 fail 1 CLEar Path to clear fail indication IMMediate Clear fail indication AUTO lt b gt Enable or disable auto clear ON QMMediate Re perform limit tests 3 8 6 Limits NOTES 1 The fail message 0 for a limit test indicates that the reading is outside the specified limits 2 With auto clear enabled the fail message 0 is cleared when the instrument goes back into the idle state If programmed not to go back into idle you can manually clear the fail condition by sending the CLEar IMMediate command With auto clear disabled the fail condition will have to be cleared manually 3 When not in a continuous measurement mode waiting fo
263. nsitive instrumentation is connected to other instrumentation with more than one signal return path such as power line ground As shown in Figure C 2 the resulting ground loop causes current to flow through the Measurement Considerations C 7 instrument LO signal leads and then back through power line ground This circulating current develops a small but undesirable voltage between the LO terminals of the two instruments This voltage will be added to the source voltage affecting the accuracy of the measurement Figure C 2 Power line ground loops Signal Leads Instrument 1 Instrument 2 Instrument 3 Loop n X Current X Power Line Ground Figure C 3 shows how to connect several instruments together to eliminate this type of ground loop problem Here only one instrument is connected to power line ground Ground loops are not normally a problem with instruments like the Model 2182 that have isolated LO terminals However all instruments in the test setup may not be designed in this manner When in doubt consult the manual for all instrumentation in the test setup Figure C 3 Eliminating ground loops Instrument 1 Instrument 2 Instrument 3 Power Line Ground C 8 Measurement Considerations Shielding Proper shielding of all signal paths and sources being measured is important to minimize noise pickup in virtually any low level measurement situation Otherwise interference from such noise sources as line frequen
264. nt stack the connector Two screws are located on each connector to ensure that connections remain secure Current standards call for metric threads which are identified with dark colored screws Earlier versions had different screws which were silver colored Do not use these types of connectors on the Model 2182 because it is designed for metric threads Figure 11 2 shows a typical connecting scheme for a multi unit test system Remote Operation 11 7 Figure 11 2 IEEE 488 connections Instrument Instrument Instrument Controller To avoid possible mechanical damage stack no more than three connectors on any one unit NOTE To minimize interference caused by electromagnetic radiation use only shielded IEEE 486 cables Available shielded cables from Keithley are Models 7007 1 and 7007 2 To connect the Model 2182 to the IEEE 488 bus follow these steps 1 Lineup the cable connector with the connector located on the rear panel The connector is designed so that it will fit only one way Figure 11 3 shows the location of the IEEE 488 connector Figure 11 3 IEEE 486 connector location 11 8 Remote Operation 2 Tighten the screws securely making sure not to over tighten them 3 Connect any additional connectors from other instruments as required for your application 4 Make sure that the other end of the cable is properly connected to the controller Most controllers are equipped with an IEEE 488 style c
265. nt enable register sess nennen 12 5 Standard event status register 0 eee eee eeeeeseeeseeseeeseeseeeaeeseeeaeceeseaeeeeeeaeseaeeaes 12 7 Service request enable register sess eee 12 13 Status byte feglslef curet e rte Ra ade e p REP e ER RR ERE Ree 12 15 Additional SCPI Commands ASCII data format o1 tie e t t FE CR atte HE A gr pna 15 4 IEE754 single precision data format 32 data bits esses 15 5 IEEE754 double precision data format 64 data bits sess 15 5 Measurement event register rennen eene eene 15 8 Questionable event register ciere trie eerte rne rb Tet ica ope kc 15 9 Operation event register sess nen ene etre enne nenne 15 10 Measurement event enable register essere nennen 15 12 Questionable event enable register eese 15 12 Operation event enable register eese eee 15 13 Keypress ende 15 21 Measurement Considerations Thermal EMF generation rettet tette cenae ttti tere ete tbc Power line ground loops titt tetti etiamne iis Eliminating ground loops eese nemen nen enne Shielding example hn Rp erp rte tri e et P tex E n ERR Meter loading vsisi IEEE 488 Bus Overview IEBE 488 bus configuratiOn ettet ttr entree eos tar snb IEEE 488 handshake sequence
266. nts are then used in an algorithm to calculate the reading of the input signal This process is known as autozeroing Internally the Model 2182 has two amplifiers that have an impact on speed noise drift and offset These performance aspects can be controlled to some degree by controlling the available autozeroing modes The front end amplifier is controlled by Front Autozero and the second amplifier is controlled by Autozero Voltage and Temperature Measurements 2 7 Front Autozero With Front Autozero for the front end amplifier enabled which is the default setting the Model 2182 performs two A D measurement cycles for each reading The first one is a normal measurement cycle and the second one is performed with the polarity of the amplifier reversed This two cycle polarity reversal measurement technique is used to cancel internal offsets in the amplifier With Front Autozero disabled the second A D measurement cycle is not performed Benefits of Front Autozero disabled Twice as fast Lower Pumpout Current noise Drawbacks of Front Autozero disabled High drift 20u V C in normal voltage mode High offset voltage 500uV in normal voltage mode NOTE To increase the speed of Delta measurements disable Front Autozero The two measurement cycle polarity reversal technique used by Front Autozero is not required for Delta Delta uses its own polarity reversal technique to cancel offsets Delta measurements are cov
267. nue External Event detection is satisfied for any of the following three conditions Aninput trigger via the Trigger Link line EXT TRIG is received The front panel TRIG key is pressed The Model 2182 must be taken out of remote before it will respond to the TRIG key Use the LOCAL key or send LOCAL 707 over the bus Trigger command TRG or GET received over the bus Delay A programmable delay is available after event detection It can be set manually or an auto delay can be used With auto delay the Model 2182 selects a delay based on the selected voltage range The auto delays are listed in Table 7 1 There is no auto delay for temperature measurements Auto Delay is typically used for external scanning The nominal delay will be just long enough to allow each relay to settle before making the measurement Table 7 1 Auto delay times Delay Time Range DCV1 DCV2 10mV lms 100mV lms lms 1V lms lms 10V lms lms 100V 5ms The delay function is accessed by pressing SHIFT and then DELAY The present delay setting AUTO or MANual is displayed Press the amp or W key to display the desired setting and press ENTER If MANual is chosen also enter the duration of the delay using the lt q P A and V keys The maximum is 99H 99M 99 999S Press ENTER to accept the delay or EXIT for no change Triggering 7 5 Device action The primary device action is a measurement However the device acti
268. odel 182 device dependent command summary Mode Command Description Note Display ASCII String AO Restore display to normal 1 Al string Display string up to 12 characters Display Resolution BO 5 2 digit resolution Bl 6 2 digit resolution B2 3V5 digit resolution B3 4V5 digit resolution Calibration None C Calibration commands not supported 2 Filter Damping DO Configure filter damping off same as P2 DI Configure filter damping on same as P3 Reading Source FO Latest reading from A D converter Fl One reading from buffer F2 All readings in buffer F3 Maximum value in buffer F4 Minimum value in buffer Reading Format GO Reading only 3 Gl Reading with prefix G2 Reading with buffer location G3 Reading with buffer location and prefix Immediate Trigger HO Initiate manual trigger 4 Buffer Configuration IO Disable buffer 5 Il value Buffer on value buffer size Analog Output JO Disable analog output relative 6 Relative J1 Enable analog output relative using last reading as Rel value J2 value Enable analog output relative using value le 9 to 120 J3 Enable analog output relative EOI Bus Hold off KO Enable EOI enable bus hold off on X Kl Disable EOI enable bus hold off on X Model 182 Emulation Commands D 3 Table D 1 Model 182 device dependent command summary cont d Mode Command Description Note K2 Enable EOI disable bus hold off on X K3 Disable EOI disable bus hold off on X Sa
269. of silver solder to minimize thermal EMFs You can order a 20 foot length of silver solder from Keithley part number 2182 3254 Included with the solder is an MSDS sheet listing the solder chemical contents CAUTION _ Silver solder has a high temperature melting point Take care not to damage a LEMO connector or any other device by applying excessive heat Model 2107 input cable The Model 2107 Input Cable which is a supplied accessory is terminated with a LEMO con nector on one end and copper lugs on the other end The cable is shielded to chassis ground when connected to the Model 2182 The cable wires are made from twisted silver wire The input cable is shown in Figure 2 2 This cable can be used to make voltage measurements and temperature measurements that use an external simulated reference junction Voltage and Temperature Measurements 2 13 Figure 2 2 Model 2107 input cable 2182 Red HI CHANNEL 1 Channel 1 LO HI CHANNEL 2 120V MAX Channel 2 12V MAX CATI 350V PEAK ANY TERMINALTO CHASSIS Voltage Connections Mechanically connect clamp the cleaned copper lugs of the cable to the cleaned copper connectors of the test circuit For the test circuit use clean 10 copper bus wire wherever possible Clean copper to copper connections minimize thermal EMFs which could corrupt a measurement See Cleaning test circuit connectors located in this section If
270. og output to zero CALL SEND CALL SEND CALL SEND CALL SEND CALL SEND 7 7 7 7 7 u He u u u Syst pres status sens volt rang 0 01 status routp gain 10 status 0utp on status soutp rel on status Restore System Preset defaults Select 10mV range Set analog output gain to 10 Enable analog output Enable analog output rel Remote Operation 11 2 Remote Operation Selecting and configuring an interface Explains how to select and configure an interface GPIB or RS 232 GPIB operation and reference Covers the following GPIB topics e GPIB Bus Standards GPIB Bus Connections e Primary Address Selection e QuickBASIC Programming General Bus Commands Front Panel GPIB Operation e Status Structure e Programming Syntax e RS 222 interface reference Provides basic reference information for the RS 232 interface and explains how to make connections to the computer Remote Operation 11 3 Selecting and configuring an interface Interfaces The Model 2182 Nanovoltmeter supports two built in remote interfaces e GPIB Interface e RS 232 Interface You can use only one interface at a time At the factory the GPIB bus is selected You can select the interface only from the front panel The interface selection is stored in non volatile memory it does not change when power has been off or after a remote interface reset GPIB interface The
271. ointer detects a colon that immediately follows a semicolon it resets back to the root level The path pointer can only move down It cannot be moved up a level Executing a command at a higher level requires that you start over at the root command 11 26 Remote Operation Using common commands and SCPI commands in the same message Both common commands and SCPI commands can be used in the same message as long as they are separated by semicolons A common command can be executed at any command level and will not affect the path pointer stat oper enab lt NRf gt ESE lt NRf gt Program message terminator PMT Each program message must be terminated with an LF line feed EOI end or identify or an LF EOI The bus will hang if your computer does not provide this termination The following example shows how a program message must be terminated out sscan 1 5 lt PMT gt Command execution rules e Commands execute in the order that they are presented in the program message An invalid command generates an error and of course is not executed Valid commands that precede an invalid command in a multiple command program message are executed Valid commands that follow an invalid command in a multiple command program message are ignored Response messages A response message is the message sent by the instrument to the computer in response to a query command program message Sending a response message
272. old example Press SHIFT and then HOLD to display the present window 0 01 0 1 1 or 10 To change the window press the amp or W key to display the desired window Press ENTER The present hold count is displayed 2 to 100 To change the hold count use the lt q P gt A and V keys to display the desired count Press DCV1 to measure voltage on Channel 1 Apply the test signal to Channel 1 of the Model 2182 Once the signal becomes stable enough to satisfy the hold condition the reading is released and the beeper sounds if enabled 7 Remove the hold condition by disconnecting the signal from Channel 1 Hold will then seek a new seed 8 To disable HOLD press SHIFT and then HOLD QNUM dS DIS p Beeper control The beeper for Hold can be enabled or disabled from the ON OFF LIMITS menu as follows 1 Press ON OFF to display the beeper selections NEVER OUTSIDE and INSIDE Perform step A or B A To enable the beeper use the or to key to display OUTSIDE or INSIDE B To disable the beeper use the amp or V to key to display NEVER 3 Press ENTER The instrument returns to the normal display state However limit testing is enabled 4 Ifyou wish to disable limit testing press ON OFF Limit testing is covered in Section 8 Triggering 7 7 External triggering The EX TRIG key selects triggering from two external sources trigger link and the TRIG key When EX TRIG is pressed the TRIG annunciator ligh
