Home

Model DRC-93C - Lake Shore Cryotronics, Inc.

1. 8223 3 2 Word Structure Selection The word structure is determined by switch settings for character length parity and stop bits using DIP switch package 52 the Interface Card 6 switches Refer to Table 8223 4 for settings where 0 is OPEN and 1 is CLOSED COPYRIGHT 12 87 LSCI Model DRC 91C 93C Table 8223 4 Switch S2 Switch S2 123456 Word Structure Word Structure Choices Stop Bits Invalid 1 Bit 15 not supported 2 Bits Parity Genertn Chck Even Odd Parity Enable Enable Disable Character Length Bits 5 not supported 6 not supported 7 Supported 8 not supported Note For the not supported settings the interface will respond but the card has not been tested with these settings at the factory X is a don t care setting for that switch 8223 4 SPECIFICATIONS Specifications for the Model 8223 RS 232C Interface are given in Table 8223 5 8223 5 INSTALLATION The 8223 RS 232C Interface is factory installed if ordered with a DRC 91C Temperature Controller or can be field installed at a later date If field installation is required use the following procedure 1 Configure the 8223 baud rate and word structure switches as outlined in Section 8223 3 COPYRIGHT 12 87 LSCI Model 8223 RS 232C Interfa
2. JA1 000000000 2 LI wae r 4 ss eU v 664 63 o 1 4 dmi em nel D pag m 4810 m hig mis CO CD uL N Ea XU26 XUS1 Figure 93C 1a Component Layout DRC 93C Main Board a oe ur mun um ss D 281 86 01 HH TOU48_ J7 48 r O Ds NE RN12 gt ra gt e cL 2 cL we XU21 JA2 ue memet mem ee ET TER 1 1 1 J L_ I I I I t 1 I t I I i 1 I I I I TX1 1 I 1 i I 1 1 1 1 I ec 1 I I 2 lt E d 23 r l i I 1 1 e o I t l l i 3 oJ l 4 I TX2 I l i I i 1 i i 1 I 1 TE BE 8 E NU C55 656 2 I ATI ESO 1 T E SES pL XU26 e GO RE Figure 93C 1a Component Layout DRC 93C Main Board gt w REAA RASA E dg BLU ES o c VIO 3 5 Q dt Q MOUNTED ON TOP i RIGHT SIBERAIL Th 4 gt AES en O Q o C11
3. 741465 o gt e E T 8 8 n 8 x wsese Ndqn N i gee Ii 2 X 5 3 9 pig gt 2200 lo wo p Figure 93C 2f Schematic DRC 93C Display Driver Board 2 Bar Graph Drive 5 cis 8 1 UNIT SELECT SELECT B UNIT D 3 11 rae RESET eq A cso 00 61 1 AB ar WR A B OVL j B 10001 x B B81 ied 0 17 A at Ap is 1 gt is m 1 9 DS ms sins DS AAA c Am 5 2 AAA Ser xs a TRANS DRIVER pos o ieu ue s Suc 2 2 v usss v7 8 012187 DS dp e 2227221 Q PAK 6 7406 7408 7 RN1 22x8 3 b 4 eg 8 gt O IVA PROG KEYED olf ur NOTE INTERFACE 46 7496 9 8 US U7 U13 AND U14 d UTE 7406 3466 we PIN 14 VCC 9 1 2 7486 9 8 PIN 7 GND ROW 3 jJ3 2 it Pool 7486 RON 2 3 30 sl pos ROW 1 Is C18 B ALE 3 reset 1 8 BUELL SP em a gee ina INS mp0 um iL idm a Fa AAA GET s Pd at ee Ae pe Gear lee c ADM 053 ide AD3 uuo 22222216 gt OAB SP d Ne see ADL AAA 0 ue BAV iT oe 8 po 1486 uc 4 g 7406 RN2 22 8
4. e s e e eo 4 16 4 9 3 Setting the GAIN Proportional The P Command 4 16 4 9 4 Setting the RESET Integral The I Command 4 16 4 9 5 Setting the RATE Derivative The D Command 4 16 4 9 6 Heater Range The R Command e e e e e 4 16 4 9 7 Manual Heater Power The Command 4 16 4 9 8 The W3 Data String amp amp amp 5 e s e s s X X lt s 4 16 4 10 THE SCANNER INPUT CARD UR cer seb E So den 4 16 4 10 1 SCAN Programming Instructions Bae et ow 4 16 4 10 2 Setting the Dwell Time The YAN N2N3 and YBON9N4 Commands 4 16 4 10 3 Enabling the Scan Function The YS Command gt ser har cel 22 4 17 4 10 4 Holding the Scan Function YH Command 4 18 4 10 5 The WY Data String 2 s e n s 4 18 4 11 THE SERVICE REQUEST STATUS REGISTER STATUS REPORTS AND THE STATUS REGISTER MASK 4 18 4 11 1 The Service Request US eR ey ro ng 4 19 4 11 2 The Status Register and Status Reports ue 4 19 4 11 2 1 Status Reports 0 and 1 Display and Control Data Ready 4 19 4 11 2 2 Status Report 2 The Control Channel Limit 4 19 iv COPYRIGHT 3 88 LSCI 4 12 4 13 4 14 4 15 4 16 4 11 3 TABLE OF CONTENTS CONT D 4 11 2 3 Status Report 3 Display Sensor Channel Change 4 11 2 4 Status Report 5
5. e e ooo 4 7 4 7 2 3 Local Lockout gt ue cm s s s o 4 9 4 7 3 Terminating Characters The TN Command 4 9 4 7 4 Clear e Ae Moro RO See 4 9 4 7 5 The W2 Data String 2789 a owe dox 5 ee e ere 4 11 4 7 6 The WI Data String so 4 11 4 8 SELECTION OF QUANTITIES FOR THE CONTROL AND SAMPLE DISPLAYS UNITS SENSORS RESOLUTIONS AND DEVIATION Table 4 7 4 11 4 8 1 Units for Control Display and Set Point The FOC Command 4 11 4 8 2 Units for Sample Display The 1 1 command ae Vel ye 4 11 4 8 3 Control Sensor Selection The F2CC N Command 4 11 4 8 4 Sample Sensor Selection The F2SC N Command 4 11 4 8 5 Resolution for The Control and Sample The F3CNq and F3SN Commands 4 11 4 8 6 Selection of Deviation for Control and Sample The FACON F4COFF F4SON and F4SOFF Commands 4 12 4 8 7 Selection of MATH Functions ON OFF and CLEAR The 5 F5OFF and F5CLR Commands e e 4 12 4 8 8 Sensor Curve Selection The NC N NoN3 Command 4 12 4 8 9 The A and B ID Information 2 1 gt 2 Commands 4 12 4 8 10 The WD Data String 255 5 s s eee so 4 12 4 9 THE CONTROL COMMANDS o 44402 490 4 12 4 9 1 The Set Point Value The s Command SU ode 4 12 4 9 2 The WP Request Data String
6. response from the interface The balance of the commands are Programing Code style commands which do not result in a response from the interface Care must be taken with the XCN N gt command not to overrun the 256 character buffer of the 8223 interface As in the IEEE operation if a hardware problem is detected in modifying one of the memory locations an ERRO1 error will be displayed in the Display and instrument operation will be halted Consult factory representative if this error occurs There are three errors that could be detected by the 8223 interface as defined in Table 8223 6 Detection of an error does not effect the operation of the interface The software that interprets the data tries to match the character input to the possible command inputs and processes the command The error is also transmitted by the interface the next time it is asked for a response The error is transmitted in addition to the Output Statement data output For example if a framing error were detected in a command string transmitted to a DRC 91C 93C as P50W3 the interface might respond with Err12 50 25 20 2 047 CR LF If the error were detected in the transmission of the P the gain change would be ignored if it was in the 50 one or two numerics may have been generated If the error were detected in the W the interface may not respond in which COPYRIGHT 12 87 LSCI Model 8223 RS 232C Interface
7. Variable Max Set Point n Power porua 0 Heater Sensor Deviation Power Stage Amplifier Non Inverting Inverting FIGURE 1 Block diagram of Cryogenic Temperature Controller A is amplifier voltage gain Proportional Proportional 8 Band 100 1000 Deviation A 1000 Amplifier Output 0 Error Signal FIGURE 2 Output plot of the deviation amplifier showing Proportional Bands for gain settings of 100 and 1000 For the DRC 82C the maximum available gain is 1000 50 5 V EAD T Error Signal 40 mV 0 0 8 0 K 16 0 FIGURE 3 Output Power versus error signal in voltage or equivalent temperature of sensor for two different power settings A corresponds to a sensor sensitivity of 50 mV K B corresponds to a sensor sensitivity of 2 5 mV K Note that the curves are linear in voltage not power producing the error signal in Figure 2 had a sensitivity of 1 mV K and the set point full scale range was 100 mV 100 K The proportional band would then be 8 or 8 K and 80 or 80 K for Ay 1000 and 100 respectively In cryogenic applications this terminology is less significant gain which is multiplicative is usually more useful since it is more easily understood by the user The power output stage of a cryogenic controller may or may not have variable gain associated with it If the controller has several output power stage ranged for ex
8. 10 Input A D Cal 10 Input A D Verify 10K 100K Current Verify 1K ohm Current Verify 100 ohm Current Verify 10 ohm Current Verify 9317 9318 8 COPYRIGHT 12 87 5 R19 1 37K R17 Y SK R18 36 RIG ALE P3 3 P3 4 80 61 5 ut PLUGGED IN 33233243 33 P2 1 P2 4 P2 6 P2 917 27064 M R4 49K al 2731 4 DATA E ers 97 ww eer ee 1 39 a 4 76 4 76K DATA A i a IN Eies 4 SHEET 1 OF 1 Figure 9317C 1 Model 9317C Resistance Input Card REPLACEABLE PARTS LIST 9317C RESISTANCE SENSOR INPUT CARD ITEM LSCI Part NO Number 101 137 101 067 101 025 105 405 104 509 104 652 104 001 104 345 104 419 104 060 104 078 104 465 104 089 104 098 104 020 104 660 103 990 106 142 CAP TANT T10MF 35V CAP CER 30PF 500V CAP PP 33MF 100V CAL ENABLE 4 DIP RA IC MICROPROCESSOR 1 EEPROM AMP IC OPTOCOUPLER IC D A CONVERTER IC ANALOG SWITCH IC SWITCHED CAPACITOR IC A D CONVERTER AMP IC BINARY COUNTER REGULATOR 5 EPROM CRYSTAL 5 000MHZ CONNECTOR 6 POST RA HDR PM S CE MFR PART NO 119D106X0035081 015 500 03 MPP 11 33MFD 7625804 80 51 5 X2404 OPOTEP HCPL 2731 DAC7O3BH 5 LF13202 LTC1043 TSC500CPE MAX430CPA CD4020BCN 79405 27 64 3 1 5 000MHZ
9. E e e 0 poe in Figure 3 2 Model DRC 93C Temperature Controller Rear Panel Description 1 Line cord receptacle with fuse and voltage selection 2 Sensor INPUT A connector J1 3 Sensor INPUT B connector J2 4 HEATER RESISTANCE selector switch 5 Monitors output of Sensor INPUT A and Sensor INPUT B buffered voltages and 8225 linear analog output option J3 6 REMOTE SENSOR ID J5 Connects to POSITION DATA of Models 8084 or 8085 Scanner optional 7 488 address switch 8 IEEE 488 connector J4 9 Heater Power output terminals J6 J7 J8 10 Optional interface access plate J9 8229 Scanner Option 11 Optional interface access plate J10 8223 RS 232C Option 12 MAX HEATER POWER Limit 13 Optional connector access plate J11 3 18 COPYRIGHT 3 88 Model DRC 93C LOCAL REMOTE BIOCK 3 12 1 LOCAL 3 12 The LOCAL key is used to return the instrument from remote control by the IEEE 488 BUS or the RS 232C op tional interface to front panel con trol 3 12 2 REMOTE The REMOTE key is used to place the controller under remote control and to disable the front panel When the REMOTE key is pressed for more than one second the display shows the IEEE 488 address of the instru ment REAR PANEL DESCRIPTION 3 13 REMOTE SENSOR ID The REMOTE SENSOR ID connector is connected to the REMOTE POSITION DATA output of a Model 8084 or Model 8085
10. BC41C2 commands in the instrument manual 9215 7 PRINCIPLE OF OPERATION The 9215 15 configuration provides a charging current switched at a frequency of 5 kilohertz The frequency is precisely controlled by a crystal oscillator The operation of the 9215 150 is identical except that the frequency is 1 kilohertz The charging current produces a sawtooth voltage waveform with a peak to peak voltage of about 7 volts Another voltage of precise amplitude is generated which has a duty cycle dependent on the charging time of the capacitor This waveform is averaged and filtered to produce a positive DC voltage proportional to the capacitance This DC voltage is sent to a 16 bit A D converter on the card The A D converter has a resolution of 50 microvolts and a full scale input voltage of 3 0000 volts With the 9215 15 Configura tion the 3 0000 volts corresponds to a capacitance of 30 nanofarads and on the 9215 150 configuration to 150 nanofarads digitized 9215 5 9215 Capacitance Input Card value is converted to a serial data string and transferred to the main microprocessor using optical isolation A relay on the Card configures the sensor voltage as negative or positive based on the temperature coefficient sign selected by the user Section 9215 5 That voltage is buffered and transferred to the rear panel MONITORS connec tor for external monitoring as well as to the main board control circuitry 9215
11. 5 5 6 Heater Output Test 5 5 6 1 Heater Output Conditions The heater should output power when the setpoint temperature is above the display temperature as long as the heater is on and a gain value has been entered If the sensor is a diode the voltage across the device will change inversely with temperature Therefore the higher the voltage the lower the tempera ture For Platinum sensors the resistance increases as the temper ature increases Germanium and carbon glass sensors are negative temperature coefficient resistance sensors which vary several orders of magnitude in resistance with temperature 5 3 Section V 5 5 6 2 Test Setup Test the heat er by placing an appropriate test resistor see Table 1 into the control sensor input and place a 10 ohm at least 10 watts up to 50 ohm at least 50 watts resistor across the heater terminals 5 5 6 3 The Heater Display The heater display is shipped from the factory reading the percent of power out If the heater is 10 ohms then at 100 percent output current the heater will have 1 amp through it and 10 volts across it If the heater bar graph is reading 50 then the instrument is deliver ing 5 watts 0 707 amps and 7 07 volts to the 10 ohm load If the unit is reading in current a read ing of 50 will mean 2 5 watts 0 5 amps and 5 volts The heater dis play can be changed from power to current by switching internal dip switch S4 1 5 5 7 Checking Ga
12. D CURVE El CURVE DT 470 CURVE 10 ENE F d VOLTAGE VOLTAGE BP VOLTAGE BP VOLTAGE 2 2 2 2 2 2 2 5735 2 2 2 2 2 2 2 2 2 2 4527 2 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 5984 5958 5932 5906 5880 5854 5828 5643 5551 5458 5366 5226 5086 4946 4807 4667 4387 4247 2570 2220 1871 1521 1172 0909 0646 0119 9592 9066 8338 7610 6984 6359 5646 4932 4219 3505 3006 2507 2114 1720 30 one 2 6591 2 6567 2 6542 2 6518 2 6494 2 6470 2 6446 2 6355 2 6265 2 6175 2 6084 2 5994 2 5868 2 5742 2 5616 2 4791 2 4648 2 4290 2 3932 2 3574 2 3216 2 2858 2 2500 2 2142 2 1784 2 1516 1 7769 1 7148 1 6527 1 5724 1 4922 1 4120 1 3317 1 2837 1 2357 1 1877 1 69808 1 69674 1 69521 1 69355 1 69177 1 68987 1 68912 1 68352 1 67880 1 67376 1 66845 1 66292 1 65721 1 65134 1 64529 1 64112 1 63263 1 62602 1 61920 1 61220 1 60506 1 59782 1 56027 1 54097 1 52166 1 50272 1 48443 1 46700 1 44850 1 43488 1 42013 1 39287 1 36687 1 34530 1 32412 1 30422 1 28527 1 26702 1 24928 1 23184 1 21555 1 19645 1 17705 1 15558 1 13598 1 12463 1 0970 1 0902 1 0850 1 0798 1 0746 1 0633 1 0520 1 0407 1 0287 1 0166 1 0046 1 0630 1 0515 1 0399 1 0284 1 0159 1 0035 0 9911 0 9849 0 9780 0 9649 0 95
13. E 5 p gt 6 5 i LAKE SHORE CRYOTRONICS INC 8 1 9 zg 8 7406 DRC 99C DISPLAY DRIVER BOARD DISPLAY MATRIX 2486 W PROG KEYED 7486 INTERFACE dd 49 U13D NO 5888888 D yes es 93cddb3 Figure 93C 2g Schematic DRC 93C Display Driver Board 3 Display Matrix 374 86 010 pe YP19 Tei2 Pie TP 5 D BA Q v 5 lt gt 7446 V gt V F ADJ Ra Figure 93C 3 Schematic and Component Layou 10 10 10 500 CAP 047MF POLY 600V CAP TANT 33MF 25V JC MICR PROCESSOR 1C 4 16 LINE DECODER 1 8 LATCH rie IC EPROM PROGRAM IC 8KX8 NOVRAM gt j 1C 8 BIT MULTIPLEXER Lo te 02C HEX INVERTER C HEX INVERTER 8 cRYsTAL 5 000 MEZ 119D0106X0035D81 CD15CD100003 WMF 6SAT7 2 199D336X0025EA2 748C154 P82c82 27c256 DSs1225Y DMB1LS95 7406 741504 5 000 MHZ D C B A s ou E mm aj S BBs 58813823 Yee Emm bat ate K Fir g b a A 2 ANOS S V lt S
14. from AC line power and all test equipment before removing cover 2 Remove the four screws that secure the calibration cover to its clips and remove the cover 3 If an Input Card must be removed disconnect the wiring harness mating connector by lifting the locking tab on the Input Card connector and gently pulling on the body of the wiring harness mating connector 4 Plug the new 9210 Input Card into the A Input Card Slot 5 or tthe B Input Card Slot 6 with the component side to the left of the unit as viewed from the front Connect the wiring harness mating connector to the 9210 making sure that the wiring harness locking tab is seated over the extended edge of the wiring harness mating connector Verify that the wiring harness is in place correctly by noting that the or the 9210 2 DRC 91C 93C harness mating connector is facing up if it is not review the harness installation again Thread the wiring harness along the rear edge of the unit and slip it into the harness strain relief on the rear panel 5 Install the calibration cover by reversing procedure 2 6 Install the top panel 9210 5 OPERATION The Model 9210 3 Diode Configuration provides the 10 microampere excitation current to the sensor resulting sensor voltage is digitized by a 16 bit A D converter with a resolution of 50 microvolts and a full scale input voltage of 3 0000 volts 100 microvolts and 6 5535 volts
15. 2 6 6 The W60 Output Option will deliver 60 watts at 1 5 amperes at approximately 43 volts into a 25 ohm load This is a factory installed option COPYRIGHT 3 88 LSCI Section II 2 7 ENVIRONMENTAL REQUIREMENTS WARNING To prevent electrical fire or shock hazards do not expose the instrument to rain or excess moisture 2 7 1 Operating Temperature In order to meet and maintain the specifications in Table 1 1 the DRC 93C should be operated at an ambient temperature range of 23 C The unit may operated outside the range of 15 359 with less accuracy 2 7 2 Humidity Altitude The DRC 93C is for laboratory use and no humidity or altitude speci fications have been determined for this unit 2 8 REPACKAGING FOR SHIPMENT If the Model DRC 93C appears to be operating incorrectly refer to the Troubleshooting Guide in Section 5 7 If the tests indicate that there is a fault with the instru ment contact Lake Shore or a fac tory representative for a returned Goods Authorization RGA number before returning the instrument When returning an instrument for service photocopy and complete the Service Form found at the beginning of Appendix A The form must be filled in to ensure efficient solu tion of the problem The following information must be provided before Lake Shore will attempt any repair Section IT 1 Instrument Model and Serial s 2 User s Name Company Address and Phone Number
16. 3 Malfunction Symptoms 4 Description of system 5 Returned Goods Authorization No If the original carton is avail able repack the instrument in a plastic bag place it in the carton using original spacers to protect protruding controls Seal the carton with strong paper or nylon tape Affix shipping labels and FRAGILE warnings If the original carton is not available pack the instrument similar to the above procedure being careful to use spacers or suitable packing material on all sides of the instrument Model DRC 93C COPYRIGHT 3 88 LSCI SECTION OPERATING 3 1 INTRODUCTION This section contains information and instructions concerning the operation of the Model DRC 93C Temp erature Controller Included is a description of the front and rear panel controls and indicators 3 2 INSTRUMENT CONFIGURATION 3 2 1 Input Card Configurations The Model DRC 93C can be used with either one or two input cards The input cards available for use with the DRC 93C are summarized in Sec tion I The input cards available allow the 93C to be used with almost any type of cryogenic sensor Input cards can be mixed allowing two different sensor types to be used with the DRC 93C 3 2 2 Single Input Card When only one input card is present within the unit it occupies the INPUT CARD 1 slot of the DRC 93C mainframe and is connected to the Sensor A input of the controller Only one sensor can be used with the controlle
17. 6 20 is the Sign Control Sensor reading and units N24 N25 is the Sign MIN Control Sensor reading and units No6 N39 is the Sign MAXDEV Control Sensor reading and units COPYRIGHT 3 88 LSCI 4 29 Section IV Model DRC 93C 4 15 SAMPLE PROGRAMMING 4 15 1 HP86B Keyboard Interactive Program The following program for the HP86B is an interactive program with the keyboard of the computer For example when the user sees the prompt on the screen and types in a valid DRC 93C command such as WO the program will result in the display of the DRC 93C response on the screen 10 REM Set IEEE Address to 12 20 REM Address Switch 1 OPEN O to get CR LF 30 REM This program allows the user to communicate with the 93C interactively from the computer keyboard 40 DIM A 100 Must be increased for curve information 50 INPUT BS INPUT KEYBOARD COMMAND 60 OUTPUT 712 5 SEND COMMAND TO 93C 70 ENTER 712 A RECEIVE ANSWER FROM 93C 80 DISP A DISPLAY ANSWER 90 GOTO 50 100 END 4 15 2 National Instruments GWBASIC or BASICA Example The following is the same program written for the National Instruments GPIP PC2 IEEE 488 Card for IBM PCs and Compatibles using Quick Basic 3 0 10 CLEAR 60969 BASIC DECLARATIONS 20 IBINIT1 60969 This number is different for each computer 30 IBINIT2 IBINIT1 3 40 BLOAD bib m IBINIT1 50 CALL IBINIT1 IBFIND IBTRG IBCLR IBPCT IBSIC IB
18. 8 8 8 8 8 in both the upper lower and setpoint windows The CONTROL Block indicates 8 8 in the GAIN RATE and RESET windows The COPYRIGHT 3 88 Model DRC 93C HEATER POWER Bar Graph indicates 100 The UPPER and LOWER DISPLAY SENSORS have 8 The indicators for the six sets of UNITS for both the Upper and Lower displays are dis played to the far left of the front panel The control CTRL annun ciators are between the SENSOR nunciators The RANGE from OFF to MAX annunciators are below the Bar graph and the LOCAL REMOTE PROG programming and internal program to the far right of the front panel 2 Instrument Name and IEEE Address Next the unit displays LSCI in the Upper Display 93 in the Setpoint Display and the 488 interface address in the Lower Display Fora factory set IEEE address of 12 the display would indicate Add12 This address can obviously be changed by the user and verification of that change is always given on power up Note that this address is only read by the instrument on power up 3 Input Card Configuration The unit then displays the input cards associated with the inputs on the upper and the lower displays 4 Normal Operation into normal The unit then goes operation 3 7 2 Power up Status A provision has been made to store parameter changes in the DRC 93C memory NOVRAM The sample and control units as well as the curve numbers and scan dwell tim
19. N7Ng NgN19 N11N12 BC13C14 3 14 46 characters plus up to 2 terminators where the Sample Sensor AO A1 A2 A3 A4 or BO the Sample Units K C F V Nor R the Sample Resolution O xxx through 4 x xxxx the Sample Form N for normal D for Deviation the Control Sensor AO A1 A2 A3 A4 or BO the Control Units K C F V Nor R the Control Resolution O xxx through 4 x xxxx the Control Form N for normal D for Deviation the Remote Position 00 through 1 the A ID 00 through 1F the curve number 00 through 30 the curve number 00 through 30 the curve number 00 through 30 the curve number 00 through 30 the curve number 00 through 30 the B ID 00 through 1F the B Curve Number 00 through 30 Table 4 8 and in A ID and B ID the SENSOR ID s c C1 4 3 2 1 4 is 1 is LSB 8 4 2 1 Binary Weighting Remote Position On Curve Off Bit L Thermal Correction Digital Filtering Thermal Correction or Ice Point Compensation 2 3 4 t Card Thermal Correction OU OO NEO nj J J G J 0 4 14 COPYRIGHT 3 88 LSCI Model DRC 93C input range may be above the values possible for the various sensors the set point is limited by the input card present as shown in the table Note that the temperature limit can be different for the DT 470 depending on whether curve 02 324 9K or curve number 04 474 9K has been selected If a number
20. USER S MANUAL Model DRC 93C Temperature Controller Obsolete Notice This manual describes an obsolete Lake Shore product This manual is a copy from our archives and may not exactly match your instrument Lake Shore assumes no responsibility for this manual matching your exact hardware revision or operational procedures Lake Shore is not responsible for any repairs made to the instrument based on information from this manual akeShore Lake Shore Cryotronics Inc 575 McCorkle Blvd Westerville Ohio 43082 8888 USA E Mail Addresses sales lakeshore com service lakeshore com Visit Our Website www lakeshore com Fax 614 891 1392 Telephone 614 891 2243 Methods and apparatus disclosed and described herein have been developed solely on company funds of Lake Shore Cryotronics Inc No government or other contractual support or relationship whatsoever has existed which in any way affects or mitigates proprietary rights of Lake Shore Cryotronics Inc in these developments Methods and apparatus disclosed herein may be subject to U S Patents existing or applied for Lake Shore Cryotronics Inc reserves the right to add improve modify or withdraw functions design modifications or products at any time without notice Lake Shore shall not be liable for errors contained herein or for incidental or consequential damages in connection with furnishing performance or use of this material Obsolete Manual March 1988 SE
21. check and monitor signal frequency shape and distortion but the FIGURE 3 Measurement circuit schematic diagram oscilloscope was removed from the circuit when actual data were recorded Data were recorded at the three dc current values of 1 10 and 100 pA with the temperature stabilized at 305 77 or 4 2 K At each temperature and dc current value the dc voltage and the ac voltage across the diode were recorded as the amplitude and frequency of the signal generator were varied The dc voltage reading across the 10 kQ standard resistor was also monitored to verify that the dc component of the current remained constant to within 0 0596 In addition the IV characteristic of the diode was measured at each temperature from 0 1 to 150 pA Although detailed measurements were taken on only one diode other diodes were randomly selected and spot checked at all three temperatures and frequencies to verify consistency with the measured data The diodes tested were of the DT 500 series of Lake Shore Cryotronics Inc and have been in production long enough to have a substantial reliability and calibration history II RESULTS AND DISCUSSION The data were analyzed by calculating a voltage offset AV This offset is defined as the difference between the dc voltage reading across the diode when operated with an ac dc current and the dc voltage reading when operated with a pure dc current see Fig 2 At first glance the logical choice seems to be to exa
22. ed press the PROG key The PROG indicator will turn off and operation will return to normal or Aborting the COPYRIGHT 12 87 LSCI Model DRC 93C 6 6 RUNNING THE PROGRAM To begin execution of the internal program the user does the following 1 Press the INTernal key The INTernal indicator will begin to blink on and off 2 Select the Program Step using the POINT key followed by the ENTER key 3 If another Program Step is desired repeat step 2 The 4 key or key can be used to examine the next higher or lower Program Step respectively 4 If it is desired to return to normal operation thus aborting the programming setup press the INTernal key The INTernal indicator will turn off and normal operation will resume 5 Press the SCAN key to begin execution of the program beginning at the Program Step selected in part 2 The INTernal indicator will turn on and stay on showing that the instrument is in the programming mode 6 The only keys active while a program is being executed are the CLEAR key and the TIME key Pressing the CLEAR key causes execution of the program to cease and operation to be returned to normal Pressing the TIME key causes the elapsed time in a particular cycle to be displayed 7 To exit from the programming mode press the CLEAR key The INT indicator will turn off It is also possible to exit the program by using command 9 COPYRIGHT 12 87 LSCI Section VI 6
23. 1 2 DESCRIPTION The DRC 93C Temperature Controller is a microprocessor based instru ment which provides true analog control It is capable of scanning multiple sensor inputs and display ing temperature with up to 5 digits of resolution in K C or F or sensor units volts ohms or nanofarads to five digits The DRC 93C be used with either 1 or 2 input cards When two input cards are used these cards can be different to allow two separate types of sensors to be used with the controller The dual sensor input with the optional 8229 Scanner Conversion Card expand the input capability of the DRC 93C to up to 6 input sensors Depending on the input option selected the DRC 93C handles silicon 9210 3 or 9220 3 or the patented Gallium Aluminum COPYRIGHT 3 88 LSCI INFORMATION Arsenide 9210 6 or 9220 6 diodes platinum or rhodium iron resistors 9220 series germanium or carbon glass resistors 9317C 9318C or capacitance sensors 9215 With or without the 8229 Scanner Card the DRC 93C can be set to scan automatically with an in dividual dwell time of 1 to 99 seconds per channel or stepped to any available input and held there Setting the dwell time to zero causes a particular channel to be skipped If all dwell times are zero the instrument stays on the channel selected The DRC 93C gives a direct reading in temperature when used with any DT 470 Series Temperature Sensor All DT 470 Sensors
24. 4 T5Kx1 190K 81 49 9K 2 2 gt NOTE U31 BITes 1 U32 PIN 4 D o lt 431 PIN 11 8 gt BIT34 2 PONER BUSS SUPPLIES V AND GND A 031 BIT3S TO THE ANALOG CIRCUITRY 15 LA sore ne LAKE SHORE CRYOTRONICS INC A DRC 93C MAINBOARD SETPOINT AND SUMMATION 82 19 99 mso sre mc 14 56 59 sacseTPr SHEET S OF 3 2 1 Figure 93C 1f Schematic DRC 93C Main Board 5 Setpoint and Summation o 4 Ss 19 PID DATA E ox S m m 8 pe pa pa pa NOTE 1 URS 4 8 Al PIN il BIAT 2 POWER BUES SUPPLIES 8V BV AND GND 538 B S883882 08N2 8 5 Rs T y iene zl 476K Vat BIT Ris 4 76 lt usi BITI 00 21135 7 Figure 93C 1g Schematic DRC 93C Main Board 6 PID Control D V F Apu SL4 83 V F 654 12 C 1 40 0 14 3 PWR VREF 108 RTE 18 TP19 i N HTR DRY 514 6 gt m 5 ee dial CUN REED HTR REF Ue LAKE SHORE CRYOTRONICS INC DRC B3C MAINBOARD PONER OUTPUT STAGE ARE 1N4148 82 28 89 s SIZE DWG NOs 13 06 91 R it 7 6 5 4 3 e 1 Figure 93C 1h Schematic DRC 93C Main Board 7 Output Stage NOTE 1 J1 J2 AND J3 ARE
25. 45 A 7138 d S A Lc 383333 RRA HPCL 2731 2724 are R24 R26 HPCL 2791 4 76K ae ig _ 4 76 Er 131 ue ny ot IN DVD NOTE Re7 R38 FORM RN 2 RAT Y BK R19 1 37K 3 _ LAKE SHORE CRYOTRONICS INC yu gt e wea vr g o MODEL 9318C RESISTANCE OPTION CARD I VERSION 2 a RISI MN see BUE E i ache SHEET 1 OF 1 8 7 6 s i 4 3 2 1 Figure 9318C 1 Model 9318C Resistance Input Card E 8 XU14 P1 XU4 C JMP1 REPLACEABLE PARTS LIST 9318C RESISTANCE SENSOR INPUT CARD 101 137 101 067 101 025 105 405 104 509 104 652 104 001 104 345 104 419 104 060 104 078 104 465 104 089 104 098 104 020 104 660 103 990 106 142 10 35 500V CAP PP 33MF 100V CAL ENABLE 4 DIP RA IC MICROPROCESSOR IC EEPROM IC OP IC OPTOCOUPLER 1C D A CONVERTER IC ANALOG SWITCH IC SWITCHED CAPACITOR IC A D CONVERTER 1 AMP IC BINARY COUNTER REGULATOR 5V IC EPROM CRYSTAL 5 000MH2 CONNECTOR 6 POST RA HDR 1190106 0035081 CD15ED3004J03 MPP 11 33MFD T6PSBO4 MBOC51VS X2404 OPO7EP HCPL 2731 DAC703BH 5 LF13202 LTC1043 5 500 MAX430CPA CD4020BCN 79L05 27C64 3 1 5 000MH2 Model DRC 91C 93C Model 8223 RS 232C Interface MODEL 8223 RS 232C INTERF
26. 9220 9305 9317C 9318C 8223 8225 8229 9126 SECTION VII ACCESSORIES INPUT CARDS AND OPTIONS TABLE OF CONTENTS DESCRIPTION ACCESSORIES Rack Mounting Kit e lt IEEE 488 Interface Cable Scanner Sensor Cable for 8229 Sensor Heater Cable e lt o Sensor Heater Output Cable 50 ohm Cartridge Heater 50 W 25 ohm Cartridge Heater 25 W INPUT CARDS Old Input Card Dip Switch Definitions 8210 8211 8219 P2 8219 P3 8219 R1 Diode Input Card 4 99 o Capacitance Input Card User configurable Input Card Thermocouple Input Card Ultra low 0 3K Resistance Card Germanium Carbon Glass Resistance Card OPTIONS RS 232C Interface Option Analog Output Option Scanner Conversion Option gt High Resolution Set Point PAGE WWNHNNNN 9210 1 9215 1 9220 1 9305 1 9317C 1 9318 1 8223 1 8225 1 8229 1 9126 1 Section VII 7 1 INTRODUCTION This section contains information concerning the Accessories Input Cards and Options for use with the DRC 93C Temperature Controller Each Accessory Input Card and Option is listed by part number in the Table on page 7 1 7 2 ACCESSORIES The DRC 93C can be rack mounted in a standard 19 inch instrument rack by using the RM 3F Rack Mounting Kit The RM 3F mounts one controller in a height o
27. Adjust the trimpot marked AMP Z on the calibration cover until the DVM reads as close to 0 volts as possible Set the standard to 0 2500 volts and adjust the trimpot marked AMP S on the calibration cover until the voltage reads 2 5000 volts 4 Calibrate the A D Converter Verify that the Display Sensor is the desired Input Card and that the units are ohms Set the standard to 0 2700 volts and adjust the trimpot marked A D until the display reads 270 00 ohms for the 9220 P3 an input of 0 2700 volts results in a display of 2700 0 ohms and for the 9220 R1 an input of 0 2700 volts results in a display of 81 00 ohms Check linearity by inputting 0 2000 and 0 1000 volts and verify that the unit displays 200 00 and 100 00 ohms within 0 01 ohms or equivalent for the 9220 P3 and 9220 R1 5 Install the top panel 9220 7 SENSOR CURVE INFORMATION Sensor Curve data for use with the 9220 RTD Configurations must be put in table form consisting of voltage and temperature points with the voltage in ascending voltage order Since the 9220 raw data would be in resistance form it must be converted prior to entering Refer to Section 4 of this manual for a discussion of how the data must be converted and formatted for entry into the unit over the remote interface and to Appendix B for a discussion of Precision Option curves and examples of curves that would be used with the 9220 9220 3 9220 Input Card 9220 8 REPLACEABLE
28. Current Return Voltage Sense Voltage Sense Shield The use of a four lead connection arrangement a is required for a four lead sensor Figure 2 2 Sensor Connections I E a 4 Lead Sensor 4 Lead Hook up e g Germanium Carbon Glass Rhodium Iron D B 1 gt _ V _ b 2 Lead Sensor 4 Lead Hook up e g Platinum Silicon Diode Ei 909 c M t 58 N c 2 Lead Sensor 2 Lead Hook up e g Silicon Diode 1 9 J 909 The use of four wire connection Figure 2 2a and b is highly re COPYRIGHT 3 88 LSCI Model DRC 93C commended for resistive elements to avoid introducing IR drops in the voltage sensing pair which trans lates into a temperature measure ment error An alternate two line wiring method Terminals A and E shorted toget her B and D shorted may be used for the DT 470 and TG 120 series diodes in less critical applica tions where lead resistance is small and small readout errors can be tolerated c Measurement errors due to lead resistance for a two lead hook up can be calculated using T IR dV dT where I is 10 microamperes R is the total lead resistance is the diode sensitivity and T is the measure ment error For example R 250 ohms with dV dT 2 5 milli volts kelvin results in a tempera ture error of 1 kelvin Two wire connections are not r
29. D 0 18 amp 3 tx GaTTON LAKE SHORE ne as g i 2 MODEL 9285 THERTDCOUPLE CARD DIGITAL AKD POER BUPPLY SECTIONS 14 42 37 dr 688 35 21 SISSE LS ncc KP LM T suo We 6 5 Figure 9305 1 Model 9305 Thermocouple In Card REPLACEMENT PARTS LIST MODEL 9305 INPUT MODULE BOARD LSCI PART NUMBER 113 180 LSCI Part Number Qty Description MFR MFR PART NO 2 101 022 0 1 100 FDYNE MPP11 0 1 100 ITEM NO C1 2 102 064 18914 CR1 2 DIODE SWITCHING 2139139 09 50 3061 P3 106 140 CONNECTOR POS SOCKET 01 LTC1050CN8 104 081 OP AMP IC E L IR Pe im ERE Figure 9305 3 M 9305 Thermocouple Input Card Module LAKE SHORE CRYOTRONICS INC 58 SSSA 8 E a fae Pare 2 4 TES TC LAKE SHORE CAYDTRONICS THE oma d MODEL 965 THERHOCOUPLE CARD Figure 9305 2 Model 9305 Thermocouple Input Card Model DRC 91C 93C 9317C 9318C Input Cards 9317C 9318C RESISTANCE INPUT CARD 9317C 9318C 1 INTRODUCTION This section contains information pertaining to the Model 9317C 9318C Resistance Input Card Included is a description specifications
30. IBSAD IBIST IBDMA IBEOS IBTMO IBEOT IBRDF 60 CALL IBINT2 IBGTS IBCAC IBWAIT IBPOKE IBWRT IBWRTA IBCMD IBCMDA IBRD IBRDA IBSTOP IBRPP IBRSP IBDIAG IBXTRC IBRDI IBWRTI IBRDIA IBWRTIA 70 TEMPS 93C 93C is IEEE address label set up when running IBCONF 80 CALL IBFIND TEMPS TEMP Required command to address 93C 90 OPEN A PROGRAM1 FOR INPUT AS 1 Open file to get data 100 FOR I 1 TO 10 Program Steps 01 10 110 INPUT 1 C 120 BS E Assemble command 130 13 CHR 10 CR and LF to command 140 CALL IBWRT TEMP BS Send data to 93C 150 FOR Z 1 TO 1000 160 NEXT Z 170 NEXT I 180 CLOSE 1 190 END 4 12 3 5 National Instruments QUICK BASIC IBM Example of 1 gt Request Quick Basic 3 0 Example 2 THIS PROGRAM WAS WRITTEN FOR THE NATIONAL INSTRUMENTS GPIP PC2 IEEE 488 CARD FOR IBM PC AND COMPATIBLES This program will store Programs Step 1 thru 10 in File PROGRAM1 m on Disk COMMON SHARED IBSTA IBERR IBCNT 12 93C CALL TEMP Required to address instrument OPEN A PROGRAM1 FOR OUTPUT AS 1 Open file to store data FOR I 1 TO 10 Program Steps 01 Thru 10 IF I 10 THEN N1S 0 N2 LTRIM RTRIMS STR I ELSE N RTRIM LTRIMS STRS I N1 LEFT N 1 N2 RIGHTS NS 2 N2 RIGHTS STR I 1 END IF 4 26 COPYRIGH
31. Ready Signal Ground COPYRIGHT 12 87 LSCI Model 8223 RS 232C Interface Figure 8223 6 General Serial Interface Interconnection for Half Protective Ground Transmitted Data Received Data Signal Ground Note It may be necessary to jumper pins 5 6 8 and 20 to disable the handshake functions of the Host This is not required for the 8223 Interface 8223 8 REPLACEABLE PARTS Included in this section is Figure 8223 1 It includes the Model 8223 RS 232C Interface Option Schematic replaceable parts list and illustrated component layout Refer to the manual for ordering information 8223 7 cr W 1 crt C T 0 p C 11229 DATA TERMINAL READY OPTION SLOT 2 Ji 4 REQUEST TO SEND C 21 2 8A TRANSMITTED DATA C5 4 21 43 gt DEF P1 25 gt 11 9 DATA SET READY C 41 5 8 CLEAR TO SEND C 21 3 a8 RECEIVED DATA C 41 8 RECEIVED LINE SIG DET lt J1 7 JAB SIGNAL GROUND C di 1 PROTECTIVE GROUND 41 MOUNTS ON BACK INTERFACE CUTOUT H1 43 MATE WITH HOOD TO 41 ta 2 BAUD RATES NOTE U4 74L802 GND PIN 7 5 PIN 14 v1 1 432 MHz L 5 4 2 Figure 8223 1 Model 8223 RS 232C Interface Option REPLACEABLE PARTS LIST MODEL 8223 RS 232C INTERFACE OPTION LSCI Part Number 106 253 102 071 105 408 105 406 104 053 102 018 104 310 104 203 104 523 104 720 104 721 25 PIN D STYLE PLUG XST
32. Section IV above the limitation for the card is entered the set point is set to the upper temperature limit Also note that an S sent by itself to the 93C sets the set point to O kelvin or its equivalent in the units chosen which will result in shutting down the heater output stage of the temperature controller Table 4 9 DRC 93C Command Request Summary for Setpoint Setup Functional Description Set Point Input The decimal point is FREE FIELD and its allowable position depends on the control units Limits are Units Range 0 through 999 9 through 0 0000 through 0 through 0 through 999 9 999 9 9 9999 99999 99 999 or 999 99 The Set Point is limited based on input card and Sensor Lower limit is 0 K 273 1 C or 459 6 OF t Upper Set Point Limit Input Card Sensor Type K Sensor Units 9210 20 3 DT 470 DT 500 2 9999 volt 9210 20 6 TG 100 TG 120 6 5535 volt 9317C Germanium Carbon Glass 9999 9 ohms 9318C Germanium Carbon Glass 99999 ohms 9215 15 5 400 5 501 29 999 9215 150 CS 401 CS 501 149 99 nF 9210 20 3 DT 470 474 9 201 7 395 1 2 9999 volt 9220 2 100 Series 526 7 980 1 299 99 ohms 9220 P3 PT 1000 Series 2999 9 ohms 9220 R1 Rhodium iron 99 999 ohms kkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkk Output of Instrument Data Set Point Data N11N12N13 N44N45 8 Characters plus up to 2 terminators where the N44 N45 variations a