273. on block could include the following additional actions refer to Figure 7 2 Figure 7 2 Device action From Delay block To Output Trigger of Figure 7 1 block of Figure 7 1 Filter DEVICE ACTION Filtering If the repeating filter is enabled the instrument samples the specified number of reading conversions to yield single filtered reading Only one reading conversion is performed if the filter is disabled or after the specified number of reading conversions for a moving average filter is reached After a reading Rdg is procured operation proceeds to Hold Hold The Hold feature is used to screen out reading anomalies When enabled the user selects a window and count for Hold In general when a reading is outside the window it is rejected operation loops back to be beginning of the Device Action as shown in Figure 7 2 The hold count specifies how many readings have to be within the window before it is accepted See Reading hold autosettle for operation details After a Hold Reading is acquired operation proceeds to Channel Closure Channel closure When stepping or scanning the last device action is channel control Using the hold feature provides an auto settling time for switching relays Each open close transition will restart the hold process and a reading for each channel will not occur until the relay settles Output trigger After the device action an output trigger occurs and is avail
274. onding to the SDC command GTL Go To Local The GTL command is used to remove instruments from the remote mode With some instruments GTL also unlocks front panel controls if they were previously locked out with the LLO command GET Group Execute Trigger The GET command is used to trigger devices to perform a specific action that depends on device configuration for example take a reading Although GET is an addressed command many devices respond to GET without addressing Address commands Addressed commands include two primary command groups and a secondary address group ATN is true when these commands are asserted The commands include LAG Listen Address Group These listen commands are derived from an instrument s primary address and are used to address devices to listen The actual command byte is obtained by ORing the primary address with 20 TAG Talk Address Group The talk commands are derived from the primary address by ORing the address with 40 Talk commands are used to address devices to talk SCG Secondary Command Group Commands in this group provide additional addressing capabilities Many devices including the Model 2182 do not use these commands Unaddress commands The two unaddress commands are used by the controller to remove any talkers or listeners from the bus ATN is true when these commands are asserted UNL Unlisten Listeners are placed in the listener idle state by the U
275. onization When enabled noise induced by the power line is reduced at the expense of speed Select filter analog and or digital and configure digital filter window count and type Enables disables relative for Analog Output Enables disables Analog Output Configure temperature measurement units junction type thermocouple type sensor type Selects external triggering front panel bus or trigger link as trigger Source Triggers a measurement from the front panel Sets reading count for buffer and enables buffer Displays stored readings including maximum minimum peak to peak average and standard deviation The amp and range keys scroll through the buffer and the lt q and P gt key toggles between reading number and reading Set the upper and lower limits for limit testing Enables disables limit testing and selects beeper mode for limit testing Controls cursor position for making selections or editing values Sets user delay between trigger and measurement Holds reading when the specified number of samples is within the selected tolerance Getting Started 1 9 Bottom Row Un shifted STEP Steps through channels sends a trigger after each channel SCAN Scans through channels sends a trigger after last channel SAVE Saves present configuration for power on user default RESTR Restores factory or user default configuration DIGITS Changes number of digits of reading resolution RATE Changes reading ra
276. onnection points for the input cable and the thermocouple wires are immersed in the ice bath Figure 2 7 Connections temperature simulated reference 2107 Thermocouple Input Cable Test Circuit Ice Bath Cable to thermocouple wire connection one of two Voltage and temperature connections Channel 1 should be used for voltage measurements since it supports a wider range of measurements leaving Channel 2 to measure temperature A connection example using the internal reference junction for temperature measurements is shown in Figure 2 8 In this example Channel 1 measures the voltage drop across the DUT and Channel 2 measures the temperature of the DUT Notice the jumper wire from the thermocouple to test circuit low If the case of the DUT is metal and already connected to test circuit low the jumper would not be needed Also if there is enough thermal bonding between the DUT and test circuit low the thermocouple can be connected directly to low Figure 2 8 Connections voltage and temperature internal reference Copper wire soldered directly Cable to copper to LEMO connector one of wire connection two one of two J Thermocouple HI o y CH 1 DCV1 D LO o HI o CH 2 TEMP2 Test Circuit LO o 2182 2 Thermocouple wire soldered directly to LEMO connector one of two Voltage and Temperature Measurements 2 17 Figure 2 9 shows the same test except that a
277. onnector but a few may require a different type of connecting cable See your controllers instruction manual for information about properly connecting to the IEEE 488 bus NOTE You can only have 15 devices connected to an IEEE 486 bus including the controller The maximum cable length is either 20 meters or two meters times the number of devices whichever is less Not observing these limits may cause erratic bus operation Primary address selection The Model 2182 ships from the factory with a GPIB address of 07 When the instrument powers up it momentarily displays the primary address You can set the address to a value of 0 30 Do not assign the same address to another device or to a controller that is on the same GPIB bus Usually controller addresses are 0 or 21 but see the controllers instruction manual for details Make sure the address of the controller is the same as that specified in the controllers programming language The primary address is checked or changed from the GPIB menu which is accessed by pressing SHIFT and then GPIB Press the amp or WV key to display the present address i e ADDR 07 To change the GPIB address 1 Press SHIFT and then GPIB to access the GPIB configuration menu 2 Usethe A or V key to display the present address i e ADDR 07 3 Use the lt q gt A and V keys to display a valid address value and press ENTER 4 Return to the main display by pressing EXIT QuickBASIC program
278. ontrols except for LOCAL and POWER are inoperative while the instrument is in remote You can restore normal front panel operation by pressing the LOCAL key IFC interface clear The IFC command is sent by the controller to place all instruments on the bus in the local talker listener idle states The initialize routine CALL INITIALIZE uses this command internally The Model 2182 responds to the IFC command by canceling front panel TALK or LSTN lights if the instrument was previously placed in one of those states Note that this command does not affect the status of the instrument settings data and event registers are not changed To send the IFC command the controller must set the IFC line true for a minimum of 100 Program Fragment CALL INITIALIZE 21 0 Initialize GPIB system sends IFC and set interface card address to 21 LLO local lockout Use the LLO command to prevent local operation of the instrument After the unit receives LLO all its front panel controls except the POWER are inoperative In this state pressing LOCAL will not restore control to the front panel The GTL command restores control to the front panel Remote Operation 11 11 Program Fragment CALL TRANSMIT UNL LISTEN 7 LLO status Lock out front panel CALL TRANSMIT UNL LISTEN 7 GTL status Lock out front panel GTL go to local Use the GTL command to put a remote mode instrument into local mode The GTL command also
279. ore enabled conditions occur The STB query command does not clear the status byte register This register can only be cleared by clearing the related registers and queues For example for an acquired decimal value of 48 the binary equivalent is 00110000 This binary value indicates that bits 4 and 5 of the Status Byte Register are set The bits of the Status Byte Register are described as follows Bit 0 Measurement Status MSB A set bit indicates that a measurement event has occurred The event can be identified by reading the Measurement Event Status Register using the STATus MEASurement command see Section 5 for details Bit 1 Not used Bit 2 Error Available EAV A set bit indicates that an error or status message is present in the Error Queue The message can be read using one of the following SCPI commands SYSTem ERRor STATus QUEue See Section 15 for more information Bit 3 Questionable Summary Bit QSB A set bit indicates that a calibration error has occurred Bit 4 Message Available MAV A set bit indicates that a message is present in the Output Queue The message is sent to the computer when the Model 2182 is addressed to talk Bit 5 Event Summary Bit ESB A set bit indicates that an enabled standard event has occurred The event can be identified by reading the Standard Event Status Register using the ESE query command Bit 6 Master Summary Status MSS Request Service RQS A
280. other Delta measurement Ratio and Delta 5 15 Filter considerations The filter configuration for DCV1 is applied separately to each measurement phase V1t1 and V1t2 of the Delta process NOTE The repeating filter cannot be used for Delta measurements When Delta is selected the Filter will automatically switch to the moving filter if the repeating filter was enabled Moving filter After filtering yields a reading for V1t1 an output trigger is sent After filtering yields a reading for V1t2 another output trigger is sent The Delta calculation is performed and the reading is displayed For example assume the filter count for the Moving Filter is 5 Two filter stacks are used one for V1t1 readings and one for V1t2 readings The filter stack for V1t1 readings is filled with five measurement conversions The five readings are averaged to yield the V1t1 value and an output trigger is sent on each V1t1 A D conversion The filter stack for V1t2 readings is then filled with five measurement conversions The five readings are averaged to yield the V1t2 value and an output trigger is sent On each V1t2 A D conversion the Delta calculation is performed using the filtered V1t1 and V1t2 values and the result is displayed on the Model 2182 For every subsequent Delta measurement the operation is basically the same except that each stack only requires one reading to fill it The oldest reading in each stack is discarded NOTE The filter con
281. ounter COUNt lt n gt Set sample count 1 to 1024 1 Notes 1 The lt list gt parameter is formatted as follows lt list gt X Y Where X is the Min channel Y is the Max channel 2 The parameters are explained as follows NONE Disables all operations associated with a scan INTernal Enables an internal scan EXTernal Enables an external scan 3 Defaults for trigger count SYSTem PRESet sets the count to INF infinite RST sets the count to 1 Stepping and Scanning 9 13 Programming example The following program fragment performs a five measurement internal scan The five readings are stored in the buffer and displayed on the computer CRT CALL SEND 7 rst status Restore RST defaults CALL SEND 7 samp coun 5 status Set sample count to 5 CALL SEND 7 rout scan int cco 4 status Set channel 1 count to 4 CALL SEND 7 rout scan lsel int status Enable internal scan CALL SEND 7 read status Trigger scan and request readings reading SPACES 80 CALL ENTER reading length 2 7 status Address 2182 to talk PRINT reading Display the 5 readings on the CRT 9 14 Stepping and Scanning Application l V curves using internal scan SCAN for IV curves Measure V sweep I constant H magnetic field or T temperature SCAN can be used to measure V while sweeping the current through a sample with a constant magnetic field or a constant tempera
282. ow voltage 1V measurements If using Channel 2 for measurements below 1V and the impedance between Channel 2 LO and Channel 1 LO is 2100kQ pumpout current could be high enough to corrupt measurements For details see Performance considerations Pumpout current low charge injection mode in this section Voltage measurements The Model 2182 has two voltage measurement functions DCV1 and DCV2 DCV1 is available for input Channel 1 and DCV2 is available for Channel 2 DCV1 Channel 1 has five measurement ranges 10mV 100mV 1 V 10V and 100V and can measure voltage from InV to 120V DCV2 Channel 2 has three measurement ranges 100mV 1V and 10V and can measure voltage from 10nV to 12V Accuracy for each channel is listed in the specifications Appendix A Temperature measurements The Model 2182 has two temperature measurement functions TEMP1 and TEMP2 TEMPI is available for input Channel 1 and TEMP2 is available for Channel 2 Depending on which thermocouple type is used J K T E R S B or N the Model 2182 can measure temperature from 200 C to 1820 C The specifications Appendix A provide the measurement ranges for the various thermocouple types 2 4 Voltage and Temperature Measurements NOTE The Model 2182 can also measure its internal temperature Whenever the internal temperature changes more than I degree an ACAL must be performed to maintain specified accuracy See Performance considerations
283. p the SourceMeter can function as a bipolar fixed amplitude source For example if the test requires a fixed current of 1mA the custom sweep can be configured to alternate between 1mA and 1mA see Figure 5 8 By enabling Delta measurements on the Model 2182 the effects of thermal EMFs in the test leads will automatically be canceled during the source measure process Figure 5 8 SourceMeter output 2 point custom sweep atm PO PO 0 1mA P1 P1 The procedure to use the SourceMeter and Model 2182 to perform Delta measurements is provided in Delta measurement procedure using a SourceMeter That procedure presented earlier in this section under Delta uses a 2 point custom sweep which is required for this application 5 22 Ratio and Delta Superconductor Application 2 fixed magnetic field Another typical test on a superconductor sample DUT is to source an increasing amplitude current I through the DUT while maintaining the magnetic field H at a fixed level The I V curve in Figure 5 9 shows that the measured voltage across the DUT remains at OV for low currents I This is the flat portion of the curve where the DUT remains at 0 At some point the voltage drop across the DUT will start increasing as current through the DUT increases The actual resistance of the DUT can be calculated at any current source point using Ohm s law R V I where R is actual resistance of the DUT V is the measured voltage a
284. places the coded result 0 or 1 in the Output Queue When the Model 2182 is addressed to talk the coded result is sent from the Output Queue to the computer A returned value of zero 0 indicates that the test passed and a value of one 1 indicates that the test failed 12 16 Common Commands WAI Wait to Continue Prevent execution of commands until previous commands are completed Description Two types of device commands exist Sequential commands A command whose operations are allowed to finish before the next command is executed Overlapped commands A command that allows the execution of subsequent commands while device operations of the Overlapped command are still in progress Use the WAI command to suspend the execution of subsequent commands until the device operations of all previous Overlapped commands are finished The WAI command is not needed for Sequential commands The Model 2182 has three overlapped commands e INITiate e INITiate CONTinuous ON TRG NOTE See OPC OPC and TRG for more information The INITiate commands remove the Model 2182 from the idle state The device operations of INITiate are not considered complete until the Model 2182 returns to idle By sending the WAI command after the INITiate command all subsequent commands will not execute until the Model 2182 goes back into idle The TRG command issues a bus trigger that could be used to provide the arm scan
285. ple 7 6 ice bath 2 16 2 17 Idle 7 3 IEEE command groups F 12 IEEE 488 and SCPI Conformance Information G 1 IEEE 488 Bus Overview F 1 Inspection 1 3 Interface function codes F 13 Interface selection and configuration procedures 11 4 Interfaces 11 3 Internal scanning 9 4 9 8 Internal stepping 9 9 Internal Stepping Scanning Channels and 2 9 3 IV curves 9 14 Josephson Junction Arra 2 27 Languages 11 3 Limit operations 8 3 Limits 8 1 Line power connection 1 14 Log sweep 5 24 Low power switches 2 24 Low level considerations 2 22 Low resistance measurement 2 23 LSYNC line cycle synchronization 2 8 magnetic field 5 20 5 22 C 6 Manualranging 3 3 Maximum readings 3 3 Measurement Considerations C 1 Measurement considerations C 2 Measurement overview 2 3 Measurement Queries H 1 Measuring voltage and temperature 2 19 Meter loading C 9 Model 182 Emulation Commands D 1 Model 2107 input cable 2 12 mX b 4 6 mX b and percent 4 6 Nanovoltmeter features 1 6 Noise 2 22 One shot reading DC volts bus trigger auto ranging H 5 One shot reading DC volts no trigger fastest rate H 5 One shot reading external trigger auto delay enabled H 5 One shot triggering E 4 Options and accessories 1 4 Other Stepping Scanning operations 9 6 OUTPut command summary 14 6 Output trigger 7 5 Percent 4 7 Performance commands 15 16 Performance considerations 2 5 Power Up 1 14 Power up sequen
286. pm of range for 1PLC with 10 reading Digital Filter 6 Channel 2 must be referenced to Channel 1 Channel 2 HI must not exceed 125 referenced to Channel 1 LO of Channel 2 range selected 7 Noise behavior using 2188 Low Thermal Short after 2 5 hour warm up 1 C Analog Filter off Observation time 10X response time or 2 minutes whichever is less 8 For Lsync On line frequency 0 1 If Lsync Off use 60dB 9 For 1kQ unbalance in LO lead AC CMRR is 70dB 10 For Low Q mode On add the following to DC noise and range accuracy at stated response time 200nV p p 25s 500nV p p 4 0s 1 20 V p p 1s and 5uV p p 85ms After 2 5 hour warm up 1 C 5PLC 2 minute observation time Channel 1 10mV range only 2 For Channel 1 or Channel 2 add 0 3 C for external reference junction Add 2 C for internal reference junction 3 Speeds are for 60Hz 50Hz operation using factory defaults operating conditions RST Autorange Off Display Off Trigger Delay 0 Analog Output off 4 Speeds include measurements and binary data transfer out the GPIB Analog Filter On 4 readings s max Auto Zero Off NPLC 0 01 LOmV range 80 readings s max a nw Sample count 1024 Auto Zero Off 8 For Lsync On reduce reading rate by 15 9 For Channel 2 Low Q mode Off reduce reading rate by 30 20 Front Auto Zero Off Auto Zero Off 21 Applies to measurements of room temperature resistances lt 10Q I
287. r On Logical OR Always Zero ESR ESE ESE Measurement Measurement Measurement Event Condition Event Enable Register Register Register Reading Overfolw ROF Low Limit 1 High Limit 1 97 Low Limit 2 S High Limit 2 Reading Available Buffer Available Logical Buffer Half Full Buffer Full Logical OR Error Queue Service Request Enable Register Status Byte Register MSB 1 EAV QSB MAV ESB RQS MSS STB Master Summary Status MSS MSB Measurement Summary Bit EAV Error Available QSB Questionable Summary Bit MAV Message Available ESB Event Summary Bit RQS MSS Request for Service Master Summary Staus OSB Operation Summary Bit Note RQS bit is in serial poll byte MSS bit is in STB response Operation Operation Operation Event Condition Event Enable Calibrating Measuring Trigger Layer Filter Settled Idle Register Register Register Logical OR Remote Operation 11 15 Condition registers As Figure 11 4 shows some register sets have a condition register A condition register is a real time read only register that constantly updates to reflect the present operating conditions of the instrument For example while a measurement is being performed bit
288. r a trigger you can change the limits and re test the last reading After changing the limits send CALCulate3 IMMediate to re perform the limit tests on the last reading Note that sending IMMediate does not initiate trigger a reading It simply repeats the limit tests on the last reading Programming example The following program fragment performs limit tests on a voltage input to Channel 1 Configure 2182 for one shot DCV1 measurements Put 2182 in CALL SEND 7 rst status Configure limit tests CALL SEND 7 calc3 lim upp 0 1 status CALL SEND 7 calc3 lim low 0 1 status CALL SEND 7 calc3 lim2 upp 1 status CALL SEND 7 calc3 lim2 10w 1 status CALL SEND 7 calc3 lim stat on status CALL SEND 7 calc3 lim2 stat on status Trigger one reading and display it CALL SEND 7 read status reading SPACES 80 CALL ENTER reading lengths 7 status PRINT reading Check result of Limit 1 test CALL SEND 7 calc3 lim fail status reading SPACES 80 CALL ENTER reading length 7 status PRINT reading Check result of Limit 2 test CALL SEND 7 calc3 lim2 fail status reading SPACES 80 CALL ENTER reading length 7 status PRINT reading Set HI1 Set LO1 Set HI2 Set LO2 a one shot mode limit to 0 1 limit to 0 1 limit to 1 limit to 1 Enable Limit 1 test Enable Limit 2 test Trigger and request a reading
289. r channels are not averaged with the present channel NOTES The repeating filter cannot be used with Delta measurements If the repeating filter is selected when Delta is enabled the instrument will default to the moving filter Delta measurements are covered in Section 5 The moving filter cannot be used when stepping or scanning If the moving filter is selected when a step or scan is enabled the instrument will default to the repeating filter Stepping and scanning are covered in Section 9 3 10 Range Digits Rate and Filter Figure 3 2 Moving and repeating filters Conversion 10 Conversion 9 8 7 6 L Reading 5 1 4 3 2 i Conversion 1 Conversion A Type Moving Average Readings 10 Conversion 10 Conversion 9 8 7 ji 6 L e Reading e 5 1 e 4 e 3 2 Conversion 1 Conversion B Type Repeating Readings 10 Digital filter example Filter Count 10 Filter Window 0 01 of range Filter Type Moving 11 10 9 8 7 6 5 4 3 2 20 19 18 17 16 15 14 13 12 11 L Reading 2 Reading 2 Conversion 12 11 10 9 8 Reading 7 3 6 5 4 Conversion 3 Conversion Reading 3 Conversion Ten readings fill the stack to yield a filtered reading Now assume the next reading which is the 11 is outside the window A reading will be processed displayed however the stack w
290. racter THEN found an individual reading so store it as such Readings ReadingOn VAL OneReading OneReading clear out so able to read next individual reading ReadingOn ReadingOn 1 increment counter for next individual reading ELSE still building an individual reading so add on the next character OneReading OneReading OneCharacter END IF CurrentPosition CurrentPosition 1 increment character on in the buffer response LOOP UNTIL CurrentPosition length loop until pass the number of characters read in with the buffer response Readings ReadingOn VAL OneReading store last individual reading since it will not be separated by a comma Calculate DataIC and DataV values where Chan2 is the CH2 numerical representation for string CH2 data and Chanl is the CH1 numerical representation for string CH1 data CHlpos is the positive portion for channel 1 CHlneg is the negative portion for channel 1 k 1 represents the reading in Reading to use in calculation FOR j 1 TO CalcReadings Chan2 Readings k Chan2 Chan2 2 DataCH2 j STR Chan2 CHlpos 0 CHineg 0 FOR i Stepping and Scanning Reading k NumRdgsPerStep 1 TO NumRdgsPerStep 1 CHlpos CHlpos Reading k i CHineg NEXT i Chanl DataCH1 j STRS Chan1 k k NumRdgsPerStep 2 NEXT j Printing results to a file OPEN chanl xls FOR OUTPUT A
291. rcuit connection to the Model 2182 Temperature configuration Explains how to configure the Model 2182 for temperature measurements Measuring voltage and temperature Provides the basic step by step procedure to make measurements Includes the SCPI commands for remote operation Low level considerations Explains two external factors that can corrupt low level measurements thermal EMFs and noise Applications Provides some typical applications for the Model 2182 These include Testing Switch Contacts Voltage and Temperature Measurements 2 3 Measurement overview The Model 2182 provides two input channels for DC voltage and temperature measurements Table 2 1 lists the measurements that can be performed by the two channels NOTE Measurement queries are used to trigger and or return readings Details are provided in Section 7 Section 13 and Appendix H Table 2 1 Measurement channels Measurement Input Channel s To Use Voltage Channel 1 Temperature Channel 1 Voltage and Voltage Channel 1 and Channel 2 Voltage and Temperature Channel 1 and Channel 2 Channel 1 is used as the fundamental measurement channel while Channel 2 provides sense measurements Because of this operational relationship between the two channels Channel 2 cannot be used as an independent stand alone measurement channel Its inputs must be referenced to Channel 1 LO NOTE Asa general rule use Channel 1 whenever possible for l
292. rials include hard anodized aluminum sapphire and diamond Nulling residual thermal offsets Even if all reasonable precautions are taken some residual thermal offsets may still be present These offsets can be minimized by using the Model 2182 Relative feature to null them out To do so place the instrument on the 3mV range and short the end of the connecting cable nearest the measured source first disconnect the cable from the source to avoid shorting out the source After allowing the reading to settle press the front panel REL button to null the offset Select the appropriate range and make your measurement as usual If the offset voltage varies the DC current reversal technique should be used instead of REL The DC current reversal technique requires a source that can output currents equal in magnitude but opposite in polarity In general a voltage measurement is performed on both the positive and negative alternations of the current source The averaged difference of those two readings cancels the thermal EMF component of the measurements The Model 2182 can automatically perform the measurements and calculate and display the result by using the Delta measurement mode See Delta in Section 5 for details Source resistance noise Noise present in the source resistance is often the limiting factor in the ultimate resolution and accuracy of Model 2182 measurements The paragraphs below discuss the generation of Johnson noise as well a
293. rs the trigger model must be configured for it Figure 7 4 Trigger link input pulse specifications EXT TRIG Triggers on Leading Edge TTL High 2V 5V TTL Low lt 0 8V lt 2us Minimum Voltmeter complete The VMC output provides a TTL compatible output pulse that can be used to trigger other instruments The specifications for this trigger pulse are shown in Figure 7 5 Typically you would want the Model 2182 to output a trigger after the settling time of each measurement Figure 7 5 Trigger link output pulse specifications VMC Meter Complete TTL High 3 4V Typical TTL Low 0 25V Typical 1 Ops Minimum Triggering 7 9 External triggering example In a typical test system you may want to close a channel and then measure the DUT connected to the channel with the Model 2182 Such a test system is shown in Figure 7 6 which uses a Model 2182 to measure eight DUTs switched by a Model 7168 Nanovolt Scanner Card in a Model 7001 7002 Switch System See Section 9 for details on external scanning Figure 7 6 DUT test system H o DCV1 Output Channel 1 A e o L S o Channel 2 p e epo Ax o ks Channel 8 og aio 7168 Nanovolt Scanner Card The Trigger Link connections for this test system are shown in Figure 7 7 Trigger Link of the Model 2182 is connected to Trigger Link either IN or OUT of the