33. Service Request will remain on the Bus until either a Serial Poll is initiated or the cause of the setting of the SRQ is eliminated The Status Register mask and control channel limit is part of the power up save settings like the set point and units It is updated on power up to the last settings with internal switch 2 set On power up the Status Register mask is set to 00 and the control channel limit to 000 0 if switch 2 is off 4 11 3 5 Examples for setting Mask Example 1 061 Sample Data Ready with the Service Request bit SRQ With the SRQ bit of the Status Register mask enabled the DRC 93C SRQ interrupt will be generated The BUS CONTROLLER can read the Status Register to determine appropriate instrument conditions In this case bits 1 is continuously updated to reflect current instrument status of the Sample Data Ready Q61 also results in a service request if an OVERLOAD ERROR is indicated Example 2 Q2F000 1 All Status Reports with the SRQ bit off With the SRQ bit of the Status Register mask disabled SRQ interrupt by the DRC 93C will be generated however the BUS CON TROLLER can still read the Status Register and this command will give all five Status Reports Example 3 Q06000 1 Enable the Control Data Ready and Control Channel Limit with a band of 0 1 about the control point 4 21 Section IV Model DRC 93C Figure 4 2 DRC 93C Status Register Mask and Status Register Form
34. Table 4 12 Commands to Fix the Status Register Mask 4 22 Table 4 13 93C Command Request Summary for Status Register Mask 4 23 Table 4 14 DRC 93C Command Request Summary for Program Step 4 24 Table 4 15 DRC 93C Output Data Requests s e e e lt x 4 29 viii COPYRIGHT 3 88 LSCI TABLES OF TABLES AND ILLUSTRATIONS CONT D Table 4 16 Sensor Curve Commands and Description 4 34 Table 4 17 Sensor Curve Information Table Output Format 4 35 Table 4 18 XDN41N5 Sensor Curve output Format 4 35 Table 4 19 Conversion of Raw Units Data for the XC Command ctn ec 4 38 SECTION PROGRAMMING INSTRUCTIONS Table 6 1 Programmer Summary e e e s ee Table 6 2 PROGRAMMING COMMANDS e s lt s eee SO COPYRIGHT 3 88 LSCI ix SECTION I GENERAL 1 1 INTRODUCTION The information contained in this operations manual pertains to the installation operation remote programming options acces sories for the Lake Shore Cryotro nics Inc Model DRC 93C Tempera ture Controller This manual also contains troubleshooting and calibration procedures schematics component layouts and replaceable parts lists This section contains general information for the Lake Shore Cryotronics Inc DRC 93C Tempera ture Controller Included is an instrument description specifica tions instrument identification option and accessory information
35. UI ee eo gt mw an d md Na Wea Ul we oo Q 9500 15 CAP ELECT 470MF 35 CAP ELECT 2100MF 75V 1 100 BRIDGE RECTIFIER DIODE RECTIFIER DIODE RECTIFIER DIODE ZENER 24V DIODE ZENER 5 1V CONNECTOR IEEE CONNECTOR REMOTE ID CONNECTOR TX1 TO MB CONNECTOR TX2 TO MB CONNECTOR BP TO MB CONNECTOR POSTS RELAY DPST DRY REED DRY REED RELAY 20 W DRY REED RELAY 50 W TRANSISTOR PNP RES PREC 100K 01X MATCHED PAIR RES MTF 30 1 1 4W 1 RES MTF 9 84 1 4M 1X RES MTF 2 92 1 W 1 RES MTF 3 5 1 25 3 M RES WWD 587 5 POWER SWITCH 2 P DIP SWITCH 8 POS CONNECTOR 25 50 CONNECTOR 18 36 REGULATOR 5V REGULATOR 5V REGULATOR 15V REGULATOR 15V REGULATOR 8V REGULATOR 8V REGULATOR ADJ 1 2 57V IC IEEE CHIP IC IEEE SUPPORT CHIP IC IEEE SUPPORT CHIP IC PORT EXPANDER IC 8 BIT MULTIPLEXER IC 16 BIT D A CONVERTER IC DISPLAY DRIVER IC 10 BIT D A CONVERTER IC DUAL SPDT ANL SWITCH IC QUAD OP AMP IC DISPLAY DRIVER OPTOCOUPLER OPTOCOUPLER 8 BIT A D CONVERTER HEX INVERTER 0 1C LIN F V OR V F 1c OP AMP JFET INPUT POWER MOSFET 90 N CH IC OP AMP DUAL MC1741 POWER MOSFET 100 CABLE MB TO U1 SOCKET TO 3 REPLACEABLE PARTS LIST DRC 93C MAIN BOARD s1888A952U015AMA1 ECEAIVV471S 3186BA
36. clockwise during the setup of the instrument so that full power is available on the MAX power scale if desired 2 3 9 2 Current or Power Output Display The HEATER meter can be set to read either of output power or of output current The internal DIP switch setting switch 1 con trols whether the meter reads in current closed or power open The DRC 93C is shipped to read in power 2 4 REMOTE SENSOR ID Connector The REMOTE SENSOR ID connector J5 on the rear panel receives POSITION DATA from a Model 8084 or 8085 Sensor Scanner or a Model SW 10A Ten Sensor Selector Switch The 2 4 Model DRC 93C REMOTE SENSOR ID Interconnecting Cable and REMOTE SENSOR ID connec tor assignments are given in Table 2 4 Table 2 4 REMOTE SENSOR ID Connector Assignments REMOTE SENSOR ID Connector Pin Function Bit 0 BO LSB Bit 1 1 Bit 2 2 Bit 3 Bit 4 B4 MSB Digital Ground The POSITION DATA is the binary representation of the remote posi tion Table 2 4 gives the POSITION DATA binary combinations equivalent hexadecimal remote pos ition The remote position input can be used to select specific sensor curve tables stored in the DRC 93C The correlation between remote position and sensor curve is given in Section III 2 5 IEEE 488 INTERFACE Connector The IEEE 488 Connector on the back of the DRC 93C is in full compli ance with the IEEE Standard 488 1978 The connector has
37. for the input is then determined from Table 3 4 the Curve Number to Position Number Correlation Table complete discussion of curve selection is given in Section 3 9 and in particular Section 3 9 2 1 8229 6 REPLACEABLE PARTS Included in this Section is Figure 8229 1 It includes the Model 8229 Scanner Conversion Option schematic replaceable parts list and illustrated component layout Refer to the manual for ordering information 8229 3 P4 8 POSITION DATA 12 24 23 CR 24g2 184148 R3 348 8255 5 BUFFV BUFFV I I4 V 2 6 WIRE CABLE TO INPUT CARD NOTE 5 Ue AND ARE OPEN COLLECTOR INVERTERS 7406 PIN 14 IS PIN 7 IS GND LAKE SHORE CRYOTRONICS INC A MODEL 0229 SCANNER OPTION CARD a e 6 8 99 16 87 DWG NO 17 27 06 525 86 01 SHEET 1 OF 1 1 3 e Figure 8229 1 Model 8229 Scanner Conversion Option ITEM NO REPLACEABLE PARTS LIST MODEL 8229 SCANNER CONVERSION OPTION LSCI Part Number 105 321 105 322 106 250 106 142 106 424 104 524 104 210 ee PUR RELAY DPST DRY REED RELAY DPST DRYREED CONNECTOR KIT 6 POST LOCKING RA HDR 26 PIN RA HEADER I I PORT EXPANDER OC HEX INVERTER 609 26024R gt C P8255A 5 MFR PART NO CR 3402 05 91 CR 7102 05 1010 57 30240 2420 09075 1061 APPENDIX A Standard Diode Voltage Temperature Characteristics
38. lines inhibits transmission by the Interface Clear to Send CB indicates to the Interface that data transmission is allowed Internally pulled up to maintain ON state when left disconnected Data Set Ready CC indicates to the Interface that the host computer or terminal is not test mode and that power is ON Signal Ground AB this line is the common signal connection for the Interface Received Line Signal Detector CF this line is held positive ON when the Interface is receiving signals from the host computer When held low OFF the BB line is clamped to inhibit data reception Internally pulled up to maintain ON state when left disconnected Data Terminal Ready CD asserted by the Interface whenever the DRC 91C 93C 8223 power is to indicate that the Interface is ready to receive and transmit data 8223 2 tParity Bit optional 8223 3 Switches Configuration of Dip 8223 3 1 Selection of Baud Rate The Model 8223 has field selectable baud rate using DIP switch package S1 8 switches on the Interface card The baud rate is selected by closing the switch position for the desired baud rate and making sure all other positions are open Table 8223 3 gives the baud rate selection table Only the 300 and 1200 baud rates have been tested and are fully supported Table 8223 3 Baud Rate Switch S1 Switch S1 12345678 Baud Rate
39. selection since the transformer output is shorted momentarily by COPYRIGHT 3 88 LSCI Section I changing the setting The maximum power can also be limited by using the rheostat on the rear panel Power can be reduced on the MAX scale to any value between MAX and a reduction of a factor of ten in power When greater output power is required the optional W60 output stage can provide 60 watts into a 25 ohm load An IEEE 488 interface is standard in the DRC 93C This interface can be used to remotely control all front panel functions When two input cards are used data from both inputs is available via the interface 1 3 SPECIFICATIONS Instrument specifications are listed in Table 1 1 These specifications are the performance standards or limits against which the instrument is tested 1 4 OPTIONS The options for the DRC 93C Controller are listed in Section VII Three option ports are designed into the DRC 93C The options are field installable by the user 822x series options can be factory installed in the DRC 93C or field installed at a later time The 8223 RS 232C Interface Option operates similar to the IEEE 488 interface With the display in temperature units the Model 8225 Analog Output option is available to provide a linearized analog output of 10mV K independent of the display temperature units chosen If the display is in sensor units the output for diodes is 1V V for 100 ohm platinum 10mV
40. that the proper fuse is installed before inserting the power cord and turning on the instrument 2 3 2 Power Cord A three prong detachable power cord for 120 VAC operation which mates with the rear panel UL IEC ICEE standard plug is included with the instrument 2 3 3 Grounding Requirements To protect operating personnel the National Electrical Manufacturer s Association NEMA recommends and some local codes require instru ment cabinets be grounded This instrument is equipped with a three conductor power cable which when plugged into an appropriate receptacle grounds the instrument Line Voltage Selection Section II Figure 2 1 Model DRC 93C Typical Rack Configuration 2 3 4 Bench Use The DRC 93C is shipped with plastic feet and a tilt stand installed and is ready for use as a bench instrument The front of the in strument may be elevated for con venient operation and viewing by extending the tilt stand 2 3 5 Rack Mounting The DRC 93C can be installed in a standard 19 inch instrument rack by using the optional RM 3F or RM 3F H rack mounting kit A typical RM 3F H kit installation is shown in Figure 2 1 2 3 6 Sensor Input Connections The DRC 93C has two rear panel 5 pin input connectors for sensors The lead connection definition for the sensor s is given in Table 2 2 and is shown in Figure 2 2 Table 2 2 INPUT Connections for J1 Input A and J2 Input B Current Out
41. tive temperature dependence tempera ture sensor such as platinum and rhodium iron the default curve is Curve 03 which is the standard 3750 DIN curve for platinum This de fault will only occur if a curve of opposite temperature dependence has been inadvertently selected by the user the case of the 9215 card temperature units are not allowed due to the inability of this sensor to hold a calibration upon cycling 3 8 6 2 Sensor Units Mode 3 8 6 2 1 Voltage Units The voltage mode is allowed for the 9210 3 and 6 configurations the 9220 3 and 6 configurations as well as the older version 8210 and 8211 cards In the voltage mode the display has a resolution of 0 1 mil livolt with the full scale range de pendent on the input card 2 9999 volts for the 3 configurations and the 8210 card and 6 5535 volts for the 6 configurations and the 8211 input card The actual Input Card resolution is 0 05 millivolts and 0 1 millivolts respectively Ifa voltage exceeding full scale is ap plied to the displayed input an overload condition is present and is indicated by OL on the display 3 8 6 2 2 Resistance Units The Resistance mode is allowed for COPYRIGHT 3 88 Section III the 9317C 9318C and the 9220 P2 P3 and R1 configurations as well as the older 8219 P2 the 8219 P3 and 8219 R1 cards The display range and resolution for the 9317C is 0 000 to 9999 9 ohms the 9318C is 0 000 to 99999 ohms Note that the resista
42. 1 TO CLOSE THE FILE END 4 COPYRIGHT 3 88 LSCI Model DRC 93C Section IV 4 12 3 2 Program to Restore Program Step 1 thru 10 using the HP86B The following program for the HP86B restores Program Steps 01 thru 10 from a file called PROGRAMI previously stored a floppy with the volume label 93c 10 REM RESTORE 20 REM PROGRAM TO RESTORE THE INTERNAL PROGRAM AND PRINT ON THE SCREEN 30 DIM A 62 N1 1 N2 1 40 REM PROGRAM1 93C WAS CREATED AND WRITTEN BY PROGRAM STORE 50 ASSIGN 1 TO PROGRAM1 93C OPEN THE FILE 60 FOR I 1 TO 10 PROGRAM STEP 01 TO 10 70 READ 1 A GET PROGRAM STEP I FROM THE FILE 80 OUTPUT 712 E AS SEND PROGRAM STEP I 90 DISP 5 DISPLAY THE PROGRAM STEP THE SCREEN 100 WAIT 200 WAIT 200 MILLISECONDS 110 NEXT I 120 ASSIGN 1 TO CLOSE THE FILE 130 END 4 12 3 3 National Instruments GWBASIC and BASICA IBM Example of WEN N gt Request This program will store Programs Step 1 thru 10 in File PROGRAM1 on Disk A using GWBASIC or BASICA and the National Instruments GPIP PC2 IEEE 488 Card for the IBM PC and compatibles 10 CLEAR 60969 BASIC DECLARATIONS 20 IBINIT1 60969 This number is different for each computer 30 IBINIT2 3 40 BLOAD bib m IBINIT1 50 CALL IBINIT1 IBFIND IBTRG IBCLR IBPCT IBSIC IBLOC IBPPC IBBNA IBONL IBRSC IBSRE IBRSV IPPAD IBSAD IBIST IBDMA IBEOS IBTMO IBEOT IBRDF IBWRTF 60 CA
43. 10 is 5 for Setpoint ramping The setpoint of step 05 will be set to 40K to indicate where the ramping will end Note that even if the time were selected incorrectly the ramping would still end at 40K It is necessary to select the timer increment per tenth to arrive at the 40K in the 10 minutes From 40K to 100K is 600 tenths It will require 600 increments of 1 seconds each to end up at 40K in 10 minutes 600 seconds The gain will ramp up during Step 08 and ramp down during Step 10 6 8 4 Example 4 Repeat of Example 3 with a Limit of 10 Cycles STEP 11 Step Command REPEAT COUNT 11 0 10 STEP 12 Step Command JUMP VECTOR 12 2 14 Days Hours 00 00 Minutes Seconds 10 00 Setpoint 40 0 Gain 10 Rate 0 Reset 10 STEP 13 Step Command JUMP VECTOR 13 8 17 STEP 14 Step Command JUMP VECTOR 14 5 15 Days Hours 00 00 Minutes Seconds 00 03 Setpoint 100 0 Gain 20 Rate 0 Reset 5 COPYRIGHT 12 87 LSCI Model DRC 93C STEP 15 Step Command JUMP VECTOR 15 1 16 Days Hours 00 01 Minutes Seconds 00 00 Setpoint 100 0 Gain 20 Rate 0 Reset 5 STEP 16 Step Command JUMP VECTOR 16 5 12 Days Hours 00 00 Minutes Seconds 00 01 Setpoint 40 0 Gain 10 Rate 0 Reset 10 STEP 17 Step Command 00 17 9 00 Setpoint 40 0 Gain 10 Rate 0 Reset 10 COPYRIGHT 12 87 LSCI Section VI MODEL OR PART NUMBER RM 3F 8072 8271 04 8271 21 8271 22 HTR 50 HTR 25 9210 9215
44. 10 millivolt signal to the V and V Thermocouple Input terminals on the Terminal Block 3 The Display should read about 10 millivolts Adjust the trimpot labeled A D Thermocouple A D Span so that the voltage read on the Display is 10 000 millivolts 4 This test is to verify that the A D converter is symmetrical Apply a 10 millivolt signal to the V and V Thermocouple Input terminals The DVM should read 2 0000 0 0006 volt The Display should read 10 000 0 003 If it does not meet these specifications the unit should be returned to the factory for calibration 9305 9 4 Reference Junction Test This test is to verify that the Reference Junction Compensation circuitry is operating properly If this test does not produce the following results please consult the factory 1 Apply a zero volt signal to the 9305 10 Model DRC 91C 93C V and V Thermocouple Input terminals by shorting across the Terminal Block with a short jumper wire 2 Select the controller to display the 9305 card in temperature units 3 Enable the Reference Junction Compensation as described in Section 9305 6 The reading on the display should read Room Temperature 4 Disable the Reference Junction Compensation and the display should read Zero degrees Celcius the normalization point of the curves 9305 9 4 Calibration Completion 1 Close 1 S1 1 to return the 9305 to normal Secondary Sensor update operation 2 R
45. 1630 609 1631SP 107 017 MDL 1 MDL 1 2 105 671 105 676 105 677 FN372 6 22 2139 09 50 3061 2878 08 50 0116 126 218 126 198 111 0113 001 111 0103 001 15 1 765 IRF9130 M8080 1640 C696 114 C696 115 107 180 REPLACEABLE PARTS LIST DRC 93C DISPLAY AND DISPLAY DRIVER BOARDS ITE NO LSCI Part 106 151 106 150 105 651 101 132 101 137 101 144 102 062 106 153 106 152 102 072 104 526 104 277 104 522 104 270 104 120 104 654 104 661 104 528 104 511 104 653 Q WW 1 1 1 3 3 1 1 2 2 1 1 2 1 1 1 1 1 CONNECTOR HEADER ON DB CONNECTORCHEADER ON DB SWITCH CAP TANT 1 5MF 10V CAP TANT 10MF 35V CAP TANT 33MF 25V DIODE SIL SWITCHING CONNECTOR SOCKET ON DDB CONNECTOR SOCKET ON DDB TRANSISTOR SIGNAL PNP IC KEYBOARD INTERFACE 4 16 LINE DECODER 1 0 EXPANDER 4 10 LINE DECODER 3 8 LINE DECODER 2K NOVRAM W CLOCK EPROM 8 BIT LATCH MICROPROCESSOR NOVRAM G y O O O O O w w w o GN TOB24SG TDB10SG KEF10901 OD155X9010A2 9D106X0035DB1 60336X9025PE 14 4 MK48TO8B 25 270256 82C82 P80C31BH DS1225Y s ett 45 D 28 1 86 01 9 1 Ce ruo e c3 mc MEN T i 101 1 PS Ree XU21 JA2 we ee we eee ee ee wee a t 2 TX1 lt x m ooo
46. 168 46 p C14 ere lt gt ae eee eee JA ci m CS A 1 9 12 CS CHANNEL A CURRENT SOURCE SUPPLY z Q CS A cs 12v CS B Wasi CHANNEL B CURRENT SQURCE SUPPLY 4 ev cse H HS H6 AC POMER BUSS 5 i 4 3 C12 68 cis R84 68 2 2K 02 18 88 RED BLK 45 MICROPROCESSOR TP14 CARD 5 0 MAIN BOARD O TP13 5 D 15 0 15 0 8 1 2 15 A 15 A DWG NO B 438 06 91 1 OF 7 Figure 93C 1b Schematic DRC 93C Main Board 1 Input Power Supply AJ Figure 93C 1c Schematic DRC 93C Main Board 24 DWG NO amp 39 06 01 98 85 08 LAKE SHORE aoe INC DRC 93C MAINBOARD OUTPUT POWER SUPPLY 5 C31 NOTE 4 U48 7496 D PIN 14 7 GND D cag WITH C61 ACROSS PINS 7 AND 14 QPAK 2g 5 BN ge eee R R 9 L8 rs 3 E n p TL di E 17 944 x i pei ya 5 Sara De ET 9 19 LT T 33 ee ee ner 12 See LL L3 88 p Ebr eol A R 1 ele DL 29 a pe zo Le DAV 4 di del 96 15 4 94 1 Nw p anle DAV DAC De 25 L 16 R
47. 170 Part 4 Reset and Rate Control October 1984 pp 133 145 Part 5 Selecting the Mode of Control December 1984 pp 132 136 Some of this material has appeared in Principles of Temperature Control available from Gulton Industries West Division Unlike reference 1 the discussion is not related to cryogenics but temperature control system principles are briefly and clearly explained C L Pomernacki Micro Computer Based Controller for Temperature Programming the Direct Inlet Probe of a High Resolution Mass Spectrometer Review of Scientific Instruments 48 1977 pp 1420 1427 W M Cash E E Stansbury C F Moore and C R Brooks Application of a Digital Computer to Data Acquisition and Shield Temperature Control of a High Temperature Adiabatic Calorimeter Review of Scientific Instruments 52 1981 pp 895 901 R B Strem B K Das and S C Greer Digital Temperature Control and Measurement System Review of Scientific Instruments 52 1981 pp 1705 1708 Application Notes Lake Shore Cryotronics Inc Standard Curve 10 Standard Curve 10 Measurement Current 10 uA 0 05 Voltage mV K T K Voltage mV K T K Voltage mV K 1 69812 1 69521 1 69177 1 68786 1 68352 1 67880 1 67376 1 66845 1 66292 1 65721 1 65134 1 64529 1 63905 1 63263 1 62602 1 61920 1 61220 1 60506 1 59782 1 57928 1 56027 1 54097 1 52166 1 50272 1 48443 1 467
48. 3 8 2 Upper and Lower SENSOR Number The selection of A or B inputs for the Upper Display is changed by holding in the SENSOR key and pres sing the 44 Up key The selection of A or B inputs for the Lower Display is changed by holding in the SENSOR key and pres sing the vv Down Key The A input is distinguished by a uppercase letter A in the Sensor window and the B input by a lower case b in the Sensor window While the SENSOR key is held down the Upper and Lower Displays will show the card types being used by the displayed sensor The GAIN RATE and RESET windows are blank 3 5 Section III They are used to indicate REMOTE POSITION DATA when an External Scan ner Models 8084 or 8085 are at tached see Section 3 9 2 When the 8229 Scanner Conversion Option is not present the display toggles between the A and B input cards 3 8 3 8229 Scanner Input Option With the addition of the Model 8229 Scanner Input Option four more inputs are added to the A channel input These additional inputs are designated 1 2 3 and 4 in the SENSOR window With the scanner conversion option present the SENSOR key and 44 Up key increments the Upper Display inputs in the sequence A 1 2 3 4 b A etc Similarly for the Lower Dis play with the SENSOR key and vv Down key The 8229 Scanner Input Option is covered in Section VII 3 8 4 SCAN Function The SCAN function allows the instru ment to step between the two i
49. 3 88 LSCI Model DRC 93C Section IV Table 4 10 DRC 93C Command Request Summary for the Control Parameters Functional Description Setting of all other Control Parameters PN4 N 2 Proportional GAIN 1 2 is 0 1 through 99 Examples or PN4N5 the command are P PO P0 0 and P99 Integral RESET is 0 0 OFF through 99 three characters including the decimal point Forms of the command are IO 10 0 through 199 Derivative RATE N4N5 is 0 0 OFF through 99 three characters including the decimal point Forms of the command are DO 00 0 through D99 Heater Range Nq is 0 through 5 Forms of the command are RO through R5 N4 Range Heater Current 0 OFF 0 1 4 10 2 3 33 mA 3 2 100 mA 4 zl 330 mA 5 MAX 1A Manual Heater Power 00 to 99 of Heater Range 1 2 kkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkk Functional Functional Description N4N5N5 NAN5Ng N7NgNo N41N12N45 N14N45 Control Parameters 20 characters plus up to 2 terminators where N41N3N5 the Gain Value NAN5Ng the Rate Value N4NgNo the Reset Value N10 the Heater Range N11N12N13 the of Heater Power or Current out 14 15 the of Manual Heater Power or Current Out 4 10 3 Enabling the Scan Function The YS Command time is set to zero being skipped It is strongly recommended that the Upon sending the YS command fr
50. 31 indicates that there are 31 lines or points in the curve data Points are numbered from 1 to the total number of points here 31 The 0 0 in the Upper Display is the temperature in kelvin for point 31 and the 6 5536 the sensor voltage of point 31 at 0 0 K NOTE A Standard Curve cannot be edited but the standard curve data can be examined To examine Point 12 first hit the POINT key The Point in the Set point Display will begin to flash Enter 12 using the keypad followed by the ENTER key The displays will read 115 0 02 12 0 9445 to indicate that Point 12 of Curve 02 is 0 9445 volt at 115 0 K At any time that the POINT key is appropriate the 4 key and v key can be used to examine the next higher numbered point and lower numbered point respectively If the 4 key was pressed after point 12 was displayed in the example given above the display would change to 95 0 02 13 0 9857 The 4 key and v key do not operate when the instrument is requesting a Curve temperature or voltage To exit the Curve Programming routine hit the PROG key 3 14 Model DRC 93C 3 9 3 2 Entering New Curves The user should know what Curve is available for new data by keeping accurate records and updating Table 3 3 as curves are added If an error is made in record keeping the instrument will catch it since 00 number of points indicates an avail able set of data storage It is suggested that the curve data be
51. 8 CALIBRATION The 9215 was calibrated to specifi cation prior to shipment The card meets specification for operation either in the 9215 15 or 9215 150 configuration by simply pressing the switches located on the card This Section provides information to permit recalibration if needed NOTE Calibration for zero capacitance may be required to meet accuracy specifications if your sensor lead capacitance or stray capacitance is excessive The following equipment is used to calibrate the 9215 Capacitance Input Card 1 Digital Voltmeter Multimeter DVM 4 digit resolution or better 2 Precision Standard Capacitors 10 nanofarad and 100 nanofarad with tolerance of 0 1 or better 3 Precision Voltage Source capable of supplying a voltage with an accuracy and resolution of 100 microvolts out of 10 volts or better 9215 6 DRC 91C 93C The unit should be allowed a one hour warm up time to achieve rated specifications To begin remove the three top panel screws and slide the panel off The procedure is divided into three parts as follows 1 Calibration of the A D verter 2 Zero calibration 3 Span Calibration The zero and span calibration is done with the instrument and system wiring configured as it will be used This will provide optimum accuracy because lead and stray capacitance will be taken into account 9215 8 1 A D Calibration 1 Locate DIP switch package S1A Switch
52. A A DATA OUT GND Ald GND Add 6 5 A 5 5 A 15 15 A DVD A A DATA IN GND A CLK 6 0 SLOT 1 OPTION 1 RD A2 AB OPT1 ID RE 42 1 _ tes 44 60 46 48 15 50 5 0 PWR V PWR VREF V CS A i2V CS CS B 1eV CS B PNR V ADJ F v CNT V AN OUT 18 PWR V 15 A OUT i 15 A V F ADJ GND D RESET V 6 D MICROPROCESSOR AND OPT3 ID _OPTi ID INT OPTS INT OPT1 DBIN RD IEEE CLK PID DATA INTE A2 2 B CLK _A CLK CS POT POT CLK PID CLK1 PID CLK2 B DATA IN A DATA IN CS PDAT TS OLD CARD CS DISP CS OPT1 CS oPTs 5 D SLOT 4 CALIBRATION AND SERVICE CARD GND A HTR REF KTR IRV PWR LOW HTR V GND A GAIN V B 8 5 15 A OUT SP SPAN ADJ F V ADJ SP V SP ZERO ADJ RATE V 2 4 6 8 1g 12 14 16 18 28 22 24 28 28 32 34 26 SLOT 8 MEMORY CARD OPT2 ID CONT ID INT OPT2 DRC 939C MAINBOARD INTERCONNECTIONS ee 8441 66 81 m W gt TTT mm pu m ES ja RN2 4 15K i r N SP ZERO ADJ 544 34 lo iso Pitt tt 12 14 BASEBE ELSI As ong 8 ERE t RARE sss pn Hw a 7 9 RN3
53. COPYRIGHT 3 88 LSCI Model DRC 93C DRC 93C from interrupting the BUS CONTROLLER However the BUS CON TROLLER can still read the Status Register to determine appropriate instrument conditions 4 11 1 The Service Request The Service Request Message is independent of all other IEEE 488 activity and is sent on a single line called the SRQ line When the Service Request is sent and more than one instrument on the Bus has the capability to send this message the BUS CONTROLLER must decide which instrument is sending the request This is done by conducting a Serial Poll of the instruments on the Bus The instrument polled responds by sending a Status Regis ter The Status Register indicates whether the device has requested service and if so for what reason Once the reading on a given channel becomes stable or valid a service request is issued by the DRC 93C provided that Bit 6 in the Status Register Mask is set See 4 11 2 5 With the SRQ bit of the Status Register mask disabled SRQ interrupt by the DRC 93C will be generated however the BUS CON TROLLER can still read the Status Register to determine appropriate instrument conditions 4 11 2 The Status Register and Status Reports The DRC 93C Status Register is a single byte of data from the DRC 93C containing five bits called the Status Reports which give information indicating which process is complete whether the channel was changed or a limit overload
54. Characters when all 32 Curves are present plus up to 2 Terminators where N4N29N4N4 is the decimal number of curve locations available BYTES FREE H H2H3H is the Hex address the next curve will start at C4C2 is the Sensor Curve assigned to Remote Position AOO through and BOO through BIF Table 4 18 Sensor Curve Output Format 1 gt N1N5 1 18 19 N3N4 X XXXXX TTT T A minimum of 54 Characters for a curve with the minimum of 2 data points and a maximum of 1412 Characters for a curve the maximum of 97 data points plus up to 2 Terminators where is the Sensor Curve number 00 thru 31 is the 18 Character Information line Cig is the Temperature Coefficient P or N N4N4 is the number of data points 00 thru 99 X XXXXX is the Voltage Equivalent V or Log R TIT T is the Temperature to 0 1 only COPYRIGHT 3 88 LSCI 4 35 Section IV Note that the last character to be displayed is number 460 since the Terminators CR LF have to be 00 STANDARD DRC D N 31 Model DRC 93C input but not displayed This results in the following display 0 00000 499 9 0 19083 365 0 0 24739 345 0 0 36397 305 0 0 42019 285 0 0 47403 265 0 0 53960 240 0 0 59455 220 0 0 73582 170 0 0 84606 130 0 0 95327 090 0 1 00460 070 0 1 04070 055 0 1 07460 040 0 1 09020 034 0 1 09700 032 0 1 10580 030 0 1 11160 029 0 1 11900 028 0 1 13
55. DRC 93C Command Summary of Instrument Setup Choices of the commands are Summary of Input Command Formats Table Interface Setup Commands Selects EOI status Selects Remote Interface Mode Changes terminating Characters Clear Command Instrument Setup Commands Select Control Units Select Sample Units F2CC4N4 Select Control Setpoint Sensor F2SC4N4 Select Sample Sensor F3CN4 Select the Control Setpoint Resolution F3SN4 Select the Sample Resolution FACON FACOFF Select the control Sensor Deviation ON or OFF FASON F4SOFF Select the Sample Deviation ON or OFF F5ON F5OFF Select the MATH Function ON OFF or CLeaRed and 5 NC4N4N3N45 Assign Curve Number for Input Channel selected Table Control Setup Commands 4 9 S etc Set Point Input 4 10 PN N gt etc Proportional GAIN IN1N5 etc Integral RESET DN4N5 etc Derivative RATE RN Heater Range HN N gt Manual Heater Table Scanner Setup and Selection Commands 4 11 YANN oN3 Set the Scanner channel dwell time or YBON3N4 YS Enable the S CAN function Disable or H old the SCAN Table Status Register Mask Command 4 13 QC1C2 Set the Status Register mask Table Restoring Executable Programs Command 1 2 1 Transmit Restore Program Step N4N5 data 4 8 COPYRIGHT 3 88 LSCI Model DRC 93C 4 7 2 3 Local Lockout This mess
56. Example of E Command COMMAND OPERATIONS amp 4 s ee x x 9 s s s s s OUTPUT DATA STATEMENTS ete 4 14 1 WS WC and WP Data Strings pe 4 14 2 The WO Data String e e se s eevee SAMPLE PROGRAMMING Ue mo 4 15 1 HP86B Keyboard Interactive Program TE a 4 15 2 National Instruments GWBASICA or BASICA IBM Example 4 15 3 National Instruments QUICK BASIC IBM Example 4 15 4 HP86B Bus Commands Program e e s o eo SENSOR CURVE PROGRAMMING INSTRUCTIONS e e s s e e eo 4 16 1 The XDT Command 4 16 2 The XDN4N5 Command e s e e s s s s s COPYRIGHT 3 88 LSCI 4 19 4 20 4 20 4 20 4 21 4 21 4 21 4 21 4 21 4 23 4 23 4 23 4 23 4 23 4 24 4 24 4 25 4 25 4 26 4 26 4 27 4 28 4 28 4 28 4 28 4 30 4 30 4 30 4 31 4 31 4 32 4 32 4 33 TABLE OF CONTENTS CONT D 4 16 3 The XDA Command 4 36 4 16 4 The 1 2 Command 4 36 4 16 5 1 2 Command 4 37 4 16 6 XKN1N5 Command lt s lt lt on n 4 37 4 16 7 2 182 and 2 1 2 Commands 4 37 SECTION V MAINTENANCE 5 1 INTRODUCTION 5 55 5256 5 1 5 2 GENERAL 5 1 5 3 FUSE REPLACEMEN
57. I and I the Secondary current source adjustment 104A the Control Amplifier Span adjustment CNT V and the A D converter span adjustment A D on the calibration cover for the 9305 Card 5 Locate the Rear Panel Offset Adjustment on the Terminal Block 6 Locate the test points 24 CNT V and TP1 GND 2s of the Calibration Card 7 Avoid using clip on leads during calibration because they do not make good electrical connections Attach test equipment lead wires with the terminal screws The calibration procedure is divided into three parts 1 Calibration of the Secondary Sensor Current Source 2 Calibration of the Control Signal Amplifier and Rear Panel Offset Adjustment 3 Calibration of the Thermocouple and Secondary Sensor A D converters the 9305 Thermocouple card 9305 9 1 Secondary Sensor Current Source Calibration 1 Connect the DVM plus lead to terminal I and the DVM minus lead to the I terminal 2 Adjust the trimpot labelled 10 so that the DVM reads 1 000 volt 0 001 volt COPYRIGHT 6 88 LSCI 9305 Thermocouple Input Card 9305 9 2 Control Amplifier and Rear Panel Offset Adjustment Calibration 1 2a 2b With the front panel of the instrument select the thermocouple input and place in the V voltage units On the DRC 91C disable Reference Junction Compensation by opening 0 switch 3 of the appropriate SENSOR ID on the rear of the instrument See S
58. Mask Bit 2 The Control Channel Limit Enable If the control channel limit Figure 4 2 Bit 2 is selected the limit must follow the Q command and is in a free field format Examples are XXX X X X X XX X X etc If Bit 2 of the Mask is set 1 then when the control sensor reading gets within the chosen limit from the set point the corresponding bit is set in the Status Register 4 11 3 3 Status Register Mask Bit 3 Sample Sensor Channel Change Enable If the Sensor Channel Change Bit 3 is selected then bit 3 in the Status Register is set when a channel change occurs 4 11 3 4 Status Register Mask Bit 5 Overload Error Indicator Enable If the Overload Error Indicator Enable Bit 5 is set then if the display has an overload condition on any channel or an error occurs the corresponding bit on the Status Register is set and a Service Request is issued if the SRQ bit of the mask is a 1 The user can check which overload or error was detected by sending the Output Data Statement WO See Section 4 14 2 and Table 4 15 in Figure 4 2 For example Q21 COPYRIGHT 3 88 LSCI Section IV will allow the setting of the Overload Error Indicator and Sample Data Ready bits in the Status Register but will not send an Service Request if either condition is met Q61 however will allow either of these bits to be set and when either is set an Service Request will be issued by the DRC 93C over the IEEE 488 Bus This
59. O for a resolution of XXX 1 for a resolution of XXX X 2 for a resolution of XXX XX 3 for a resolution of XX XXX 4 for a resolution of X XXXX Examples 1 for a resolution of xxx x on the Control Sensor Display F3S3 for a resolution of xx xxx on the Sample Sensor Display 4 11 Section IV 4 8 6 Selection of Deviation for Control and Sample FACON FACOFF FASON and FASOFF Commands Deviation output instead of magnitude and sign output can be selected for the sample and control displays independently using the F4CON FACOFF F4SON and F4SOFF commands 4 8 7 Selection of MATH Functions ON OFF and CLEAR The F5OFF and F5CLR Commands The MATH function can be turned on off or cleared using the 5 F5OFF and F5CLR commands 4 8 8 Sensor Curve Selection The NC1N41N N4 Command The Curve Number to be selected for the inputs can be changed by the NCQ4N4N2N4 command The quantity 1 1 is the input 0 1 A2 A4 or BO quantity NoN3 is the curve number from OO thru 30 Examples NAOO0 006 405 NBOO2 etc 4 8 9 The A and B Sensor ID Informa tion The and BC1C gt Commands The purpose of this command is to select Filtering of the A or B input whether the Remote Position Data is used to establish the curve numbers the Temperature Coefficient sign for the 9215 card and whether or not thermal correction is desired on the 9317C 9318C cards T
60. P S SHIFT REGISTER A D CONVERTER A D REFERENCE TIMER MPP2X 1 0 100 10 MPP 11 33MFD 2420 09 75 1061 283906 2XMTA7 5CNONE 4UGRP 3N163 LM308 LM399H 76016000 74016010 CD4021BCN ICL7104 16CPL 1CL8068ACPD ICM7555IPA 101 101 106 102 105 102 104 102 104 104 104 104 104 034 025 142 072 649 074 005 043 001 355 356 104 099 461 460 104 051 Ud UN IQ IQ REPLACEABLE PARTS LIST 9210 ANALOG INPUT CARD 1 0 100 33 100 CONNECTOR BP 6 POST LOCKING HEADER TRANSISTOR PNP SIGNAL SWITCH 2 POS 4 POLE INTERLOCKING MOSFET P CHANNEL IC OP ANP VOLTAGE REFERENCE 6 95V IC OP AMP IC OPTOCOUPLER IC OPTOCOUPLER IC P S SHIFT REGISTER IC A D CONVERTER IC A D REFERENCE IC TIMER MPP2X 1 0 MPP2X 1 0 100 10 10 MPP 11 33MrFD 2420 09 75 1061 283906 2 5 NONE 4UGRP 3N163 1 308 LM399H OPO7E 74016000 74016010 CD4021BCN ICL7104 16CPL ICL8068ACPD ICM75551PA Model DRC 91C 93C 9210 Diode Input Card 9210 DIODE INPUT CARD OPTION 9210 1 INTRODUCTION This section contains information pertaining to the Model 9210 Diode Input Card Included is a description specifications installation operation and maintenance information 9210 2 DESCRIPTION The Model 9210 Diode Input Card is designed to be i
61. PARTS Included in this section is Figure 9220 1 It includes the Model 9220 input schematics replaceable parts list and illustrated component layout Refer to the manual for ordering information 9220 4 Model DRC 91C 93C COPYRIGHT 9 87 LSCI 15 ROGERS BUSS STRIP H1 1 26 5 D lt 21 32 CND O 925522238 GND 5 GND Ald TANE LEA AN GND Vv VREF C H 2 ds REF CAP c C P1 91 DATA IN DVD A D 1 18 DATA OUT C 1 36 TYPE Cis Pd Kov s 9220 INPUT CARD A D SECTION oe e V ce 99 19 97 gt 4 B 46 1 86 21 13 06 30 A Sti tine si Sitchin as iA See INPU SHEET t OF 2 ES A HC MN UN CAE E 5 4 3 2 1 Model 9220 1 Model 9220 User Configurable Input Card REPLACEABLE PARTS LIST 9220 AWALOG INPUT CARD LSCI Part Number Description PART NO PART NO 101 034 101 025 106 142 102 072 105 649 102 074 104 005 102 043 104 001 104 355 104 356 104 099 104 461 104 460 102 020 104 051 104 078 CAP PP 1 0MF 100V CAP PP 33MF 100V CONNECTOR CIC TO BP 6 POST LOCKING HEADER TRANSISTOR PNP SIGNAL SWITCH 2 POS 4 POLE INTERLOCKING MOSFET P CHANNEL VOLTAGE REFERENCE 6 95V IC OP AMP IC OPTOCOUPLER IC OPTOCOUPLER IC P S SHIFT REGISTER A D CONVERTER A D REFERENCE REGULATOR 5V IC TIMER IC SWITCHED CAPACIT
62. Point A 19 26 Display Set Point Reading COPYRIGHT 3 88 LSCI 4 31 Section IV 100 DISP 110 OUTPUT 712 W1 120 ENTER 712 A 130 DISP W1 140 DISP 150 OUTPUT 712 w2 160 ENTER 712 A 170 DISP W2 180 DISP 190 OUTPUT 712 W3 200 ENTER 712 A 210 DISP 220 DISP Gain 1 3 230 DISP Rate 5 7 240 DISP Reset 9 11 250 DISP Heater Range A 13 260 DISP Power A 15 17 270 DISP 280 OUTPUT 712 ws 290 ENTER 712 A 300 DISP WS A 310 DISP 320 OUTPUT 712 Wc 330 ENTER 712 A 340 DISP WC A 350 DISP 360 OUTPUT 712 WP 370 ENTER 712 A 380 DISP WP 390 DISP 400 OUTPUT 712 Wy 410 ENTER 712 A 420 DISP WY 430 DISP 440 OUTPUT 712 WI 450 ENTER 712 A 460 DISP WI 470 END 4 16 SENSOR CURVE PROGRAMMING INSTRUCTIONS The commands which will either output input edit or erase a Sensor Curve are given in Table 4 16 In addition the commands to assign or change assignments of the various curves to the Sensor ID tables both A and B are given in Table 4 16 4 16 1 XDT Command This command from the BUS 4 32 Model DRC 93C Space a Line A and B Input information Ask for string W1 Display string W1 Space a Line Interface Status Ask for string W2 Display string W2 Space a Line Control Data Gain Reset etc Ask for string W3 Display string W3 Display Gain settin
63. Program Step is desired the user presses the POINT key the point desired followed by the 6 3 Section VI ENTER key The new Program Step and information is then displayed At any time that the POINT key is appropriate the key or v key can be used to select the next higher or lower Program Step respectively key and v key do not operate in any other case for any other purpose except to increment or decrement the Program Step at a time when it could be entered using the POINT key After the desired Program Step has been selected and displayed the user can enter or modify as required the Command the JUMP VECTOR REPEAT COUNT or RAMP COUNT Sensor Units Setpoint Gain Rate Reset Manual Heater Power Heater Range and Timer 6 5 3 Entering the Program Command and JUMP VECTOR REPEAT COUNT or RAMP COUNT When a Steps is selected the command position will flash If a number is entered then the command will change to that number When the desired number is displayed press the ENTER key Then the JUMP VECTOR REPEAT COUNT or RAMP COUNT position will flash If it is correct press the ENTER key If not then enter the new value with the keypad followed by the ENTER key At this point the setpoint gain etc may be changed 6 5 4 Entering the Setpoint Gain Rate and Reset The Setpoint Gain Rate Reset and Manual Heater Power for the Program Step are changed as described in