294. rs based on a number of power line cycles NPLC where 1 PLC for 60Hz is 16 67msec 1 60 and 1 PLC for 50Hz and 400Hz is 20msec 1 50 In general the Model 2182 has a parabola like shape for its speed vs noise characteristics and is shown in Figure 3 1 The Model 2182 is optimized for the 1 PLC to 5 PLC reading rate At these speeds Lowest noise region in the graph the Model 2182 will make corrections for its own internal drift and still be fast enough to settle a step response 100ms Figure 3 1 Speed vs noise characteristics A Lowest Voltage noise Noise region a aaa 166 7us 16 67ms 83 33ms Is Aperture Time You can have a separate rate setting for voltage and temperature functions The rate setting for a voltage function applies to the other voltage function For example if you set DCV1 for 0 1 PLC fast DCV2 will also be set for 0 1 PLC fast Similarly the rate setting for a temperature function applies to the other temperature function Setting TEMPI for 5 PLC slow also sets TEMP2 for 5 PLC slow Front panel RATE selections are explained as follows 0 1 PLC Selects the fastest front panel integration time Select 0 1 PLC fast if speed is of primary importance at the expense of increased reading noise 1 PLC Selects a medium integration time Select 1 PLC medium when a compromise between noise performance and speed is acceptable e 5 PLC Selects the slowest front panel integr
295. rst DATA data SYSTem PRESet isystem preset Long form and short form versions A SCPI command word can be sent in its long form or short form version The command subsystem tables in Section 14 are in the long form version However the short form version is indicated by upper case characters SYSTem PRESet long form SYST PRES short form SYSTem PRES long form and short form combination Note that each command word must be in either long form or short form For example SYSTe PRESe is illegal and will generate an error The command will not be executed 11 24 Remote Operation Short form rules Use the following rules to determine the short form version of any SCPI command If the length of the command word is four letters or less no short form version exists auto auto These rules apply to command words that exceed four letters If the fourth letter of the command word is a vowel delete it and all the letters after it immediate imm Rule exception The short form version of the following command uses only the first two letters of the word TCouple tc If the fourth letter of the command word is a consonant retain it but drop all the letters after it format form If the command contains a question mark or a non optional number included in the command word you must include it in the short form version delay del Command words or characters that are enclosed in brackets
296. ry Reads the Status Byte Register TRG Trigger command Sends a bus trigger to the 2182 TST Self test query Performs a checksum test on ROM and returns the result WAI Wait to continue command Wait until all previous commands are executed Common Commands 12 3 CLS Clear Status Clear status registers and error queue Description Use the CLS command to clear reset to 0 the bits of the following registers in the Model 2182 Standard Event Register e Operation Event Register Error Queue e Measurement Event Register Questionable Event Register This command also forces the instrument into the operation complete command idle state and operation complete query idle state 12 4 Common Commands ESE lt NRf gt Event Enable Program the standard event enable register ESE Event Enable Query Read the standard event register Parameters lt NR amp O Clear register 1 Set OPC BO 4 Set QYE B2 8 Set DDE B3 16 Set EXE B4 32 Set CME B5 64 Set URQ B6 128 Set PON B7 255 Set all bits Description Use the ESE command to program the Standard Event Enable Register This command is sent with the decimal equivalent of the binary value that determines the desired state 0 or 1 of the bits in the register This register is cleared on power up This register is used as a mask for the Standard Event Register When a standard event is masked the occurrence of that event will not set t
297. s 962 DDC Ready SE 963 DDC Reading Done SE 964 DDC Buffer Half Full SE 965 DDC Buffer Full SE 966 DDC Reading overflow SE EE error event SE status event SYS system error event B 5 B 6 Status and Error Messages C Measurement Considerations C 2 Measurement Considerations Measurement considerations Low level voltage measurements made using the Model 2182 can be adversely affected by various types of noise or other unwanted signals that can make it very difficult to obtain accurate voltage readings Some of the phenomena that can cause unwanted noise include thermoelectric effects thermocouple action source resistance noise magnetic fields and radio frequency interference The following paragraphs discuss the most important of these effects and ways to minimize them NOTE For comprehensive information on low level measurements see the Low Level Measurements handbook which is available from Keithley Thermoelectric potentials Thermoelectric potentials thermal EMFs are small electric potentials generated by differences in temperature at the junction of dissimilar metals The following paragraphs discuss how such thermals are generated and ways to minimize their effects Thermoelectric coefficients As shown in Table C 1 the magnitude of thermal EMFs generated depends on the particular materials involved Best results are obtained with clean copper to copper connections as indicate
298. s connections esesseeeeneene een nennen nennen nennen 11 6 Primary address selection ie itt reete riori etre histo epa Rn 11 8 QuickBASIC programming esses nennen enne nnne nnne 11 8 General bus commands eerte rtt tnter siers iiis daia 11 9 Front panel GPIB operation esses nennen nennen 11 12 Status SIMUCLUTS 5 11 13 Programming Syntax oo eeeeesceseeesseceseeeseceseeeeaeceseeesaeceeecsaeseneeeeaeeeneeeeaeees 11 21 12 13 14 RS 232 1ntetface Teference see a etre cece eeu E ERE e vessesusdecdedsoectaeteeee 11 27 Sending and receiving data ssseseisvaresseieisscesgscoasecousevecseeacsveraveasesuadatateaesnsectes 11 27 Baud rate flow control and terminator ccccccsssccceeeessseeeeeesssseeeeeesseee 11 27 RS 232 COMMECHONS 3 esi etie cr Ue PH E ERR ERE RE EET ERR ean 11 29 Io messages PE m 11 30 Common Commands CLS Clear Status Clear status registers and error queue 12 3 ESE NRf Event Enable Program the standard event enable register 12 4 ESE Event Enable Query Read the standard event register 12 4 ESR Event Status Register Query Read register and clear it 12 6 DN Identification Query Read the identification code 12 7 OPC Operation Complete Set the OPC bit in the standard event register af
299. s continue to be placed in the stack If the signal changes to a value outside the window the filter resets and the filter starts processing again starting with a new initial conversion value from the A D converter The five window selections from the front panel are 0 01 0 1 1 10 of range and NONE no window For remote operation the window can be set to any value from 0 01 to 10 or NONE For voltage the filter window is expressed as a percent of range For example on the 10V range a 10 window means that the filter window is 1 V For temperature the filter window is expressed as a percent of the maximum temperature reading The maximum temperature depends on which thermocouple is being used For example for a Type J thermocouple the maximum reading is 760 C a 10 window means that the filter window is 76 C Filter type There are two digital filter types moving and repeating The moving average filter uses a first in first out stack When the stack becomes full the measurement conversions are averaged yielding a reading For each subsequent conversion placed in the stack the oldest conversion is discarded and the stack is re averaged yielding a new reading This process is depicted in Figure 3 2A For the repeating filter the stack is filled and the conversions are averaged to yield a reading The stack is then cleared and process starts over see Figure 3 2B Choose this filter for scanning so readings from othe
300. s enabled when XonXoFF is selected from the RS232 FLOW menu When the input queue of the Model 2182 becomes more than 3 4 full the instrument issues an X_OFF command The control program should respond to this and stop sending characters until the Model 2182 issues the X_ON which it will do once its input buffer has dropped below half full The Model 2182 recognizes X_ON and X_OFF sent from the controller An X_OFF will cause the Model 2182 to stop outputting characters until it sees an X_ON Incoming commands are processed after the lt CR gt character is received from the controller NOTE For RS 232 operation OPC or OPC should be used with slow responding commands A list of the slowest responding commands and details on OPC and OPC are provided in Section 12 If NONE is the selected flow control then there will be no signal handshaking between the controller and the Model 2182 Data will be lost if transmitted before the receiving device is ready Terminator The Model 2182 can be configured to terminate each program message that it transmits to the controller with any of the following combinations of lt CR gt and lt LF gt e LF line feed CR carriage return e LFCR line feed carriage return e CRLF carriage return line feed RS 232 connections The RS 232 serial port can be connected to the serial port of a controller i e personal computer using a straight through RS 232 cable terminated with DB 9 connectors Do not
301. s the proportional relationship between the two voltage input channels DCV1 and DCV2 Ratio is calculated as follows Ratio V1 V2 Where V1 is the voltage reading for Channel 1 DCV1 V2 is the voltage reading for Channel 2 DCV2 Basic procedure Ratio is selected by pressing the V1 V2 key The CH1 CH2 message appears briefly before displaying the result of the calculation The RA message is displayed while in Ratio Ratio is disabled by selecting a single measurement function DCV1 DCV2 TEMPI or TEMP2 or by selecting Delta NOTES When Ratio is selected one of the channel annunciators CH1 or CH2 will turn on briefly This indicates the channel that can be controlled by the manual range key After that both the CH1 and CH2 annunciators will turn on See Ranging considerations for details f an overflow condition OVRFLW occurs the range that overflowed will format the display Ratio readings can be stored in the buffer See Section 6 for details on using the buffer Reading HOLD cannot be used with Ratio Selecting Ratio or Delta disables HOLD LSYNC line cycle integration must be enabled when RATIO is selected LSYNC turns on automatically when RATIO is selected and turns off automatically when exiting RATIO Ratio and Delta 5 3 Step 1 Connect voltages to be measured to the Model 2182 Details on connecting the Model 2182 to the voltages to be measured are provided in Section 2 see
302. s ways to minimize such noise Measurement Considerations C 5 Johnson noise equation The amount of noise present in a given resistance is defined by the Johnson noise equation as follows Egus V4kTRF where Eggs rms value of the noise voltage k Boltzmann s constant 1 38 x 1025J K T Temperature K R Source resistance ohms F Noise bandwidth Hz At a room temperature of 293K 20 C the above equation simplifies to Epms 127 x 10 RF Since the peak to peak noise is five times the rms value 99 of the time the peak to peak noise can be equated as follows EL 22435 1079 JRE For example with a source resistance of 10kQ the noise over a 0 5Hz bandwidth at room temperature will be E 6 35 x 10 4 10 x 10 0 5 E 45nV Minimizing source resistance noise From the above examples it is obvious that noise can be reduced in several ways 1 lower the temperature 2 reduce the source resistance and 3 narrow the bandwidth Of these three lowering the resistance is the least practical because the signal voltage will be reduced more than the noise For example decreasing the resistance of a current shunt by a factor of 100 will also reduce the voltage by a factor of 100 but the noise will be decreased only by a factor of 10 Very often cooling the source is the only practical method available to reduce noise Again however the available reduction is not as large as it might seem because t
303. sabling Front Autozero Delta uses its own current reversal technique to cancel offsets Therefore the dual measurement technique of Front Autozero is not required See Autozeroing modes in Section 2 for more information including benefits and drawbacks on Front Autozero Additional SCP Commands 15 17 AZERO STATe lt b gt SYSTem AZERo STATe lt b gt Control Autozero Parameters lt b gt 0 or OFF Disable Autozero 1 or ON Enable Autozero Description With autozero disabled measurement speed is increased However the zero and gain reference points will eventually drift resulting in inaccurate readings of the input signal It is recommended that autozero only be disabled for short periods of time NOTE See Performance considerations in Section 2 for more information on autozero LSYNc lt b gt SYSTem LSYNe lt b gt Control line cycle synchronization Parameters lt b gt 0 or OFF Disable line cycle synchronization 1 or ON Enable line cycle synchronization Description When enabled A D conversions are synchronized with the power line frequency This reduces noise at the expense of speed Line cycle synchronization LS YNC is not available for integration rates lt 1 PLC regardless of the LSYNC setting NOTE See Performance considerations in Section 2 for more information on LSYNC FRequency SYSTem LFRequency Read power line frequency setting Description On power up the Model 218