64. Range 4 Value 60 Finally substitute the 1 ohm 9317C or 10 ohm 9318C resistor for the previous resistor and enable the last COPYRIGHT 12 87 LSCI 10 ll 9317C 9318C Input Cards switch CAL 1 The display will indicate 460 for ap proximately 30 seconds and then a 0 indicating that the calibration of the card is complete Disable CAL 1 and then CAL 8 Set Point D A Calibration A special set point calibration is required for a DRC 91C or DRC 93C with two 9317C 9318C Input Cards or if the 9317 9318 is the only Input Card Since the set point voltage is related to the set point resistance and is determined with the individual card calibration constants there is no way to enter a set point that results in a pre determined value for the set point The Internal ID Switch S7 on the Main Board is used in the calibration Note the position of the Internal ID switches before proceeding Attach the plus and minus leads of the DVM to TP25 SP V and TP1 GND 2s respectively of the Calibration and Service Card Make switch 7 CLOSED ON This forces the unit to output set point of 0 volts Adjust the SP ZERO ADJ trimpot until the DVM reads as close to zero as possible Turn ON switch 6 of the Internal ID This forces the unit to output a set point of 2 7 volts Adjust the SP SPAN ADJ trimpot until the DVM reads as close to 2 7000 volts as possible This procedure should be done until the 0 and 2 7 re
65. Setpoint voltage is applied to the Setpoint D A to obtain the Setpoint voltage for control If the Reference Junction Compensation is enabled a voltage corresponding to the Terminal Block temperature is subtracted from the Setpoint voltage A signal which is 200 times the digital value as 9305 5 9305 Thermocouple Input Card calculated above is applied to the Setpoint D A to obtain the Setpoint voltage for control The control analog hardware compares the Setpoint voltage from the Setpoint D A converter and the amplified thermocouple voltage to obtain an error signal error signal is minimized through the PID control circuitry 9305 7 OPERATING INSTRUCTIONS 9305 7 1 Selection Thermocouple Curve Thermocouple Tables are chosen by selecting one of the Curves numbers given in Table 9305 3 The instruments detect the presence of the Thermocouple Input Card and then select the proper Thermocouple Table rather than the Standard Diode or Resistance curve listed in the Instruction Manual The SENSOR ID Switches on the rear panel of the DRC 91C are used to select curves described Instruction Manual Section 2 3 8 Curve selection can also be made over Computer Interface as described in Section 4 8 5 On the DRC 93C the Thermocouple Table is selected by selecting the Curve as described in the DRC 93C Instruction Manual Section 3 9 1 Curve selection can also be made over Computer Interface as descri
66. an HP 86B Serial Interface The arrows indicate the source direction of signal flow Figure 8223 4 with Handshake Connector to HP 86B Half Duplex Protective Ground Transmitted Data Received Data Request to Send Clear to Send Data Set Ready Signal Ground Carrier Detect Data Terminal Ready Protective Ground Transmitted Data Received Computer DRC 91C 93C COPYRIGHT 12 87 LSCI Transmitted Line Signal Model DRC 91C 93C The Auto Handshake capability of the HP 86B Serial Interface must be enabled The addition of the program line 16 CONTROL DSR DCD CTS 10 2 7 ENABLE to the program above enables the HP to receive and transmit in a handshake mode Example 3 General Serial Interface Interconnection The HP 86B Serial Interface Standard cable configuration already takes care of some of the interface interconnection problems to route signals to their proper pins Figures 8223 5 and 8223 6 give more general interconnection configurations for Half Duplex with and without Handshake Figure 8223 5 General Serial Interface Interconnection for Half Duplex with Handshake Protective Ground Transmitted Data Received Data Request to Send Clear to Send Protective Ground Data Received Data Request to Send Clear to Send Received Line Signal Detector Data Terminal Ready Data Set Ready Signal Ground Received Detector Data Terminal Ready Data Set
67. and return to normal ope ration The second method in which the entry can be changed is by using the keypad to enter an amount which is to be added or subtracted from the previous value Hitting the 44 key will add the amount and the vv key will subtract the amount The two methods can be used at will The ENTER key will enter the final value into the instrument or the CLEAR key will cancel the operation at any time 3 8 6 Upper and Lower Display Units 3 8 6 1 Units Select The units of the Upper Display is changed by holding down the UNITS key and pressing the 44 Up key until the units desired are obtain ed Each time the 44 key is pressed the units of the Upper Display cycle clockwise The units which do not pertain to the input card selected are automatically skipped i e only one of the sensor units V Q or nF is possible depending on which sensor input card is present COPYRIGHT 3 88 Model DRC 93C within the instrument Similarly the units of the Lower Display are changed by holding down the UNITS key and pressing the vv Down key For any input card except the 9215 the DRC 93C will read temperature regardless of whether a curve is stored within the instrument which corresponds to the temperature sen sor being interrogated For diodes germanium carbon glass and all other negative temperature depen dence sensors the default curve is Curve 00 which is the D curve for the DT 500 DRC sensors For a posi
68. be supplied by the controller We have seen in Figures 2 and 3 that a non zero temperature error signal is necessary to produce an output and that the magnitude of the error or temperature offset is a function of the power output level and the loop gain Let us demonstrate the nature of the offset also called droop with an example Assume that a system sample block the mass whose temperature is to be controlled has a finite heat capacity but that its thermal conductivity is infinite as is the thermal conductance between the block and the sensor and heater The result will be that the temperature within the block will be isothermal no matter at what rate the block is heated or cooled For the following discussion ignore any noise associated with the system and assume that to control at 20 kelvin the heating power required is 0 2 watts Assume also that 50 watts of heater power is available reducible in five steps of one decade each Figure 5 shows the control offset for an amplifier gain of 100 and three output power settings which will deliver enough power to the system to balance the cooling power The temperature offsets for a power level of 0 2 watts at 20 kelvin are easily calculated from Figures 2 and 4 for the three maximum 50 mV kelvin 2 5 100 200 Temperature kelvin 300 FIGURE 4 Idealized curve for Lake Shore Cryotronics Inc DT 500 Series silicon diode temperature sensors Heat
69. contribution of each term to the temperature calculation and where to truncate the series if full accuracy is not required FUNCTION Chebychev Z as double as double REM Evaluation of Chebychev series REM Evaluation of Chebychev series X 2 ZL ZU Z ZU ZL X Z ZL ZU Z ZU ZL 0 1 0 1 FOR I 0 to Ubound A 0 1 T T A COS I ARCCOS FOR I 2 to Ubound A NEXT I Tc I 2 I 1 1 2 Chebychev T T T A I Tc I END FUNCTION NEXT I Chebychev T END FUNCTION FUNCTION Chebychev Z as double as double X NOTE arccos X arctan 2 1 Program 1 BASIC subroutine for evaluating the temperature T from the Chebychev series using Equations 1 and 3 An array Tc idegree should be dimensioned See text for details Program 2 BASIC subroutine for evaluating the temperature T from the Chebychev series using Equations 1 and 4 Double precision calculations are recommended Table 1 Chebychev Fit Coefficients 2 0 K to 12 0 K 12 0 K to 24 5 K 24 5 K to 100 0 K 100 to 475 K VL 1 32412 VL 1 32412 VL 1 32412 VL 1 32412 VU 1 69812 VU 1 69812 VU 1 69812 VU 1 69812 A 0 7 556358 A 1 5 917261 2 0 237238 A 3 0 334636 4 0 058642 5 0 019929 A 6 0 020715 A 7 0 014814 8 0 008789 9 0 008554 10 0 039255 A 0 17 304227 A 1 7 89468
70. designation type E indicates a thermocouple pair consisting of a Ni Cr alloy 9305 4 Model DRC 91C 93C Chromel as the positive thermoelement and Cu Ni alloy Constantan as the negative thermoelement EN This thermocouple has the highest sensitivity of the three ASTM standard thermocouple types typically used for low temperature applications types E K and T The E thermocouple is the best choice for temperatures down to about 40 K It is recommended for use in oxidizing environments or in sulphurous or reducing atmospheres It should not be used in environments that promote corrosion 9305 5 3 Type K Thermocouples The ASTM designation type indicates a thermocouple pair consisting of Ni Cr alloy Chromel as the positive thermoelement KP and Cu Al alloy Alumel as the negative thermoelement KN It should not be used in sulphurous or reducing atmospheres or environments that promote corrosion 9305 5 4 Type T Thermocouples The ASTM designation type T indicates thermocouple pair consisting of Cu Copper as the positive thermoelement TP and a Cu Ni alloy Constantan as the negative thermoelement TN This type of thermocouple may be used in vacuum as well as oxidizing or reducing environments down to about 90 K At temperatures below 80 K the thermoeletric properties of the positive thermoelement TP are very dependent on the impurity of iron 9305 6 PRINCIPLE OF OPERATI
71. e immediately following the sensor input This would then prevent the rate circuit from operating on changes in the set point such as in temperature seep applications Fortunately most sweeping is done slowly enough so as to be unaffected by typical rate time constants To determine the rate control setting in seconds for a system an abrupt increase in power is applied to the system while in equilibrium The time delay is then observed to the start of the resulting temperature increase as indicated by the control sensor This delay corresponds to the value to be set on the rate control Application Notes 5 Lake Shore Cryotronics Inc VI SENSOR CONSIDERATIONS Sensor Gain Revisited Since a controller will amplify input noise as well as sensor signal it becomes important to consider sensor performance when designing a complete system The Lake Shore DT 500 Series Sensors have a voltage temperature characteristic which lend themselves to cryogenic temperature control use because of their high sensitivity at low temperatures Figure 3 Coupled with this sensitivity is an extremely low noise level which results in part from assembly techniques used for all DT 500 Sensors which comply with the relevant portions of MIL STD 750C It is therefore possible to obtain short term control at low temperatures which can approach 0 1 mK in specially designed Systems such as the Lake Shore calibration facility Even above 30 K where the sensitivity is red
72. follow the same temperature response curve Four bands of tracking accuracy are available Refer to DT 470 technical data for details Diode sensor voltages are digitized to a resolution of 100 microvolts with full scale dependent on input card configuration The tempera ture display has resolution capability of 0 01 kelvin above 100 kelvin and 0 001 kelvin below 100 kelvin For greater precision individual sensor calibrations can be accommo dated with the 8001 Precision Calibration Option which programs the instrument with calibration data for a specific Sensor The algorithm within the instrument interpolates between data points to an interpolation accuracy which exceeds 0 01K over the entire temperature range of the Precision Option The 16 bit analog to digital converter is accurate to Section I plus or minus the least significant bit which for the 470 series sensor results in an uncertainty of 1mK below 28K and 45mK above 40K with a transitional region between these two temperatures Therefore at temperatures below 28K the overall system accuracy the sum of the instrument accuracy 11mK and that of the calibration itself Lake Shore calibrations are typically better than 20mK within this region is 30mK Above 28K system accuracy gradually moderates to a typical value of 75mK above 40K See the Lake Shore Low Temperature Calibration Service brochure for additional discussion of calibration ac
73. given in Table 4 18 The information is output as one very long character string The following program is for the HP86B and is an example of the XDNQN to output Sensor Curve 00 10 REM Program to output Curve Table 20 DIM Curve 462 30 OUTPUT 720 XDOO 40 ENTER 720 Curve 50 REM Display Curve 14 Temperature 60 REM Coefficient and Number of Breakpoints 70 DISP Curve 1 27 80 REM Display voltage and temp data points 90 I 28 100 DISP Curve I I 41 Temp 110 IF I 447 THEN 140 D Pnt 31 120 1 1 42 130 GOTO 100 140 DISP Curve 448 460 150 END Title Voltage I 477 for Section IV Model DRC 93C Table 4 16 Sensor Curve Commands and Description Output of Information Table Sensor Curve or All Curves XDT Output the Sensor Curve Information Table Refer to Table 4 17 for the format of the output Output Sensor Curve number N4N5 where NjN5 is from 00 to 31 Refer to Table 4 18 for the format of the Sensor Curve output Output the Sensor Curve Information Table XDT and all the Sensor Curves stored in the unit Refer to Table 4 17 for format of the Information Table output and Table 4 18 for format of the Sensor Curve output Curve Input Curve Edit and Curve Erasure XCN1N5 8 X XXXXX TTT T Sensor Curve Input NiN5 is Sensor Curve number from 06 to 31 Immediately after Sensor Curve cmmnd XCN4N5 a comma is required Up to 18 characters be in
74. in overheating the sensor If for some reason the leads have to be cut short they should be heat sunk with a copper clip or needle nose pliers before soldering Standard rosin core electronic solder m p 180 C is suitable for most applications Applications involving the use of the SD package up to 200 C will require a higher melting point solder A 90 Pb 10 Sn solder has been used quite successfully with a rosin flux For all adapters except the CY CU and DI the leads are a gold plated Kovar Prolonged soldering times may cause the solder to creep up the gold plated leads as the solder and gold alloy This is not detrimental to the device performance When installing the sensor make sure there are no shorts or leakage resistance between the leads or between the leads and ground GE 7031 varnish or epoxy may soften varnish type insulations so that high resistance shunts appear between wires if sufficient time for curing is not allowed Teflon spaghetti tubing is useful for sliding over bare leads when the possibility of shorting exists Also avoid putting stress on the device leads and allow for the contractions that occur during cooling which could fracture a solder joint or lead if installed under tension at room temperature The DT 470 sensor is designed for easy removal for recalibration checks or replacement and the following discussions for each of the adapters are geared in this direction If semi permanent mountings are desired the u
75. input connector and enable both CAL 8 and CAL 7 of the 9317C 9318C 6 hardware 4a 4b Model DRC 91C 93C card Attach the plus and minus leads of the DVM to the test points marked V and V respectively the 9317 9318 PCB and adjust the trimpot marked IZ so that the voltage reads as close to zero as possible If this voltage is not close to zero it may effect the sensor current setting Consequently this operation should be performed before any current calibrations are performed Disable CAL 7 and continue Note that CAL 8 will remain enabled for all calibration operations Voltage Match or Span Connect the DVM plus and minus leads to the V and V Sensor Output Signal terminals of the MONITORS connector for the input being calibrated Apply a 1 9317C or 10 9318C millivolt signal to the V and V Sensor Input terminals Enable CAL 6 on the card CAL 8 is still enabled The DVM should read about 1 volt and the display of the unit should read approximately 10000 Adjust the trimpot labeled A D so that the voltage read on the DVM matches the display of the unit if the DVM reads 1 0085 make the display read 10085 If the trimpot is adjusted wait a minimum of 10 readings before disabling CAL 6 Apply 1 9317C or 10 9318C millivolt signal to the input and enable CAL 5 Do not adjust any of the trimpots Disable CAL 5 after approxi mately 30 seconds When the display goes to 0 the un
76. is 12 see Table 4 2 Address switch numbers 5 and 6 should be CLOSED 1 which will result in the Address Switch having a setting of 00001100 or 10001100 dependent on the requirements for the delimiters 4 5 IEEE 488 BUS COMMANDS 4 5 1 The Uniline Command A Uniline Command Message is a command which results in a single Signal line being asserted The DRC 93C recognizes two of these messages from the BUS CONTROLLER REN and IFC See Table 4 3 When the BUS CONTROLLER executes the ap propriate software code the effect is to pull the corresponding Inter face Management line low For example when the software command REMOTE712 is executed by the HP86 digital computer the management line REN is pulled low and the listen address 12 issued to signal the instrument having address 12 DRC 93C to go into the remote mode The SRQ is a uniline command asserted by the DRC 93C when it wishes to signal the BUS CONTROLLER The BUS CONTROLLER will in turn use the Addressed command SPE Serial Poll Enable described below to inter rogate the DRC 93C about the reason or reasons for the communication 4 5 2 The Universal Commands The Universal Commands shown in Table 4 3 are those multiline commands that address all devices on the bus A multiline command involves a group of signal lines COPYRIGHT 3 88 LSCI Section IV All devices equipped to implement such commands will do so simul taneously when the command is transmitt
77. lac 1 v 2 ME 5 wal e 8 5 Evaluation of Eq 5 and substitution back into 4 yields 2 1 2 Suis 6 I ldc AV 1 1 2 where 2 eVms nkT 1 for a physical solution Equation 6 predicts an offset voltage which is independent of both frequency and dc operating current and is shown plotted in Fig 4 by the solid line The agreement with the experimental measurements is quite good verifying the overall picture as to the effect of induced currents on diode temperature sensors The results recorded at 305 K are described equally well by Eq 6 16 10 10K 10 AK 3 qu 01K 10 10 uA 100 uA 0 1 2 3 4 5 6 7 8 RMS AC VOLTAGE mV FIGURE 4 DC offset voltage as a function of rms ac voltage across a silicon diode temperature sensor operating at 77 K The symbols represent data recorded at three different dc operating currents with a 60 Hz signal superimposed The solid curve gives small signal model results while the dashed curve represents the extended calculations Equivalent temperature errors are indicated along the right edge 10 AK 10 01K S gt 102 4 001 K 1uA 10 10 100 uA 1 0 4 8 12 16 20 24 28 32 RMS AC VOLTAGE mV FIGURE 5 DC offset voltage as a function of rms ac voltage across a silicon diode temperature sensor operating at 4 2 K The symbols represent data recorded at
78. no difference The details of the extended calculation have not been given as the mathematics is somewhat tedious and the slight discrepancies between the small signal model and the extended model do not justify the added complexity For all practical purposes Eq 6 can be reliably used above 40 K The physics of a p n junction at 4 2 K is not clearly understood and attempts to correlate the present data by modeling low temperature IV characteristic of a diode failed If the diode does take on a p i n type behavior the different curves shown in Fig 5 for 1 10 and 100 can possibly be understood terms of the additional current dependent terms in the IV curve 6 Another explanation for the significant offset voltage at 100 pA could be self heating in the diode If the diode is operated at too high a power level the diode has a tendency to warm slightly above the surrounding environment This will have the effect of distorting the IV curve in the direction of lower voltages at higher currents This distortion will then increase the offset voltage At 4 2 K self Heating usually becomes a problem as the current approaches 100 pA Application Notes 10 T 77K 10 UA 10 1 kHz 20 kHz 0 1 2 3 4 5 6 7 8 RMS AC VOLTAGE mV FIGURE 6 DC offset voltage as a function of rms ac voltage across a silicon diode temperature sensor operating at 77 K The symbols represent data recorded at a 10 pA dc current with the a
79. of 100 uy out of 3 V or better The unit should be allowed one hour to warm up to achieve rated specifications Use the following procedure to calibrate the 8225 Analog Output 1 Remove the three top panel screws and slide the panel off 2 Connect the DVM plus lead to the J3 MONITORS connector pin C and the minus lead to pin D 3 With the load resistors or the voltage standard to simulate the input sensor go to a low temperature and adjust the trimpot labeled Z for Zero on the calibration cover until the voltmeter reading corresponds to 10 nV K Go to a high temperature and adjust the trimpot labeled S for Span 4 Repeat procedure in paragraph 3 until there is no further Zero or Span adjustment required 5 Install the top panel 8225 7 REPLACEABLE PARTS Included in this Section is Figure 8225 1 It includes the Model 8225 Analog Output schematic replaceable parts list and illustrated component layout Refer to the manual for ordering information COPYRIGHT 12 87 LSCI C2 68 42 8 D CSR 15 0 aD1 _P 1 34 S33 OPTION SLOT 402 1 32 2 t 10R2 3 gt RESET 1 16 gt DAC 7 1 CCD V C8 OPT1 OR Tan P1 45 gt C8 6 on CB 4 P1 43 gt H SAMPLE P8255A 6 HJ CONTROL C8 JUMPER TO SELECT SAMPLE OR CONTROL ANALOG OUTPUT GND D V N V OUT Figure 8225 1 Model 8225 Analog Output Option B 312 83 01A REPLACEABLE PARTS LI
80. or error encounter ed The Status Register can be read at any time by means of a Serial Poll Enable command Reading the Status Register resets the Status Register to all zeros so COPYRIGHT 3 88 LSCI Section IV that only new status reports will be registered by the DRC 93C Executing the Q command Section 4 11 3 also resets the Status Register to all zeros Reading the Status Register resets all of its bits to zero 4 11 2 1 Status Reports 0 and 1 Display and Control Data Ready Bit 0 of the Status Register is set when a valid Display data reading is available Bit 1 of the Status Register is set when a valid Control data reading is available If the Service Request is enabled either one of these being set will cause the DRC 93C to pull the SRQ manage ment low to signal the BUS CON TROLLER These bit s are reset to zero upon reading the Status Register on response to a serial poll or if the reading is no longer valid These functions can be inhibited by turning their corresponding bits in the Status Register mask off 4 11 2 2 Status Report 2 The Control Channel Limit When the control sensor reading gets within the chosen limit from the set point bit 2 is set in the Status Register If the Service Request is enabled this bit being set will cause the DRC 93C to pull the SRQ management low to signal the BUS CONTROLLER As with all of the Status Reports this bit is reset to zero upon reading the Status Reg
81. overshoot is still occurring the system design should be carefully reviewed V ADDING DERIVATIVE RATE TO THE TEMPERATURE CONTROL LOOP If there is still an overshoot of the control temperature during transient changes of the set point within one s system it can be significantly reduced by the addition of a third control function to the controller called rate or derivative control Normally overshoot can be attributed to one of two causes 1 the application of much more power than is required to maintain the system at its desired set point or 2 the result of the thermal response relationships between the cooling power the heating power and the control sensor The best solution to the first possibility is to reduce the available power as discussed previously The second problem normally occurs with a large thermal mass where response is slow and overshoot due to the thermal inertia of the system can be quite large This overshoot is caused by the time lag between a change in output power and the control sensor sensing this change In very large non cryogenic systems this time lag can be 10 30 minutes In cryogenic systems it is usually less than a minute even near room temperature Consequently placement of the control sensor with respect to the heater is extremely important in the design of a cryogenic system as is the placement of both the heater and sensor with respect to the cooling power Rate action can be achieved by means of a diff
82. owns a DRC 93C and wants new sensor cali bration data stored in the instru ment LSCI stores the calibration data in a PROM chip and sends the programmed chip to the customer The PROM is then installed in the DRC 93C by the customer Note that additional calibrations can be added to the instrument at a later time by specifying with the sensor calibration at time of order the serial number of the instrument 3 2 Model DRC 93C and with which input the sensor will be associated if remote operation is used 3 5 CONTROL FUNDAMENTALS An application note entitled Fundamentals for Usage of Cryogenic Temperature Controllers is included as an appendix in this manual and should be read in detail if you are not familiar with cryogenic tempera ture controllers 3 6 CONTROLS AND INDICATORS Figures 3 1 and 3 2 identify the DRC 93C displays annunciators con trols and connectors The iden tification of each item is keyed to the appropriate figure FRONT PANEL DESCRIPTION 3 7 POWER ON Before connecting AC power to the DRC 93C make sure the rear panel voltage selector is set to corre spond to the available power line voltage Be certain the correct fuse is installed in the instrument 3 7 1 Power Up Sequence Immediately on POWER ON the DRC 93C runs through a power up sequence as follows 1 Light Test All digits annunciators and the bar graph turn on to test the lights The TEMPERATURE Block indicates
83. put in ascending Raw Units order prior to the curve entry session The data must be in ascending units order The temperature will follow the temperature coefficient of the curve being entered The tempera ture will be in decreasing order for a negative temperature coefficient curve and increasing for a positive temperature coefficient curve Let us say that we wish to enter a new set of curve data into an avail able slot at Curve 21 From normal operation the user presses the PROG key followed by the CURVE key to enter the Curve Programming routine Pressing the 2 1 and ENTER keys tell the instrument to find Curve 21 and will indicate that it is avail able by showing 00 number of points The displays will read as follows The dashes indicate there is no data present for curve number 21 No entries will flash At this time one of four keys can be selected PROG CURVE or POINT The PROG key will abort the curve programming and return the instru ment to normal operation Pressing the CURVE key will cause the Curve portion of the Setpoint Display to flash allowing the user to select another curve COPYRIGHT 3 88 Model DRC 93C Pressing the POINT key will cause the point entry in the Setpoint Display to begin flashing and the Upper and Lower displays to be cleared The keypad 0 9 is used to enter a point to be inserted Type 01 and press the ENTER key Now the Upper and Lower displays will go to 0 0 and
84. reading corresponding to lac When a voltmeter operating in a dc voltage mode reads this signal the signal is processed by integrating filtering etc to give an a Nur average dc voltage reading which will be lower than expected The FIGURE 2 IV curve for a silicon diode sensor showing apparent temperature measurement will then be too high Note that effect of induced ac current superimposed on the dc this voltage offset is due to induced currents in the total measuring operating current lac The expected dc operating system and is not simply a voltage pickup by the diode itself An ac voltage is Vac which is shifted from the average voltage voltage superimposed symmetrically about the dc operating voltage Vave indicated by the voltmeter in a dc measurement of the diode would not cause a dc voltage offset mode DC OPERATING POINT 14 Application Notes Lake Shore Cryotronics Inc There are two simple techniques which can be used to test whether these errors might be present in a measuring system The first is to connect a capacitor about 10 UF in parallel with the diode to act as a shunt for any ac noise currents The capacitor must have low leakage current so as not to alter the dc current through the diode The capacitor may also alter the time response of the measurement system so allow sufficient time for the capacitor to charge and for the system to equilibrate If the dc voltage reading across the diode increases with the ad
85. saved at power down provided switch 2 of the internal 8 switch package is on 4 11 4 The WQ Data String This command gives the Status Register Mask and control channel limit information 4 12 SAVING AND RESTORING EXECUTABLE INTERNAL PROGRAMS 4 12 1 Requesting a Program Step for Saving The WEN N gt Command The WEN N gt command requests the Program Step N4N5 from the 93C The data of the Program Step will be in the next output transmitted from the instrument The Data COPYRIGHT 3 88 LSCI consists of the the Program Step in ASCII followed by sixty charac ters These characters are to be stored by the user for later trans mission back to the instrument by the command described below Examples of this command and the ENN command are given in section 4 12 3 4 12 2 Transmitting a Program Step to the 93C The EN4N5C4 Cgo Command The E command requests that Program Step and its data thru C o be sent to the 93C The form is ENjN5C1 Cgg data must have been previously received from the instrument using the WENjN5 command and stored for transmission back to the instrument using this command Examples of the E command in con junction with the WEN4N5 command are given below 4 23 Section IV Model DRC 93C Functional Description Table 4 14 DRC 93C Command Request Summary for Program Step Transmit Restore Program Step data 1 to the 93C kkk
86. screws and slide the panel off Note on the calibration cover the position of Option Slot 2 which the 8229 will occupy 2 Remove the four screws that secure the calibration cover to its clips and remove the cover Remove the two back panel mounting clips that secure the J9 blank cover plate to the interface opening and remove the plate 3 Plug the internal sensor lead cable into the 8229 printed circuit board PCB with the locking tab configured properly Plug the 8229 PCB into Option Slot 2 with the component side to the left of the unit as viewed from the front Thread the 8229 internal cable along the inside edge of the rear panel so that it won t interfere with the installation of the calibration cover or top cover 4 Position the 24 pin 8229 Scanner connector in the J9 opening on the back panel and secure it in place using the screws provided 5 Disconnect the Input Card wiring harness from the A Input Card by lifting the locking tab on the Input Card connector and pulling on the body of the wiring COPYRIGHT 12 87 LSCI Model DRC 91C 93C harness mating connector Plug the Input Card wiring harness into the 8229 input making sure that the wiring harness locking tab is seated properly Thread the 8229 output cable along the component side of the 8229 and plug the cable into the Input Card making sure the locking tab is seated properly 6 Install the calibration cover by reversing procedure 2 7 Insta
87. sensor current to the lowest value to avoid any potential sensor damage The unit displays the error stores it in the WS data location and halts operation The Input Card calibration procedure should be preformed to try to correct the problem If the error code still exists the Input Card EEPROM needs to be replaced COPYRIGHT 5 88 Possible Cause Corrective Action COPYRIGHT 5 88 Unrecognized A Input Card type The 92xx Series cards and Smart microprocessor controlled Input Cards tell the main processor what card type they transmitted the error could be caused by the Input Card not being present or if the card had a selection switch de selected for example if it were not pressed correctly or came out of detent in shipping When the error occurs the unit displays dashes if it is the DISPLAY SENSOR input and continues operation until the fault is corrected The error is stored in the WI A Input data location and is displayed when the LOCAL key is pressed to determine the Input Card type Unrecognized B Input Card type Operation is the same for Err25 except the error is stored in the WI B Input data location Incorrect A Input Card polarity The 92xx Series Input Cards determine the input signal polarity doesn t match the temperature coefficient of the sensor type selected there is either an error in the sensor wiring an open circuit or a fault on the Input Card When the error oc
88. the harness installation again Replace the calibration cover making sure to align the cards so that their respective 9305 3 9305 Thermocouple Input Card adjustment trimpots are accessible through the cover Place the cover on top of the cover clips and start the screws Carefully move any misaligned cards to their proper position and tighten the cover screws Replace the top panel and three top panel screws 9305 4 SENSOR ATTACHMENT Thermocouple leads are attached to the Terminal Block by aluminum Screws Be sure to tighten the terminal screws carefully Loose connections will result in unstable readings and control The leads must be connected with the proper polarity or the 29305 will not operate properly The positive terminal of the terminal block is marked with a plus sign and should correspond with the positive thermoelement listed for each type of thermocouple in Section 9305 5 9305 5 NOTES ON THERMOCOUPLES Lake Shore s 9305 Thermocouple Input Card supports the Chromel vs Gold E K and T type thermocouples 9305 5 1 Gold Chromel Thermocouples The Gold Chromel thermocouple consists of a Gold Au 0 03 at or 0 07 at Iron Fe alloy as the negative thermoelement and a Ni Cr alloy Chromel as the positive thermoelement KP This type of thermocouple can be used at very low temperatures even below 10 K 9305 5 2 Type E Thermocouples The ASTM American Society for Testing and Materials
89. the load If a 100 ohm resistor is used on the Max scale the unit will output 40 volts at 0 4 amps or 16 watts The lower ranges are scaled as explained in 5 5 7 1 above except the voltage limit is 43 volts NOTE The values given above are nominal values If they are slight ly off it should not effect opera tion since the heater circuit is part of a feedback loop 5 6 CALIBRATION The adjustments and test points referred to in this section are la beled on the instrument calibration cover Remove the two top panel screws and slide the top cover off to gain access to the adjustments and test points Note The unit should be allowed a one hour warm up time to achieve rated specifications This cali bration procedure is for a DRC 93C with standard diode A and B inputs For other configurations refer to Section VII for the specific Input Card present in the unit 5 6 1 Input Card Calibration Calibrate each input card as speci fied in Section VII for that card 5 5 Section V 5 6 2 Set Point Voltage Calibration Calibrate the Set Point Voltage as follows 1 Remove the instrument cover 2 Calibrate with the Control Switch selecting either a 9210 or 9220 Input Card and the 3 configuration If the DRC 93C does not contain one of these input cards calibrate the set point by following the procedure described with that Input Card 3 To calibrate the Set Point volt age with a 9210 or 9220 card connect the
90. the minus lead to the I pin Adjust the trimpot marked 10LA on the calibration cover for the appropriate Input Card until the voltage across the resistor is 1 0000 0 0001 volts 3 Calibrate the Buffered Sensor Output Signal Connect the DVM plus lead to the V Buffered Sensor Output Signal pin for the appropriate Input Card and the minus lead to the V pin on the MONITORS connector Connect the precision voltage source across the E V and D V pins of the five pin input connector for the appropriate input Set the standard to 1 5000 volts and adjust the trimpot marked B on the calibration cover until the DVM reads as close to 1 5000 volts as possible for the 9210 3 configuration and adjust the value to 0 68666 volts for the 9210 6 configuration COPYRIGHT 12 87 LSCI 9210 Diode Input Card 4 Calibrate the A D Converter Verify that the Display selects the desired Input Card and that the units selected are V Set the standard to 1 5000 volts for the 9210 3 and adjust the trimpot marked A D until the display reads 1 5000 V Check linearity by inputting 2 0000 and 1 0000 volts and verify that the unit displays those settings within 0 0001 volts 5 0000 and 1 0000 volts for the 9210 6 If this specification is not met check the Technical Service Guide for further instructions 5 Install the top cover panel 9210 7 SENSOR CURVE INFORMATION Sensor Curve data for use with the 9210 Diode Input Card must be
91. the thermocouple in a reference bath of known temperature liquid nitrogen ice etc Allow the system to stabilize to the Reference Temperature 2 With the front panel of the instrument select the thermocouple input and the desired temperature units the DRC 91C enable Reference Junction Compensation by closing 1 Switch 3 of the appropriate SENSOR ID on the rear of the instrument Hold the LOCAL key and verify the display as 9305 See Section 9305 7 2 3b On the DRC 93C enable Reference Junction Compensation by using the SENSOR SCAN and or v keys The Display should show 9305 when the SENSOR key is pressed See Section 9305 7 3 4 Adjust the Offset Adjustment trimpot so that the Display reads the Reference Temperature Note The Offset Adjustment compensates for the thermocouple used in the calibration If another thermocouple is attached or the thermocouple has aged or the configuration of the system is changed then the Offset Adjustment must be repeated 9305 7 6 Curve Data Format The 9305 Thermocouple Input Card will operate with a user defined curve as well as the Internal Curves listed in Table 9305 4 Temperature is calculated by linear interpolation between curve points 9305 7 9305 Thermocouple Input Card The card is hardware limited to reading input between 15 millivolts and 15 millivolts All curves should be limited in temperature so not to exceed