304. se A carrying case for a Model 2182 Includes handles and shoulder strap 1 6 Getting Started Nanovoltmeter features The Model 2182 is a 7V5 digit high performance digital nanovoltmeter It has two input channels to measure voltage and temperature The measurement capabilities of the Model 2182 are explained in Section 2 of this manual see Measurement overview Features of the Model 2182 Nanovoltmeter include Ratio Provides comparison readings between two voltage inputs Ratio performs VI1 V2 Delta Provides average difference of Channel 1 inputs Delta performs V1t1 V1t2 2 Enhanced Delta Pulse Delta and Differential Conductance The following tests can be performed when using a Model 2182 2182A with a Model 6220 or 6221 Current Source Delta Uses a square wave output and a 3 point measurement algorithm to cancel the effects of thermal EMFs Pulse Delta 6221 and 2182A only Provides a pulse output and a 3 point or 2 point measurement algorithm for testing of temperature sensitive Device Under Test DUT Differential Conductance Uses a differential current output and a 3 point moving average algorithm to perform differential measurements mX b and Percent These calculations provide mathematical manipulation of readings Relative Null offsets or establish baseline values Buffer Store up to 1024 readings in the internal buffer Limits Set high and low reading limits to test dev
305. seeseesceeseeeeceseeesseseseoeseneeeesenecsetenerseeseeerers 9 7 Stepping Scanning examples eseeeeeeseeeeee nennen eene eee nennen nennen 9 8 Internal Scannig ncc aie te tr tee Dg EPE ERE RE ETETEN 9 8 Internal Steppithg L2 ertet recie ener tee tace AEE RAE NEEE 9 9 Io dont Ae M 9 10 SCPI programming stepping and scanning see 9 12 Programming example 52 2 tin tr Rn pe He p Re Perna 9 13 Application I V curves using internal scan esee 9 14 SCAN for IV curves Measure V sweep I constant H magnetic field or T t mper tute ei eee tetur tate t UR EN E PATE Ms eR URA S Reges 9 14 Analog Output c n 10 3 nocle mE 10 5 Analog output connections ssesseseeeeeeeneenen een ene eere eere 10 5 Configure and control analog output esee 10 5 Analog output rel eee epe edere pute Y dede Dod edis rada 10 5 SCPI programming analog output eeeseeeeeeeeeneeen ene em nee 10 6 Programming example etes assetto es tede e dta eene ii ia 10 6 Remote Operation Selecting and configuring an interface sss 11 3 Interfaces m RR 11 3 WAP BUA DCS EE 11 3 Interface selection and configuration procedures sess 11 4 GPIB operation and reference sess nennen rennes 11 6 GPIB bus standatds 5 nne ero tecie mti e Ree eges 11 6 GPIB bu
306. sidered finished until the Model 2182 goes back into the idle state See the description for WAI for more information on command execution When used with the TRG command the OPC bit will not set until the operations associated with the TRG command and the initiate command are finished The TRG command is considered to be finished when the Device Action completes or when operation stops a control source to wait for an event see Trigger model in Section 7 To use the OPC exclusively with the TRG command first force the completion of the initiate command so that only the TRG command is pending Do this by sending the ABORt command to place the instrument in idle which by definition completes the initiate command Since continuous initiation is on operation continues into the Trigger Model After sending the TRG command the OPC bit sets when the TRG command is finished Common Commands 12 9 Program example The first group of commands send the OPC command after the INITiate command and verifies that the OPC bit in the Standard Event Status Register does not set while the instrument continues to make measurements not in idle The second group of commands returns the Model 2182 to the idle state and verifies that the OPC bit did set SYST PRES INIT CONT OFF Return 2182 to default setup Disables continuous initiation ABORt Aborts operation Places 2182 in idle INIT IMM Initiate one trigger cycle OP
307. so note that channel voltage differential reduces the maximum measurement capability of Channel 2 Normally Channel 2 can measure up to 12V However a 2V differential reduces the maximum measurement capability of Channel 2 to 10V In Figure 2 5A a gt 10V input to Channel 2 will cause an overflow condition NOTE Channel 2 HI or LO cannot be more than 12V peak from Channel 1 LO Figure 2 5 Connections dual channel voltage Cable to copper 2107 wire connection Input Cable one of four red HI 9 CH 1 DCV1 black ae LO 10V HI 9 green CH2 green CH 2 DCV2 DUT 10V range DCV2 o LO white LO white 2182 Test Circuit 2182 Note Channel 2 HI or LO must not exceed 12V from Channel 1 LO A Typical Measurement Configuration B Voltage Differential Between Channels Temperature only connections Channel 1 of the Model 2182 can be used to make temperature measurements Figure 2 6 shows connections using the internal reference junction Keep in mind that the thermocouple wires must be soldered directly to a LEMO connector as previously explained Figure 2 6 Connections temperature internal reference Thermocouple wire soldered directly to LEMO connector one of two Test Circuit Thermocouple 2 16 Voltage and Temperature Measurements Figure 2 7 shows temperature only connections using an ice bath as a simulated reference junction Note that the c
308. source range lt 20uA 22 Display off delay 1ms RKN 6 08 04 Rev A Page 3 of 3 Status and Error Messages B 2 Status and Error Messages Table B 1 Status and error messages Number Description Event 440 Query unterminated after indefinite response EE 430 Query deadlocked EE 420 Query unterminated EE 410 Query interrupted EE 363 Input buffer overrun SYS 350 Queue overflow SYS 330 Self test failed EE 314 Save recall memory lost EE 315 Configuration memory lost EE 260 Expression error EE 241 Hardware missing EE 230 Data corrupt or stale EE 225 Out of memory EE 224 Illegal parameter value EE 223 Too much data EE 222 Parameter data out of range EE 221 Settings conflict EE 220 Parameter error EE 215 Arm deadlock EE 214 Trigger deadlock EE 213 Init ignored EE 212 Arm ignored EE 211 Trigger ignored EE 210 Trigger error EE 202 Settings lost due to rtl EE 201 Invalid while in local EE 200 Execution error EE 178 Expression data not allowed EE 171 Invalid expression EE 170 Expression error EE 168 Block data not allowed EE 161 Invalid block data EE 160 Block data error EE 158 String data not allowed EE 154 String too long EE 151 Invalid string data EE 150 String data error EE Table B 1 cont Status and error messages Status and Error Messages Number Description Event 148 Character data not allowed EE 144 Character data too long EE 141
309. t and a READ NOTE Appendix H provides additional information on the measurement query commands This appendix describes what each command does its limitations and appropriate situations for its use CONFigure function Parameters function VOLTage DC Voltage TEMPerature Temperature Query CONFigure Query the selected function Description This command configures the instrument for subsequent measurements on the specified function Note that the input channel does not change For example if TEMP2 Channel 2 is presently selected sending CONFigure VOLT selects DCV2 Channel 2 This command places the instrument in a one shot measurement mode You can then use the READ command to trigger a measurement and acquire a reading see READ When this command is sent the Model 2182 will be configured as follows The function specified by this command is selected Input channel remains the same Allcontrols related to the selected function are defaulted to the RST values Continuous initiation is disabled INITiate CONTinuous OFF The control source of the Trigger Model is set to Immediate The count values of the Trigger Model are set to one The delay of the Trigger Model is set to zero The Model 2182 is placed in the idle state All math calculations are disabled SCPI Signal Oriented Measurement Commands 13 3 Buffer operation is disabled A storage operation presently
310. t operation 1 or ON enables the operation and 0 or OFF disables the operation Upper case characters indicate the short form version for each command word Default Parameter Listed parameters are both the RST and SYSTem PRESet defaults unless noted otherwise Parameter notes are located at the end of each table Ref Refers you to the section Sec that provides operation information for that command or command subsystem SCPI A checkmark V indicates that the command and its parameters are SCPI confirmed An unmarked command indicates that it is a SCPI command but does not conform to the SCPI standard set of commands It is not a recognized command by the SCPI consortium SCPI confirmed commands that use one or more non SCPI parameters are explained by notes SCPI Reference Tables 14 3 Table 14 1 CALCulate command summary Default Command Description Parameter Ref SCPI CALCulate 1 Path to configure and control KMATh calculations Sec 4 V FORMat lt name gt Select math format NONE MXB or PERCent NONE V FORMat Query math format Vv KMATh Configure math calculations MMFactor lt NRf gt Set m for mX b calculation 100e6 to 100e6 1 MMFactor Query m factor MBFactor lt NRf gt Set b for mX b calculation 100e6 to 100e6 0 MBFactor Query b factor MUNits lt name gt Specify units for mX b result up to 2 characters MX A through Z V degrees symbol P o
311. t panel trigger models for stepping and scanning are shown in Figure 9 1 and Figure 9 2 These are expansions of the basic front panel trigger model that is presented and explained in Section 7 see Figure 7 1 The following discussions focus on the stepping and scanning operations Be sure to refer to Section 7 for additional information on the various components of trigger models Internal scanning Figure 9 1 shows the front panel trigger model for internal scanning The components of the trigger model are explained as follows Control source Immediate With immediate triggering event detection occurs immediately allowing operation to drop down to the next trigger model block Delay Timer The timer is used to control the time interval between internal scans It has no effect on the time interval between each measurement in a scan cycle When SCAN is pressed the timer starts and event detection occurs immediately allowing operation to drop down to Delay If configured for an additional scan operation will later loop back to this control source where it will wait until the timer interval expires If the timer interval is already expired event detection will be satisfied immediately External trigger After the internal scan is configured pressing the EX TRIG key places the instrument in the external trigger mode When the SCAN key is pressed the internal scan is enabled However it doesn t start until an external trig
312. t the thermal EMF component of the measurements The Model 2182 can automatically perform the measurements and then calculate and display the result by using the Delta measurement mode For Delta measurements a Keithley SourceMeter Model 2400 2410 or 2420 or the Keithley Model 220 Current Source can be used to provide current reversal Details on performing Delta measurements are provided in Section 5 Testing switch contacts Low power switches Figure 2 11 shows how the Model 2182 can be used to measure the resistance of a switch contact The constant current is provided by the Keithley Model 220 current source which can source up to 100mA To avoid oxide puncture the voltage across the switch contact should be lt 20mV Voltage is limited by choosing a current that will not result in a larger voltage drop than 20mV For example with a contact resistance specified at 5 00mQ the current should be no larger than 40mA Figure 2 11 Measuring switch contact resistance Model 220 Current Source DCV1 Test Circuit 2182 With current known and voltage measured resistance can be calculated using Ohms Law R V I Voltage and Temperature Measurements 2 25 High power switches Heat is a factor in high power switching As the temperature of the switch increases so does the contact resistance In Figure 2 12 heat is generated in the switch by sourcing a constant high current i e 10A through it Figure 2 1
313. t voltage will be 0 316V The measurement ranges in C for the various thermocouple types are listed in the specifications see Appendix A With Gain set to 1 and Offset set to 0 analog output voltage for temperature measurements is calculated as follows Analog Output 1 2 x Rdg Rng Rng is a magnitude Therefore it is always a positive value Example Calculations Type J 100 C Reading Type J 100 C Reading Analog Output 1 2 x 100 760 Analog Output 1 2 x 100 760 158mV 158mV When using Gain and Offset the calculation is expanded as follows Analog Output Gain x 1 2 x Rdg Rng Offset Ratio Analog Output can be used with Ratio When enabled the analog output voltage is scaled to a Ratio value of 1 That is the analog output will be 1V for a Ratio result of 1 If for example the Ratio is 0 4 analog output voltage will be 0 4V Gain Offset and Analog Output Rel can also be used However the maximum analog output is 1 2V Analog Output 10 5 Operation Analog output connections The analog output is accessed from the rear panel BNC connector that is labeled ANALOG OUTPUT This connector requires a cable that is terminated with a standard male BNC connector Output resistance The output resistance of Analog Output is 1kQ 5 To minimize the effects of loading the input resistance of the device connected to Analog Output should be as high as possible For example with a devi
314. tage setting fuse replacement and the power up sequence Display Provides information about the display of the Model 2182 Default settings Covers the two instrument setup configurations available to the user user defined or factory default Getting Started 1 3 General information Warranty information Warranty information is located at the front of this manual Should your Model 2182 require warranty service contact the Keithley representative or authorized repair facility in your area for further information When returning the instrument for repair be sure to fill out and include the service form at the back of this manual to provide the repair facility with the necessary information Contact information Worldwide phone numbers are listed at the front of this manual If you have any questions please contact your local Keithley representative or call one of our Application Engineers at 1 800 348 3735 U S and Canada only Safety symbols and terms The following symbols and terms may be found on the instrument or used in this manual The AX symbol on an instrument indicates that the user should refer to the operating instructions located in the manual The A symbol on an instrument shows that high voltage may be present on the terminal s Use standard safety precautions to avoid personal contact with these voltages The WARNING heading used in this manual explains dangers that might result in personal injury or