92. v to indicate Raw Units Data see Table 4 19 4 When no digits are flashing the Curve is accessed using the CURVE key and the POINT by the POINT key 5 The keypad 0 9 is used to enter a quantity after it begins to flash The decimal point can be used with Temperature or Raw Units Data but not with Curve or Point 6 The PROG key always returns operation to normal operation 7 The CLEAR key clears the display if pressed after an entry is begun 8 The instrument will return to normal operation if no key is pressed for 20 seconds 3 10 SETPOINT and CONTROL BLOCK Parameters entered using a blue key with a black legend SETPOINT GAIN RATE RESET and MANUAL HEATER require the use of the ENTER key When one of these keys is pressed and released the least significant digit or digits will flash to indi cate that the parameter can be en tered The quantity can be entered in three ways NOTE IN ALL CASES pressing the CLEAR key will result in the old value being inserted and the opera tion completed Pressing the ENTER key enters the quantity in the ap propriate display into the DRC 93C 1 Enter the digits via the key board 7 minus sign can be used with the Setpoint and must preced the digits The decimal point can be entered as desired 3 16 Model DRC 93C The operation is completed with the ENTER key or cancelled with the CLEAR key 2 Increment the quantity using the ke
93. variations are the same as for WO see below Set Point Data N31N12N43 N14N45 8 Characters plus up to 2 terminators where the N44 N45 variations are the same as for WO see below Sample WS Control Sensor WC and Set Point WP Data NyN2N3 N4N5 NgN7Ng NgN 0 N31N12N35 N14N15 26 characters plus up to 2 terminators where may vary in position dependent on units and temperature 1 5 is the Sign Display Sensor reading and units 10 is the Sign Control Sensor reading and units 11 15 is the Sign Set Point and units Examples of the Display reading are N NoN3 N4N5 F 2 gt 3 NAN5 C N1N2N3 NAN5 or N4 N2N3NAN5S V Note that all are free field where the units are K C F V or R and the sign may be for the and C scales Display Math Data Ci N1N2N3 N4N5 NgN7Ng 1 0 8N31N32N45 N14N35 2 N16N17N18 Ni9Na0 N24N22N25 N24N25 N26N27N2g N29N50 57 characters plus up to 2 terminators where may vary in position dependent on units and temperature is 0 if the MATH Function is off and 1 if on N1 N5 is the Sign MAX Sample Sensor reading and units Ng N19 is the Sign MIN Sample Sensor reading and units N33 N35 is the Sign MAXDEV Sample Sensor reading and units c is 0 if the MATH Function is off and 1 if on
94. 0 1 2 3 XX XXX Or 4 Forms of the command 0 F3C2 F3C3 F3C4 F3SN1 Function 3S Select the Sample Resolution is 0 1 2 3 or 4 Forms of the command F3S0 51 F3S2 F3S3 F3S4 FACON Function 4C Select the Control Sensor Deviation ON or OFF FACOFF FASON Function 4S Select the Sample Sensor Deviation ON or OFF FASOFF Function F5 Select the MATH Function on off or cleared F5OFF F5CLR Function N assigns Curve Number to Input Channel Forms of the command are NAOOO thru 031 NA431 with Scanner Card and NBOOO thru NBO31 NC4Nq1N3N5 AC Co Input A ID and B ID 1 2 00 thru 1F Forms of or the command are A00 thru AFF C ranges between 0 and F BC1 C3 If C9 is between 0 and 7 then selects the Sensor Curve number 00 0 thru 15 F If Cy is between 8 and F then corresponds to a Remote Position between 0 and F COPYRIGHT 3 88 LSCI 4 13 Section IV Model DRC 93C Table 4 7 Cont d DRC 93C Request Summary for Instrument Setup dee e e e e de de de ede e dee dese dece REIKI kk kk kk dek kk kk kk kk k k kk kk kk kk dee dee dee III kk kkk kkk Output of Instrument Variables Sample Control A and B Input Information C1C2 C3 N1 5 6 C7 N2 Cg C9C10 AC11C12
95. 0 100 MPP 11 33MFD 2420 09 75 1061 2N3906 2 5 NONE 4UGRP ICM75551PA VN0535N2 ICL7104 16CPL CD4021BCN 1CL8068ACPD LM331N 79105 TSC913A LT1043CN 740L6000 REF O1EN8 56 10 10 4029CBN 740L6010 Model DRC 91C 93C 9220 Input Card 9220 USER CONFIGURABLE INPUT CARD OPTION 9220 1 INTRODUCTION This section contains information pertaining to the Model 9220 Diode and Platinum User Configurable Input Card Included is a description specifications installation operation and maintenance information 9220 2 DESCRIPTION The Model 9220 Diode and Platinum Input Card is designed to installed in a DRC 91C or DRC 93C to convert either the Input A or Input B or both with two options to accommodate either diode or positive temperature coefficient sensors such as platinum or rhodium iron The 9220 3 configuration is equivalent to the 9210 3 configuration described earlier The 9220 6 configuration is equivalent to the 9210 6 configuration The 9220 P2 converts either Input A or B or both with two options to accommodate 100 ohm platinum RTD s which conform to DIN 43760 tolerances 0 1K have interchangeability of 0 1 at OC and a temperature coefficient of 0 00385 c from 0 to 100 This card may also be configured as a 9220 P3 1000 ohm platinum or 9220 R1 rhodium iron input card 9220 3 SPECIFICATIONS Specifications for the Model 9220 User Configurab
96. 00 1 45048 1 43488 1 42013 1 40615 1 39287 1 38021 1 36809 1 35647 1 34530 1 33453 1 32412 1 31403 1 30422 1 29464 1 28527 1 27607 1 26702 1 25810 1 24928 1 24053 1 23184 1 22314 1 21440 19645 17705 15558 13598 12463 11896 11517 11212 10945 10702 10263 1 09864 1 09490 1 09131 1 08781 1 08436 1 08093 1 07748 1 07402 1 07053 1 06700 1 06346 1 05988 1 05629 1 05267 1 04353 1 03425 1 02482 1 01525 1 00552 0 99565 LA DAI 0 98564 0 97550 0 95487 0 93383 0 91243 0 89072 0 86873 0 84650 0 82404 0 80138 0 77855 0 75554 0 73238 0 70908 0 68564 0 66208 0 63841 0 61465 0 59080 0 56690 0 54294 0 51892 0 49484 0 47069 0 44647 0 42221 0 39783 0 37337 0 34881 0 32416 0 29941 0 27456 0 24963 0 22463 0 19961 0 17464 0 14985 0 12547 0 10191 0 09062 Lighter numbers indicate truncated portion of Standard Curve 10 corresponding to the reduced temperature range of DT 471 diode sensors The 1 4 325 K portion of Curve 10 is applicable to the DT 450 miniature silicon diode sensor Application Notes Lake Shore Cryotronics Inc POLYNOMIAL REPRESENTATION Curve 10 can be expressed by a polynomial equation based on the Chebychev polynomials Four separate ranges are required to accurately describe the curve Table 1 lists the parameters for these ranges The polynomials represent Curve 10 on the preceding page with RMS deviatio
97. 06 Days Hours 00 00 Minutes Seconds 00 03 Setpoint 100 0 Gain 10 Rate Reset 5 The command selected is 5 for Setpoint ramp The JUMP VECTOR is 06 so that operation after the ramp goes to Step 06 The setpoint of step 05 will be set to 100K to indicate where the ramping will end Note that even if the time were selected incorrectly the ramping would still end at 100K It is necessary to select the timer increment per tenth to arrive at the 100K in the 30 minutes From 40K to 100K is 600 tenths It will require 600 increments of 3 seconds each to end up at 100K in 30 minutes 1800 seconds Thus the setpoint will ramp up by 0 1K every 3 seconds up to 100K and will reach 100K in 30 minutes The reset will ramp from the value given in Step 04 to those specified in Step 05 The soak is covered by Step 06 as follows STEP 06 Step Command JUMP VECTOR 06 1 03 Days Hours 00 O1 Minutes Seconds 00 00 Setpoint 100 0 Gain 10 Rate 0 Reset 5 After the soak the next Program Step will be Step 403 which has a Command 9 and is explained at the end of Example 1 COPYRIGHT 12 87 LSCI Section VI 6 8 3 Example 3 Repeated Setpoint Ramp Up Soak and Ramp Down with Gain Ramping The ramp up soak and ramp down shown in Figure 6 3 will be repeated indefinitely this example The first part of the example is identical to that given in Example 2 except that the gain will be rampe
98. 080 027 0 1 14860 026 0 1 07200 025 0 1 25070 023 0 1 35050 021 0 1 63590 017 0 1 76100 015 0 1 90660 013 0 2 11720 009 0 2 53660 003 0 2 59840 001 4 6 55360 000 0 the silicon temperature For the The N indicates that diode is a negative coefficient device platinum curve 03 which is a positive temperature coefficient device a P will appear in that position 4 16 3 The XDA Command The XDA command asks for the output of the Sensor Curve Information Table as well as all the Sensor Curves stored in the unit When the command XDA is used the 93C will output the Information Table formatted as in Table 4 17 followed by a comma in place of the Terminators followed each Sensor Curve in ascending order with a comma between each Sensor Curve in place of the Terminators as in Table 4 18 until all the curves have been output followed by the Terminators The information is output as one lon character string 4 16 4 The XCN N gt Command The 2 command is the most powerful curve command in the 93 It allows for the remote input of Sensor Curves The Sensor Curves that be input using the XC 4 36 command are 06 thru 31 note that the first five curves 00 thru 04 are the Standard Curves with Curve 05 reserved The format for the XC command is given in Table 4 16 The format for the XC command must be followed for the curve entry to be successful Following the where is
99. 18 0 9388 0 9257 0 9122 0 8988 0 8853 0 8718 0 8584 0 8449 0 8311 0 8173 0 8035 0 7896 0 7758 0 7620 0 7482 0 7344 0 7202 0 7060 0 6918 0 6777 0 6635 0 6493 0 6351 0 6210 0 6068 0 5926 0 5789 0 5651 1 11896 1 11517 1 11202 1 10945 1 10702 1 10465 1 10263 1 09864 1 09477 1 09131 1 08781 1 08105 1 07053 1 05277 1 04353 1 03425 1 02482 1 02044 1 01525 1 00552 99565 98574 97550 91243 90161 89082 87976 86873 0 4853 0 4722 0 4588 0 4454 0 4320 0 4186 0 4045 0 3904 0 3763 0 3622 0 3476 0 3330 0 3184 0 3038 0 2893 12536 11356 10191 09032 APPENDIX DIN Standard Curve for 100 ohm Platinum Sensors 4 23481 4 68000 5 14601 5 65000 6 17000 6 72621 7 31000 7 90899 8 57000 23 52499 25 67000 27 82000 29 95000 32 08087 34 16000 36 25000 38 34000 40 42000 42 49000 65 00000 67 01000 69 02000 71 03000 73 03000 75 04385 77 02000 79 00000 80 98000 82 96000 84 94000 86 92000 88 90000 90 88000 92 86000 182 03545 183 85000 185 67000 187 49000 189 32000 191 13000 192 94000 194 75000 196 56000 APPENDIX B Sensor Curve 18 Character Information Line Reserved Character Definitions Each Sensor Curve has an 18 character information line Some of the characters are reserved for specific operations The definitions are as follows 1 Curve type 2 L Uni
100. 2 Model DRC 93C cepted Signals these lines operate in an interlocking hand shake mode The two signal lines NRFD and NDAC are each connected in a logical AND to all devices connected to the bus The DAV line is pulled low by the TALKER after it places its data on the DATA lines This tells the LISTENERS that information on the DATA lines is valid A LISTENER holds the NRFD line low to indicate it is not ready Since these lines are connected in a logical AND to all other devices then the NRFD line will not go high until all of the devices are ready The NDAC line is pulled low by a LISTENER while it is receiving the DATA and lets it go high when the DATA is captured Since the NDAC lines of all devices are connected in a logical AND the NDAC line will not go high until all devices have received the DATA 4 3 INTERFACE CAPABILITTES The IEEE 488 Interface capabilities of the Model DRC 93C are listed in Table 4 1 as well as in mnemonic format on the instrument s rear panel Table 4 1 Interface Functions Mnemonic Interface Function Name Source Handshake Capability Acceptor Handshake Capability Basic TALKER serial poll cap ability Talk only Unaddressed to Talk if addressed to Listen Basic LISTENER Unaddressed to Listen if addressed to Talk Service Request capability Complete Remote Local capablty No Parallel Poll capability Full Device Clear capability No Device Trigger capability No System Cont
101. 2 Under normal opera tion this switch is CLOSED 1 Change this switch to the OPEN 0 position 2 Connect the DVM plus lead to the V Buffered Sensor Output Signal pin for the appropriate Input Card and the minus lead to the pin on the MONITORS tor Connect the precision voltage source across the E and D V pins of the five pin input connector for the input corresponding to the Capacitance Card 3 Set the volts standard to 1 5000 4 Verify that the Display indi cates the Capacitance Input Card 5 Adjust the trimpot marked A D until the display reads 15 000nF for the 9215 15 or 75 00nF for the 9215 150 Check linearity by inputting 2 0000 and 1 0000 COPYRIGHT 2 88 LSCI Model DRC 91C 93C volts and verify that the unit displays 20 000 and 10 000nF within 0 001nF for the 9215 15 or 100 0 and 50 0nF within gt 0 01 for the 9215 150 6 Return 51 Switch 2 to the CLOSED 1 position 9215 8 2 Zero Calibration 1 Be sure that the leads are in the configuration which will be used in your system Detach the capacitance sensor 2 Verify that the Display indi cates the Capacitance Input Card 3 Adjust the trimpot marked ZERO so that the display reads 0 000 on the 9215 15 or 0 00 on the 9215 150 9215 8 3 Span Calibration 1 Be sure that the leads are in the configuration which will be used in your system Attach the standard capacitor in place of the capacitan
102. 20 1 9220 Input Card 9220 4 INSTALLATION The 9220 can be installed in the 91C 93C as either Input A or Input B or both with two options The 9220 is factory installed if ordered with 91C or 93 Temperature Controller or can be field installed at a later date If field installation is required use the following procedure WARNING To prevent shock hazard turn off the instrument and disconnect it from AC line power and all test equipment before removing cover 1 Set the POWER switch to OFF and disconnect the power cord from the unit Remove the three top panel screws and slide the panel off Note on the calibration cover the position of the Input Card the 9220 will occupy 2 Remove the four screws that secure the calibration cover to its clips and remove the cover 3 If an Input Card must be removed disconnect the wiring harness mating connector by lifting the locking tab on the Input Card connector and gently pulling on the body of the wiring harness mating connector 4 Plug the new 9220 Input Card into the A Input Card Slot 4 or the B Input Card Slot 5 with the component side to the left of the unit as viewed from the front Connect the wiring harness mating connector to the 9220 making sure that the wiring harness locking tab is seated over the extended edge of the wiring harness mating connector Verify that the wiring harness is in place correctly by noting that the A or B on the 92
103. 20 2 Model DRC 91C 93C harness mating connector is facing up if it is not review the harness installation again Thread the wiring harness along the rear edge of the unit and slip it into the harness strain relief on the rear panel 5 Install the calibration cover by reversing procedure 2 6 Install the top panel 9220 5 OPERATION The 9220 3 and 9220 6 configurations are equivalent to the 9210 3 and 9210 6 configurations in terms of operation The Model 9220 P2 Configuration provides the 1 milliampere excitation current to the platinum sensor the 9220 P3 supplies 0 1 milliampere and the 9220 R1 supplies 3 milliamperes The resulting sensor voltage is amplified by a factor of 10 negative 10 and digitized by a 16 bit A D converter with a resolution of better than 100 microvolts out of 3 0000 volts full scale The digitized value is converted to a serial data string and transferred to the main microprocessor using optical isolation The amplified 10 sensor voltage is transferred to the J3 MONITORS connector for external monitoring 9220 6 CALIBRATION The 9220 was calibrated to specification prior to shipment If recalibration is needed refer to the following procedure The following equipment is used to calibrate the 9220 Input Card 1 Digital Voltmeter Multimeter DVM 4 digit resolution or better COPYRIGHT 9 87 LSCI Model DRC 91C 93C 2 Precision Standard Resistor 1 kilohms for 9
104. 212U075AMA1 MPP2X 1 0 100 10 WO2M MR501 1N4006 1N4749A 1 751 57 92245 12 609 1602M 2630 09 74 1091 2630 09 74 1041 2630 09 74 1061 TSW 120 04 06 CR 3402 05 91 B1A5AH P1A5A 283906 F 01 2UEE NE15 18 76SB08 PWBH25DBF1F PWBH18D0BS1B 7805 7905 7815CT 7915 7808 7908CT LM317HVK STEEL TMS9914ANL SN75160AN SN75161AN 82 55 5 811595 DAC703BH 5 MM5480N AD7533JN HI5043 5 TSC914A MM5451N 740L6000 76016010 0831 7406 LM331N LF356N VN0109N5 1458PI IRF9130 M8080 1G40 REPLACEABLE PARTS LIST DRC 93C LSCI Part Number 113 131 106 010 106 012 106 414 106 415 7 017 5 006 0 014 10 11 11 105 671 105 676 105 677 106 028 106 140 110 150 106 011 106 013 106 002 106 001 103 765 102 095 106 571 109 019 109 021 107 180 CONNECTOR KIT consisting of 5 PIN PLUG MATE TO J3 7 PIN PLUG MATE TO 45 16 PIN IDC SOCKET 16 PIN STRAIN RELIEF RMA INSERTS POWER CORD FUSE 1 0A SB 115 VAC 0 5A SB 230 VAC KEY TOP BLUE KEY TOP LiGHT GREY KEY TOP MEDIUM GREY AC LINE CORD PLUG FUSE HOLDER LINE VLTG SLCTR CNNCTR J3 ON RB TO MB CONNECTOR TERMINALS CONNECTOR 5 PIN SOCKET CONNECTOR 7 PIN SOCKET HEATER HI OUT GRAY HEATER LO OUT BLACK HEATER GND BLACK POT 20 OHM 10X LIN TAPER POWER MOSFET 100V P CH SOCKET TO 3 INPUT TRANSFORMER OUTPUT TRANSFORMER FAN ASSEMBLY 113 11 131 126 127 126 195 609
105. 220 P3 or 100 ohms for 9220 P2 and 9220 R1 with a tolerance of 0 01 or better 3 Precision Voltage Source capable of supplying a voltage with an accuracy and resolution of 10 microvolts out of 1 volt or better The unit should be allowed a one hour warm up time to achieve rated specifications Refer to the 9210 section for the calibration procedure for the 9220 3 and 9220 6 configurations Use the following procedure to calibrate the 9220 P2 P3 and R1 Configurations 1 Remove the three top panel screws and slide the panel off 2 Set 100 uA 1mA 3mA Current Connect the appropriate precision resistor across the A I and B I pins of the five pin input connector for the input J1 or J2 the 9220 occupies Connect the DVM plus lead to the I pin and the minus lead to the I pin Adjust the trimpot marked 1mA for 2 on the calibration cover 100A for P3 3mA for R1 for the appropriate Input Card until the voltage across the resistor is equal to the sensor current times the resistance the tolerance of the resistor 3 Calibrate the Input 10 Amplifier Connect the DVM plus and minus leads to the V and V Sensor Output Signal pins for the appropriate Input Card of the J3 MONITORS connector Connect the precision voltage source across the E V and D V of J1 INPUT A or J2 INPUT B COPYRIGHT 12 87 LSCI 9220 Input Card for the appropriate input and set the standard to 0 0000 volts
106. 26 3 8830 4 5494 3 8126 4 3810 3 7411 4 1733 3 5948 3 9952 3 4436 3 8132 3 2026 3 6270 3 0374 3 4370 2 8689 3 2435 2 6957 2 9477 2 5184 2 6452 2 2468 2 3372 2 0615 2 0242 1 8725 1 6004 1 5839 1 1693 1 2905 0 6232 0 9912 0 0705 0 6847 0 5986 0 1670 0 7158 0 0378 0 8431 0 2387 0 9944 0 6350 1 1940 1 0387 1 4841 15 0010 15 0010 00 J AU P Q P 9305 12 COPYRIGHT 6 88 LSCI Model DRC 91C 93C 9305 Thermocouple Input Card Table 9305 4 cont 9305 Thermocouple Curves Chromel vs Copper vs Constantan E Constantan T Temp K nV Temp K Vqc mV 715 0000 15 0000 15 0000 9 8355 6 4582 6 2584 9 8298 6 4551 6 2523 9 8182 6 4486 6 2401 9 7956 6 4376 6 2184 9 7570 6 4205 6 1888 9 7013 6 3951 6 1404 9 6204 6 3529 6 0615 9 5071 6 2913 5 9535 9 3366 6 2149 5 7995 9 1345 6 1022 5 5753 8 9030 6 0099 5 3204 8 6475 5 8634 5 0337 WOMAN AU gt Q F 8 3673 5 6989 4 7194 7 9064 5 5156 4 3767 7 3943 5 3166 3 8781 6 8386 4 9881 3 3278 6 2400 4 6240 2 7342 5 3831 4 2267 1 9295 4 4564 3 7994 1 0586 3 4702 3 1866 2 1605 2 5259 0 7666 1 6463 0 9948 0 5186 2 8428 0 8688 4 7704 3 1298 7 0419 7 1149 4 9999 9 1113 9 5570 7 6164 11 2758 12 4425 9 6125 13 8053 13 5573 12 2790 14 9685 15 0010 15 0010 15 0010 0 1254 1 0616 2 3247 3 6639 5 3095 1 COPYRIGHT 6 88 LSCI 9305 13 1 ta REPLACEMENT PARTS LIST MODEL 9305 INPUT CARD LSCI PAR
107. 6 55360 000 0 Fora positive temperature coefficient curve the first end point is 0 00000 000 0 and the last end point is 6 55360 999 9 Therefore the minimum number of data points which the user can input for a curve is 1 which would result in a 3 data point curve and the maximum number of data points is 97 which would result in a 99 point curve The XC information must be output to the unit as very long character string The first character of the 18 character management string indicates the type of breakpoints to be entered If the character is an L then the unit performs Lagrangian calculations on the data If the character is anything else the unit performs Straig ht Line interpolation on the data See Appendix B for a description of the difference between the two In addition sensor type and temperature range is included in this 18 characters as well Curves 06 thru 31 are stored in Non Volatile RAM NOVRAM where the first 0200 hex bytes reserved for file management COPYRIGHT 3 88 LSCI Section IV There are 3584 bytes free for the storage of curves If the curve stored has 31 data points it will take up 177 bytes For this length curve up to 20 curves be stored in the unit Refer to Appendix B for additional infor mation on curve entry and how the curves are generated 4 16 5 The XEN N gt Command The command XEN4 N5 X XXXXX TTT T either adds a point to or edits the
108. 7 CLEARING All INTERNAL PROGRAM MEMORY ALL internal program memory can be cleared of program material from the front panel procedure is as follows 1 Press the PROGRAM key 2 Press and hold the CLEAR key for approximately 15 seconds until the PROG indicator goes off ALL program steps will be Cleared and front panel operation restored 6 8 EXAMPLES 6 8 1 Example 1 Ramp and Soak In Figure 6 1 is shown a graph of a simple ramp from 40K to 100K in a period of 30 minutes and a soak dwell of 1 hour Step 02 lt dwell 1 hour gt lt Step 01 Ramp for 30 minutes 40K Figure 6 1 Simple Ramp and Soak It is assumed that the system has stabilized at 40K prior to execution of the program Step 01 and 02 will be used for the program Step 01 will ramp and Step 02 will dwell It is assumed that the system can follow the setpoint in the time provided Section VI Step 01 will look as follows STEP 01 Step Command RAMP COUNT 01 3 60 Days Hours 00 00 Minutes Seconds 00 30 Setpoint 1 0 Gain 20 Rate 0 Reset 10 The command selected is 3 for Setpoint ramp up The RAMP COUNT is 60 setpoint will ramp up by the amount specified in the Step 01 setpoint display every 30 seconds for 60 times The setpoint of step 01 will be set to 1K to indicate 1K step up every 30 seconds for a total of 60 steps or 60K in 30 minutes 1800 seconds The gain rat
109. 8 A 2 0 453442 A 3 0 002243 4 0 158036 A 5 0 193093 A 6 0 155717 A 7 0 085185 A 8 0 078550 9 0 018312 A 10 0 116823 A 0 71 818025 A 1 53 799888 A 2 1 669931 A 3 2 314228 A 4 1 566635 A 5 0 723026 A 6 0 149503 A 7 0 046876 A 8 0 388555 A 9 0 056889 A 10 0 015619 A 11 0 058580 A 0 287 756797 A 1 194 144823 A 2 3 837903 A 3 1 318325 A 4 0 109120 A 5 0 393265 A 6 0 146911 A 7 0 111192 A 8 0 028877 A 9 0 029286 Application Notes Lake Shore Cryotronics Inc DT 470 SERIES TEMPERATURE SENSORS INSTALLATION AND OPERATION There are three aspects of using a temperature sensor which are critical to its optimum performance The first involves the proper electrical and thermal installation of the connecting leads which run to the sensor while the second aspect is the actual mounting of the sensor to the sample assembly The final concern is the measurement electronics used for reading and recording temperature data from the sensor CONNECTING LEADS Although the majority of the DT 470 series sensors are two lead devices measurements should preferably be made using a four wire configuration to avoid all uncertainties associated with the lead resistance This is done by using four connecting leads to the device and connecting the V and I leads to the anode and the V and I leads to the cathode as shown in F
110. 8002 05 Precision Option COPYRIGHT 3 88 LSCI Controller IQ IN ID IO ID ID IO ID ID ID IO IO IO ID IND IO Ld l l l gd gd d dE E dog dod od 1 OU Ul Ut Ui Oe PR o C FO IN IN P P IB B IB TABLE OF CONTENTS CONT D 3 5 CONTROL FUNDAMENTALS 3 2 3 6 CONTROLS AND INDICATORS 3 2 FRONT PANEL DESCRIPTION 37 POWER 4 we cat moe Ce eet ce X ar UR ep 3 2 3 7 1 Power Up Sequence 3 2 3 7 2 Power up Status e s lt x e e e s lt s 3 3 3 7 3 Blue Legend Keys 3 3 3 7 2 Black Legend Keys 3 5 3 8 TEMPERATURE BLOCK 4 sses s lt s lt s e s ooo 3 5 3 8 1 Sample and Control Sensor Inputs 3 5 3 8 2 Upper and Lower SENSOR Number e e e e e o 3 5 3 8 3 8229 Scanner Input Option 3 6 3 8 4 SCAN Function 6 s s s e e s s s e 3 6 3 8 5 The SCAN Dwell Time drca Dato rid 3 6 3 8 6 Upper and Lower Display Units SiS SLE Sue 3 6 28 62 Unite Select 3 6 3 8 6 2 Sensor Units Mode ae 10 ee ee e 3 8 6 2 1 Voltage Units te Ses 3 7 3 8 6 2 2 Resistance Units yrs eh fe cet ta 3 7 3 8 6 2 3 Capacitance Units e 3 7 3 8 7 Display Resolution 3 8 7 1 Temperature Display Resolu
111. 956 Swinehart L A Smith and J Krause private communication values are consistent with numerous other measurements made at Lake Shore Cryotronics Inc R Morrison Grounding and Shielding Techniques in Instrumentation Wiley New york 1977 Vol 2 18 Application Notes
112. ACE 8223 1 INTRODUCTION This Section contains information pertaining to the Model 8223 RS 232C Interface for the DRC 91C 93C Temperature Controller Included is a description specifications installation operation and maintenance information 8223 2 DESCRIPTION The 8223 RS 232C Interface is designed to be installed in a DRC 91C 93C and provide an interface with an external RS 232C instrument such as a computer modem or CRT The interface operates in a half duplex mode it can only transmit and receive information one direction at a time and data transmission is asynchronous each character is bracketed by start and stop bits that separate and synchronize the transmission and receipt of data The baud rate is Switch selectable at 300 or 1200 baud and the interface maintains EIA voltage levels for data transmission Figure 8223 2 gives a transmission format which shows the data bits framed by the start and stop synchronization bits The data is transmitted using two voltage levels which represent the two binary states of the digit A logic 0 or SPACE is 3 to 12 VDC logic 1 or MARK is 3 to 5 VDC When data is not being transmitted the line is held low MARK state When the transmission device is ready to send data it takes the line to the high SPACE state for the time of one bit This transition is called the start bit The remaining data is then transmitted If a parity bit is used it fol
113. C 5 9317C 9318C Input Cards Since very often these values will not be available to the user of this instrument Lake Shore Cryotronics Inc offers re calibration service Contact a factory representative for informa tion concerning re calibration Note that the card believes that the correct resistance and voltage is applied during calibration therefore the accuracy of the calibration depends on the accuracy of the standards used 9317C 9318C 7 CALIBRATION The 91C 93C should be allowed a one hour warm up time to achieve rated specifications References are made in the calibration procedure to eight calibration switches CAL 8 through CAL 1 Refer to Table 9317C 9318C 2 for the switch definitions of CAL 8 through CAL 1 References are made to test points adjustments and calibration switches that are labeled on the calibration cover Use the following procedure to calibrate the 29317C 9318C Resistance Input Card 1 Remove the three top panel screws and slide the panel off 2 Configure the input that contains the 9317C 9318C as the SAMPLE input only and make the units f Turn off Digital Filtering and Thermal Cor rection DIP switches of the appropriate SENSOR ID switches 2 and 3 to the OPEN OFF position for the DRC 91C or disable from the front panel on the DRC 93C 3 Current Source Zero Connect the 10K 9317C ohm precision resistor across the I and I pins of the Resistance Input Card
114. Chapter 3 For example to change the Setpoint press the SETPOINT key followed by the keypad digits key or Y key as desired Pressing the ENTER key stores the result Note that for 6 4 Model DRC 93C Commands 3 and 4 the entry into the Setpoint is an incremental value whereas for all others it is an actual Setpoint 6 5 5 Entering Other Parameters In addition the sensor units resolution filtering of either display Manual Heater Power and Heater Range can be changed for any POINT 6 5 6 Entering the Timer Value The Time Timer displayed is changed using the TIME key Pressing the TIME key causes the Days entry to flash The keypad is used to enter the Days After the Days desired is shown the user presses the ENTER key The Days will stop flashing and the Hours will flash The Hours Minutes and Seconds are entered in the same way The time value should be non zero for commands 1 2 3 4 and 5 6 5 7 Entering the Program Step into Memory Once all parameters of a step are as desired pressing the SCAN 1 key will enter that program step into memory If the SCAN key is not pressed the program step is not stored and subsequent request for the program step will produce the old configuration 6 5 8 Ending Programming Mode If it is desired to end or abort the operation at any time except when the setpoint gain rate reset manual heater power or time is in the progress of being enter
115. Codes TN and ZN will be accepted and updated even though they have no relevance to the interface the EOL terminator sequence is always CF LF and there is no EOI status The MN command can be OFF LINE Local and ON LINE Remote or Remote with Local Lockout states When OFF LINE Local parameters such as SENSOR ID as well as Gain Rate and Reset are updated from the hardware settings while ON LINE these parameters can be updated from the computer only The Output Statement commands given in Tables 4 9 and 4 10 will result in the requested data being output immediately following the reception of the EOL sequence If more than one Output Statement command is given the last one received will be acknowledged Programming Codes and Output Statements can be sent in the same command string For example the command string 524 5 40120025 2 would result in the Set Point being updated to 24 5 the Gain to 40 the Reset to 20 the Rate to 25 the Heater Range to 1073 No Output Statement was given so no response will be output by the interface The command string S24 5P40I20D25R2WO will result in the WO contents being output by the interface Refer to Section 4 for a detailed discussion of the Output Statement commands COPYRIGHT 12 87 LSCI Model DRC 91C 93C Tables 4 11 and 4 12 give the Program Curve Summary The XDT XDA and XDN4N5 commands are Output Statement style commands which result
116. E KEYS WILL CARRY OUT THE FUNCTION DESCRIBED BY THE BLUE LEGEND THE ENTER AND CLEAR KEY ARE ONLY EFFEC TIVE WHEN A QUANTITY IS FLASHING THE 4 KEY AND v KEY ARE USED IN CONJUNCTION WITH BLUE LEGEND KEYS TO CHANGE THE QUANTITY BEING REQUESTED 3 8 TEMPERATURE BLOCK The TEMPERATURE block consists of the Upper Display Setpoint Display and the Lower Display The Upper and Lower Displays each have 1 SENSOR Number 2 1 SCAN indicator in the upper left hand corner of the SENSOR Number COPYRIGHT 3 88 Section III 3 Units K C V N 4 A 5 digit display with sign 5 An indicator in the upper left hand corner of the sign to signal FILTER ON A Control arrow CTRL to the far left of the TEMPERATURE block points to the Controlling Sensor The Setpoint Display is discussed in Section 3 10 with the CONTROL Block 3 8 1 Sample and Control Sensor Inputs The choice of which input is assoc iated with the Control Sensor or the Sample Sensor is determined by the CONTROL key of the keypad and indi cated by the CTRL annunciator arrow If the CTRL Arrow points up then the Upper Display with its associated SENSOR Number and UNITS are the Control sensor The Lower Display is then the Sample Sensor with its associated SENSOR number and UNITS Similarly if the CTRL Arrow points down then the Lower Display and its associated SENSOR and UNITS is the Control Sensor and the Upper Display is the Sample Sensor
117. ER 3 11 2 The HEATER POWER RANGE o 3 12 LOCAL REMOTE BLOCK s s e oo 3 12 1 LOCAL 3 12 2 REMOTE e e REAR PANEL DESCRIPTION 3 13 REMOTE SENSOR ID 3 14 HEATER CURRENT LIMIT SECTION IV REMOTE OPERATION 4 1 IEEE 488 INTERFACE 4 2 GENERAL IEEE SPECIFICATIONS AND OPERATION 4 3 INTERFACE CAPABILITIES e o 4 4 DRC 93C IEEE 488 ADDRESS SWITCH 4 4 1 Terminating Characters delimiters 4 4 2 Talker and or Listener Configuration 4 4 3 The IEEE 488 INTERFACE bus address 4 5 488 BUS COMMANDS eo 4 5 1 The Uniline Commands Jw is 4 5 2 The Universal Commands IDEE 4 5 3 The Addressed Commands ERES 4 5 4 The Unaddress Commands 4 5 5 Device Dependent Commands 4 5 6 Talker and Listener Status 4 6 PROGRAMMING INSTRUCTIONS 4 6 1 Commands and Requests 4 7 INSTRUMENT SETUP COMMANDS AND REQUESTS 4 7 1 EOI Status The ZN Command 4 7 2 Interface Mode The MN Command 4 7 2 1 Local COPYRIGHT 3 88 LSCI 3 16 3 16 3 16 3 16 3 17 3 17 3 17 3 17 3 17 3 19 3 19 3 19 Ow yai I OA GO O Ut OI gt gt 1 I M TV Moo M iii TABLE OF CONTENTS CONT D 4 7 2 2 Remote s e s o lt s lt lt eR
118. FD rT iz E 17 3 u fla toe reat CR uer HHH 12 Tis 9 ducis end Pere 18 GND 75161 HEATER N 148 E IVA OUTPUT 8 B M 58 18 B DATA OUT HIHI S HC 01 243986 HIIS Ree 5 lt 45 4 TSK 1 2 GND D m 256 11384 9 1 NY 7 Se B4 2 U ss 35 H 1 B gt Hx HH DVD HE 12 21 om FREE ERR LL UU g 10 34 A 111 DRC 83C MAINBOARD V DIGITAL SECTION 62 04 98 ne DWG NO 6448 06 91 SHEET 3 OF 7 5 i 4 3 2 1 Figure 93C 1d Schematic DRC 93C Main Board 3 Digital Section TNT OPT3 8 0 Figure 93C 1e Schematic DRC OPTION 3 2 4 18 1 14 18 1 1e e8 22 24 26 28 29 3e 22 38 38 48 42 44 46 8 sg 350 50 GND D 15 D 7185 D GND Als iev CS 8 av cs B VIN 5 5 15 DVD 8 B DATA IN B CLK INT OPT2 DBIN RD 55 4 CS OPT2 YTS TES PE ei ee SLOT B CHANNEL ANALOG INPUT 9552556999980 8288293229885S5SZENSeo nsn 15 715 A V cS 8 B A D IN 15 AY B DATA OUT Ald GND Ald 5 A 6 A 15 GND D 50 Main Board 4 interconnections GND A s 18 A 12V CS A 15 4 av CS A V CS A AVIN A A D IN 15
119. IPTION AND SPECIFI 9305 2 1 Description The Model 9305 Thermocouple Input Card is designed to be installed in a Lake Shore DRC 91C or DRC 93C Temperature Controller It allows either Input A or Input B or both with two cards to accommodate thermocouple sensors Chromel vs Gold 0 03 at Fe Chromel vs Gold 0 07 at Fe E K and thermocouples are supported with internal curves that enable the controllers to operate in temperature units C F and K as well as voltage in millivolts The 9305 utilizes secondary temperature sensor to monitor the Reference Junction room temperature and provide curve compensation The Reference Junction Compensation can be disabled so the 9305 can be used with external compensation techniques An Offset Adjustment is provided adjacent to the Terminal Block to compensate for thermocouple variations and system irreqularities COPYRIGHT 6 88 LSCI 9305 2 2 Specifications Specifications for the Model 9305 Thermocouple Input Card are given in Table 9305 1 The temperature range for each type of thermocouple is given in Table 9305 2 9305 3 INSTALLATION The 9305 can be installed in a DRC 91C or a DRC 93C as either Input A or Input B The 9305 is installed prior to shipment if ordered with a controller If only one card is ordered and its input is not specified when ordered it is installed in Input A When a card is ordered for field installation the Input Card Co
120. Input Cards set point results under temperature condition the opposite operation is performed If the thermal correction is active the 91C 93C monitors the sensor resistance until it is within 0 5 of the set point resistance Once it is the 91C 93C signals the 9317C 9318C card to reverse the sensor current and update the thermal value The 9317C 9318C card and the 91 93 use this new thermal to determine the resistance and correct the set point The thermal value 15 updated every 120 instrument update cycles about 2 minutes after the initial update When the set point is changed the previous thermal value is used until the correction criteria is met and the thermal updated again 9317C 9318C 6 CALIBRATION SCHEDULE AND EQUIPMENT The design of the 9317 9318 Resistance Input Card is such that re calibration should not be required more often than every six to twelve months in order to keep the card within its accuracy specification However if re calibration is required the following equipment is needed to re calibrate the card 1 Digital Voltmeter DVM 5 1 2 digit resolution or better 2 Five 5 Precision Standard Resistors which are accurate in value to at least 0 01 Their values in ohms must be 9317C 9318C 1 10 100 1K 10K 10 100 1K 10K 100K f 3 Precision Voltage Standard capable of a plus and minus 10 millivolt signal to within 0 1 microvolt 9317C 9318
121. LL IBINT2 IBGTS IBCAC IBWAIT IBPOKE IBWRT IBWRTA IBCMD IBCMDA IBRD IBRDA IBSTOP IBRPP IBRSP IBDIAG IBXTRC IBRDI IBWRTI IBRDIA IBWRTIA IBSTA IBER R IBCNT 70 TEMPS 93C 93C is IEEE address label set up when running IBCONF 80 CALL IBFIND TEMPS Required command to address 93C 90 OPEN A PROGRAM1 FOR OUTPUT AS 1 Open file to store data 100 FOR I 1 TO 10 Program Steps 01 TO 10 110 IF I 10 THEN GOTO 150 120 N1 MID STR I 2 1 140 GOTO 160 150 N1S 0 160 N2 RIGHTS STR I 1 170 BS WE N1 N2 Assemble command 180 13 CHR 10 CR and LF to command 190 CALL IBWRT TEMP BS Send request to 93C 200 CALL IBRD TEMP A Get data from 93C 210 PRINT 5 Display received information on screen 220 PRINT 1 5 Save in file A PROGRAM1 230 NEXT I 240 CLOSE 1 250 END COPYRIGHT 3 88 LSCI 4 25 Section IV Model DRC 93C 4 12 3 4 National Instruments GWBASIC and BASICA IBM Example of E Command This program will restore Programs Step 1 thru 10 previously stored in file PROGRAM1 on Disk A using GWBASIC or BASICA and the National Instruments GPIP PC2 IEEE 488 Card for the IBM PC and compatibles 10 CLEAR 60969 BASIC DECLARATIONS 20 IBINIT1 60969 This number is different for each computer 30 IBINIT2 IBINIT1 3 40 BLOAD bib m IBINIT1 50 CALL IBINIT1 IBFIND IBTRG IBCLR IBPCT IBSIC IBLOC IBPPC IBBNA IBONL IBRSC IBSRE IBRSV IPPAD
122. LO lead of your DVM to TP1 and the HI lead to TP25 SP V 4 Enter a set point of 0 0000V and adjust the potentiometer labeled SP ZERO ADJ until the DVM reads 0 0000 volts 5 Enter a set point of 2 7000V and adjust the potentiometer labeled SP SPAN ADJ until the DVM reads 2 7000 volts 6 Repeat the two settings until the values are constant 5 6 4 Calibration of Power Output If the heater output is not the standard 50 watts for the DRC 93C the optional power output installed should be indicated on the front page of this manual 1 Verify that the back panel HEATER RESISTANCE switch is on 10 25 and use a load resistor between 10 and 25 ohms with a wattage rating equivalent to its resistance The W60 output re quires a load between 10 and 25 ohms with a wattage rated 1 5 times the resistance value 5 6 Model DRC 93C Set a set point and gain value which results in full scale output on the MAX Heater Range scale 2 With full power across the load resistor on the 1 scale place the DVM LO probe in TP19 PWR V and the DVM HI probe in TP21 and adjust PWR V until the DVM reads 1 000 volts There now should be one ampere through the load 1 5 amperes in the case of the W60 The heater can now be turned off 3 Place the DVM LO into TP15 PWR V and the DVM HI into TP17 HTR V and adjust PWR V ADJ until the DVM reads 1 0000 volts 4 Place the DVM IO into TP20 PWR LO and the DVM HI into TP16 VREF and adj
123. LOC IBPPC IBBNA IBONL IBRSC IBSRE IBRSV IPPAD IBSAD IBIST IBDMA IBEOS IBTMO IBEOT IBRDF IBWRTF 60 CALL IBINT2 IBGTS IBCAC IBWAIT IBPOKE IBWRT IBWRTA IBCMD IBCMDA IBRD IBRDA IBSTOP IBRPP IBRSP IBDIAG IBXTRC IBRDI IBWRTI IBRDIA IBWRTIA IBSTA IBERR 70 TEMP 93C 93C is IEEE address label set up when running IBCONF 80 CALL IBFIND TEMP TEMP Required command to address 93C 90 255 255 largest data transfer allowed by IBM format 100 INPUT BS Entered from keyboard while running 110 BS BS CHRS 13 10 Add CR and LF to command 120 CALL IBWRT TEMP B Send command to 93C 130 CALL ENTER from 93C SEE NOTE BELOW 140 PRINT A Display received information on screen 150 AS SPACES 255 Clear A 160 GOTO 110 170 END 180 REM 93C will return data requested but if the command input does 190 REM not request new information the 93C will give the information last requested 4 30 COPYRIGHT 3 88 LSCI Model 93 Section IV 4 15 3 National Instruments QUICK BASIC IBM Example IEEE 488 TEST PROGRAM Quick Basic 3 0 Example THIS PROGRAM WAS WRITTEN FOR THE NATIONAL INSTRUMENTS GPIP PC2 IEEE 488 CARD FOR IBM PC AND COMPATIBLES This program will allow the user to communicate with Lake Shore s instruments interactively from the keyboard of an IBM compatible computer which has a National Instruments GPIB PC2 insta
124. ON The 9305 Thermocouple Input Card has the capability of interfacing 5 different thermocouple types in COPYRIGHT 6 88 LSCI Model DRC 91C 93C Table 9305 2 to the Lake Shore DRC 91C and DRC 93C Temperature Controllers over their respective temperature ranges The thermocouple voltage is amplified by 100 by a circuit which is attached to the Terminal Block The thermocouple voltage is further amplified by a factor of 2 tunable by the Control Amplifier on the 9305 Thermocouple Input Card The amplified signal is sent to the main board analog control circuitry and can be accessed from the Buffered Output line of the J3 Monitor Connector on the controllers back panel In addition the amplified thermocouple voltage is applied to a 15 bit A D converter on the Thermocouple Input Card so that digitized thermocouple voltage can be sent to the main board microprocessor The Thermocouple A D converter has auto zero function which means that the only calibration required is for the relative gain A secondary diode temperature sensor is attached to the Terminal Block to monitor the reference junction temperature needed for Reference Junction Compensation A constant current source on the 9305 Card is applied to the Secondary Sensor A 15 bit A D converter on the 9305 Card digitizes the secondary sensor voltage and sends the data to the main board microprocessor The microprocessor on the main board of the controller ca
125. OR MPP2X 1 0 100 10 MPP 11 33MFD 2420 09 75 1061 2N3906 eXMTA7 5 NONE 4UGRP 38163 LM308 LM399H 740L6000 740L6010 CD4021BCN ICL7104 16CPL ICL8068ACPD 79105 ICM75551PA LTC1043 V C S 6 C S 9 c BJ un 27 624 REPLACEABLE PARTS LIST 9220 AWALOG INPUT CARD ITEM LSCI Part NO Number c4 5 11 17 18 28 C16 P2 Q1 101 034 101 025 106 142 102 072 105 649 102 074 104 005 102 043 104 001 104 355 104 356 104 099 104 461 104 460 102 020 104 051 104 078 1 0 100 CAP PP 33MF 100V CONNECTOR IC TO BP 6 POST LOCKING HEADER TRANSISTOR PNP SIGNAL SWITCH 2 POS 4 POLE INTERLOCKING MOSFET P CHANNEL IC OP AMP VOLTAGE REFERENCE 6 95V IC OP AMP IC OPTOCOUPLER IC OPTOCOUPLER IC P S SHIFT REGISTER IC A D CONVERTER IC A D REFERENCE REGULATOR 5V IC TIMER IC SWITCHED CAPACITOR MPP2X 1 0 100 10 MPP 11 33MFD 2420 09 75 1061 283906 2XMTA7 5CNONE 4UGRP 501635 LM308 LM399H OPO7EP 740L6000 740L6010 CD4021BCN ICL7104 16CPL gt ICLBO68ACPD TOLOSCT 1CM7555IPA LTC1043 9305 THERMOCOUPLE INPUT CARD 9305 1 INTRODUCTION This section contains information pertaining to the Model 9305 Thermocouple Input Card Included is a description and information on specifications installation operation and field calibration 9305 2 CATIONS DESCR
126. ORMATION 1 1 INTRODUCTION 1 2 DESCRIPTION 1 3 SPECIFICATIONS s s 1 4 OPTIONS e es lt X SECTION II INSTALLATION 2 1 INTRODUCTION ss s e o so e oo 2 2 INITIAL INSPECTION 2 3 PREPARATION FOR 05 3 1 Power Requirements Power Cord Grounding Requirements e Bench Use Rack Mounting Sensor Input Connections J3 Sensor Output Monitors SENSOR ID Switches Heater Power I 2 3 9 1 MAX HEATER POWER Limit c Q Q Q Q Q WWW o O QI i Wd NNNNNNNNN o o 2 3 9 2 Current or Power Output 2 4 REMOTE SENSOR ID Connector 2 5 IEEE 488 INTERFACE Connector 2 6 OPTIONS 2 7 ENVIRONMENTAL REQUIREMENTS oem 2 7 1 Operating Temperature 2 7 2 Humidity Altitude 2 8 REPACKAGING FOR SHIPMENT SECTION III OPERATING INSTRUCTIONS 3 1 INTRODUCTION 3 2 INSTRUMENT CONFIGURATION e e 3 2 1 Input Card Configurations 3 2 2 Single Input Card 3 2 3 Dual Input Cards gt 3 2 4 Old Version Input Cards 3 3 CURVE ENTRY 4 amp es s gt o lt o o oo 3 4 PRECISION OPTIONS o 3 4 1 The Model 8000 Precision Option 3 4 2 The Model 8001 Precision Option 3 4 3 The Model
127. Overload Error Indicator 4 11 2 5 When operating without the Service Request The Status Register Mask The QC1C2 Command 4 11 3 1 Status Register Mask Bits 0 and 1 Display and Control Data Ready Enables 4 11 3 2 Status Register Mask Bit 2 The Control Channel Limit Enable 4 11 3 3 Status Register Mask Bit 3 Display Sensor Channel Change Enable 4 11 3 4 Status Register Mask Bit 5 Overload Error Indicator Enable 4 11 3 5 Examples for setting Mask eo 4 11 3 6 Status Register Mask at Power Up 4 11 3 7 The WO Data String ee ee lt s SAVING AND RESTORING EXECUTABLE INTERNAL PROGRAMS 4 12 1 Requesting a Program Step for Saving WENJN Command 4 12 2 Transmitting a Program Step to the 93C The ENJN2C1 C6o Command gt gt 4 12 3 Examples of Saving and Restoring Executable Internal Program Steps 4 12 3 1 Program to Request and Store Program Step 1 thru 10 using the HP86B 4 12 3 2 Program to Restore Program Step 1 thru 10 using the HP86B si owe oue dos 4 12 3 3 National Instruments GWBASIC and BASICA IBM Example of WEN4N5 Request 4 12 3 4 National Instruments GWBASIC and BASICA IBM Example of E Command sv fey Je wy fe 4 12 3 5 National Instruments QUICK BASIC IBM Example of WEN4N5 Request 4 12 3 6 National Instruments QUICK BASIC IBM
128. R GEN PURP NPN DIP SWITCH 8 POS DIP SWITCH 6 POS IC BAUD GENERATOR REGULATOR 12 IC 8 BIT MUX IC QUAD 2 INPUT NOR UART IC TRANSCEIVER IC TRANSCEIVER was MFR PART NO DB 25S 2N5225 76B08 768806 MC14411 78112 DM81LS95AN 741502 825 MC1488L MC1689NL Model DRC 91C 93C Model 8225 Analog Output MODEL 8225 ANALOG OUTPUT 8225 1 INTRODUCTION This section contains information pertaining to the Model 8225 Analog Output for the DRC 91C 93C Temperature Controller Included is a description specifications installation operation and main tenance information 8225 2 DESCRIPTION The 8225 Analog Output is designed to be installed in a DRC 91C 93C and provide an analog output proportional to the Kelvin temperature of the display or control sensor for the purpose of recording either with strip chart recorder or other similar device the sensor temperature The analog output is present on the J3 MONITORS connector the 91C 93C back panel with pin C being the V output and pin D being the V output 8225 3 SPECIFICATIONS Specifications for the Model 8225 Analog Output are given in Table 8225 1 8225 4 INSTALLATION The 8225 can be installed in the DRC 91C 93C Option Slot 1 or Option Slot 2 if a Model 8223 RS 232C Interface is not present The 8225 Analog Output is factory installed if ordered with a DRC 91 93 or be field installed at a later
129. R normally switches two and three should both be OPEN 0 These switches are usually of use when one instrument is a TALKER and another instrument is a LISTENER and they are to share the same address IEEE 488 Address Switch for the DRC 93C CLOSED 1 OPEN 0 Address Addresa switch sr 4 is MSB 16 8 is LSB 1 Switch 3 CLOSED 1 position sets the 93C in the talk only mode by disabling LISTENER capability Switch 2 CLOSED 1 position sets the 93C in the Jisten only mode by disabling TALKER capability Switch 1 used to define the instrument s delimiters Refer to Section 4 4 1 of the text for details COPYRIGHT 3 88 LSCI Model DRC 93C Section IV Allowable Address Codes for the DRC 93C Factory preset address is decimal 12 Table 4 2 piene Te Vr Be 1 in sixth and seventh bits These bits are the same for the TAIK BUS CONTROLLER originated determine whether the instrument is being addressed to TALK or LISTEN Only the first five bits of the binary code are listed and LISTEN address COPYRIGHT 3 88 LSCI Model DRC 93C 4 4 3 The IEEE 488 INTERFACE bus address for the DRC 93C is set by switches 4 through 8 which are reserved for the address selection Switch 4 is the most significant bit MSB 16 and 8 is the least sig nificant bit LSB 1 The factory preset address of this instrument
130. REMOTE SENSOR ID Connector will be called the REMOTE POSITION DATA The user must provide the DRC 93C the information which relates the REMOTE POSITION DATA to the Curve Number This information is stored within the DRC 93C in its Correla tion Table See Table 3 4 In addition the user must enable the DRC 93C to use the REMOTE POSI TION DATA This is done by using the CURVE REM 44 and vv keys as described in the next section 3 9 2 1 Selection of the REMOTE POSITION DATA To allow the REMOTE POSITION DATA to determine the curve selection the user does the following 1 Press the CURVE key and hold it down The Curve associated with the Upper and Lower Displays will be given and the GAIN RATE and RESET blanked 3 11 Section III 2 While holding in the CURVE key press the REM REMote key Release the CURVE key 3 Now press the 44 Up key to tog gle the Upper Display External curve selection The REMOTE POSITION DATA will appear in the GAIN windows to indicate that the REMOTE POSITION DATA will be used for curve selection by the Upper Display Sensor Hitting the aa key again will blank the GAIN window indicating that the REMOTE POSITION DATA will not be used The operation is the same for the vv key except that the Lower Display Sensor and RESET window are involved 4 When the desired condition is reached release all keys 3 9 2 2 The Correlation Table The CURVE key will show tha
131. RIAL NUMBER MB SOFTWARE DB SOFTWARE INSTRUCTION MANUATL MODEL DRC 93 C TEMPERATURE CONTROLLER Input Card Configuration Input A Input B 9210 3 Standard 3 volt Configuration 6 6 Volt Diode Configuration 9215 15 Standard 15 Nanofarad Capacitance Input 150 150 Nanofarad Configuration 9220 3 Standard 3 volt Configuration 6 6 Volt Configuration P2 100 ohm platinum conversion module P3 1000 ohm platinum conversion module R1 27 ohm Rh Fe conversion module 9305 Thermocouple Input Card O O 9317C Ultra low 0 3K Germanium input Card L 9318C Germanium Carbon Glass Input Card 1 No Input Card Precision Option s 8223 RS 232C Interface m 8001 8002 8225 Analog Output Interface 0 10 volt Output Power Option 8229 Scanner Input Option wo 9126 High Resolution Set Point L This manual applies directly to instruments with Serial Number 17000 and higher COPYRIGHT 1988 Lake Shore Cryotronics Inc Westerville Ohio U S A WARRANTY Lake Shore Cryotronics Inc the manufacturer warrants this product to the owner for a period of 12 months from the date of shipment During the warranty period under authorized return of instruments or component parts to Lake Shore freight prepaid the company will repair or at its option replace any part found to be defective in material or workmanship without charge to the Owner for parts service labor or associated customary shipping cost Replacement or
132. S S lt ge gt s 77 p 22222 Wd 0 6070 012 4 ae gje N i 5 G e s fe 3 8 uut i 228 2 6 228 8 vie B5B SEE S HH m ee pe E Wrd 0 LI Uv wo zie 2122122 24838433 daek E RST P1713 8 GND D pi Eg IEEE Figure 053 Microprocessor Card Model DRC 93C SECTION PROGRAMMING 6 1 INTRODUCTION This section contains information and instructions concerning the Internal Program feature of the Model DRC 93C Temperature Controller The feature permits simple ramp and Dwell or Soak as well as elaborate sequences including ramping the setpoint up and down and ramping of the gain rate and reset The DRC 93C is capable of automatically executing internally stored programs The programs are entered into the instrument from the front panel The programs are permanently stored in a nonvolatile memory permitting their execution even though the instrument has been turned off and on unplugged and moved The instrument comes from the factory with a repertoire of example stored programs which ramp and soak etc These programs allow the user to quickly learn the contents of this chapter and many can be used directly with minor modification of the setpoint and control parameters 6 2 PROGRAM STEPS AND SIZE The Prog
133. SHOWN AS VIEWED FROM INSIDE THE UNIT Figure 93C 1i Schematic DRC 93C Main Board 8 Rear Panel Il HN AAG E DS15 08516 0517 DS19 5228 DS28 0529 0832 O 15 195 dE EHE 0845 0846 17 847 1 ps4s _ TD 3 Figure 93C 2a Component Layout DRC 93C Display Board 2 16 HP LEDS GAIN 18 2 11 RATE 19 J2 14 RATE 1 0634 011 6 0636 5082 7611 0538 0541 2543 0546 0245 OFF 3 1 Loc GI Qo 11 5517 0518 011 7 ULi U11 18 0011 11 11 12 6882 7811 5892 7611 5892 7611 fes Tes pes Yel 0548 1542 1544 1546 aL gem 9 DRC 93C DISPLAY BOARD SCHEMATIC SETPOINT SECTION Figure 93C 2c Schematic DRC 93C Display Board 1 Setpoint Section B UNIT 8 1 mM E ie lt we x A A AND B INPUT SECTION DWG NO 6437 06 01 LAKE SHORE CRYOTRONICS INC DRC 93C DISPLAY BOARD SCHEMATIC 82 18 88 S3CDISe WORE 98 RIE ROR BER 2 251 052 2514 052 AND 0527 ARE ROTATED 198 DEGREES NOTE 7 I 5 m pee DRC 93C Display Board 2 Input Display Section tic Sche Figure 93C 2d Y ina 5883855859 iol I log
134. ST MODEL 8225 ANALOG OUTPUT OPTION LSCI Part Number Description 2 MFR MFR PART NO 104 524 PORT EXPANDER IN P8255A 5 104 425 4 DIGIT DAC DAC71 CCD V 104 001 P j OPOTEP Model DRC 91C 93C 8229 Scanner Conversion Option 8229 SCANNER CONVERSION OPTION 8229 1 INTRODUCTION This Section contains information pertaining to the Model 8229 Scanner Conversion for the DRC 91C 93C Temperature Controller Included is a description Specifications installation Operation and maintenance information 8229 2 DESCRIPTION The 8229 Scanner Conversion is designed to be installed in a DRC 91C 93C and provides four additional channels of sensor input to Input A 8229 inputs designated Al through A4 and their selection is identified in the display window at the left of the display With the 8229 installed the DRC 91C 93C is expanded from the standard dual sensor input to handle six input sensors The 8229 Al through A4 channels can be selected directly using the SENSOR A key or included in the SCAN sequence An independent Dwell time 0 to 99 seconds can be assigned to each of the additional inputs The Al through A4 channels of the Model 8229 Scanner are accessed through a 24 style connector located in the J9 Option Port on the 91C 93C rear panel Pin assignments for the connector are shown in Table 8229 1 The pin configuration for this connector is identical to the pi
135. Sensor Scanner or a Model SW 10A ten position switch This input is called the REMOTE POSITION DATA and allows the user to automatically call up different cu rves for different sensor channel positions when the instrument is used with either remote switch see Section 3 9 2 The Parallel input data format is given in Table 3 5 The user may supply to the REMOTE SENSOR ID his own parallel BCD 5 volt signal referred to the DIGITAL GROUND on pin 12 COPYRIGHT 3 88 Section III 3 14 HEATER CURRENT LIMIT The DRC 93C Temperature Controller has a current drive output with a maximum current rating of one ampere unless the optional 1 5 ampere out put W60 was ordered or the cur rent limiting vernier has been set at a lower value With the current limiting vernier on the back of the instrument the out put current on the MAX scale can be limited anywhere between 1 ampere and_the maximum current for the 1071 scale 330 mA This allows the user to limit the maximum power to between 50 watts and 5 watts dependent on his requirements Table 3 5 Pin Assignments for the J5 REMOTE SENSOR ID Connector J5 CONNECTOR Pin Assignments 15 13 11 9 7 5 3 1 16 14 1210 8 6 4 2 ONLY BOLD PINS USED Bit 3 Bit 2 Bit 1 Bit O LSB DIGITAL GROUND Bit 4 MSB SECTION REMOTE 4 1 IEEE 488 INTERFACE The IEEE 488 INTERFACE is an in strumentation bus with hardware and programming standards designed to simplify instr
136. System the sensor voltage is digitized by an analog to digital AD converter The digitized temperature is then compared to the digital set point within the microprocessor and by means of an appropriate algorithm the average power to the heater is adjusted A converter with a 14 bit resolution 1 part in 16 384 enables the microprocessor to determine the temperature to approximately 4 mK at 4 2 kelvin using the diode sensor of Figure 2 In a system which is inherently stable the control temperature stability can be no better than the temperature resolution of the AD converter 4 mK for this example Cost effective AD converters with such resolution have sampling times in the half second range In the world of ovens furnaces and other large industrial processes which operate above room temperature stable control can be maintained by digital systems updating temperature only once or twice a second This is for the same reason that ON OFF controllers are successful in these cases the large thermal time constants of the controlled environments However as discussed in Section II the time constants are much shorter in cryogenic systems so much so that temperature can and frequently does change at a rate which exceeds the sampling frequency of a typical digital cryogenic controller approximately 2 Hz A good example is a mechanical refrigerator based on the Gifford McMahon cycle At 10 kelvin and below these refrigerators unloaded often have a
137. T 5 1 5 4 LINE VOLTAGE SELECTION 5 1 5 5 PERFORMANCE VERIFICATION 5 5 1 Performance Verification Connector 5 5 2 Performance Verification Procedure e TI 5 6 CALIBRATION es d W WU PES 1952 5 6 1 Input Card Calibration ET lee ee ier ERR ere Ier Ze 5 2 5 6 2 Set Point Voltage Calibration a vis S UM der BLUR ca 5 2 5 6 3 Calibration of GAIN RATE and RESET a etic ee ul 5 3 5 6 4 Calibration of Power Output s e e e e e 5 3 5 7 TROUBLESHOOTING gt gt gt o o 5 4 SECTION VI PROGRAMMING INSTRUCTIONS 6 1 INTRODUCTION e emm ds wo Se a ee ee Q e 6 1 6 2 PROGRAM STEPS AND SIZE 6 1 6 3 PROGRAM STEP FORMAT lt lt s o9 4 s s 9 6 1 6 4 SUMMARY OF COMMANDS 6 1 NTERNAL PROGRAM ENTRY lt s s s e s s wwe Starting the Program Edit Mode e s e e e s so Program Step Selection at Stee Term de See tar SU SS as Entering the Program Command and JUMP VECTOR REPEAT COUNT or RAMP COUNT a iat Wee ad RS Entering the Setpoint Gain Rate and Reset eee ae Entering Other Parameters Entering the Timer Value Ge Entering the Program Step into Memory Ending o
138. T 3 88 LSCI Model DRC 93C Section IV BS WE N1S N2 Assemble command 13 CHR 10 CR and LF to command CALL IBWRT TEMP BS Request Program Step I CALL IBRD TEMP AS Get Program Step I PRINT Display received information on screen PRINT 1 Save on disk in file PROGRAMI NEXT I CLOSE 1 Close the file END 4 12 3 6 National Instruments QUICK BASIC IBM Example of E Command Quick Basic 3 0 Example 3 THIS PROGRAM WAS WRITTEN FOR THE NATIONAL INSTRUMENTS 2 IEEE 488 CARD FOR PC AND COMPATIBLES This program will restore Programs Step 1 thru 10 from File PROGRAM1 on Disk COMMON SHARED IBSTA IBERR IBCNT TEMPS dev12 93C CALL IBFIND TEMPS TEMP address instrument OPEN A PROGRAMI FOR INPUT AS 1 Open file with data FOR I 1 TO 10 Program steps 01 Thru 10 INPUT 1 C Get data from file PROGRAM1 Assemble command BS B CHR 13 CHR 10 Add CR and LF to command CALL IBWRT TEMP B Send command to instrument FOR Z 1 TO 1000 NEXT Z NEXT I CLOSE 1 Close the file END COPYRIGHT 3 88 LSCI 4 27 4 13 COMMAND OPERATIONS The following example in HP Basic sets the set point to 123 4 K the gain to 45 the reset integral to 30 the rate derivative to 25 the heater range to 1071 and the output statement sent to be W3 OUTPUT 712 S123 4P45130D25R4W3 Data 12 93C preset address 7 IEEE 488 ca
139. T F degreaser and remove grime with dry low pres sure air 5 3 FUSE REPLACEMENT The line fuse is accessible from the rear of the DRC 93C Use the following procedure to check and or replace the fuse COPYRIGHT 3 88 To prevent shock hazard turn off instrument and disconnect it from AC line power and all test equipment before replacing the fuse 1 Set the POWER switch to OFF and disconnect the power cord from the unit The fuse compartment is located just to the right of the power connector 2 Open the fuse compartment by prying open the cover with a small screw driver 3 Remove the lower fuse holder by sliding it out of its position with the aid of the small screw driver CAUTION For continued protection against fire hazard replace only with the same type and rating of fuse as specified for the line for the line voltage selected 4 Replace the fuse per Table 2 1 5 Replace fuse holder close fuse compartment and connect power cord 5 4 LINE VOLTAGE SELECTION The rear panel three pronged line power connector permits the DRC 93C to be connected to 100 120 220 or 240 VAC line voltages Use the following procedure to the line voltage Section V To prevent shock hazard turn off the instrument and disconnect it from AC line power and all test equipment before changing the line voltage selection 1 Pull fuse compartment cover using the procedure found in Se
140. T NUMBER 099 LSCI Part Number j UnP gt gt Y SS C3 4 14 101 034 CAP PP 1 0MF 100V MPP2X 1 0 100 10 101 001 CAP POLY 0015 100V WMF1D15 C10 13 101 137 10MF 35V 1190106 0035081 23 32 16 26 101 027 47 100 MPP 11 47MFD 19 27 101 132 1 5 10 1500 155 9010 2 CRI 102 064 DIODE SWITCHING 10914 P2 P3 106 142 CONNECTOR 6 POST LOCKING 2420 09 75 1061 RA HDR R1 16 103 077 TRIMPOT 2K 3299 1 202 21 22 51 105 403 1 SWITCH 4 DIP PIANO 76 5804 01 104 081 1 LTC1050CN8 2 104 005 1 IC OP AMP LM308 U3 104 001 1 IC OP AMP 148 5 104 465 2 IC A D CONVERTER 5 500 06 104 078 1 MOSFET CHANNEL 3N163 U7 104 020 1 REGULATOR 5V 7905 08 102 010 1 REGULATOR 5V 7805 u 102 041 1 VOLTAGE REFERENCE 2 5V LM336BZ 2 5 U10 11 104 345 2 IC OPTOCOUPLER 2731 012 104 511 1 1 MICROPROCESSOR P80C31 U13 104 660 1 IC EPROM PROGRAM 27C64 3 U14 104 528 1 IC 8 BIT LATCH P82CB82 U15 102 040 1 VOLTAGE REFERENCE 1 22V LM313 MP1 5 000M HZ 103 990 CRYSTAL 5 000 HZ 253528838 58 auo e 6 me P 4 Marta 1 18 234 1 Iu
141. The error may be caused by problems with the signal lines or incorrectly specified parity The error and any of the other DRC91 RS errors is transmitted when the unit is asked to output and is cleared following the first transmission after the error Possible Cause Corrective Action C 2 8223 RS 232C Interface Overrun Error The error is caused by the unit s main processor not reading the input character before the next one becomes available The overrun character s are lost 8223 RS 232C Interface Framing Error The error may be caused by signal line transients or incorrectly specified stop bits or character length 8223 RS 232C Interface Input Buffer Overrun Error The error occurs when more than 256 characters are input to the FIFO buffer of the unit Any characters received after the 256th character are lost Input Overload When an input signal which exceeds the maximum allowed for that input is applied the error occurs When the error occurs the displays OL if it is the DISPLAY SENSOR input and stores OL in either the WS and or WC data locations 8217C 8218C Input Card Error The 8217C and 8218C Input Cards have an EEPROM that stores the calibration constants used to set the sensor current and determine the resulting voltage accurately When the card detects an error in the EEPROM storage it tries to correct it If it cannot correct the error it transmits the Err20 code to the main processor and resets the
142. The SCAN key is pressed to store the Program Step section 6 5 7 8 Stages 3 through 7 are repeated to enter more Program Steps 9 After all steps of the program COPYRIGHT 12 87 LSCI Section VI are entered the PROGram key is pressed to exit the programming mode The PROGram indicator turns off and normal operation will resume Section 6 5 8 6 5 1 Starting the Program Edit Mode NOTE There must be a valid input present when editing program The DRC 93C incorporates fault protection that will automatically force the HEATER RANGE to the OFF state on an input overload OL condition To enter or modify a program in the DRC 93C the operation must started with the PROGram key Next press the INTernal key and it is now possible to create or edit a program The Program Edit Mode is depicted by having both the PROGram and INTernal annunciator lights lit 6 5 2 Program Step Selection Upon entering the Program Edit Mode the display will always enter at Program Step 01 The Temperature and Setpoint Blocks will show the contents of the first Program Step 01 as for example 01 2 02 00 00 20 00 The upper display shows the Program Step 01 the Program command 2 and the JUMP VECTOR 02 which tells the program which Program Step will next be executed The Setpoint Display contains the Days and Hours and the Lower Display the Minutes and Seconds of Program Step 01 If another
143. Use the following procedure for the installation of the 9317 9318 Resistance Input Card Note when a card is ordered for field installation the Input Configuration Table located on the first page of the Instruction Manual should be updated to keep documentation current WARNING To prevent shock hazard turn off the instrument and disconnect it from AC line power and all test equipment before removing cover 1 Set the POWER switch to OFF and disconnect the power cord from the unit Remove the three top panel screws and slide the panel off Note from the calibration cover the position of the Input Card the 9317C 9318C will occupy 2 Remove the four screws that secure the calibration cover to its clips and remove the cover 3 If the 9317C 9318C is to replace an existing Input Card unplug the Input Card which is to be replaced Disconnect the wiring harness mating connector by lifting the locking tab on the Input Card and gently pulling on the body of the wiring harness mating connector 9317C 9318C 1 9317C 9318C Input Cards Model DRC 91C 93C Table 9317C 9318C 1 Specifications 9317C 9318C Resistance Input Cards Input Range 9317C Less than 1 ohm to 10 000 ohms with a resolution of 1 part in 10 000 and an accuracy of 0 1 of reading for resistances from 1 to 1 000 ohms and 0 5 of range for resistances from 1 000 to 10 000 ohms 9318C Less than 1 ohm to 100 000 ohms with a resolution of 1 par
144. a new conduction mechanism becomes dominant suggesting the influence of impurity conduction carrier freezeout increased ohmic behavior of the bulk material and p i n diode type behavior 9 The only adjustable parameter in Eq 1 which is necessary for the present analysis is the parameter n This parameter can be determined quite easily from the IV characteristics of the silicon diode temperature sensor The parameter Is is eliminated by normalizing the IV curve to an arbitrarily chosen point on the curve The value of n 1 8 was found to give a relatively good fit to the IV data for both 305 77 K and has been assumed in the present discussion 7 Equation 1 can now be solved for V I nkT e In I ls 1 2 Substituting a dc current with an ac modulation lac lac cosa the average voltage read by the voltmeter in the dc voltage mode can be calculated from 1T V 0 1 COS at dt 3 where T the period of integration of the voltmeter or approximately 2 Implied in this derivation is the assumption that o is sufficiently small so that effects from diode capacitance on the order of picofarads can be ignored On carrying out the integration of Eq 3 and subtracting V lac the dc offset voltage is 2 1 Sims J 4 nkT 1 AV V V I 1 lac e 2 where lac lt lac Is If a small signal linear model is used the rms voltage across the diode can be easily related to
145. able 4 8 defines and in the ACC and 1 gt commands defines whether the Remote Position Data should be used to select the Curve Number defines whether the thermal correction is on or off on the 9317C 9318C cards filtering on or off and the sign of the temperature coefficient with a 9215 Capacitance Card A02 Enable digital filtering to be used to determine display value 4 12 Model DRC 93C A10 Enables the REMOTE SENSOR ID If the remote position data is 0 then the sensor curve reverts to the curve 00 or BOO rather than being selected from the REMOTE SENSOR ID Table A12 Enable digital filtering addition to the 10 description 4 8 10 The WD Data String An example of the data received when requesting Sample Control A information using the WD command is as follows 0 3 0 2 00 00 02 00 00 00 00 02 04 above string indicates that the Sample Sensor is AO sample units are kelvin sample resolution is 3 and the sample form is normal the Control Sensor is BO control units are kelvin control resolution is 2 xxx x and control form is normal the remote position is off the SENSOR A ID indicating that the Digital Filtering is Off and the REMOTE SENSOR ID is off the curve being used for INPUT AO is 2 and Al A2 and A3 are using curve 0 the SENSOR B ID indicates that Digital Filtering for this channel is On a
146. able Option Standard 25 pin socket Since the HP default Baud rate character length parity and stop bit configuration are the same as those of the 8223 Interface when shipped none of the switches on the 8223 board need to be changed When connecting the HP 86B Serial Interface to the 8223 Interface a transition cable needs to be made to connect the socket connector of the HP to the socket connector of the 8223 Interface Figure 8223 3 shows the adapter cable that must be made The arrows indicate the source and direction of signal flow Figure 8223 3 Half Duplex W O Handshake Connection to HP 86B Protective Ground Protective Ground Transmitted Data Received Data Signal Ground The following program will input a command from the keyboard and 8223 6 Model DRC 91C 93C output it to the 8223 will then input the specified 8223 s response display it and return for another command The program 10 REM HALF DUPLEX W O HANDSHAKE 15 REM I O TEST RS232 TEST1 20 DIM A 256 B 3000 25 REM A IS OUTPUT BS IS INPUT 30 INPUT A MAKE SURE TO GIVE AN 35 OUTPUT STATEMENT COMMAND 40 OUTPUT 10 AS OUTPUT COMMAND 50 ENTER 10 BS INPUT THE DATA 55 FROM THE CONTROLLER 60 DISP B DISPLAY DATA 70 30 RETURN FOR MORE 80 END Example 2 HP 86B Computer Half Duplex with Handshake Figure 8223 4 shows the adapter cable for Half Duplex with handshake communications with
147. adings are as close as possible to the calibration values Before returning to normal operation make sure switches 7 and 6 of the Internal ID are OPEN OFF Replace the calibration cover and then the top cover 9317C 9318C 7 9317C 9318C Input Cards Model DRC 91C 93C Table 9317C 9318C 2 Calibration 9317C 9318C 8 SENSOR CURVE Switch Definitions INFORMATION Viewed from the Component Side of The curves used with the 9317C 9318C 9317C 9318C Input Card are generat ed using a proprietary Polynomial Interpolation Algorithm developed by Lake Shore format for the data to be stored using the 1 command as outlined in Section 4 is the same as for a standard curve except the resistance is converted to a LOG value where 1000 ohms would look like 4 0000 Refer to Micro APPENDIX B for a definition of the curve requirements The curve data is in resistance order The resistance and temperatures for the 9317C 9318C are in ohms up to 100 000 ohms and in kelvin up to 399 9 9317C 9318C 9 REPLACEABLE PARTS Edge of PCB Included in this section is Figure 9317C 9318C 1 It includes the Model 9317 9318 Resistance Input Viewed through Calibration Cover Schematic replaceable parts list and illustrated component layout Refer to the manual for ordering information closet Definition switch closed Calibration Enable Current Source DAC Zero 9317 9318
148. age M2 Table 4 6 disables the DRC 93C s Local Front Panel controls including the IOCAL button The message is in effect until the message is cleared over the Bus or power is cycled Many IBM PC IEEE 488 cards automa tically place addressed instruments into Local Lockout To be able to place the DRC 93C into Remote without Local Lockout the user may need to reconfigure his IEEE 488 Section IV the unit has completed its message transfer Switch 1 of the IEEE address defines the terminator status If switch 1 is OPEN 0 the terminator status is defined as TO CR LF and terminator status can not be changed over the interface When switch 1 is CLOSED 1 the terminator status is defined as T1 LF CR and the status can be changed using the To T1 T2 or T3 commands 4 7 4 Clear card The C lear Message see Table 4 4 sets the DRC 93C to the turn on state This action is similiar to turning the instrument OFF and then turning it back ON except that it occurs in milliseconds rather than seconds and the DRC 93C does not go through the power up display se quence DRC 93C Summary of Output Requests mee Eve 700 Input and Option Card Data wo Saree control A and B input Information _ EE GNI 4 7 3 Terminating Characters The TN Command Terminating characters TO T1 2 and 3 Table 4 6 are used to indicate the end of a r
149. ailable on request from Lake Shore Cryotronics Inc Krause J K and Dodrill B C 1986 Measurement System Induced Errors in Diode Thermometry Review of Scientific Instruments 57 4 661 665 Available on request from Lake Shore Cryotronics Inc Sparks L L 1983 Temperature Strain and Magnetic Field Measurements In Materials at Low Temperatures Ed By R P Reed and A F Clark American Society of Metals Metals Park 515 571 White G K 1979 Experimental Techniques in Low Temperature Physics Clarendon Press Oxford Application Notes 13 Lake Shore Cryotronics Inc MEASUREMENT SYSTEM INDUCED ERRORS IN DIODE THERMOMETRY by John K Krause and Brad C Dodrill Diode temperature sensors are capable of being used at the accuracy level of a few hundredths of a kelvin However in order to achieve this performance proper measurement techniques must be used Poorly shielded or improperly grounded measurement systems can introduce ac noise which will create an apparent shift in the dc voltage reading across a diode sensor This results in a temperature measurement error which may approach several tenths of a kelvin The presence of the ac noise in question is not obvious during normal usage and several quick tests are outlined to verify whether or not a noise problem exists Experimental data and derivations from theoretical p n junction characteristics are given which correlate the ac noise level with possible voltage temperatu
150. al contact The SD package can also be bonded with an epoxy such as Stycast The sensor should be pressed firmly against the surface during curing to assure a thin epoxy layer and good thermal contact The device may be removed in the future by using the appropriate epoxy stripper The SD adpater can be soldered using a rosin flux non corrosive if extreme care is exercised First tin the base of the sensor using a low wattage temperature controlled soldering iron which will not exceed 200 C Use only a minimal amount of solder Tin the surface to which the sensor is to bonded and again avoid an excessive thickness of solder Clean both the sensor and mounting surface of any residual flux Next re heat the mounting surface to the melting point of the solder press the device into position and allow the sensor to warm to the melting point of the solder After both tinned surfaces have flowed together remove the heat source and let the sample and sensor cool Under no circumstance should the sensor be heated above 200 C and the solder must be limited to only the base of the sensor Excess solder running up the sides of the SD package can create shorts Repeated mounting and demounting of a soldered sensor may eventually cause wetting deterioration and ruin the thermal contact to the sensing element although the nickel buffer layer should minimize these problems CAUTION The preferred method for mounting the SD sensor is either the CO adapter or bo
151. ample 5 covering 5 orders of magnitude in power as does the DRC 82C then the controller output into a 50 ohm load and with a gain of 200 for 5 watts and 50 watts would have the response shown in figure 3 Note that the overall voltage and power gain of the controller is modified by changing the output power settings Application Notes Lake Shore Cryotronics Inc To illustrate the effect of the sensor in more detail consider the idealized curve Figure 4 for a Lake Shore silicon diode which has a nominal sensitivity of 50 mV K below 30 kelvin and 2 5 mV K above 30 kelvin Figure 3 illustrates the effect of converting the voltage error signal horizontal axis to its equivalent temperature error for the two sensitivity regions of 2 the silicon diode sensor These curves introduce the concept of loop gain dP dT watts kelvin which includes the gain of the sensor as well as that of the deviation amplifier and power output stage As the transition in temperature 1 from above 30 kelvin to below 30 kelvin is made the loop gain is increased by a factor of 20 because of the increased sensitivity of the silicon diode thermometer Because of noise and thermal phase lag the deviation amplifier gain will normally have to be reduced by the same factor so that the loop gain remains relatively constant In order to maintain any desired temperature above that of the cryogen in a cryogenic system of course some level of heater power must
152. an be adequately described by the mathematical model which is presented below One surprising aspect of the data acquisition was how well the signal processing in the voltmeter could hide even high ac levels in the dc measurement modes For example operating at 10 uA dc and 77 K with a rms noise level of 6 mV gives a dc voltage offset of about 1 5 mV which is about a 0 6 K temperature error When reading the voltage signal using the filtering and integrating capabilities of the HP 3456A the dc voltage reading is stable to better than 0 02 mV 8 mk Application Notes 15 Lake Shore Cryotronics Inc This stability gives a deceptive view of exactly how accurate the temperature measurement really is and emphasizes the importance of checking all aspects of a measuring system The measured offset voltages shown in Figs 4 and 6 can be understood by using the well known result from p n junction theory ls exp eV nkT 1 1 where the forward current through the junction 15 the reverse saturation current e the electron charge V the voltage across the junction k Boltzmann s constant and T the absolute temperature n is a parameter depending on the location of the generation and recombination of the electrons and holes and typically has a value between 1 and 2 This expression for the IV characteristics of a p n junction is valid from approximately 40 K to above 300 K for the silicon diodes discussed here Below 40 K