315. te number of power line cycles PLC EXIT Cancels selection moves back to measurement display ENTER Accepts selection moves to next choice or back to measurement display Shifted CONFIG Configures a scan type timer channel count and reading count HALT Turns off step scan operation GPIB Enables disables GPIB sets address and selects language RS232 Enables disables RS 232 interface selects baud rate flow control and terminator CAL Accesses calibration TEST Tests display annunciators and front panel keys 3 Range keys A Selects the next higher voltage measurement range v Selects the next lower voltage measurement range AUTO Enables disables autorange 1 10 Getting Started 4 Display annunciators asterisk lt gt more speaker AUTO BUFFER CHI CH2 CH1 and CH2 ERR FAST FILT HOLD LSTN MATH MED REAR REL REM SCAN SHIFT SLOW SRQ STAT STEP TALK TIMER TRIG 5 Input connector CHANNEL 1 CHANNEL 2 6 Handle Readings being stored in buffer Indicates additional selections are available Beeper on for limit testing Autorange enabled Recalling readings stored in buffer Channel 1 input displayed Channel 2 input displayed Ratio V1 V2 reading displayed Questionable reading or invalid cal step Fast 0 1 PLC reading rate selected Filter enabled Instrument in hold mode Instrument addressed to listen over GPIB mX b or Percent calculation enabled Medium
316. ted temperature RTEMperature Query internal temperature Sec 2 NPLCycles n Set integration rate in line cycles PLC 0 01 to 60 5 Sec 3 60Hz or 0 01 to 50 50Hz NPLCycles Query NPLC APERture n Set integration rate in seconds 166 67e 6 to 1 83 33 60Hz or 200e 6 to 1 50Hz APERture Query Aperture DIGits n Set display resolution 4 to 7 6 Sec 3 DIGits Query display resolution CHANnell Channel 1 temperature commands REFerence n Specify reference Rel value for Channel 1 328 0 Sec4 to 3310 STATe lt b gt Enable or disable Rel OFF STATe Query state of Rel ACQuire Use input signal as Rel REFerence Query Rel value LPASs Control analog filter for TEMPI Sec 3 STATe lt b gt Enable or disable analog filter OFF STATe Query state of analog filter DFILter Configure and control digital filter Sec 3 WINDow n Specify filter window in 96 0 to 10 0 01 WINDow Query filter window COUNt n Specify filter count 1 to 100 10 COUNt Query filter count TCONtrol lt name gt Select filter type MOVing or REPeat MOVing TCONtrol Query filter type STATe lt b gt Enable or disable digital filter ON STATe Query state of digital filter 14 10 SCPI Reference Tables Table 14 7 SENSe command summary cont Default Command Description Parameter Ref SCPI CHANneD Channel 2 temperature commands REFerence n Spec
317. ter to output the next source value The trigger link connections required for this application are shown in Figure 5 12 Notice that the output trigger VMC required from the Model 2182s is provided by unit 1 VMC from unit 2 must not be used Figure 5 12 Trigger link connections using two Model 2182s SourceMeter 2182 1 2182 2 Rear Panel Rear Panel Rear Panel 8501 Trigger Link Cable 8503 Trig Link DIN to BNC I Trigger Cables Adapter VMC not used 8502 Trigger Link Adapter Buffer 6 2 Buffer Buffer operations Explains how to store and recall readings including buffer statistics minimum maximum peak to peak average and standard deviation SCPI programming Covers the SCPI commands used to control buffer operations Buffer operations The Model 2182 has a buffer to store from two to 1024 readings and units It also stores the channel number for step scan readings and overflow readings In addition recalled data includes statistical information minimum maximum peak to peak average and standard deviation NOTE _ Statistics are not calculated when an overflow reading has been stored in the buffer The buffer fills with the specified number of readings and stops Readings are placed in the buffer after any math operations are performed Math operations include Relative Ratio or Delta and mX b or Percent Buffered data is overwritten each time the storage opera
318. ter all pending commands are complete 12 8 OPC Operation Complete Query Place a 1 in the output queue after all pending operations are completed 12 10 RCL Recall Return to setup stored in memory eee 12 11 RST Reset Return 2182 to RST defaults see 12 12 SAV Save Save present setup in memory sseeeeeeeeee 12 12 SRE lt NRf gt Service Request Enable Program service request IEDJESIC Scam 12 12 SRE Service Request Enable Query Read service request enable teglstet ete eh ette eee top ee trees FER PESE NAE NER e ase Fey tS 12 12 STB Status Byte Query Read status byte register esses 12 14 TRG Trigger Send bus trigger to 2182 sss 12 15 TST Self Test Query Run self test and read result 12 15 W AI Wait to Continue Prevent execution of commands until previous commands are completed sssseeee 12 16 SCPI Signal Oriented Measurement Commands CONFigure function Lese da terret rrt tiu be ead eno asta d CER ea e eua seasons 13 2 SPECI ges D H 13 3 READ iii bct a e tee ae Ute antes ea enn des 13 3 MEASure functlon uicina tire rte ede eE te abate ea Heap s db ESA 13 4 SCPI Reference Tables 15 Additional SCPI Commands DISPlay Subsystem ccccseccis T
319. the voltage across the DUT is now negative Therefore the Model 2182 will measure 90 V Voigg Vruerm Vpur 10V 1000V 90uV As demonstrated in Figure 5 1 neither measurement by the Model 2182 accurately measured the voltage across the DUT However if you take a simple average of the magnitudes of the two readings 110p V and 90uV the result is 1009 V which is the actual voltage drop across the DUT This is what the calculation for Delta does 5 8 Ratio and Delta To use the DC current reversal technique replace the constant current source with a bipolar current source as shown in Figure 5 2 The current source will alternate between 1mA and 1mA When using Delta the Model 2182 performs the first voltage measurement V 1t1 while sourcing 1mA The second voltage measurement V1t2 is performed while sourcing 1mA NOTE When using the Model 2182 to perform Delta measurements RATE must be set to 1 PLC or 5 PLC to optimize measurement performance At 1 PLC or 5 PLC Delta measurements will cancel thermal EMFs to a 50nV level Vitl Vguggu VpurV 1127 Vrgggu Vpur 10nV 100p V 10uV 100nV 110uV 90nV Delta is then calculated as follows Vitl V1t2 _ 110uV 90uV _ y 100uV Delta 2 2 Using Delta with a bipolar source effectively canceled the 10u V thermal EMF External triggering is required to control the timing between voltage measurements and current source reversals Trigger synchronizat
320. the voltage measured by the nanovoltmeter is V Figure C 5 Meter loading Ae Vs VM Source Measured Voltage Voltage The voltage actually measured by the meter is attenuated by the voltage divider action of Rg and Ry and it can be calculated as follows z SU MR Rg This relationship can be modified to directly compute for percent error 100R Percent error Ri Rs From the above equation it is obvious that the input resistance of the Model 2182 must be at least 999 times the value of source resistance if loading error is to be kept to within 0 1 C 10 Measurement Considerations D Model 182 Emulation Commands D 2 Model 182 Emulation Commands The Model 2182 can be configured to accept device dependent commands of the Keithley Model 182 Sensitive Digital Voltmeter The commands for controlling the Model 2182 with the 182 language are provided in Table D 1 For details on Model 182 operation refer to the Model 182 Instruction Manual Since the architecture of the Model 2182 differs from that of the Model 182 some commands are different and cannot be used Be sure to refer to the notes at the end of the table for information on command restrictions CAUTION The 182 language is intended to be used only over the IEEE 488 bus Using front panel controls in conjunction with this language may cause erratic operation In this case results cannot be guaranteed Table D 1 M
321. three A D measurements for the 21st Delta reading n Delta Cycle Number 1 21 1 20 Therefore Delta f e p _ X 2Y Z 4 The 1 term in the Delta calculation is used for polarity reversal of every other calculated Delta reading This makes all calculated Delta readings in the test the same polarity l 8 Delta Pulse Delta and Differential Conductance Delta calculation example Assume you wish to measure the voltage across a 1Q DUT using a constant 10mA cur rent source and a voltmeter Ideally the measured voltage would be 10mV V I x R However due to a 10y V thermal EMF in the test leads the voltmeter actually reads 10 01mV 0 1 error due to EMF The error contributed by EMF can be eliminate by using Delta Assume the square wave output of the Model 622x is set to 1OmA high and 10mA low and the following Model 2182 2182A measurement conversions A Ds are made for the first Delta cycle A D A 10 01mV A D B 9 99mV A D C 10 01mV The first Delta reading is calculated as follows Delta o xy 4 E 10 01mV 2 9 99mV 10 01m i 4 Ru E 4 10mV The 10mV Delta reading effectively cancelled the 10uV EMF to provide a more accurate measurement Measurement units The fundamental measurement for Delta is voltage Volts V However the voltage read ing can converted into a conductance Siemens S resistance Ohms W or power Watts W reading by the Model 622x
322. tiation SYSTem PRESet enables continuous initiation RST disables continuous initiation 2 Defaults for Trigger Count SYSTem PRESet sets count to INF infinite RST sets count to 1 14 14 SCPI Reference Tables Table 14 12 UNIT command summary Default Command Description Parameter Ref SCPI UNIT TEMPerature name Select temperature units C F or K C Vv TEMPerature Query temperature units v 15 Additional SCPI Commands 15 2 Additional SCP Commands DISPlay subsystem Covers the SCPI commands that are used to control the display e FORMat subsystem Covers the SCPI commands to configure the format for read ings that are sent over the bus e STATus subsystem Covers the SCPI commands to configure and control the status registers e SYSTem subsystem Covers miscellaneous SCPI commands Additional SCPI Commands 15 3 DISPlay subsystem The commands in this subsystem are used to control the display of the Model 2182 and are summarized in Table 14 3 ENABle lt b gt DISPlay ENABle lt b gt Control display circuitry Parameters lt b gt 0 or OFF Disable display circuitry 1 or ON Enable display circuitry Description This command is used to enable and disable the front panel display circuitry When disabled the instrument operates at a higher speed While disabled the display is frozen All front panel controls except LOCAL are disabled Normal display
323. ting average measurements to calculate Pulse Delta voltage For each pulse the Model 2182A performs an A D conversion measurement at pulse low pulse high and pulse low Each set of three A D readings yield a single Pulse Delta reading Figure I 1B shows Pulse Delta measurements If device heating is a concern 2 point measurements can instead be used 2nd low pulse not measured due to corruption from heat Differential Conductance The Model 622x outputs a differential current dI sweep and measures differential voltage dV This function uses a 3 point moving average algorithm to calculate dV With dI known and dV calculated the Model 622x can then calculate dif ferential conductance dG or differential resistance dR Figure I 1C shows Differential Conductance measurements l 4 Delta Pulse Delta and Differential Conductance Figure l 1 Delta Pulse Delta and Differential Conductance measurements A Delta measurements 2182 2182A 2182 2182A 2182 2182A A D A D 1st Delta Cycle I High 622x DELTA I Source Reading LOW c i 2182 2182 2182 2182A 2182A 2182A AD i AD A D lt _ 2nd Delta Cycle 3rd Delta Cycle r 4th Delta Cycle B Pulse Delta measurements 2182A 2182A 2182A A D A D A D I High esas 6221 I Source 2182A 2182A 2182A 2182A 2182A 2182A A D A D A D A D A D A D I Low Pulse Delta Pulse Delta
324. tion is selected The data is volatile it is not saved through a power cycle NOTE Measurements performed during stepping or scanning are automatically stored in the buffer There is no need to configure and enable the buffer Stepping and scanning is covered in Section 9 NOTE When changing the interface GPIB to RS 232 or vice versa all data in the buffer clears Store Perform the following steps to store readings 1 Set up the instrument for the desired configuration 2 Press the STORE key 3 Use the cursor keys q and p gt and the RANGE A and W keys to set the number of readings to store 2 to 1024 4 Press ENTER to enable the buffer If in the immediate trigger mode the storage process will start immediately If in the external trigger mode each input trigger or press of TRIG key will store a reading NOTE The asterisk annunciator turns on to indicate that the data storage operation is enabled It will turn off when the storage process is finished buffer full Buffer 6 3 Recall Perform the following steps to view stored readings and buffer statistics 1 Press RECALL The BUFFER annunciator turns on to indicate that stored readings are being displayed The arrow annunciator lt gt also turns on to indicate that additional data is available for viewing 2 As shown in Figure 6 1 use the RANGE A and W keys and the cursor lt q and gt keys to navigate through the reading numbers reading values