153. and ENTER functions for CTRL Arrow use with keypad 0 1 2 3 4 5 6 7 8 9 decimal point Control Display and 1 minus sign 16 Return to LOCAL key with annun 6 GAIN proportional display ciator 7 RATE derivative display 17 REMOTE key with annunciator 8 RESET integral display 18 INT INTernal Program Key with 9 HEATER CURRENT or HEATER POWER annunciator Bar Graph in percent of full 19 POWER ON OFF switch scale COPYRIGHT 3 88 Model DRC 93C 3 7 4 Black Legend Keys When one of the Black Legend keys GAIN RATE RESET SETPOINT MANUAL HEATER TIME or POINT is pressed it is not to be held down released immediately The quantity described by the key will begin to flash indicating that it can be changed The keypad 0 9 and is then used to enter the new value Negative quantities are preceded by the minus t 1 key The ENTER key completes the operation and inserts the new value The CLEAR key will cancel the entry and return the instrument to normal operation When the 44 up and vv down keys are used after selecting a Black Legend key the 44 key will increment and the vv key decrement the quanti ty Detailed operation of these keys will be discussed in the sections dealing with the specific Black Legend functions SUMMARY THE KEYPAD 0 9 AND ARE ONLY THE NUMBERS 0 9 AND DECIMAL POINT WHEN DISPIAY SETPOINT GAIN RATE RESET OR MANUAL HEATER POWER IS FLASHING OTHERWISE TH
154. at l l q 02 3 2 1 0 lt Bit 8 4 2 1 Weighting 0 1 0 1 0 1 0 1 Bit Choices gt Sample Sensor Channel Change SRQ Bit lt Overload Error lt Indicator Table 4 12 Commands to Fix the Status Register Mask Overload Not Sample 1 1 Sample Error Used Indicator on On on Note means 1 Those entries left blank are OFF 0 4 22 COPYRIGHT 3 88 LSCI Model DRC 93C Section IV Table 4 13 DRC 93C Command Request Summary for Status Register Mask Functional Description e The Status Register mask is set using the Q command Forms of the command are 00 2 02 2 04 2 Q6Cy and 10 11 0 12 0 13 QC44 0 15 QC46 0 17 When C4 is Status Register Mask is Service Request OFF Error Overload Indicator Request OFF Error Overload Indicator Request ON Service Request is ON Status Register Mask Status is Sample Data Control Data and Limit OFF Sample Data Service Request is ON Control Data Service Request is ON Control Channel Limit SRQ is ON kkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkk Output of Instrument Setup SRQ Mask Data C1C2 N1N2N3 N4 8 Characters plus up to 2 terminators where C1C2 N1N3N4 N4 is the SRQ Mask Byte is the control channel limit band 4 11 3 6 Status Register Mask at Power Up The Status Register Mask is
155. at ninety degrees if at all possible The heater output is current drive and does not have to be fused The DRC 93C is designed to power a 50 ohm heater for maximum heater output If a smaller resis tance is used the maximum heater power corresponds to the heater resistance i e 10 ohms yields 10 watts A larger heater can also be used Since the compliance voltage is 50 volts a 100 ohm heater will allow a maximum power output of 25 watts 50 2 100 A slide switch on the back panel sets the available output power Gependent on the value of the heater resistance This slide switch must only be changed with the instrument turned off since it shorts the windings of the output 2 3 Section transformer between positions The setting range of the switch should coincide with the heater resistance to minimize power dis sipated within the DRC 93C Three setting ranges are available 10 25 25 35 and 35 to 50 ohms An optional output power stage W60 of 60 watts is available for the DRC 93C The W60 is rated at 1 5 amperes at approximately 43 volts into 25 ohm load A 50 ohm 50 watt 1 4 dia x 1 long cartridge heater is available as well as a 25 ohm 25 watt 3 8 dia x 1 long cartridge heater A 30 gauge stranded copper lead wire ND 30 is recommended for connecting to the heater 2 3 9 1 MAX HEATER POWER Limit Make sure that the MAX HEATER POWER limit potentiometer is turned fully
156. atinum input card and no Precision Option curves present the DRC 93C will select Curve 03 regardless of the curve selected using the CURVE key 3 9 1 3 Addition of 8229 Scanner Option Adding the 8229 Scanner to Input A adds four more Inputs 1 2 3 and 4 Each of these inputs has its own curve assigned using the CURVE key 3 9 1 4 Changing the Curve used by a Sensor No External Scanners With the CURVE key held in press ing the 44 up key allow the user to change the curve used by the Upper Display Sensor When the CURVE key is let up the instrument will return to normal operation with COPYRIGHT 3 88 Section III the new curve being selected for calculation by the Sensor associated with the Upper Display Similarly the CURVE key and the vv down key change the curve for the sensor associated with the Lower Display 3 9 2 External Scanner Model 8085 Up to three 8085 Scanners can be daisy chained together to give 30 remote positions for either the A input or the B input of the DRC 93C In order for the instrument to se lect the correct curve for the sen sors connected to an 8084 or 8085 Scanner it is necessary for the user to make a connection between the REMOTE POSITION DATA Connector of the Scanner to the DRC 93C REMOTE SENSOR ID Connector In this way the DRC 93C will have the data re garding which position the scanner is in and thus which external sensor is being examined The data on the
157. ays 0 000 to 9999 9 ohms for the 9317C and 0 000 to 99999 ohms for the 9318C Resultant temperature accuracy is a function of sensor characteristic and is the product of the input accuracy in percent times R dT dR plus any transfer inaccuracy introduced by the sensor response curve Temperature Control Signal Card generates an analog voltage output signal which is related to the sensor temperature The instrument generates a similarly related set point voltage based on the set point resistance or temperature selected Real time analog comparison of these two voltages provides the required control signal 9317C 9318C 2 COPYRIGHT 12 87 LSCI Model DRC 91C 93C 4 Connect the wiring harness mating connector to the 9317C 9318C Input Card making sure that the wiring harness locking tab is seated over the extended edge of the wiring harness mating connector Plug the 9317C 9318C into the Input Card Slot with the component side facing to the left of the unit as viewed from the front Make sure the card is thoroughly seated Verify that the wiring harness is in place correctly by noting that the A or B on the harness connector is facing up if it is not review the harness installation again 5 Install the calibration cover by reversing step 2 6 Install the top panel 9317C 9318C 5 OPERATION The 9317C 9318C is a highly complex microprocessor controlled Input Card It s resistance measuring technique is distinctly diffe
158. be used for the current connections and the other pair for the voltage connections The pin contact of the connector is and the socket 9215 6 SELECTION OF THE SIGN OF THE TEMPERATURE COEFFICIENT The temperature coefficient of some Capacitance Sensors can be positive or negative depending on the temperature range The 9215 Card produces a voltage proportional to the Capacitance which is sent to the control circuitry of the DRC 91C 93C to be conpared to a user selected setpoint For control to operate properly the sign of the voltage must reflect the tempera ture coefficient of the sensor It is necessary for the user to determine which range the sensor is in and to inform the controller of the sign of the temperature coefficient This is accomplished on the DRC 91C by a switch switch 1 of the SENSOR ID on its rear COPYRIGHT 2 88 LSCI Model DRC 91C 93C panel and on the DRC 93C by a Sequence of key strokes from its front panel Also the Sign of the temperature coefficient can be entered via the computer interface using the 2 or BC Cz command 9215 6 1 Selection of Temperature Coefficient Sign on the DRC 91C The sign to be used on the Tempera ture Coefficient of the capacitance is selected using Switch 1 of the appropriate SENSOR ID located on the rear panel of the DRC 91C When Switch 1 of the SENSOR ID is closed the Temperature Coefficient is Positive When Switch 1 of the SENSOR ID is open the Tem
159. bed in Section 4 8 9 9305 7 2 Selection of Reference Junction Compensation on the DRC 91C Whether or not Reference Junction Compensation is used is selected using Switch 3 of the SENSOR ID When Switch 3 of the SENSOR ID is closed 1 the Reference Junction 9305 6 Model DRC 91C 93C Compensated value of the thermocouple voltage is displayed When Switch 3 of the SENSOR ID is open 0 the actual measured thermocouple voltage or uncompensated temperature is displayed With the 9305 selected as the Display Sensor hold the LOCAL key to show card type and curve number If compensation is active the display will show 9305 and if it is inactive 9305 Table 9305 3 Curve Numbers Thermocouple Standard Type Curve Chromel vs Au 0 07 at Fe Chromel vs Au 0 03 at Fe 9305 7 3 Selection of Reference Junction Compensation the DRC 93C When a 9305 Thermocouple Input Cards is installed pressing the SENSOR key will display either 9305 or 9305 The 9305 means that the thermocouple voltage is corrected for the Terminal Block temperature 9305 means that the thermocouple voltage is being displayed with no compensation To select whether Reference Junction Compensation is used or not is accomplished from the front panel by combination of the SENSOR key SCAN tl key and the 44 key and vv key The procedure is as follows COPYRIGHT 6 88 LSCI Model DRC 91C 93C 1 Press and hold th
160. between 06 and 31 is a comma Then up to 18 characters can be entered as a curve information line At least one character is required and any more than 18 characters are ignored If 18 characters are input the last 6 are used in the Sensor Curve Information Table as a capsule description of the curve in the 8000 Series Precision Option curves these 6 characters are used to indicate the sensor serial number The 18 characters must be immediately followed by a comma The data points are then input in the form X XXXXX comma X XXXXX input is Voltage or LogR Refer to Table 4 19 for the conversion of the raw units information into the format required for the XC command The unit automatically fills in leading and trailing zeroes in the data point A data point entered as 0 8 70 would be converted by the unit into COPYRIGHT 3 88 LSCI Model DRC 93C 0 80000 070 0 data points must be entered in ascending units order After all the data points are entered the character terminates the Sensor Curve input Following the input of the to indicate to the unit that the there are no more data points it determines and stores whether the curve is a positive or negative temperature coefficient curve Based on temperature coefficient the unit then stores the curve end points For a negative temperature coefficient curve the first end point is 0 00000 499 9 and the last end point is
161. by holding down the SENSOR key 5 5 5 2 Check units display Verify that the A units can be changed by holding in the UNITS key and using the 44 or the vv to scroll through the sequence K C F V K etc Note the unit goes to V for a diode configuration 9210 3 6 or 9220 3 6 or Q for a resistance card configuration 9220 2 P3 R1 or 9317C 9318C Input card 5 5 5 3 Check sensor units reading Next check to see if the instru ment is reading the correct sensor units volts ohms or nanofarads value for the appropriate test resistor or capacitor from Table 5 1 reading should match the value given in the Display in Sen sor Units column of Table 5 1 The allowable error is provided in the Input A D Accuracy column 5 5 5 4 Check temperature reading Confirm that the temperature in kelvin displayed corresponds to the selected curve number COPYRIGHT 3 88 Section V a Check the Sensor Curve Table Table 3 2 or below to deter mine the curve number that selects the standard curve or precision option that is needed 9215 card will not read temp erature The 9317C 9318C will not read accurately in temp erature unless a precision option is present b Select the curve as described in Section 3 9 5 5 5 5 Check Input B Change the connector from J1 INPUT A to J2 INPUT B Repeat the above process by verifying the current source and the A D settings for this input as well as the units change
162. c current modulation at 60 1000 and 20 000 Hz 10 10 N x e e 60 Hz 10 1kHz 20 kHz 1 0 4 8 12 162024 28 22 RMS AC VOLTAGE mV FIGURE 7 DC offset voltage as a function of rms ac voltage across a silicon diode temperature sensor operating at 77 K The symbols represent data recorded at a 10 pA dc current with the ac current modulation at 60 1000 and 20 000 Hz 17 Lake Shore Cryotronics Inc IV CONCLUDING REMARKS Noise in any measurement circuit is undesirable and should be eliminated to as great an extent as possible The first step is to electrically shield all instrumentation and wiring and use proper grounding techniques Secondly the diode measurement circuit should have a single circuit ground which is generally made at the voltmeter and which then requires a floating current source The installation of the diode and its connecting leads should be done carefully to avoid introducing any unwanted circuit ground connections such as an electrical short to a cryostat As a last resort a quick fix can be used to eliminate much of the dc offset voltage with some degradation in the diode circuit performance A good quality capacitor low leakage can be placed across the diode to shunt the induced ac currents similar to the test procedure used for identifying a noise problem This is most easily done by connecting the capacitor across the input to the voltmeter The s
163. case it would need to see another Output Statement command If the error was in the 3 the interface may or may not have responded with data it may default to wo Although errors rarely occur it is suggested that any commands sent to the 91C 93C be echoed back by sending the appropriate Output Statement command and inputting the stored parameters Any error that is detected is cleared following the first transmission after the error Table 8223 6 Interface Error Codes Error Possible Cause Parity Error may be caused by signal line transients or incorrectly specified parity Overrun Error caused by the main processor not reading the input character before the next one becomes available The overrun character s are lost Framing Error may be caused by signal line transients or incorrectly specified stop bits or or character length Input Buffer Overrun caused by more than 256 characters being input input to the FIFO buffer Any characters received after the 256th character are lost 8223 7 INTERFACING EXAMPLES Example 1 86 Computer Half Duplex Without Handshake 8223 5 Model 8223 RS 232C Interface The HP82939A Serial Interface for the HP 86B is preset at the factory for the following default values 1 Interface select code 10 2 Baud rate 300 Baud 3 Autohandshake Off 4 Character Length 7 bits 5 Parity Odd 6 Stop bits 1 7 C
164. ce Table 8223 5 Model 8223 RS 232C Interface Specifications Timing Format Asynchronous Transmission Mode Half Duplex Baud Rate 300 or 1200 Bits sec Factory set to 300 Bits per Character 7 excluding start stop or parity bits Parity Enable Enabled Disabled Factory set Enabled Parity Select Odd or Even Factory set Odd Number of Stop Bits 1 or 2 Factory set to 1 Data Interface Levels Transmit or receive using EIA verrage levels 12V and 5 WARNING To prevent shock hazard turn off the instrument disconnect it from AC line power and all test equipment before removing cover 2 Set the POWER switch to OFF and disconnect the power cord from the unit Remove the three top panel screws and slide the panel off Note on the calibration cover the position of Option Slot 2 which the 8223 will occupy 3 Remove the four screws that secure the calibration cover to its clips and remove the cover Remove the two back panel mounting clips that secure the J10 blank cover plate to the interface opening and remove the plate 8223 3 Model 8223 RS 232C Interface 4 Remove the red jumper JMP6 on the Microprocessor Board This is the jumper closest to the front edge of the microprocessor card 5 Plug the internal interface cable into the 8223 printed circuit board PCB with the locking tab configured properly Plug the 8223 PCB into Option Slot 2 with the component side to the left of
165. ce sensor 2 Verify that the Display indi cates the Capacitance Input Card 3 Adjust the trimpot marked SPAN so that the display reads the value of the standard capacitor 9215 9 REPLACEABLE PARTS Included in this section is Figure 9215 1 It includes the Model 9215 Capacitance Input Schematics replaceable parts list and il lustrated component layout Refer to the manual for ordering informa tion COPYRIGHT 2 88 LSCI 9215 Capacitance Input Card 9215 7 R13 9 89K ces Ten c27 Be RA d s gt 2 a EE U16 CD4029 susu ss 2 5 cs Figure 9215 1 Model 9215 Capacitance Input Card C17 _ REPLACEABLE PARTS LIST 9215 CAPACITANCE INPUT CARD 101 034 101 025 106 142 102 072 105 649 104 051 102 075 104 461 104 099 104 460 104 001 104 010 102 020 104 087 104 078 104 355 102 037 104 054 104 101 104 356 Q md ad nA dj b CAP PP 1 0MF 100V CAP PP 33MF 100v CONNECTOR IC TO BP 6 POST LOCKING HEADER TRANSISTOR PNP SIGNAL SWITCH 2 POS 4 POLE INTERLOCKING IC TIMER MOSFET N CHANNEL IC A D CONVERTER P S SHIFT REGISTER A D REFERENCE OP AMP CONVERTER REGULATOR 5 IC DUAL OP AMP IC SWITCHED CAPACITOR IC OPTOCOUPLER VOLTAGE REFERENCE 10V OSCILLATOR IC DECADE COUNTER OPTOCOUPLER WPp2x 1 0 100 10
166. changing The Status Reports for the Overload Er ror Display Data Ready and Control Data Ready are continuously updated to reflect current instrument status The Channel Change and Control Channel Limit once encount ered are latched set to 1 and remain latched until the Status Register is read 4 11 3 The Status Register Mask Command The Status Reports listed above may not be desired or perhaps only a few are of interest The Status Register 4 20 Model DRC 93C Mask is provided to allow the user to select whether he wants a given Status Report or not The various bits of the Status Register Mask enable the various Status Reports The bits in the Status Register Mask have the same bit position as the bits in the Status Register Only those bits which are allowed by the Status Register Mask Command are potentially changeable in the Status Register Note that the corresponding bit in the Status Register Mask determines whether its counterpart the Status Register can change The Status Register Mask is shown in Figure 4 2 It consists of 8 bits one bit bit 6 which deter mines whether the DRC 93C is to report via the SRQ line and five bits to determine which Status Reports to make Bit 6 is the SRQ Service Request bit and if set allows the DRC 93C to send out a Service Request on the SRQ IEEE 488 line If the SRQ bit is not set off then the DRC 93C is inhibited from producing a Service R
167. cision Voltage Standard capable of a 10 millivolt signal to within 1 microvolt The accuracy of the calibration depends on the accuracy of the Digital Voltmeter DVM and the Voltage Standards used Since very often these values will not be available to the user of this instrument Lake Shore Cryotronics Inc offers a calibration service Contact a factory representative for information concerning calibration NOTE Setpoint calibration is described in Chapter 5 of the DRC 91C and DRC 93C Instruction manual The only additional instructions required when calibrating the setpoint D A converter with the 9305 card is to make sure that the Reference Junction Compensation is turned off Section 9305 7 3 9305 9 CALIBRATION The controller should be allowed a one hour warm up time to achieve rated specifications Use the following procedure to begin calibration of the 9305 Thermocouple Input Card 1 Remove the three top panel screws and slide the panel off 2 Configure the controller so the card to be calibrated is the CONTROL input 3 Locate the DIP switch 51 on the 9305 Input Card Open 0 S1 1 for calibration This forces the 9305 to update Secondary Sensor information every conversion cycle Under normal operation 51 1 closed 1 COPYRIGHT 6 88 LSCI Model DRC 91C 93C Secondary Sensor information is updated once every 25 cycles 4 Locate the Secondary Sensor current sensing resistor terminals
168. ction 5 3 2 Remove voltage selector wheel and insert with the proper vol tage facing out Note that the wheel can only be inserted with the writing read from the left 3 Install the proper fuse as out lined in Section 5 3 5 5 OPERATIONAL CHECKS 5 5 1 Test Connector A test connector for the rear panel 21 INPUT or J2 INPUT connector to simulate a diode sensor input is required for operational checks of the DRC 93C The test connector can be made by taking one of the plugs supplied with the DRC 93C and configuring a resistor to simulate the temperature sensor in the two wire configuration as described in Section 2 3 6 The test resistors specified in Table 5 1 are used in the operational checks 5 5 2 Operational Test Procedure The operational test procedure is designed to verify the overall operation of the DRC 93C and can be used as a periodic maintenance check The following equipment is used in the test 1 Digital Voltmeter 4 resolution or better digit 5 2 Model DRC 93C 2 Test Connector fabricated per Section 5 5 1 Complete the following procedure for this test set up 1 Plug the connector into INPUT A 2 Connect the DVM across the test resistor of Input A 3 Connect the DRC 93C to line power and turn the unit ON Verify that the DRC 93C initial izes to the proper POWER ON state as defined in Section 3 7 The following procedure is used to test the overall DRC 93C op
169. curacy The Model DRC 93C can also be used with the 9220 input card which handles both diodes and positive temperature coefficient metallic resistors i e platinum or rhodium iron resistors The DIN curve is standard within the instrument and is called up automatically unless positive temperature coefficient precision option curve is selected for that input The accuracy of the reading is dictated by the sensor and its conformity to the DIN curve The tolerance on these devices is given on the technical data sheet for the Lake Shore PLATINUM RITD s The combined accuracy of the instrument and a calibrated resistor with a precision option is on the order of 40mK over the useful range of the sensor above 40K for the plat inum Note that precision option is required for a rhodiun iron to read correctly in tempera ture The Model DRC 93C with the 9318C germanium carbon glass input card results in the most accurate system below 50K in temperature For both sensors a precision option is required to read in temperature Near 4K the overall accuracy of the system including the calibra 1 2 Model DRC 93C tion accuracy the software interpolation accuracy and the calculation of the resistance results in an overall accuracy on the order of 10 These input option cards are easily installed by the user thus units can be changed or upgraded to satisfy changing requirements The ample memory space provi
170. curs the unit displays the error if it is the DISPLAY SENSOR input and continues operation until the fault is corrected The error is stored in the WI A Input data location and is displayed when the LOCAL key is pressed to determine the Input Card type Incorrect B Input Card polarity Operation is the same as for Err27 except the error is stored in the WI B Input data location Lake Shore Cryotronics Inc APPLICATION NOTES This appendix includes the following Lake Shore documentation 1 Fundamentals For Usage Of Cryogenic Temperature Controllers Application Note Page 1 2 Standard Curve 10 Technical Page 8 3 DT 470 Series Temperature Sensors Installation and Operation Application Note Page 10 4 Measurement System Induced Errors In Diode Thermometry Article Reprint Page 14 FUNDAMENTALS FOR USAGE OF CRYOGENIC TEMPERATURE CONTROLLERS by Dr John M Swartz Lake Shore Cryotronics Lawrence G Rubin MIT National Magnet Laboratory 575 McCorkle Blvd Westerville OH 43082 170 Albany St Cambridge 02139 I INTRODUCTION Cryogenic temperature controllers have been available for years but users often have an incomplete understanding of their operating principles and of the closed loop interactions between the controller and the controlled low temperature environment The object of
171. curve provided that this curve jis present The terminates the data point input If either the units or temperature information matches one of the data points in the curve the curve data point edited to match the XE data point If the information does not match any of the data points for the curve the unit inserts the point in its proper position in the table 4 16 6 The XKN N gt Command The command XKNQ4N5 erases all the data associated with curve number and repacks the remaining curves stored within the NOVRAM Standard Curves 00 thru 05 are stored a Prom and not erasable by this command 4 16 7 The and XBC41C5 N4N5 XAC4C2 N4N2 The XA an XB commands allows Table 3 4 which defines the correlation between the Remote Position and Sensor Curves for the REMOTE SENSOR ID Note that this correlation exists for both inputs and normally only one input would select the REMOTE SENSOR ID position data Once this data has been changed it would be good practice to read out the changed table by means of the XDT 4 37 Section IV Model DRC 93C command and update Table 3 4 1 gt is the hex Remote Position 00 thru 1 and NN is the decimal curve number OO thru 31 Table 4 19 Conversion of Raw Units Data for the XC Command 9210 20 3 Voltage Input range is 0 00000 to 6 55350 volts 9210 20 6 No conversion is necessary 9215 Capacitance No conversion to temperature is allowed 9317C R
172. d For the 9317C the moni tor voltage should be approxi mately a factor of ten lower The same three IC s are involved If the monitor voltage is incor rect the input card may control at an offset or not at all If the sensor voltage matches the monitor voltage and the display voltage is incorrect then the A D needs to be calibrated 5 7 2 Units Display is correct but temperature reading is incorrect If the units display matches the voltage or resistance value of the sensor but the temperature display is incorrect then check the curve selected This can be accomplished by holding down the CURVE4 button or by reading the selected curve over the interface using the W1 command COPYRIGHT 3 88 Section V If the correct curve is selected but the display in temperature is still incorrect then check the data in the curve This can be done over the IEEE by using the test program and the XDNj4No command 5 7 3 The Heater Circuit If the DRC 93C does not have output power check to see that 1 13 on Figure 93C 1C the IM317HVK is tightly screwed into its heat sink It is on standoffs near the fan in the left rear of the unit Configure the DRC 93C as in Section 5 5 6 2 Verify that there is heater current going to the load resistor Next measure the analog out signal to be sure the PID circuits are operating correctly The analog out signal can be measured at TP28 Gnd at TP1 If this is posi tive value
173. d are The cable s mechanical electrical specifications included with the cable 7 2 2 4 8271 22 Sensor Heater Output Cable 8271 22 Sensor Heater Output Cable consists of two discrete cables first is a six pair individually shielded cable with two five pin miniature hexagonal plugs which mate with the SENSOR A and SENSOR B connectors on the back panel of the DRC 93C Temperature Controller In addition to the sensor connectors it has a dual banana plug for heater output and a single banana plug for heater output shield The second cable is three pair overall shielded cable for the Monitors Outputs The cable s mechanical and electrical specifications are included with the cable COPYRIGHT 12 87 LSCI Model DRC 93C 7 2 3 Cartridge Heaters 7 2 3 1 50 Ohm Cartridge Heater This cartridge heater is 1 4 in diameter by 1 in length and is rated at 50 watts 7 2 3 2 25 Ohm Cartridge Heater This cartridge heater is 3 8 in diameter by 1 in length and is rated at 25 watts 7 3 Installation of Input Cards from a DRC 81C or DRC 82C Input cards from the DRC 81C or Section VII DRC 82C can be used in the DRC 93C The DRC 93C will recognize these cards if the dip switch settings are set correctly This Dip Switch is located in the rear right hand corner of the main board below the AC input connector WARNING To prevent shock hazard turn off the instrument and discon nect it from t
174. d in parallel All the active circuitry of the bus is contained within the individual devices with the cable connecting all the devices in parallel to allow the transfer of data between all devices on the bus The following discussion of the signal lines on the bus are for general information Your digital computer handles these lines through its circuitry and software The user need never concern himself with these lines or signals however knowledge of their purpose will help one to understand the operation of the Interface There are 16 signal lines contained on the bus 1 8 Data Lines 2 3 Transfer Control Lines 3 5 General Interface Management Lines The data lines consist of 8 signal lines that carry data in a bit parallel byte serial format These lines carry universal commands addresses program data measurement data and status to all the devices on the bus The three Transfer Control lines and the five Interface Management lines are asserted low which means that they carry out their function when pulled low When the voltage on one of these lines is high then the line is not asserted and the function is inhibited The General Interface Management Lines IFC Interface Clear ATN Attention Section IV REN Remote Enable EOI End or Identify and the SRQ Service request manage the bus and control the orderly flow of commands on the bus The IFC ATN and REN manage ment lines are issued only by t
175. d up from 10 to 20 and held at 20 for the 100K soak See Figure 6 4 Steps 07 08 and 09 and 10 will be dedicated to this example Step 09 lt 1 hr lt Step 08 N 30 minutes Step 10 N 4 40K 20 minutes N lt Step 7 Dwell 10 minutes Figure 6 3 Example 3 Setpoint Step 09 4 1 hr Figure 6 4 Example 3 Gain Step 07 and 08 are identical to Steps 04 and 05 of Example 2 and are repeated here Section VI STEP 07 Step Command JUMP VECTOR 07 1 08 Days Hours 00 00 Minutes Seconds 10 00 Setpoint 40 0 Gain 10 Rate 0 Reset 10 STEP 08 Step Command JUMP VECTOR 08 5 09 Days Hours 00 00 Minutes Seconds 00 03 Setpoint 100 0 Gain 20 Rate 0 Reset 5 The soak is covered by Step 09 is the same as Step 06 of Example 2 except that the JUMP VECTOR is to Step 10 STEP 09 Step Command JUMP VECTOR 09 1 10 Days Hours 00 01 Minutes Seconds 00 00 Setpoint 100 0 Gain 20 Rate 0 Reset 5 After the soak the next Program Step will be Step 10 which is to ramp down STEP 10 Step Command JUMP VECTOR 10 5 07 Days Hours 00 00 Minutes Seconds 00 01 Setpoint 40 0 Gain 10 Rate 0 Reset 10 The JUMP VECTOR of Step 10 is to Step 07 In this way the entire sequence is repeated until the 6 8 Model 93 operator presses the CLEAR key to terminate the program mode The command for Step
176. date If field installation is required use the following procedure 1 Configure the red jumper on the 8225 printed circuit board for SAMPLE Display Sensor or CONTROL Control Sensor COPYRIGHT 12 87 ISCI Table 8225 1 Model 8225 Analog Output Specifications Output Range 0 000 to 10 000 V Output Resolution 1 out of 10V Output Resistance Less than 100 Output Equivalence Temperature for all Input Cards Output 0 000 to 9 999 V for display of O to 999 9 K Sensitivity 10 mV K Voltage for 9210 and 9220 Output 0 0000 to 6 554 V for display 0 0000 6 5535 V Sensitivity 1 V V Resistance 9220 P2 P3 and 1 P2 Output 0 000 to 3 000 V for display 0 00 300 00 Q Sensitivity 10 mV ohm P3 Output 0 000 to 3 000 V for display 0 0 3000 0 Q Sensitivity 1 mV ohm R1 Output 0 000 to 10 000 V for display 0 000 99 999 Q Sensitivity 100 mV ohm Note a The resistance of the 9317C and 9318C Input Cards is not output by the 8225 because of the number of orders of magnitude the display can cover The analog output of temperature displayed by these Input Cards is available if a Precision Option is present for the sensor 8225 1 Model 8225 Analog Output To prevent shock hazard turn off the instrument and disconnect it from AC line power and all test equipment before removing cover 2 Set the power switch to OFF and disconnect the power cord from t
177. ded in the DRC 93C allows several response curves to be stored in the instru ment Depending on the complexity of the curves up to 25 can be programmed into the unit The active curve is selected either from the front panel or over the remote interface The data for calibrated sensors can be stored in the instrument as an 8001 Precision Option or by the customer via the front panel or remote interfaces These curves can contain up to 99 sensor temperature data points With the standard precision option format of 31 data points and an 18 character information line up to twenty curves can be stored Although data points are stored as a table the interpolation algorithm used results the equivalent of a high order Chebychev polynomial calculation in the converting of the input voltage or resistance to tempera ture This is done by means of a proprietary algorithm developed at Lake Shore Cryotronics An averaging algorithm can be selected to average up to ten temperature readings This mode eliminates noise within the system analogous to averaging with a digital voltmeter This averaging mode can be disabled from the front panel or over the remote interface for a given input if the customer prefers not to average readings COPYRIGHT 3 88 LSCI Model DRC 93C The control set point is also displayed on the front panel and can be set from the front panel The set point automatically takes on the units selected for th
178. dition of the capacitor there are probably ac noise currents present The second method simply involves measuring the ac voltage signal across the diode Although an oscilloscope is often the logical choice for looking at ac signals many do not have the sensitivity required and they often introduce unwanted grounds into the system and compound the problem Most testing can be performed with the same digital voltmeter used to measure the dc voltage by simply selecting the ac voltage function There should be no ac voltage across the diode If there is the data presented in the following sections can be used to estimate the potential error in the temperature measurement EXPERIMENTAL In order to quantify the effects of induced currents on silicon diode temperature sensors the circuit of Fig 3 was used to superimpose an ac current on the dc operating current The dc current source was 10 battery powered with currents selectable from 1 pA to gt 1 mA The signal generator could be varied in both amplitude and frequency All I voltage measurements were made with a Hewlett Packard 3456A ae HE voltmeter in either the dc voltage mode or the ac rms voltage mode The dc measurements were taken with an integration time of 10 DVM 1 power line cycles without using the filtering options available on the voltmeter The average of several readings was taken to reduce the measurement uncertainty An oscilloscope was also used to double
179. e and reset will remain constant during the ramp as specified in Step 01 The soak is covered by Step 02 as follows STEP 02 Step Command JUMP VECTOR 02 1 03 Days Hours 00 01 Minutes Seconds 00 OO Setpoint 100 0 Gain 10 Rate 0 Reset 5 If it is desired to shut down the controller after the one hour soak step 3 will be as follows STEP 03 Step Command 03 9 00 Days Hours 00 00 Minutes Seconds 00 00 Note that the Setpoint gain rate reset etc are part of command 9 and will be installed as the parameters when normal operation resumes Setting the setpoint to 0 will remove power to the system as will setting the Gain to 0 or setting the Heater Power to 0 6 8 2 Example 2 Ramp and Soak The ramp and soak of Figure 6 1 will be accomplished in this example with command 5 ramping It will be necessary to fix the setpoint at 40K prior to the ramp Here it will be set to dwell for 10 minutes The entire process is shown in Figure 6 2 Steps 4 5 and 6 are used Step 06 lt dwell 1 hour gt 4 Step 05 Ramp for 30 minutes lt Step 4 Dwell 10 minutes Example 2 Figure 6 2 Step 04 will look as follows Step 04 Step Command JUMPVECTOR 04 1 05 Days Hours 00 00 Minutes Seconds 10 00 Setpoint 40 0 Gain 10 Rate 0 Reset 10 COPYRIGHT 12 87 LSCI Model DRC 93C Step 05 will look as follows STEP 05 Step Command JUMP VECTOR 05 5
180. e control sensor In the units mode the set point can be set to five digits with the range of defined by the control sensor input card The standard set point temperature can be set to 0 1 degree This temperature is converted to equivalent voltage with a resolu tion of 100 microvolts out of 3 volts full scale The optional High Resolution Set point expands the set point resolution to 0 01 degrees 100 and 0 001 degrees below 100 The equivalent voltage is expanded to 25 microvolts out of 3 volts full scale This results in a settability of approximately 0 01 kelvin above 40K and 0 001 kelvin below 28K for the DT 470 series sensors The control section of the DRC 93C provides three term temperature control Proportional GAIN integral RESET and derivative RATE are individually set with a range from 0 1 to 99 resulting in a 990 to 1 range Heater power output of the DRC 93C Temperature Controller is a maximum of 50 watts when a 50 ohm heater is used A digital bar graph on the front panel displays the output as a percentage of output range selected Thus the user can con veniently monitor power applied to his system To accommodate systems which require lower heater power the maximum output be at tenuated in four steps of a decade each Three resistance ranges are available 0 25 25 35 and 35 50 ohms The desired range is selected by a slide switch on the rear panel The power must be off for this
181. e SENSOR key 2 While holding the SENSOR key press the SCAN 11 key You may now release the SENSOR key 3 To change the sign if in the upper Display press the 44 key while still holding down the SCAN ti key Similarly to change the sign if in the lower Display press the vv key while still holding down the SCAN t key 4 Release the 44 key or vv key and then the SCAN 1 key You should press the SENSOR key to verify that the sign is as desired 9305 7 4 Selection of Reference Junction Compensation via the Computer Interface To select or prevent Reference Junction Compensation via the IEEE interface use the ACC and BC4C2 commands described in the DRC 91C Section 4 8 5 or DRC 93C Section 4 8 9 Instruction Manual The Reference Junction Compensation bit may be listed as Switch 3 or the Thermal Correction bit used on the 9318C card Turning on 1 that position turns on the compensation Offset 9305 7 5 Panel Adjustment Rear When new or different thermocouple is attached to the instrument it is desireable to permit the addition of an offset to compensate for discrepancies in the thermocouple material leads and connections An Offset Adjustment trimpot is provided next to the Terminal Block on the Back Panel to allow quick calibration of the thermocouple without removal of the instrument cover COPYRIGHT 6 88 LSCI 9305 Thermocouple Input Card The procedure is as follows 1 Place
182. e clip onto the lid of the SD package Note that a slot is cut underneath the clip to accept the SD package Refer to the drawing for details If the device is to be used only below 325 K apply a layer of Apiezon N Grease between the SD package and mounting surface to enhance thermal contact 12 5 3 mm F 32mm 1E 12 2 mm Pee mmo _ SD Sensor Beryllium 7 6 mm Oxide Heat Sink Chip 2 95 mm diameter 1 4 mm for 4 40 machine 48 Cathode Anode 4 40 shoulder screw extends 6 9 mm above clamp SD Sensor Cathod Cathode Anode ee Application Notes Lake Shore Cryotronics Inc Current Source FIGURE 1 Four Wire Configuration for DT 470 Installation Sensor SENSOR OPERATION Temperature controllers and thermometer instrumentation manufactured by Lake Shore Cryotronics are designed to be directly compatible with the DT 470 sensor to give optimum performance and accuracy together with direct temperature readouts Simply follow the instructions provided with the instrument concerning sensor connection and instrument operation If a user supplied current source voltmeter or other instrumentation are going to used with the DT 470 sensor special attention should be given to the following details The DT 470 is designed to operate at a constant current of 10 microamperes while the voltage variation with temperature is monitored Therefore the accuracy of
183. e installed in the DRC 91C 93C as either Input A or Input B The card is factory installed if ordered with a DRC 91C 93C Temperature Controller or can be field installed at a later date If field installation is required use the following procedure 1 Set the POWER switch to OFF and disconnect the power cord from the unit Remove the three top panel screws and slide the panel off Note on the calibration cover the position of the Card will occupy WARNING To prevent shock hazard turn off the instrument and discon nect it from AC line power and all test equipment before re moving cover 2 Remove the four screws that secure the calibration cover to its clips and remove the cover Remove the two back panel 9215 3 9215 Capacitance Input Card mounting clips that secure the J11 blank cover plate to the interface opening and remove the plate Note some early DRC 91Cs do not have the J11 opening Use the J9 8229 Scanner option opening If an 8229 is present move the 8229 to the 210 RS 232 slot 3 an Input Card must be removed disconnect the wiring harness mating connector by lifting the locking tab on the Input Card connector and gently pulling on the body of the wiring harness mating tor 4 Plug the new Input Card into the A Input Card Slot 5 or the B Input Card Slot 6 with the component side to the left of the unit as viewed from the front Connect the wiring harness
184. e order of a few tenths of millikelvin minute at 4 2K several millikelvin minute at 77K and one millikelvin minute at 305K For temperatures less than 290K the short term drift is such that the equivalent tempera ture will decrease with time and for temperatures above 290K will increase with time 9215 3 2 Thermal Cycling and Reproducibility Thermal cycling of capacitance sensors can produce variations in capacitance temperature values equivalent to several tenths of a degree over the short term days Thermal cycling over the long term weeks can result in variations that exceed a degree These variations are always such that the equivalent temperature increases with time and with increased cycling The reduced capacitance C T C 4 2K for T 290K is stable to within 0 5K on the average Also these variations do not create instabilities and do not impair the sensors primary function as a control device in magnetic fields They also are not seen within a temperature cycle COPYRIGHT 2 88 LSCI 9215 Capacitance Input Card 9215 3 3 Magnetic Field Dependency _ Magnetic field sensitivity is less than 0 15 at 4 2K and less that 0 05 between 77K and 305K for fields up to 18 7 Tesla 9215 3 4 Frequency Dependence For frequencies between 1 and 5 kilohertz the frequency sensitivity is as follows 0 18K kilohertz at 4 2K 1K kilohertz at 77K 0 06K kilohertz at 305K 9215 4 INSTALLATION The 9215 can b
185. eater ranges Model DRC 93C COPYRIGHT 3 88 LSCI Table 5 1 Input Card Characteristics Sensor Sensor Temp Range Sensor Display Input Type and Current with Std Units Range Curves K Si 1 4 to 475K DRC D 00 Diodes 0 2 9999V DRC E1 01 CRV 10 02 CRV 10 04 9210 6 9220 6 8219 R1 9220 1 0 3 to 100K no std crv see note 1 10 10001 see note 3 1 4 to 325K 0 5 fr 1 to 10 0000 1k 100k 1 4 to 100K 0 05 fr 1000 100 000 see note 1 10 10kQ 0 01 see note 3 0 25 fr 10k 100k Note 1 The lower temperature limit is dependent upon resistance temperature characteristic of sensor used Note 2 0 1 to 1 0mA Sensor voltage pinned at 1mV 9317C or 10mV 9318C Note 3 To read correctly in temperature these input cards must be used with calibrated sensors and the 8001 precision option Note 4 9317C and 9318C will read to 1 ohm full scale with reduced accuracy 5 8 COPYRIGHT 12 87 LSCI 101 275 101 225 101 238 101 034 102 008 102 003 102 001 102 058 102 053 106 310 106 412 106 146 106 139 106 143 106 129 106 321 105 302 105 304 102 072 113 063 103 209 103 495 103 540 103 586 103 583 103 675 105 014 105 408 106 229 106 227 102 011 102 021 102 014 102 024 102 012 102 022 102 036 104 712 104 710 104 711 104 529 104 310 104 419 104 061 104 408 104 076 104 088 104 162 104 355 104 356 104 453 104 210 104 010 104 022 102 104 104 068 102 095 106 571 Vie IN
186. ecommended for other sensor types The Lake Cryotronics Inc QUAD LEADIM 36 Gauge Cryogenic wire is ideal for connections to the sensor since the four leads are run together and color coded The wire is Phosphor Bronze with a Formvar insulation and Butryral bonding between the four leads Color cod ing is red green clear and blue on the four leads which makes it extremely easy to determine one wire from another 2 3 7 J3 Sensor Output MONITORS Buffered voltage outputs for both Sensor Input A and B are available on the J3 connector on the back panel of the instrument The volt age from the Model 8225 Analog Output Option is present on this connector also connector pin assignments are given in Table 2 3 COPYRIGHT 3 88 LSCI Section II Table 2 3 J3 MONITORS Connections A Output Input Voltage Output Input B 10 mV K Analog Output Ground for Analog Output Setpoint Output Ground A B Setpoint Optional Shield m j j GO Z gt gt 2 3 9 Heater Power The heater output leads should be electrically isolated from the sen sor s ground s to preclude the possibility of any of the heater current affecting the sensor input signal The heater leads should not run coincident with the sensor leads due to the possibility of capacitive pick up between the two sets of leads If they are in close proximity they should be wound so as to cross the sensor leads
187. ecord Record terminators are used when Table 4 5 Request WS Sample Sensor Data WC Control Sensor Data WO Sample amp Control Sensors Setpoint Data WM MAX MIN and MAXDEV Data COPYRIGHT 3 88 LSCI 4 9 Section IV Model DRC 93C Table 4 6 DRC 93C Interface Setup Commands and Request Status Command Functional Description Selects IEEE EOI status Forms of the command are ZO and Z1 When is EOI Status is 0 EOI line is set accepted on last character input or output EOI line is not set on last character output or acknowledged on input Selects Remote Interface mode Forms of the command are MO M1 and M2 When is Mode is Local Remote Remote with Local Lockout Changes terminating characters when IEEE Address Switch 1 is CLOSED 1 Forms of the command are TO T1 T2 and T3 When is Terminators are P ENDC LF also with Switch OPEN LF END CR default unless changed END LF END DABQ Clear command returns unit to power up state Restart kkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkk Functional Description Interface Status ZN1 MN2 TN3 8 Characters plus up to 2 Terminators where is EOI status is Mode status is Terminator status Input and Option Card Data 1 2 5 6 10 11 12 3 14 1 15 16 17 18 2 19 20 21 22 3 23 24 25 26 40 Characters plus up to 2 Ter
188. ection 9305 7 2 On the DRC 93C disable Reference Junction Compensation by using the SENSOR SCAN 1 and or Y keys Display should show 9305 when the SENSOR key is pressed See Section 9305 7 3 Connect the DVM plus and minus leads to the TP24 CNT V and GND 2s found on the calibration card of the controller Apply a zero signal to the V and V Thermocouple Input terminals by shorting across the Terminal Block with a short jumper wire Allow the Terminal Block temperature to settle for five minutes Adjust the Rear Panel Offset Adjustment the Terminal Block until the output on the DVM is 0 0000 volt Be sure to remove the jumper wire after this step Apply a 10 millivolt signal to the V and V Thermocouple Input terminals on the Terminal Block and allow the temperature to settle The DVM should read about 2 volts Adjust the input card trimpot labeled CNT V Control 9305 9 9305 Thermocouple Input Card Voltage Span until the output on the DVM is 2 000 volts 0 0001 volt 9305 9 3 Thermocouple and Secondary Sensor A D Calibration The Thermocouple and Secondary Sensor A D converters have an auto zero function which means that the only calibration required is for the relative gain span The procedure is as follows 1 Make sure the instrument is setup as described in parts 1 2a or 2b and 3 in the previous section Control Amplifier Calibration 2 Apply a
189. ection for the DRC 93C When a 9317C or 9318C Resistance Input Card is installed pressing the SENSOR key will display either 9317C or 9318C for the appro priate channel The plus means the control thermal correction is enabled The minus means the control thermal correction is disabled Enable disable the control thermal correction from the front panel by using a combination of the SENSOR SCAN 1 44 and vv keys as follows 1 Press and hold the SENSOR key 2 While holding the SENSOR key press the SCAN 1 key The SENSOR key may be released 3 To change the sign change the enabled disabled status of the upper display press the 44 key Similarly to change the sign of the lower display press the vv key 4 Release the or vv key then the SCAN 1 key 5 Press the SENSOR key to verify that the proper sign is selected 9317 9318 4 Model DRC 91C 93C 9317 9318 5 3 Sample Input When the input occupied by the 9317C 9318C is selected the Sample Input Sample only not Control the 9317C 9318C deter mines the sample resistance by forcing the voltage across the sensor to 1 05 9317C or 10 5 9318C millivolts as quickly as possible with the microprocessor controlled current source Once the forward current range and value results in the desired voltage the current is reversed and the thermal value determined As long as the voltage across the sensor do
190. ed As with all multiline commands these commands are trans mitted with line asserted low There are two Universal commands recognized by the DRC 93C Local Lockout and Device Clear LLO Local LOckout LIO is sent to instruments to lock out prevent the use of their front panel controls DCL Device CLear DCL is used to return the DRC 93C to the power up conditions 4 5 3 The Addressed Commands The Addressed Commands shown in Table 4 3 are multiline commands that must include the DRC 93C listen address before it will respond to the command in question Note that only the addressed device will respond to these commands The DRC 93C recognizes three of the Addressed commands SDC Selective Device Clear Go To Local and SPE Serial Poll Enable 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 responding to the SDC command GTL Go To Local The GTL command is used to remove instruments from the remote mode With some instru ments GTL also unlocks front panel controls if they were previously locked out with the LLO command SPE Serial Poll Enable SPD Serial Poll Disable Serial polling is used to obtain the SRQ Status Register The Status Register contains important operational information from the unit reques
191. emove anything that may be shorting the two halves of the terminal block 3 Verify that thermal correction is properly selected 4 Slide the top cover onto the instrument and replace the three screws 9305 10 OPTION COMPATIBILITY The special nature of thermocouple sensors and their connections limits compatibility with Lake Shore options accessories Thermocouples must be attached directly to a terminal block The 8229 Scanner Input Option and 8085 External Sensor Scanner are not adapted with terminal blocks so they can not be used with the 9305 Thermocouple Card The 8225 Linerized Analog Output Option will function in temperature units only COPYRIGHT 6 88 LSCI Model DRC 91C 93C with a 9305 installed giving an output of 10mV K The 8000 series Precision Calibration Options are not available from Lake Shore for thermocouple sensors 9305 11 REPLACEABIE PARTS Included in this section is Figure 9305 1 showing the Model 9305 Thermocouple Input Card Schematic Replaceable Parts List and illustrated Component Layout Also included is Figure 9305 2 showing the 9305 Terminal Block Schematic Replaceable Parts List and Component Layout COPYRIGHT 6 88 LSCI 9305 Thermocouple Input Card 9305 11 9305 Thermocouple Input Card Model DRC 91C 93C Table 9305 4 9305 Thermocouple Curves 15 0000 15 0000 4 6676 5 2982 4 6067 5 2815 4 5259 5 2594 4 4571 5 2285 4 3703 5 1742 4 2869 5 0315 3 9928 4 91
192. en any of the other scanner commands are sent to the scanner 4 10 5 The WY Data String This request includes whether the instrument is scanning or holding the channel dwell information and the scan position 4 11 THE SERVICE REQUEST STATUS REGISTER STATUS REPORTS AND THE STATUS REGISTER MASK As mentioned earlier a Service Request can be initiated by the DRC 93C to indicate a function has been performed or a limit overload or error has been encountered The DRC 93C does this by pulling its SRQ Service Request management 4 18 line low The BUS CONTROLLER uses the serial poll SPOLL to obtain the contents of the register in the DRC 93C called the Status Register The DRC 93C Status Register is a single byte of data from the DRC 93C containing five bits called the Status Reports These Status Reports indicate when certain processes are complete whether the channel was changed or a limit overload or error encountered The Status Register Mask is provided so that the Status Request interrupt and undesired Status Reports can be inhibited Reading the Status Register resets the Status Register to all zeros so that only new status reports will be registered by the DRC 93C Thus through the SRQ management line and the Status Register the DRC 93C is able to signal Status Reports on five conditions immedia tely to the BUS CONTROLLER It is possible to disable the DRC 93C SRQ line thereby preventing the
193. en in the previously executed Program Step to the value Specified in is Program Step After ramping the specified amount oper or noms at the Program Step indicated by the Step _ 8 JUMP VECTOR Jump to the Program Ste specified by JUMP VECTOR The previous parameters are used and ose in the Program Step are ignored Step 9 00 Exit the Internal program resuming normal operation with the front panel Kalnes given in this command COPYRIGHT 12 87 LSCI Model DRC 93C 6 4 SUMMARY OF COMMANDS The Program Commands are summarized in Table 6 2 When the temperature has been stabilized at the Setpoint the Dwell command is essentially a Soak command 6 5 INTERNAL PROGRAM ENTRY This section discusses the procedure for entering an internal program A short description of the sequence is as follows Additional information is described in the Sections listed in parenthesis 1 Press the PROGram key The PROGram indicator will flash on and off Section 6 5 1 2 Press the INTernal key The PROGram indicator will stop flashing and turn on as will the INTernal indicator Section 6 5 1 3 The Program Step is selected using the POINT key Section 6 5 2 4 The command and JUMP VECTOR REPEAT COUNT are entered Section 6 5 3 5 The setpoint gain rate reset heater range manual heater power units etc are selected Section 6 5 4 and 6 5 5 6 The Timer value is selected Section 6 5 6 7
194. equest The Status Register can still be read by the BUS CONTROLLER to examine the Status Reports but the BUS CONTROLLER will not be inter rupted by the Service Request Five of the other seven bits select which of the five Status Reports to make If one of these five bits is set on the DRC 93C will update the corresponding Status Report bit in the Status Register Then if the SRQ bit bit 6 of the Status Register Mask is set the DRC 93C will send out a Service Request on the SRQ IEEE 488 line By means of a serial poll enable SPE the BUS CONTROLLER determines that the DRC 93C has sent out a service request and then reads the Status Register Reading the Status Register resets the Status Register to all zeros Executing the Q command also resets the Status Register to all zeros The Status Register Mask command is COPYRIGHT 3 88 LSCI Model DRC 93C the ASCII letter Q followed by two alphanumerics representing the most significant four bits and the least significant four bits respectively Note that the controller can be programmed for more than one set of conditions simultaneously To enable the Service Request Bit 6 must be al 4 11 3 1 Status Register Mask Bits 0 and 1 Sample and Control Data Ready Enables If either Bit 0 or Bit 1 of the Status Register Mask is set 1 then for that data the corresponding bit in the Status Register is set when a valid data reading is available 4 11 3 2 Status Register
195. er Output Voltage in Volts P 50 V 15 8 Temperature Error K 0 32 1 0 0 1 FIGURE 5 Effect of output power setting on offset for a proportional controller only power settings 0 1 K for a 50 watt setting 0 32 for a 5 watt setting and 1 0 for the 0 5 watt setting As expected the temperature offsets become smaller as the loop gain increases However there are limits to this approach as we move from the idealized example to a real system The Real World Unfortunately the thermal conductivity within a system is not infinite and both it and the heat capacity may vary by several orders of magnitude between 1 K and 300 K Also the controller the sensor the sensor leads and the block may all have electrical noise This noise is amplified by the controller for a high enough amplifier gain setting the output of the controller will become unstable and oscillate In addition the placement of the sensor with respect to the heater and the sensor construction and mounting itself introduce thermal lags This is due to the finite thermal conductivity of the block and the thermal resistances between the heater sensor and the block These thermal lags introduce a phase shift between the controller output and the sensor which will reduce even further the gain at which the system will be stable Therefore the thermal block design is extremely important in the proper performance of any cryogenic system No controll
196. er can make up for poor thermal design of the system nor can good design overcome the inherent limiting properties of the materials and sensor packages which are currently available Application Notes Lake Shore Cryotronics Inc Since the thermal conductivity of cryogenic materials is finite good practice dictates that the controller power output be the same order of magnitude as the cooling power If for example the cooling power is 0 2 watt and 50 watts is available a change in set point to a higher temperature outside the proportional band of the controller will dump 50 watts into the system block Due to the thermal lag of the block etc a large temperature overshoot may occur with the system stabilizing only after several oscillations This thermal lag can easily be observed since the sensor temperature will continue to rise long after the output from the controller has been reduced to zero The obvious way to reduce this effect is to limit the heater power to the system to for example 0 5 watts This can readily be done with a controller such as the DRC 82C which has multiple maximum output power settings The overshoot will therefore be smaller when the set point is changed and the system will stabilize much faster although the rate of temperature rise will be less Because changing the power output setting affects the loop gain dP dT it may be necessary to readjust the deviation amplifier gain controller gain setting for optimum co
197. er is shipped from the factory with the Bar Graph indica ting power If the user prefers he can change this to a current reading by turning on switch 1 of the eight station dip switch located at the rear center of the main board 3 11 2 The HEATER POWER RANGE The heater power range setting is determined by the keys directly below the HEATER POWER Bar Graph MAX corresponds to a 100 or 1 mult iplier while 1 2 3 and 4 corresponds to a 1071 1072 1073 and 1074 multiplier respectively The OFF key turns off the output power independent of the setpoint and the control parameters NOTE The DRC 93C is equipped with a current limit vernier on the rear panel which can limit the output current on the MAX scale between 0 33 and 1 ampere dependent setting If the instrument will not deliver full power this vernier may be set wrong or the load resistance may be too large and the unit is compliance voltage limited NOTE If a SETPOINT GAIN RATE RESET MANUAL HEATER POWER or HEATER POWER RANGE is entered too quickly the unit may not update the meter properly The instrument Display and Main Boards verify entered parameters each update cycle Changing a parameter more than once in an update cycle may result in inconsistant parameters being entered 3 17 Section III Model DRC 93C Figure 3 2 DRC 93C Temperature Controller Rear Panel OG Q L so j L een
198. er of magnitude higher sensitivity 3 The heat input for furnaces is almost always derived from a line frequency source and is controlled by relays variable transformers saturable reactors or SCRs Experiments performed in a cryostat usually involve low level signals and hence require a low noise background For that reason ripple free direct current usually controlled by a series transistor bank should be used to power the heater 4 traverses the cryogenic regime from the liquid helium range up towards room temperature there can be quite large variations in both the thermal time constants and thermometer sensitivities 5 Inthe case of the furnace in which the load does not experience large endo or exothermic reactions the heat input required to maintain a set point temperature is approximately constant This is because the heat loss through a fixed thermal conductance to the room temperature environment outside the furnace is also constant However there are cryogenic systems where the low temperature environment provided by e g a surrounding cryogen such as a liquid helium or liquid nitrogen bath may vary drastically as the level of the cryogen changes In addition the thermal conductance to the outside world is highly dependent on the gas pressure vacuum maintained in the cryostat The resulting variations in cooling power will cause the heat input requirements to be anything but constant A few cryogenic systems empl
199. eration Note The unit should be allowed a one hour warm up time to achieve rated specifications 5 5 3 Current Source Check The DVM across the test resistor should read as follows 9210 20 3 1 0000V 100uV 9210 20 6 1 0000V 100uV 9220 P2 0 10000V 10uV 9220 P3 0 10000V 104V 9220 R1 0 03000V 10uV 9317C N A 9318C N A 5 5 4 Monitor Voltage The voltage across the sensor or test resistor is also available on the monitor plug The connections are given in Section II of this manual The monitor voltage will be equal to the sensor voltage for 3 volt 3 diode inputs and all platinum P2 P3 and rhodium iron R1 inputs If the input is a GaAlAs Diode 6 input then the monitor voltage will be 0 458 times the sensor voltage This test is not applicable for the 9215 9305 9317C or 9318C input cards COPYRIGHT 3 88 LSCI Model DRC 93C 5 5 5 Temperature Display 5 5 5 1 Determine Type The first step to check the instru ment s display and operation is to determine the type of sensor input a The type of input option card s installed in the DRC 93C is located on the front page of every DRC 93C manual b The DRC 93C displays the type of input card s installed in the A and B inputs sequentially when the instrument is powered on Possibilities are 9210 3 9210 6 9215 30 9215 150 9220 3 9220 6 9220 P2 9220 P3 9220 R1 9305 9317C or 9318C C The type of input can also be displayed
200. erentiator circuit which provides a signal proportional to the rate of temperature change and 450 which is subtracted from the proportional output signal This reduces the effective overall amplifier gain driving the output power stage The reduced gain effectively increases the proportional band of the controller This slows down the rate of temperature rise and therefore allows more time for the block to stabilize Consequently the overshoot is substantially reduced or eliminated depending on the magnitude of the thermal problem as is indicated in Figure 6 100 Without Rate k The addition of rate is necessary only because of inherent thermal problems which cannot be substantially eliminated by improvements in thermal design Also note that rate is effective only during the Time has a destabilizing influence lt should therefore be normal practice to FIGURE 6 The effect of adding Rate to the contro i circuit to dynamically widen the proportional band and turn off the rate control when near the control point reduce the overshoot which would occur in its absence 150secs The differentiator circuit should precede the reset integrator in the circuit so that the deviation and derivative signals acting on the integrator input will be just sufficient to create the proper reset value by the time the temperature reaches set point In some cases it is important for the rate circuit to precede the deviation amplifier as well i
201. es can be stored as power up settings When enabled any time the parameter is changed either in the LOCAL or REMOTE mode the NOVRAM is updated The internal DIP switch setting COPYRIGHT 3 88 Section III switch 2 controls whether or not the settings are updated The up dating is enabled switch 2 on at the factory prior to shipment 3 7 3 Blue Legend Keys At the beginning of an operation if one of the grey keys of the keypad with Blue Legends also labelled 0 9 and is pressed the function described by the blue legend is im mediately displayed or carried out These functions are SENSOR UNITS CURVES RSLTN FILTER CONTROL DEV MATH MAX MIN MAXDEV The CURVE RSLIN FILTER DEV MATH MAX MIN and MAXDEV keys must be held down in order to observe the quantity continuously For ex ample if the RSLIN resolution key is pressed the display will mediately show the resolution as signed to the Upper and Lower Dis plays When the key is let up operation will return to normal operation with the displays showing temperature voltage etc The CONTROL SENSOR UNITS CURVE RSLIN FILTER DEV and MATH keys provide operations that can be changed by the user The 44 up and vv down keys are used in con junction with these Blue Legend keys to alter the quantity with the 44 key referring to the Upper Display and the vv key referring to the Lower Displays In order to change one of these qua
202. es not change more than 0 5 of reading from one reading to the next the forward and reverse readings are taken each time the input card is asked for an update approximately once a second and a new thermal value is determined If the voltage changes more than 0 5 of reading the card stops reversing the current and uses the thermal value previously determined until the sensor signal stabilizes Operation as the 9317C 9318C 5 4 Control Input Operation as the When the input occupied by the 9317C 9318C is selected as the Control Input Control only or Sample and Control the operation of the card changes Since the card has to provide a signal across the sensor that will control the heater power as well as measure resistance or temperature it can no longer force the sensor signal to 1 05 or 10 5 millivolts immediately When a set point is entered by the user the DRC 91C 93C calculates its equivalent control sensor resistance From this resistance and the calibration constants current and voltage for the 9317C 9318C input card the set COPYRIGHT 12 87 LSCI Model DRC 91C 93C point voltage which will result in a sensor voltage as close to 1 05 or 10 5 millivolts as possible when the control point is reached is calculated If the thermal correction is active and there has been a valid thermal value deter mined it is included the calculation If no valid thermal has been determined or the thermal cor
203. esistance Input range is 1 to 104 for the 9317C 1 to 9318C 10 Q for the 9318C Input must be in Log R where 1 2 would look like 0 00000 and 10 2 would look like 5 00000 9220 P2 Resistance Input range is 0 00 to 299 99 ohms 0 00 ohms looks like 0 00000 and 299 99 ohms looks like 2 99990 0 01 times R 9220 P3 Resistance Input range is 0 0 to 2999 9 ohms 0 0 ohms looks like 0 00000 and 2999 9 ohms looks like 2 99990 0 001 times R 9220 R1 Resistance Input range is 0 00 to 100 00 ohms 0 00 ohms looks like 0 00000 and 100 00 ohms looks like 3 00000 0 03 times R 4 38 COPYRIGHT 3 88 LSCI SECTION MAINTENANCE 5 1 INTRODUCTION This section contains information necessary to maintain the Model DRC 93C General maintenance fuse replacement line voltage selection and performance testing is tained in this section 5 2 GENERAL MAINTENANCE Clean the DRC 93C periodically to remove dust grease and other con taminants Use the following pro cedure 1 Clean the front and back panels and case with a soft cloth damp ened with a mild detergent and water solution Note DO NOT use aromatic hydrocarbons or chlorinated sol vents to clean the DRC 93C They may react with the plastic mater ials used in the unit or the silk screen printing on the back panel 2 Clean the surface of the printed circuit boards PCB using clean dry air at low pressure If grease is encountered spray with Freon
204. f 3 5 inches Use the following procedure to install the RM 3F Kit 1 Remove the two blue rack mount access covers if present from the front side corners of the unit to be rack mounted This is easily done by sliding the cover up as far as possible and using a blade screwdriver on the bottom edge to remove it from its position 2 If the H handles option was added mount the handles onto the rack ears 3 Attach the rack ears on opposite sides of the unit 7 2 2 Cables 7 2 2 1 8072 IEEE 488 Interface Cable The 8072 IEEE 488 Interface cable is one meter long and is equipped with double ended connectors so it may interconnected in serial or star patterns common IEEE 488 instrument configurations 7 2 Model DRC 93C 7 2 2 2 8271 04 Scanner Sensor Cable The 8271 04 Scanner Sensor cable for the 8229 Scanner Card is 3 meters long and brings out leads for the four additional input sensors provided by the 8229 Option The cable s mechanical and electrical specifications are included with the cable 7 2 2 3 8271 21 Sensor Heater Cable The 8271 21 Sensor Heater Cable is a six pair individually shielded cable with two five pin miniature hexagonal plugs which mate with the SENSOR A and SENSOR B connectors on the back panel of the DRC 93C Temperature Controller In addition to the sensor connectors it has a dual banana plug for heater output and a single banana plug for heater output shield an
205. f the deviation amplifier and the output power supply Since the controller s power output state tracks the deviation amplifier output it is evident that the power output is proportional to the magnitude of the error signal In process control nomenclature this response is described in terms of proportional control Let us examine the behavior of the sensor signal set point deviation circuit in a modern cryogenic controller the Lake Shore Cryotronics Model DRC 82C In figure 2 the amplifier output deviation gain times error is plotted against the error signal for two amplifier gains A 100 and A 1000 Gain in this closed loop system refers not to the power gain as in an audio amplifier but is related to the maximum amount of error signal allowed before the controller is directed to produce full output power The DRC 82C requires a 0 to 8 volt signal from the deviation amplifier to drive the power output stage from zero to maximum In Figure 2 For Av 1000 there is a narrow band of error signals 0 to 8 mV within which the proportional action occurs This proportional band expands tenfold for A 100 and so on for lower gains obviously gain and proportional band are inversely related Proportional band is expressed as a percentage of full scale range Note that the proportional band in mV can be converted to temperature in kelvins if the sensitivity of the sensor in mV K is known As an example suppose the sensor
206. for the 9210 6 configuration The digitized value is converted to a serial data string and transferred to the main microprocessor using optical isolation The sensor voltage is also buffered and transferred to the rear panel MONITORS connector for external monitoring as well as for control selection For the 9210 3 configuration it is multiplied by 1 for the 9210 6 configuration it is multiplied by 0 457771 3 0000 6 5535 9210 6 CALIBRATION The 9210 was calibrated to specification in the configuration specified prior to shipment If recalibration is needed refer to the following procedure The following equipment is used to calibrate the 9210 Diode Input Card 1 Digital Voltmeter Multimeter DVM 4 digit resolution or better COPYRIGHT 12 87 LSCI Model DRC 91C 93C 2 Precision Standard Resistor 100 kilohms with a tolerance of 0 01 or better 3 Precision Voltage Source capable of supplying a voltage with an accuracy and resolution of 100 microvolts out of 10 volts or better The unit should be allowed a one hour warm up time to achieve rated specifications Use the following procedure to calibrate the 9210 Diode Input Card 1 Remove the three top panel screws and slide the panel cover off 2 Set 104A Current Connect the precision resistor across the A I and B I pins of the five pin input connector for the input the 9210 occupies Connect the DVM plus lead to the I pin and
207. g Display Rate setting Display Reset setting Heater Range Power Space a Line Set for WS Ask for string WS Display Sensor Reading Space a Line Set for WC Ask for string WC Display Control Sensor Reading Space a Line Set for WP Ask for set point data Display string WP Space a Line Set for WY Ask for Scan Information Display Scan Information Space a Line Set for WI Ask Input Cards and Options Display string WI CONTROLLER tells the DRC 93C that when it is asked to output data that data should be the output of the standard Sensor Curves stored Precision Option Curves stored and the format associated with the REMOTE SENSOR ID Remote Position to Sensor Curve assignments as given in Table 4 17 This output is defined as the Sensor Curve Infor mation Table SCIT As can be seen from the output shown on this page the instrument is shipped with all remote positions calling up Standard Curve 02 COPYRIGHT 3 88 LSCI Model DRC 93C The information lines for Sensor Curves 05 through 31 will only be present if these curves are actually present either as user generated curves or as Precision Option curves The Information Table is output as one very long character string The following program is for the HP86B and is an example of the XDT output SCIT for a unit with only Standard Curves 00 thru 05 present 10 REM Program to Output SCIT 20 DIM FILETABLE 321 30 OUTPUT 712 XDT Ask for 40 ENTER 712 FILETABLE In
208. g and turn on The Upper and Lower Displays will blank and the Setpoint Display will contain 00 00 with the second zero from the left flashing The Upper Display UNITS will show K for kelvin and the Lower Display UNITS V for volts NOTE At any time if it is desired to exit from the Curve Programming routine hit the PROG key Operation will return to normal The CLEAR key is used to clear a number par tially entered but not desired IF A KEY IS NOT HIT FOR A PERIOD OF 20 SECONDS THE INSTRUMENT WILL ABORT THE CURVE PROGRAMMING ROUTINE AND RETURN TO NORMAL OPERATION The flashing quantity in the Set point Display is the Curve to be examined The other quantity is used to hold the number of points in the Curve Data of the selected Curve Using the keypad 0 9 type in the Curve to be examined followed by the ENTER key The CLEAR key may be used if there is an error in typing the curve Also the keypad can be used until the correct Curve is displayed For example if 30 shows in the display and the 2 key is hit the 3 of the 30 will disappear and the 2 show up in the units digit to give 02 Hitting the ENTER key will cause the instrument to accept the entry and to search for Curve 02 Since Curve 02 is present it is a Standard Curve see Table 3 2 the instrument will find the curve and then show 3 13 Section III 0 0 02 31 6 5536 in the displays The 02 in the Set point Display is the Curve and the
209. g as it has not received another output data statement 4 14 1 The WS WC and WP Data Strings These three commands are subsets of the WO command the WS command giving the Sample Sensor reading the WC command the control sensor reading while the WP command results in the set point value 4 14 2 The WO Data String The following example in HP Basic illustrate the commands associated with obtaining output data from the DRC 93C The addition of the MO command returns the instrument to front panel control where it stays even when data is requested from the 93C by the HP computer 10 DIM 5 19 20 OUTPUT 712 WOMO 30 ENTER 712 A The following information is sent across the bus in the 488 format as a result of the above software commands Request sent U W OM O Data returned 5 L 123 45 123 42 123 40 CR LF Data returned 93C s Talk Address BUS CONTROLLER s Listen Add Universal Unlisten Command CR LF The data above indicates that the COPYRIGHT 3 88 LSCI Model DRC 93C Section IV display temperature is 123 45K and that the set point is 123 40K Table 4 15 DRC 93C Output Data Statements Request Output of Instrument Data Sample Sensor Data N4N5N4 N4N5 8 Characters plus up to 2 Terminators where the N4 Ng variations are the same as for WO see below Control Sensor Data NgN4Ng NgN4390 8 Characters plus up to 2 terminators where the Ng N49