325. to the AC receptacle on the rear panel Connect the other end of the power cord to a grounded AC outlet WARNING _ The power cord supplied with the Model 2182 contains a separate ground wire for use with grounded outlets When proper connections are made instrument chassis is connected to power line ground through the ground wire in the power cord Failure to use a grounded outlet may result in personal injury or death due to electric shock 4 Turn on the instrument by pressing the front panel power switch to the on 1 position Figure 1 3 Power module Model 2182 Window Fuse Holder Assembly Setting line voltage and replacing fuse A rear panel fuse located next to the AC receptacle protects the power line input of the Getting Started 1 15 instrument If the line voltage setting needs to be changed or the line fuse needs to be replaced perform the following steps WARNING Make sure the instrument is disconnected from the AC line and other equipment before changing the line voltage setting or replacing the fuse 1 Place the tip of a flat blade screwdriver into the power module by the fuse holder assembly see Figure 1 3 Gently push in and move to the left Release pressure on the assembly and its internal spring will push it out of the power module 2 Remove the fuse and replace it with the type listed in Table 1 1 CAUTION For continued protection against fire or instrument damage only replace the fus
326. to the normal operation of the instrument For example when a query command is sent the response message is placed in the Output Queue When data is placed in the Output Queue the Message Available MAV bit in the Status Byte Register sets A data message is cleared from the Output Queue when it is read The Output Queue is considered cleared when it is empty An empty Output Queue clears the MAV bit in the Status Byte Register Read a message from the Output Queue by addressing the Model 2182 to talk after the appropriate query is sent Error queue The Error Queue holds error and status messages When an error or status event occurs a message that defines the error status is placed in the Error Queue This queue will hold up to 10 messages When a message is placed in the Error Queue the Error Available EAV bit in the Status Byte Register is set An error message is cleared from the Error Status Queue when it is read The Error Queue is considered cleared when it is empty An empty Error Queue clears the EAV bit in the Status Byte Register Read an error message from the Error Queue by sending either of the following SCPI query commands and then addressing the Model 2182 to talk SYSTem ERRor e STATus QUEue Remote Operation 11 19 Status byte and service request SRQ Service request is controlled by two 8 bit registers the Status Byte Register and the Service Request Enable Register Figure 11 9 shows the structure o
327. torange v REFerence n Specify reference Rel value for Channel 2 0 Sec 4 V 12 to 12 volts STATe lt b gt Enable or disable Rel ON v STATe Query state of Rel v ACQuire Use the voltage on Channel 2 as Rel REFerence Query Rel value v LPASs Control analog filter for DCV2 Sec3 STATe b Enable or disable analog filter OFF STATe Query state of analog filter DFILter Configure and control digital filter Sec 3 WINDow n Specify filter window in 0 to 10 0 01 WINDow Query filter window COUNt n Specify filter count 1 to 100 10 COUNt Query filter count TCONtrol lt name gt Select filter type MOVing or REPeat MOVing TCONtrol Query filter type STATe lt b gt Enable or disable digital filter ON STATe Query state of digital filter SCPI Reference Tables 14 9 Table 14 7 SENSe command summary cont Default Command Description Parameter Ref SCPI TEMPerature Path to configure temperature TRANsducer lt name gt Specify transducer TCouple or INTernal TCouple Sec2 TRANsducer Query transducer TCouple Thermocouple TC Sec2 TYPE type Set TC type J K T E R S Bor N J TYPE Query TC type RJUNCtion Reference junction 9662 RSELect name Set reference type SIMulated or INTernal INTernal RSELect Query reference type SIMulated n Specify simulated temperature in C 0 to 60 23 SIMulated Query simula
328. tozero ON STATe Query state of Autozero LSYNC Path to control line cycle synchronization STATe lt b gt Enable or disable line cycle synchronization OFF STATe Query state of line cycle synchronization LFRequency Query the power line frequency setting 50 50 or 400Hz 60 60Hz POSetup lt name gt Select power on setup RST PRESet or SAVO POSetup Query power on setup VERSion Query SCPI revision level v ERRor Query system error queue see Note CLEar Clear messages from error queue KCLick b Enable or disable key click feature ON KCLick Query key click status BEEPer Path to control beeper v STATe lt b gt Enable or disable beeper for limit tests ON V STATe Query state of beeper v KEY lt NRf gt Simulate key press v KEY Query the last pressed key v Note Clearing the Error Queue Power up and CLS clears the Error Queue RST SYSTem PRESet and STATus PRE Set have no effect on the Error Queue Table 14 10 TRACe command summary Default Command Description Parameter Ref SCPI TRACel DATA Use TRACe or DATA as root command see Note Sec 6 V DATA Read the contents of the buffer data store V CLEar Clear readings from buffer FREE Query bytes available and bytes in use v POINts lt n gt Specify size of buffer 2 to 1024 v POINts Query buffer size v FEED lt name gt Select source of readings for buffer SENSe 1 Vv C
329. ts and dashes are displayed to indicate the instrument is waiting for an external trigger From the front panel press the TRIG key to trigger a single reading Pressing the EX TRIG key again toggles back to continuous triggers The Model 2182 uses two lines of the Trigger Link rear panel connector as External Trigger EXT TRIG input and Voltmeter Complete VMC output The EXT TRIG line allows the Model 2182 to be triggered by other instruments The VMC line allows the Model 2182 to trigger other instruments At the factory line 1 is configured as VMC and line 2 as EXT TRIG Changing this configuration is described in the Model 2182 Service Manual A connector pinout is shown in Figure 7 3 Figure 7 3 Rear panel pinout Pin Number Description Rear Panel Pinout 1 Voltmeter Complete Output 8 7 IK 6 2 External Trigger Input 5 OCA 3 3 No Connection eo 4 No Connection a 5 No Connection 6 No Connection Pin 2 Pin 1 7 Signal Ground Ls ee 8 Signal Ground Input Output Either pin 3 or 5 may be configured as an output instead of pin 1 Either pin 4 or 6 may be configured as an input instead of pin 2 See the Model 2182 Service Manual for details 7 8 Triggering External trigger The EXT TRIG input requires a falling edge TTL compatible pulse with the specifications shown in Figure 7 4 In general external triggers can be used to control measure operations For the Model 2182 to respond to external trigge
330. ture With the use of a Keithley Model 2400 SourceMeter and a Model 8501 Trigger Link cable see Section 7 for more details on triggering the 2400 can be programmed to sweep the current in a bipolar DC current reversal technique growing amplitude fashion See waveform in Figure 9 4 This sweep will store into the 2182 memory and can be recalled at the end of the sweep By having the 2400 and 2182 in a tight hardware control the DC current reversal technique can be run at a rate of 8 sec at a PLC integration time This will greatly reduce any thermal EMFs in the system by being able to reverse the DC current before any temperature effects can occur Looking for critical currents Ic can be accomplished at a faster reading rate NOTE Channel 1 is used to measure the voltage across the sample while Channel 2 measures the voltage across a known reference Rggp resistor to determine the current in the sample Figure 9 4 Waveform to be programmed into Model 2400 P8 P10 5mA 2mA 1mA 1mA 2mA 5mA Stepping and Scanning 9 15 Set up 2182 Restore factory defaults Filters off Rate 1 plc Ch1 10mV Ch2 1V Ext Trigger on Delay Set to time needed for cable settling Config SCAN INT Timer off Ch1 Count3 Note Ch1 will store 3 readings 2400 programmed current level Ch2 will store 1 reading 2400 programmed current level Rdg Count 48 Figure 9 5 Setup of Model 2182 and Model 2400 8501 Trigger Lin
331. ture readings Clean copper to copper connections minimize thermal EMFs However when measuring very low voltages there may still be enough thermal EMFs to corrupt the measurement In this case use the Relative feature of the Model 2182 to null out that offset See Nulling thermal EMFs which follows the basic measurement procedure Step 1 Connect test circuit to Model 2182 As explained in Connections connect the test circuit to the input of the Model 2182 Figure 2 4 through Figure 2 9 show connections for voltage and temperature measurements Step2 Configure temperature if applicable If temperature measurements are going to be performed configure temperature as previously explained in Temperature configuration Step 3 Measure Channel 1 If Channel 1 is connected to measure voltage press DCV1 If connected to measure temperature press TEMPI Observe the reading on the display The CH1 annunciator indicates that Channel 1 is selected Step4 Measure Channel 2 if applicable NOTE Channel 2 inputs must be referenced to Channel 1 LO If Channel 2 is connected to measure voltage press DCV2 If connected to measure temperature press TEMP2 Observe the reading on the display The CH2 annunciator indicates that Channel 2 is selected 2 20 Voltage and Temperature Measurements Nulling thermal EMFs The following procedure nulls out thermal EMFs using the Relative feature of the Model 2182 For more infor
332. tween Channel 2 LO and Channel 1 LO is gt 100k you can enable the Low Charge Injection Mode to reduce the pumpout current However this mode increases measurement noise by up to 8 times The Low Charge Injection Mode can be enabled or disabled from the GPIB or RS 232 interface The command to control low charge injection is listed in Table 2 2 Low charge injection cannot be enabled from the front panel However it can be disabled from the front panel by restoring factory default conditions 2 10 Voltage and Temperature Measurements SCPI programming ACAL Front Autozero Autozero LSYNC and Low Charge Injection Table 2 2 SCPI commands ACAL Front Autozero Autozero LSYNC and Low Charge Injection Commands Description Default For ACAL CALibration CALibration Subsystem UNPRotected ACALibration ACAL INITiate Prepare 2182 for ACAL STEPI Perform full ACAL 100V and 10mV STEP2 Perform low level ACAL 10mV only DONE Exit ACAL see Note TEMPerature Read the internal temperature in C at the time of the last ACAL SENSe SENSe Subsystem TEMPerature RTEMperature Measure the present internal temperature in C For Front Autozero SYSTem SYSTem Subsystem FAZero state b Enable or disable Front Autozero ON For Autozero SYSTem SYSTem Subsystem AZERo state lt b gt Enable or disable Autozero ON For LYSNC SYSTem SYSTem Subsystem LSYNC state lt b gt Enable or disable line cycl
333. uch a test system is shown in Figure 5 6 A Keithley SourceMeter Model 2400 2410 or 2420 is used to source current through the DUT and the Model 2182 measures the voltage across the DUT Keep in mind that the I Source of the SourceMeter is a constant current source Therefore the current through the DUT will remain constant as the resistance of the DUT increases Figure 5 6 Test circuit Fixed I Vary H HI i SourceMeter 2182 Thermal Source l CH 1 EMFs 30 Cables g DUT aN 000 Cryostat After measuring the DUT voltage V at a series of increasing magnetic field values H you can graph H vs V The example H V curve in Figure 5 7 shows that the measured voltage across the DUT remains at OV in low magnetic fields This is the flat portion of the curve where the DUT remains at 0Q At some point the voltage drop across the DUT will start increasing as the magnetic field increases The actual resistance of the DUT can be calculated at any magnetic field point using Ohm s law R V I where R is actual resistance of the DUT V is the measured voltage across the DUT I is the known current that flows through the DUT Ratio and Delta 5 21 Figure 5 7 H V Curve Fixed I Fixed Measure V Magnetic Field H Delta measurements As previously explained the DC current reversal measurement technique must be used to cancel the effects of thermal EMFs in the test leads By configuring a custom swee
334. urce and event detection 7 4 Controlling the Model 2182 via the RS 232 COM2 port E 8 Cryostat 5 20 5 23 Custom sweep 5 9 5 21 5 25 Data lines F 4 DC current reversal measurement technique 5 21 5 23 DC current reversal measurement technique 5 19 DC current reversal technique 2 24 5 6 5 8 9 14 Default settings 1 16 Delay 7 4 Delta 5 6 I 3 I 6 Measurement units I 8 Delta measurement procedure using a SourceMeter 5 9 Delta programming example 5 17 Device action 7 5 Differential Conductance I 3 Average Voltage I 18 Calculations I 16 Measurement units I 17 Power I 18 Digital filter 3 8 Digits 3 5 Display 1 16 DISPlay commannd summary 14 5 DISPlay subsystem 15 3 Enabling limits 8 4 Example Programs E 1 External Stepping Scanning 9 3 External trigger 7 8 External triggering 7 7 External triggering example 7 9 External triggering with BNC connections 7 12 Filter 3 8 Filter considerations 5 15 Filter Rel and Ranging considerations 5 4 FORMat command summary 14 5 FORMat subsystem 15 4 Front and rear panel familiarization 1 7 Front panel GPIB operation 11 12 Front panel summary 1 7 Front panel trigger models 9 4 General bus commands 11 9 General information 1 3 Generating SRQ on buffer full E 5 Getting Started 1 1 GPIB bus connections 11 6 GPIB bus standards 11 6 GPIB operation and reference 11 6 Ground loops C 6 Handshake lines F 5 Heated Zener Reference 2 27 High power switches 2 25 Hold exam
335. us Each of these indicators is described below e REM This indicator shows when the instrument is in the remote state REM does not necessarily indicate the state of the REM line as the instrument must be addressed to listen with REM true before the REM indicator turns on When the instrument is in remote all front panel keys except for the LOCAL key are locked out When REM is turned off the instrument is in the local state and front panel operation is restored TALK This indicator is on when the instrument is in the talker active state Place the unit in the talk state by addressing it to talk with the correct MTA My Talk Address command TALK is off when the unit is in the talker idle state Place the unit in the talker idle state by sending an UNT Untalk command addressing it to listen or sending the IFC Interface Clear command e LSTN This indicator is on when the Model 2182 is in the listener active state which is activated by addressing the instrument to listen with the correct MLA My Listen Address command LSTN is off when the unit is in the listener idle state Place the unit in the listener idle state by sending UNL Unlisten addressing it to talk or sending the IFC Interface Clear command over the bus e SRQ Youcan program the instrument to generate a service request SRQ when one or more errors or conditions occur When this indicator is on a service request has been generated This indicator stays on until t
336. us subsystem not affected by RST CALL SEND 7 stat pres cls status CALL SEND 7 stat meas enab 512 status enable BFL CALL SEND 7 sre 1 status enable MSB CALL SEND 7 trac feed cont next status Start everything CALL SEND 7 init status WaitSRQ IF NOT srq THEN GOTO WaitSRQ CALL SPOLL 7 poll status IF poll AND 64 0 THEN GOTO WaitSRQ After the program has detected an asserted SRQ line it serial polls the Model 2182 to determine if it is the device requesting service This is necessary for two reasons e Serial polling the Model 2182 causes it to stop asserting the SRQ line e In test systems that have more than one IEEE 488 instrument programmed to assert SRQ your program must determine which instrument is actually requesting service Once an event register has caused a service request it cannot cause another service request until you clear it by reading it in this case using STATus MEASurement EVENt or by sending the CLS command Example Programs Storing readings in buffer The reading buffer in the Model 2182 is flexible and capable It has three controls which are found in the TRACe subsystem There are commands to control The size of the buffer in readings TRACe POINts NRf Where the data is coming from before or after the CALCulatel math post processing TRACe FEED SENSel store unprocessed readings TRACe FEED CALCulatel store math processed readings
337. use a null modem cable The serial port uses the transmit TXD receive RXD and signal ground GND lines of the RS 232 standard It does not use the hardware handshaking lines CTS and RTS Figure 11 10 shows the rear panel connector for the RS 232 interface and Table 11 2 shows the pinout for the connector Remote Operation 11 29 If your computer uses a DB 25 connector for the RS 232 interface you will need a cable or adapter with a DB 25 connector on one end and a DB 9 connector on the other wired straight through not null modem Table 11 3 provides pinout identification for the 9 pin DB 9 or 25 pin DB 25 serial port connector on the computer PC Figure 11 10 RS 232 interface connector 54321 muy 9876 RS232 Rear Panel Connector Table 11 2 RS 232 connector pinout Pin Number Description 1 No connection 2 TXD transmit data 3 RXD receive data 4 No connection 5 GND signal ground 6 No connection 7 RTS ready to send 8 CTS clear to send 9 No connections RTS and CTS are not used 11 30 Remote Operation Table 11 3 PC serial port pinout DB 9 DB 25 Signal Pin Number Pin Number DCD data carrier detect 1 8 RXD receive data 2 3 TXD transmit data 3 2 DTR data terminal ready 4 20 GND signal ground 5 7 DSR data set ready 6 6 RTS request to send 7 4 CTS clear to send 8 5 RI ring indicator 9 22 Error messages See Appendix B for RS 2
338. use the Status Byte Register to detect events 1 e serial poll you must unmask the events by setting 1 the appropriate bits of the enable registers To program and query the Standard Event Status Register use the ESE and ESE Common Commands respectively All other enable registers are programmed and queried using the ENABlIe and ENABle commands in the STATus Subsystem See Section 14 for more information An enable register is not cleared when it is read The following operations affect the enable registers Cycling power Clears all enable registers e STATus PRESet clears the following enable registers e Operation Event Enable Register Questionable Event Enable Register Measurement Event Enable Register ESE 0 Clears the Standard Event Status Enable Register 11 16 Remote Operation Figure 11 5 Standard event status ESR PON URQ CME EXE DDE QYE opc Standard Event B4 B3 Status Register P To Event Summary A Bit ESB of Status Byte Register See Figure 11 9 ESE ESE B15 B8 PON Power On amp Logical AND URQ User Request OR Logical OR CME Command Error EXE Execution Error DDE Device Dependent Error QYE Query Error OPC Operation Complete Figure 11 6 Operation event status Idle Filt Trig Meas Cal Operation B15 B11 B10 B9
339. val will be displayed Use the edit keys lt q P A and W to set the timer interval and press ENTER 5 The present Channel 1 Count CH1 CNT is displayed Use the edit keys to set the number of measurements for Channel 1 and press ENTER 6 The Present Reading Count RNG CNT is displayed it will be CH1 CNT 1 If you wish to increase the Reading Count use the edit keys to display the value and press ENTER to return to the normal display state 9 8 Stepping and Scanning External Stepping Scanning The settings for external stepping scanning are explained as follows Min Max Values These two values specify the beginning and ending channels for the step scan list Valid values for Min is 1 to 799 and valid values for Max is 2 to 800 However the Max value must be larger than the Min value Timer The maximum timer interval is 99H 99M 99 999S Hour Minute Second format Reading Count This indicates the total number of measurements that will be performed for each step scan cycle For example if Min is set to 1 and Max is set to 10 the Reading Count will automatically set to 10 For each additional step scan cycle simply add 10 to the Reading Count Therefore to perform three step scan cycles set the Reading Count to 30 Reading Count can be set from 2 to 1024 Perform the following steps to configure external stepping or scanning 1 Press SHIFT and then CONFIG Use the gt key to display the present SCANN
340. ve Recall Setup LO Save current setup as power on L1 Recall factory default setup L2 Recall power on setup SRQ Mask MO Disable SRQ MI Reading done M2 Buffer half full M4 Buffer full M8 Reading overflow M16 Ready for command M32 Error M128 Ready for trigger Enable Disable NO Enable Filter Filter NI Disable Filter Analog Filter O0 Configure analog filter off Configuration Ol Configure analog filter on Digital Filter PO Configure digital filter off Configuration Pl Configure fast response P2 Configure medium response P3 Configure slow response Trigger Interval Qvalue Interval value in msec 10 to 999999msec Range RO Enable auto range RI 10mV range R2 100mV range R3 1V range R4 10V range R5 100V range R6 NO OP no operation R7 NO OP R8 Disable auto range Integration Period S0 Line cycle integration period 7 S1 3msec integration period S2 100msec integration period S3 1 second integration period Trigger Mode TO Multiple on talk 8 T1 One shot on talk T2 Multiple on GET T3 One shot on GET D 4 Model 182 Emulation Commands Table D 1 Model 182 device dependent command summary cont d Mode Command Description Note T4 Multiple on X T5 One shot on X T6 Multiple on external T7 One shot on external T8 Multiple on manual TRIG key or bus HOX T9 One shot on manual TRIG key or bus HOX T10 Disable all triggers Alternate Output UO Send machine status 9 Ul Send error conditions U2 Send firm
341. vent Set Events BFL Buffer Full 0 Measurement Event Cleared BHF Buffer Half Full BAV Buffer Available RAV Reading Available HL1 High Limit 1 HL2 High Limit 2 LL1 Low Limit 1 LL2 Low Limit 2 ROF Reading Overflow Questionable Event Register Bits B0 through B3 Not used Additional SCPI Commands 15 9 Bit B4 Temperature Summary Temp Set bit indicates that an invalid reference junction measurement has occurred for thermocouple temperature measurements Bits B5 through B7 Not used Bit B8 Calibration Summary Cal Set bit indicates that an invalid calibration constant was detected during the power up sequence The instrument will instead use a default calibration constant This error will clear after successful calibration of the instrument Bit B9 ACAL Summary ACAL Set bit indicates that an invalid ACAL was performed This error will clear after a successful ACAL is performed Bits B10 through B15 Not used NOTE Whenever a questionable event occurs the ERR annunciator will turn on The annunciator will turn off when the questionable event clears Figure 15 5 Questionable event register Bit Position Event Decimal Weighting Value B15 B10 B9 B8 B7 B5 B4 B3 BO Value 1 Operation Event Set 0 Operation Event Cleared Events ACAL ACAL Summary Cal Calibration Summary Temp Temperature Summary 15 10 Addit
342. w PP Parallel Poll Function The instrument does not have parallel polling capabilities PPO DC Device Clear Function DC1 defines the ability of the instrument to be cleared initialized DT Device Trigger Function DTI defines the ability of the Model 2182 to have readings triggered C Controller Function The instrument does not have controller capabilities CO TE Extended Talker Function The instrument does not have extended talker capabilities TEO LE Extended Listener Function The instrument does not have extended listener capabilities LEO E Bus Driver Type The instrument has open collector bus drivers E1 IEEE 488 and SCPI Conformance Information G 2 IEEE 488 and SCPI Conformance Information Introduction The IEEE 488 2 standard requires specific information about how the Model 2182 implements the standard Paragraph 4 9 of the IEEE 488 2 standard Std 488 2 1987 lists the documentation requirements Table G 1 provides a summary of the requirements and provides the information or references the manual for that information Table G 2 lists the coupled commands used by the Model 2182 The Model 2182 complies with SCPI version 1991 0 Table 14 2 through Table 14 11 list the SCPI confirmed commands and the non SCPI commands implemented by the Model 2182 Table G 1 IEEE 488 documentation requirements Requirements Description or reference 1 IEEE 488 Interfa
343. w pulse could be adversely affected by the heat caused by the high pulse In that case the measurement at the second low pulse can be disabled This does not change the overall timing of the pulse output Eliminating the second low pulse measurement changes the basic calculation to the following Pulse Delta 2Y 2X 2 Where Y is the measurement at the high pulse X is the measurement at the first low pulse I 10 Delta Pulse Delta and Differential Conductance Pulse Delta calculation example 3 point measurement technique Assume you want to measure the voltage across a low power 1 2 DUT The Pulse Delta process will reduce DUT heating and eliminate the effects of thermal EMFs Assume the Model 6221 is configured to output 10mA and OmA pulses Due to a 10nV thermal EMF in the test leads the following Model 2182A measurement conversions A Ds are made for the first Pulse Delta cycle A D A 0 01mV A D B 10 01mV A D C 0 01mV The first Pulse Delta reading using the 3 point measurement technique is calculated as follows 2B A C PulseDelta 1 _ 2 10 01 0 01 0 01 mv 2 10mV The above 3 point measurement technique effectively eliminated the 10n V thermal EMF from the Pulse Delta reading 2 point measurement technique Assume for the above example that DUT heating causes the A D measurement at point C to be 1 01mV Using the 3 point measurement technique Pulse Delta by
344. ware revision U3 Send buffer length U4 Send buffer average U5 Send buffer standard deviation U6 Send reading relative value U7 Send analog output relative value U8 Send analog output gain value U9 Send trigger interval U10 Send trigger delay U12 Send calibration lock status U13 Send Model 181 like machine status Analog Output VO0 gain Analog output gain 0 001 to 999999 999 10 Trigger Delay WO Disable trigger delay Wvalue Enable trigger delay delay value 1msec to 999990msec Execute X Execute other device dependent commands Terminators YO CR LF gt YI LF CR Y2 CR Y3 lt LF gt Y10 lt CR LF gt Y13 lt LF CR gt Reading Relative ZO Disable reading relative 11 Zl Enable reading relative using next reading Z2 value Enable reading relative using value le 9 to 120 Z3 Enable reading relative use present value Model 182 Emulation Commands D 5 NOTES 1 A Commands The maximum number of characters for the Al command string is 12 The A2 and A3 commands are not supported 2 C Commands Calibration commands are not supported by the 182 language You pp y guag must use the SCPI language to calibrate the Model 2182 over the bus 3 G Commands The G4 through G7 commands are not supported by the 182 g pp y language The Model 182 does not use time stamp 4 H Commands The H1 command is not supported by the 182 language 5 TP Commands The minimum buffer size for the Model 21
345. y enables reading relative and uses the present Rel value D 6 Model 182 Emulation Commands Example al uas E 2 Example Programs Program examples All examples presume QuickBASIC version 4 5 or higher and a CEC IEEE 488 interface card with CEC driver version 2 11 or higher with the Model 2182 at address 7 on the IEEE 488 bus Changing function and range The Model 2182 has independent range control for each of its two voltage measurement functions This means for example that autorange can be turned on for DCV1 while leaving it off for DCV2 Another difference is in the parameter to the range command In other instruments a single number was used to denote each range The parameter of the SCPI RANGe command is given as the maximum value to measure The instrument interprets this parameter and goes to the appropriate range When you query the range with RANGe the instrument sends back the full scale value of its present range The following example program illustrates changing function and range It sets the range for several functions and then takes readings on each of those functions Note that the Model 2182 rounds the range parameter to an integer before choosing the appropriate range Sending SENSe VOLTage CHANnel1 RANGe 20 45 will set Channel 1 of the Model 2182 to the 100V range Example Programs Example program to demonstrate changing voltage function and range taking readings on DCV1 and DCV2 For Qu
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