210. ge 7 volts minimum Maximum Sensor Power Dissipation 20 microwatts 8 4 2K for DT 470 Series 25 microwatts 4 2K for DT 500 Series Dissipation under other conditions is a product of Sensor Excitation Current and developed sensor voltage 9210 3 Input Voltage Range 0 to 3 V Resolution 0 05 millivolts Accuracy 0 1 millivolts Display Resolution 5 digits Displays 0 0000 to 2 9999 volts Equivalent temperature accuracy is a function of sensor type sensitivity and curve specifica tion or Precision Option 9210 6 Input Voltage Range 0 6 5535V Resolution 0 1 millivolts Accuracy 0 2 millivolts Display Resolution 5 digits displays 0 0000 to 6 5535 volts equivalent temperature accuracy is a function of sensor type and sensitivity Precision Option required for TG 120 Sensors 9210 1 9210 Diode Input Card 9210 4 INSTALLATION The 9210 can be installed in the 91C 93C as either Input A or Input B or both with two options The 9210 is factory installed if ordered with DRC 91C 93C Temperature Controller or can be field installed at a later date If field installation is required use the following procedure 1 Set the POWER switch to OFF and disconnect the power cord from the unit Remove the three top panel screws and slide the panel off Note on the calibration cover the position of the Input Card the 9210 will occupy WARNING To prevent shock hazard turn off the instrument and disconnect it
211. he BUS CONTROLLER The IFC Interface Clear management line is pulled low by the BUS CONTROLLER to clear the interface The ATN Attention line is the management line used by the BUS CONTROLLER to get the attention of the devices on the bus The BUS CONTROLLER does this by pulling the ATN line low and sending talk or listen addresses on the DATA lines When the ATN line is low all devices listen to the DATA lines When the ATN line goes high then the devices addressed to send or receive data for example the DRC 93C perform their functions while all others ignore the DATA lines The REN Remote Enable management line is pulled low by the BUS CONTROLLER to enable a device the DRC 93C to perform the functions of TALKER or LISTENER The EOI End or Identify management line is pulled low by the BUS CONTROLLER or a TALKER the DRC 93C to indicate the end of a multiple byte transfer sequence Also the EOI line along with the ATN line are pulled low by the BUS CONTROLLER to execute a polling sequence The SRQ Service Request management line is pulled low by a device for example the DRC 93C to signal the BUS CONTROLLER that a process is completed a limit overload or error encountered In some cases this means that service is required Transfer of the information on the data lines is accomplished through the use of the three signal lines DAV Data Valid NRFD Not Ready for Data and NDAC Not Data Ac 4
212. he AC line power before changing the Input Card switch settings OLD INPUT CARD DIP SWITCH DEFINITIONS BIT O 1 2 3 4 5 6 7 cd SSES gt lt gt lt PS ano 996 6 Ox 0 0 X NEW CARD NEW CARD NON 8210 8211 OR 8219 8210 8211 OR 8219 ALSO COMBINATIONS OF A AND B BIT 7 1 ON OFF 8211 8219 P2 8219 P3 8219 1 DON T CARE SWITCHES 4 AND 8 ARE RESERVED COPYRIGHT 12 87 LSCI Us amsami mn ROGERS BUSS STRIP H1 1 36 5 D GND A s tA d i 1j cone et Cane DATA IN 1 29 DVD 245 yis 1 22 lt 1 18 OUT Ree 159K 18 R21 B gt 4 75 t lt 1 26 TYPE 5 Q ICM7555 A C14 SgPF x 8 7 6 5 4 3 Figure 9210 1 Model 9210 Diode Input LSCI Part Number 101 054 101 025 106 142 102 072 105 649 102 074 104 005 102 043 104 001 104 355 104 356 104 099 104 461 104 460 104 051 1 0 100 CAP PP 33MF 100V CONNECTOR IC TO BP 6 POST LOCKING HEADER TRANSISTOR PNP SIGNAL SWITCH 2 POS 4 POLE INTERLOCKING MOSFET P CHANNEL IC OP AMP VOLTAGE REFERENCE 6 95V OP AMP OPTOCOUPLER OPTOCOUPLER
213. he unit Remove the three top panel screws and slide the panel off Note on the calibration cover the position of Option Slot 1 or 2 which the 8225 will occupy 3 Remove the four screws that secure the calibration cover to its clips and remove the cover 4 Plug the 8225 printed circuit board into Option Slot 1 or 2 with the component side to the left of the unit as viewed from the front Thread the two black and white wires from the 8225 along the inside edge of the rear panel and solder the white wire to MONITOR connector J3 Pin C and black wire to Pin D 5 Install the calibration cover by reversing procedure in 3 6 Install the top panel 8225 5 OPERATION The output resolution equivalence is given in Table 8225 1 For a temperature display of 100 00 K the 8225 would output 1 000 V output is rounded to the equivalent unit for the 1 mV output A display of 23 42 K would result in an output of 0 234 V and a display of 23 47 K would result in an output of 0 235 V 8225 6 CALIBRATION The Model 8225 has been calibrated to specification prior to shipment 8225 2 Model DRC 91C 93C If re calibration is needed use to the following procedure The following equipment is used to calibrate the 8225 Analog Output 1 Digital Voltmeter Multimeter DVM 4 digit resolution or better 2 Precision Standard Resistor to simulate the input sensor or a Precision Voltage Source with an output resolution
214. igure 1 The exact point at which the connecting leads are soldered to the device leads results in negligible temperature measurement uncertainties In a two wire measurement configuration the voltage connections point A in Figure 1 are made near or at the current source so only two leads are actually connected to the device Some loss in accuracy can be expected since the voltage measured at the voltmeter is the sum of the diode voltage and the voltage drop across the connecting leads The exact temperature uncertainty will depend on the temperature range and lead resistance For a 10 ohm lead resistance the diode voltage will be offset by 0 1 mV which gives a negligible temperature error at liquid helium temperature but a 50mK error near liquid nitrogen temperature Note the DI and CY adapter can be used only in a two wire configuration An excessive heat flow through the connecting leads to any temperature sensor can create a situation where the active sensing element for the DT 470 this is the diode chip is at a different temperature than the sample to which the sensor is mounted This is then reflected as a real temperature offset between what is measured and the true sample temperature Such temperature errors can be eliminated by proper selection and installation of the connecting leads In order to minimize any heat flow through the leads the leads should be of small diameter and low thermal conductivity Phosphor bronze or manganin wire is c
215. in Reset and Rate Check the operation of the Gain Rate and Reset as follows 1 Place dummy load into the selected sensor input a 50K to 100K for a diode b Short vt to V for 9317C or 9318C Input Card c 10nF capacitor for 9215 Input Card 2 Place a 10 ohm 10 watt or greater resistance load on the heater terminals 3 Set the Display Units to Sensor Units i e volts ohms or nanofarads a If 9210 3 20 3 enter a volt age 0 01 volts less than the display b If 9317C or 9318C enter a resistance of 1 ohm for the set point c If 9215 enter 11 set point 5 4 Model DRC 93C 5 5 7 1 Gain Enter a gain value The heater display should now indi cate that power is being delivered to the heater The amount of power is a scaled factor of the error signal times the gain Sensor voltage Setpoint voltage Gain If the setpoint temperature is increased or the gain is in creased the output power will in crease Keep the LO lead of the DVM at TP1 and move the HI lead to TP29 Turn off the GAIN RATE and RESET by entering a value of 0 0 for each The DVM will now read approximately 0 0 volts Change the GAIN to 1 0 and the DVM will read approximately 0 1 volts which is the error Of 0 01 times the gain of 10 Change the GAIN to 10 and the DVM will read approximately 1 volt Setting the GAIN to 99 will result in a reading of approximately 7 2 volts 5 5 7 2 Reset Set up the con troller as i
216. installation operation and maintenance information 9317C 9318C 2 DESCRIPTION The Model 9317C 9318C Resistance Input Card is designed to be installed in DRC 91C 93C to convert either Input A or Input B or both with two cards to accommodate sensors where the voltage level must be kept at levels on the order of 1 or 10 millivolts and where a thermal voltage may exist The 9317C 9318C can be used with germanium carbon giass or carbon resistors or any other negative temperature coeffi cient resistors Both cards read in ohms from a full scale reading of 10 ohms with 1 milliohm resolu tion to a full scale reading of 10 000 ohms with 0 1 ohm resolution for the 9317C and 100 000 ohms with 1 ohm resolution for the 9318C To read temperature accurately a calibrated sensor and 8000 Series Precision Option re quired Refer to Section 9317C 9318C 5 for detailed description of the operation of the 9317C 9318C 9317C 9318C 3 SPECIFICATIONS Specifications for the Model 9317C 9318C Resistance Input Card are given in Table 9317C 9318C 1 of this Section COPYRIGHT 12 87 LSCI 9317C 9318C 4 INSTALLATION The 9317C 9318C can be installed in a DRC 91C or a DRC 93C as either Input A or Input B or both with two cards The 9317C 9318C is installed prior to shipment if ordered with either controller If only one 9317C 9318C is ordered and its input is not specified when ordered it is installed in Input A
217. ion III sensor plus instrument versus sen sor sensitivity 3 8 7 1 Temperature Display Resolu tion Set To examine the resolution of the Upper and Lower Display hold in the RSLIN key displays will read one of the following If it is desired to change the res olution then while holding down the RSLIN key hit the key to cycle the resolution in the Upper Display through those shown until the desi red resolution is obtained When the keys are released the new res olution is entered in the DRC 93C Similarly holding in the RSLTN key and hitting the vv key will change the resolution in the Lower Display Changing the display resolution fixes the resolution transmitted over the computer interface as well but does not change the resolution of the system Display resolution can also be different for each input card i e A and B Also note that the chosen resolution will only be displayed when appropriate TABLE 3 1 Sensor Maximum Temperature Sensitivity Resolution in kelvin Voltage Mode 9210 9220 mv K 31 61 0 1 0 5 1 1 0 0 05 0 1 10 0 0 005 0 01 100 0 0 0005 0 001 Note 1 Resistance Mode 1 R Kt Model 93 In other words only five digits can be displayed In the temperature mode the chosen input is displayed in the selected scale K C or F with a maximum display capability of 0 01 degrees above 100 kelvin to 0 001 degrees between 1 and 100 kel
218. ions If an ErrOx or an OL or Err2x error occurs for an input selected as the control input the heater range is taken to OFF and must be reset following correction of the fault condition The following is a summary of the error codes COPYRIGHT 5 88 Possible Cause Corrective Action The unit encountered an unwriteable NOVRAM data location When this error occurs the unit displays the error stores it in the WS data location and halts operation The NOVRAM initialization sequence should be performed to try to correct the problem If the error code still exists the NOVRAM needs to be replaced The unit performs a NOVRAM check on power up If the unit detects a NOVRAM data error or if the interface XR amp I function was performed the unit displays the error stores it in the WS data location and waits for the NOVRAM initialization sequence to be performed Repeated ErrO2 conditions could signal a failure by the NOVRAM to retain data and it should be replaced The REMOTE SENSOR ID for the unit allows for an input range of 00 00000 on bits B4 thru BO of the ID to 1F 11111 on bits B4 thru BO The 1F input is reversed for a REMOTE SENSOR ID error condition the Position Data Adaptor uses this code to indicate that more than one Sensor Scanner is active to the unit When the error stores it in the WS data location and continues to monitor the REMOTE SENSOR ID until the fault is corrected 8223 RS 232C Interface Parity Error
219. ister The bit will not revert to zero if the control sensor difference from the set point later exceeds the limit selected The control channel limit is entered using the Q command See Section 4 11 3 2 This function can be inhibited by turning off bit 2 in the Status Register mask 4 11 2 3 Status Report 3 Display Sensor Channel Change Bit 3 of the 4 19 Section IV Status Register is set when a channel change occurs for the Display If the Service Request is enabled this bit being set will cause the DRC 93C to pull the SRQ management low to signal the BUS CONTROLLER This Status Register bit is reset to zero upon reading the Status Register This function can be inhibited by turning off the bit 3 in the Status Register Mask 4 11 2 4 Status Report 5 Overload Error Indicator If the display has an overload condition on any selected channel or an error occurs then bit 5 of the Status Register is set and a Service Request is issued if enabled This Status Register bit is reset to zero upon reading the Status Register This function can be inhibited by turning bit 5 off in the Status Register Mask 4 11 2 5 When operating without the Service Request it is still possible for the BUS CONTROLLER to read the Status Register The Service Request is inhibited by turning off the SRQ bit bit 6 in the Status Register Mask However it must be understood that certain bits in the Status Register are continually
220. it has completed determining the voltage input calibration constants and has stored them in the 9317C 9318C calibration EEPROM COPYRIGHT 12 87 LSCI Model DRC 91C 93C 5 Simulate the sensor display Current Range 1 Value 6 Configure the 10K 9317C or 100K 9318C resistor to Enable CAL 4 and monitor the unit s The display should indicate the number 106 for approximately 30 seconds and then display 0 indicating the end of the calibration Disable CAL 4 and continue Current Range 1 Value 60 and Current Range 2 Value 6 Substitute a 1K 9317C or 10K 9318C resistor for the previous resistor and re enable CAL 4 The display will display the number 160 for approximately 30 seconds then the number 206 for another 30 seconds and when complete a 0 will be displayed Disable CAL 4 and continue Current Range 2 Value 60 and Current Range 3 Value 6 Substitute a 100 ohm 9317C or 1K 9318 0 resistor for the previous resistor and enable CAL 3 The display will indicate 260 for approximately 30 seconds then 306 for another 30 seconds and finally a 0 Disable CAL 3 and continue Current Range 3 Value 60 and Current Range 4 Value 6 Substitute a 10 ohm 9317C or 100 ohm 9318C resistor for the previous resistor and enable CAL 2 The display will indicate 360 then 406 with each time period being ap When disable CAL 2 proximately 30 seconds the 0 appears and continue Current
221. ive the output stage This latter method has a name manual reset and serves as an introduction to the next section on reset control IV PROPORTIONAL GAIN PLUS INTEGRAL RESET TEMPERATURE CONTROL The manual reset adjustment described above varies markedly with the temperature set point and with the often changing heater power demands of the system Thus it is normally neither convenient nor desirable to have to resort to such a means of eliminating temperature droop offset Instead suppose a circuit could be added to the loop that would 1 sense that there is a steady state offset signal within the proportional band 2 make a bit by bit addition to the power output proportional to the magnitude of the offset and 3 continue the corrective action until the offset is reset to zero The practical realization of this circuit is an integrator inserted between the deviation amplifier and the power stage The origin of the interchangeable terms integral control and automatic reset is evident How does a proportional plus integral controller behave in a cryogenic system First in the idealized case let us again assume an infinite thermal conductivity which results in zero thermal resistance between the sensor and the heater The reset integrator continues to integrate until the error signal reaches zero which stops the integral action but keeps its output at the level corresponding to that needed by the power stage to overcome the dro
222. ize of the capacitor needed will depend on the frequency of the noise generally related to the power line frequency of 60 Hz and the dynamic impedance of the diode on the order of a few thousand ohms at 10 pA operating current A capacitor in the range of 10 to 20 uF should reduce most noise effects to an acceptable level However because the capacitor increases the time constant in the circuit a sluggish response should be expected In switching operations 30 seconds or more may be required for the circuit to stabilize This quick fix is not meant as a substitute for proper measurement techniques but in certain circumstances it may be useful Note added in proof The capacitance values given above are for the elimination of the effects of low frequency noise such as 60 Hz If high frequency noise is a problem an additional capacitor of lower capacitance value may be needed The reason for this is because larger capacitors often have an associated inductance which limits their usefulness as a high frequency shunt S Grove Physics and Technology of Semiconductor Devices Wiley New York 1967 Chap 6 S M Sze Physics of Semiconductor Devices Wiley Interscience New York 1969 Chap 4 3 D A Fraser The Physics of Semiconductor Devices Clarendon Oxford 1983 R V Aldridge Solid State Electron 17 617 1974 5 V Chopra and G Dharmadurai Cryogenics 20 659 1980 6 D A Kleinman Bell Syst Tech J 35 685 1
223. ke Shore Cryotronics Inc DT 470 ET DT 470 MT 3mm x0 5 SD 6 32 sensor Threaded Stud sensor Metric thread Cathode a Cathode Anode p y T B 5 5 mm 5 5mm across across 6 flats 6mm 6mm flats 6mm E mm DT 470 ET DT 470 MT Both adapters are gold plated copper hex head bolts with the SD package mounted in a slot on the adapter head The ET adapter screws into a 74 inch deep 6 32 threaded hole while the MT adapter screws into a 6 mm deep 3x0 5 mm threaded hole Before assembly the threads should be lightly greased with Apiezon N Grease Do not over tighten since the threads are copper and can be easily sheared Finger tight should be sufficient DT 470 BO The BO adapter should be mounted in the same manner as the CU The BO adapter contains its own thermal anchor and is an epoxy free assembly DT 470 CO The CO adapter is a spring loaded clamp to attach the DT 470 SD package to a flat surface It maintains pressure on the SD package as the temperature varies First remove the hold down cap which holds the three piece CO assembly together The CO assembly should appear as shown in the accompanying drawings Bolt the assembly into a 4 40 threaded hole The stop on the brass screw should rest against the mounting surface and it also prevents over compressing the spring Lift the edge of the clip using a small pliers or screw driver Slide the SD package into place underneath the clip and gently lower th
224. kkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkk Functional Description Request the Program Step N N for Saving N1N2C1 C60 62 Characters plus up to 2 terminators where N4N5 is the Program Step Number 1 are the sixty characters of Program Step 4 12 3 Examples of Saving and Restoring Executable Internal Program Steps 4 12 3 1 Program to Request and Store Program Step 1 thru 10 using the HP86B The following program for the HP86B requests and get Program Steps 01 thru 10 and stores the data a file called PROGRAM1 on afloppy with volume label 93C To initialize an unused floppy in slot 0 for this purpose the command INITIALIZE 93C D700 can be executed 10 20 REM STORE REM PROGRAM TO READ AND STORE AN INTERNAL PROGRAM 30 REM SET IEEE ADDRESS TO 12 40 ADDRESS SWITCH 1 OPEN 0 TO GET CR LF 50 DIM A 62 N1 1 N2 1 60 REM CREATE PROGRAM1 93C 99 32 ONLY USE FIRST TIME TO CREATE FILE 70 ASSIGN 1 TO PROGRAM1 93C OPEN THE FILE 80 FOR I 1 TO 10 FOR PROGRAM STEPS 01 THRU 10 90 IF I 10 THEN GOTO 140 100 I VAL I 110 120 130 140 150 160 170 180 190 200 210 220 N1 I 1 1 N2 I 2 2 GOTO 160 N1S 0 N2 VALS 1 OUTPUT 712 WE N1 N2 SEND THE WE COMMAND REQUESTING PROGRAM STEP I ENTER 712 5 GET PROGRAM STEP I DISP A DISPLAY ON THE SCREEN PRINT4 1 A SAVE PROGRAM STEP I IN THE FILE NEXT I ASSIGN
225. l or over the remote in terface Section 3 9 3 discusses curve entry via the front panel and Section IV covers entry over the 488 or RS 232C interfaces The curve is stored in a battery back up non volatile RAM NOVRAM which can be read and written an unlimited number of times The num ber of data points stored per curve can be between 2 and 97 two being the lower limit which defines a straight line Section IIT 3 4 PRECISION OPTIONS 3 4 1 The Model 8000 Precision Option There are three types of Precision Options available for the DRC 93C The Model 8000 Precision Option generates the data table from a Lake Shore calibrated sensor The upper limit of data points is again 97 with a typical calibration ranging between 30 and 40 points depending on sensor type and temperature range for the calibration The data and accuracy of the fit is supplied to the user as a separate document This information can then be entered by the user via the front panel or over the computer interface 3 4 2 The Model 8001 Precision Option Lake Shore can also generate custom sensor response curves from the in dividual sensor calibrations as indicated above and store them in the DRC 93C via the 8001 Precision Option prior to shipment The data and accuracy of the fit is then supplied to the user in an Appendix of this manual 3 4 3 The Model 8002 05 Precision Option The 8002 Precision Option is used when the customer already
226. l the control point is traversed By the time this has happened a large overshoot may have occurred This problem can be prevented by disabling the reset action when controller response goes outside the proportional band A controller such as the DRC 82C accomplishes this with an anti reset windup or reset inhibit circuit 4 Application Notes Lake Shore Cryotronics Inc The Real World Revisited Since a real cryogenic system has non zero thermal resistance the value of the reset is important in setup of the controller The amount of reset desired is dependent on 1 the time required for the control sensor to reach equilibrium once it enters the proportional band and 2 the amount of output signal required from the reset action to overcome the cooling power of the cryogenic system For example assume that 50 output is required and the time to reach equilibrium is 3 seconds 05 minutes Therefore the repeats per minute is 10 and the time constant is 0 1 minutes In actuality this is not easy to determine without a few tries Almost always however the time constant increases with increasing temperature so that if one is operating over a broad temperature range finding the appropriate time constants for the two extremes will bracket the appropriate time constants within that temperature range Once the correct time constant has been selected the system should settle to its control set point within two or three time constants If significant
227. lay will show the word CLEAr to indi cate that the registers holding the Maximum Minimum and Maximum Devia If the Math Functions were enabled On then new Math Functions will be computed Once the Math Functions have been cleared and enabled On changing the Sample or Control units will result in inconsistant values being stored in the Math Function regis 3 9 Section III ters The new Math Functions can be observed at any time by depressing and holding in the appropriate key MAX MIN or MAXDEV 3 9 SENSOR CURVE SELECTION 3 9 1 Standard and Precision Option Curves The standard curves are given in Table 3 2 The Precision Option Curves are given in Table 3 3 Table 3 2 Standard Curve Informa tion Curve Temperature Description No Range K 00 DRC D 01 DRC E1 02 CRV 10 DIN PT CRV 10 RESVRD 3 9 1 1 The Precision Option For Lake Shore stored Precision Option a proprietary algorithm is used to fit the calibration data to within a few millikelvin over the entire temperature range The Precision Option Table shown in Table 3 3 gives the standard curves as well as any Precision Options which are factory installed includ ing their address and the number of data points associated with each curve This Table should be updated for the instrument if additional curves are added at a later time Up to 25 Precision Option Curves can be stored in the DRC 93C with an average of 31
228. lculates the reference junction temperature The reference junction temperature is used in compensation to account for the difference between room temperature and the normalization temperature of the curves zero degrees Celcius COPYRIGHT 6 88 LSCI 9305 Thermocouple Input Card An Offset Adjustment is provided adjacent to the Terminal Block This adjustment will zero out small voltage offsets that result from sensor lead attachment differences from the internal curve 9305 6 1 Display Operation Digitized thermocouple secondary sensor voltages on the 9305 card are sent to the main board of the controller The secondary sensor temperature is computed from its voltage and a thermocouple voltage corresponding to the secondary sensor temperature is calculated If correction is selected the compensation value is added to the thermocouple voltage Corrected voltage in millivolts is then used as a display value or converted to Celcius degrees Fahrenheit degrees or Kelvin for display 9305 6 2 Control Operation Control operation begins when the operator enters a Setpoint voltage in millivolts If the Setpoint is in temperature the main board computes an equivalent voltage using the built in Thermocouple table The main board microprocessor then checks to see if Reference Junction Compensation is enabled If the Reference Junction Compensation is disabled a signal which is 200 times the digital value of
229. le Input Card are given in Table 9220 1 of this manual The card can be configured as a 9220 3 or 9220 6 diode card a 9220 P2 or 9220 P3 platinum card or a 9220 R1 rhodium iron input card COPYRIGHT 12 87 LSCI Table 9220 1 Input Card 9220 3 See 9210 3 specifications 9220 Configurable 9220 6 See 9210 6 specifications Sensor ordered separately Platinum RTD sensor PT 100 series or any other 100 ohm or 1000 ohm platinum sensor 27 ohm rhodium iron sensor See Lake Shore Sensor brochures Temperature Range Dependent on Sensor See Sensor brochure RTD Sensor Power Dissipation Depends on Sensor Resistance Dissipation is the product of sensor excitation current squared and the Sensor resistance 9220 P2 100 ohm platinum Current Excitation 1mA 0 005 0 00 299 990 Resolution 0 005 ohms Accuracy 0 01 ohms Display Resolution 5 digits Displays 0 00 to 299 99 ohms Resistance Range 9220 P3 1000 ohm platinum Current Excitation 0 1mA 0 005 Resistance Range 0 0 to 2999 9 Q Resolution 0 05 ohm Accuracy 0 1 ohm Display Resolution 5 digits Displays 0 0 to 2999 9 ohms 9220 R1 27 ohm platinun Current Excitation 3 mA 0 005 Resistance Range 0 000 to 99 999N Resolution 0 003 ohm Accuracy 0 003 ohm Display Resolution 5 digits Displays 0 000 to 99 999 ohms Equivalent temperature accuracy is a function of sensor type sensitivity and Precision Option 92
230. lines per curve A Precision Option Curve can have up to 97 points with two additional end points automatically put into the curve table by the DRC 93C software 3 10 Model DRC 93C 3 9 1 2 Display of Accessed Curve Number To determine which curve is being used press and hold the CURVE key The displays will show the letters CU for Curve Number followed by a curve number in each display Table 3 3 Sensor Curve Table Information Precision Option Table Curve Lines Address Description COPYRIGHT 3 88 Model DRC 93C For Example by holding down the CURVE key the Displays might look as follows SENSOR DISPLAY Upper Display A CU 02 Lower Display b CU 06 The CU 02 in the Upper Display indi cates that the Sensor using the Upper Display is calculating the temperature with the data of Curve 02 Curve 02 from Table 3 2 is the CRV 10 for the DT 470 Series Sensors The CU 06 in the Lower display indicates that the Precision Option is installed and the DRC 93C is calculating the temperature with the data stored in Curve 6 Since the DRC 93C knows which type of input card is present for each input assuming that two input cards were installed it will not for example allow the selection of the platinum curve Curve 403 for a diode input card If Curve 03 is selected the DRC 93C will default to the lowest curve number with the correct temperature coefficient in this case curve 00 For the case of a pl
231. ll the top cover panel 8229 5 OPERATION Operation of the 8229 Scanner Conversion can implemented either locally from the front panel or remotely through the remote interfaces 8229 5 1 Local 8229 Operation The 8229 Al through A4 channels are accessed locally using the SENSOR A key The Display Sensor is incremented each time the SENSOR A key is pressed in the sequence A Al A2 A3 A4 A etc 8229 5 1 1 Channel Dwell Times The dwell times for the Al through A4 channels are selected the same as for A and B See Sections 3 8 3 and 3 8 4 for a complete description of this operation 8229 5 1 2 Units The units for the A1 through A4 channels are the same as for Input A and are defined by the A Input Card Selection of units is covered in Section 3 8 5 8229 5 1 3 Resolution Resolution is by input card and not channel Consequently resolution is the same for all scanner COPYRIGHT 12 87 LSCI 8229 Scanner Conversion Option channels See Section 3 8 6 fora discussion of how to set resolution 8229 5 2 Remote 8229 Operation The remote operation of the 8229 Scanner is covered in Section 4 REMOTE OPERATION See Table 4 7 and Section 4 11 entitled THE OPTIONAL SCANNER CARD 8229 5 3 Curve Selection The 8229 is considered an internal Remote Position The AO through A4 channels are interpreted as Remote Position A00 through A04 for curve selection when the SENSOR ID Switch 4 is OPEN 0 The curve
232. lled common shared IBSTA IBERR IBCNT print Input number for the type of instrument 820 93C 82C or 93C print 0 820 print 2 82c print 1 93c print 3 93C input I if IS 0 then 20 default address for 820 if IS 1 then TEMPS dev12 default address for 93C etc if I 2 then TEMP dev12 if I 3 then TEMPS dev12 set up when running IBCONF call IBFIND TEMPS Required command to address instrument A space 750 1 input B Entered from keyboard while running BS B chr 13 chr 10 Add CR and LF to command call IBWRT TEMP BS Send command to instrument call IBRD TEMP AS ENTER from instrument SEE NOTE BELOW print 5 Display received information on screen AS space 750 Clear 5 goto 1 end Lake Shore Cryotronics instruments will return the data requested but if the command input to the instrument does not request any information the instrument will respond with the information last requested 4 15 4 HP86B Bus Commands Program The following program is for the HP86B and exercises the various bus commands 10 20 REM Set IEEE Address to 12 REM Address Switch 1 OPEN 0 to get CR LF DIM A 42 For longest string OUTPUT 712 WO Note WO ENTER 712 A Ask for string WO DISP WO 5 Display string WO DISP Display Sensor A 1 8 Display Sensor reading DISP Control Sensor A 10 17 Display Control Sensor Reading DISP Set
233. lows the character The parity bit is determined by the COPYRIGHT 12 87 5 number of 1 bits in the character Refer to Table 8223 1 for parity determination Table 8223 1 Parity Determination Number of 1 s Parity Parity in ee COAT ACECE Specified Bit 0 odd 1 Odd Even 1 Even 0 The Model 8223 RS 232C Interface has a 25 pin D style connector located on the rear panel Pin Assignments are shown in Table 8223 2 Table 8223 2 Connector Pin Assignments for RS 232C Greuna Ground Transmitted Data Received Data Request to Send Clear to Send Data Set Ready Signal Ground Revd Ln Sgnl Dtctr Data Terminal Rdy 2 3 4 5 6 7 8 0 The RS 232C signals are used in the following manner Protective Ground AA conductor is taken to case ground potential and is common with the signal ground AB Transmitted Data BA transmits data using the EIA voltage levels 12V and 5V Received Data BB accepts data using EIA voltage levels 8223 1 Model 8223 RS 232C Interface Figure 8223 2 Model DRC 91C 93C Word Structure 4Stop Bit s Ede Pel Start Bitt Character 7 Bits Request to Send CA indicates to the host computer or terminal that the DRC 91C 93C Interface is ready to transmit data The Interface transmits data on line BA when the ON state is maintained on CC CB and CF while a low level on these
234. mating connector to the card making sure that the wiring harness locking tab is seated over the extended edge of the wiring harness mating connector Verify that the wiring harness is in place correctly by noting that the A or B on the harness mating connector is facing up if it is not review the harness installation again Thread the wiring harness along the rear edge of the unit and Slip it into the harness strain relief on the rear panel Thread the 9215 internal cable along the inside edge of the rear panel so that it won t interfere with the installation of the calibration cover or top cover NOTE Be sure that the card is centered in the slot The harness will have a tendency to push the card forward and may in some instances cause the card and instrument to not behave properly 9215 4 DRC 91C 93C 5 Position the 9215 connector plate in the appropriate opening and secure it in place using the screws provided 6 Install the calibration cover by reversing procedure 2 7 Select either the 9215 15 or 9215 150 configuration by pressing the appropriate pushbutton switch 8 Install the top panel 9215 5 SENSOR CONNECTIONS The 9215 connector plate supplies two independent dual isolated BNC connectors for the sensor connec tions A four lead measurement is used to minimize the effect of series resistance on the capaci tance measurement Since the capacitance sensor is non polariz ed one pair should
235. me outs must be allowed when performing these functions If a hardware problem is detected in modifying one of the NOVRAM locations an Err0l1 error will be displayed and instrument operation is halted Err02 error is displayed if the unit detects a NOVRAM hardware problem 4 34 COPYRIGHT 3 88 LSCI Model DRC 93C Section IV Table 4 17 Sensor Curve Information Table Output Format N N gt N3N 4 BYTES FREE H1H2H3HA IS NEXT LOCATION 00 31 1D40 DRC D 01 31 1DFO DRC E1 02 31 1EAO CRV 10 03 31 1F50 DIN PT 04 31 2000 CRV 10 05 31 20B0 RESVRD 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 TERMI 21 A minimum of 321 Characters when only the 6 Standard Curves are present and a maximum of 805
236. metric threaded mounting studs visually indicated by the color black Metric threaded cable lockscrews also black must be used to secure an IEEE 488 interface cable to the instrument Model 8072 IEEE 488 Interconnect Cables meter long are available from Lake Shore COPYRIGHT 3 88 LSCI Model DRC 93C 2 6 Options 2 6 1 8223 RS 232C Interface Provides remote operation of the same parameters as the IEEE 488 RS 232C interface option is described in Section VII of this manual including connections 2 6 2 8225 Analog Output Provides analog output proportional to kel vin temperature f display sensor 10mV K at 10 ohms output resis tance The 8225 Analog Output is described in Section VII of this manual 2 6 3 8229 Scanner Input Option Adds four additional channels to the A input Scans up to six sensors with programmable dwell times The 8229 Scanner Option is described in Section III and Section VII of this manual 2 6 4 The High Resolution Set Point expands the set point resolution to 0 01 kelvin above 100K and 0 001 kelvin below 100K The equivalent voltage is expanded to 25 micro volts out of 3 volts full scale This results is setability of approximately 0 01 kelvin above 40K and 0 001 kelvin below 28K for the DT 470 series sensors 2 6 5 8001 Precision Option Cus tom programming of specific Sensor calibration curve s at factory Provides highest degree of readout accuracy
237. minators where 1 7 is the A Input is the Input Card C15 C18 is the Option 1 Present 19 22 is the Option 2 Present C237C26 is the Option 3 Present a Nj corresponds to a numeric value 0 9 b The AND symbol is used to indicate messages sent concurrently c END EOI d DAB last data byte e corresponds to alphanumeric 0 F 4 10 COPYRIGHT 3 88 LSCI Model DRC 93C 4 7 5 The W2 Data String For the case of W2 the data string would have the following format 20 2 1 1 TERM2 where the 20 M2 1 defined in Table 4 6 4 7 6 The WI Data String This Data String gives the input cards present 9210 9220 9215 9317C or 9318C in Input A and B and if the analog option interface option or scanner is present A typical data string would be 9220 2 9318 1 8225 2 8223 3 8229 which indicates 9220 card configured as a 100 ohm platinum input for Input A a germanium carbon glass input for Input B a linear analog option in Option Slot 1 RS 232C option in Option Slot 2 and a Scanner Card option in Option Slot 3 4 8 SELECTION OF QUANTITIES FOR THE CONTROL AND SAMPLE DISPLAYS UNITS SENSORS RESOLUTIONS AND DEVIATION TABLE 4 7 4 8 1 Units for Control Display and Setpoint The FOC Command The FOC command set the temperature or sensor units for the control display and for the setpoint Sensor units volt
238. mine the variation of this offset as a function of the ac current amplitude However the ac rms voltage across the diode was chosen instead for two reasons the first of which is purely practical In many circumstances the ac voltage measurement can be made without any modifications to existing measurement systems so laboratory checks can be quickly taken and compared directly to the data presented here to give an estimate of potential temperature errors Second in the calculations using the model presented below one unknown parameter could be eliminated from the calculations by using the voltage across the diode instead of the current Figures 4 and 5 give the offset voltage as a function of the ac rms voltage across the diode for dc currents of 1 10 and 100 pA with the ac current modulation at 60 Hz The equivalent temperature error corresponding to the dc offset voltage is indicated along the right edge of the figure Figures 6 and 7 give similar plots but at a fixed 10 pA dc current with the current modulation at 60 1000 and 20 000 Hz The magnitude of the dc offset voltages is consistent with what has been observed in measurement systems when corrective action has been taken to eliminate noise problems Special note should be taken of the dc current independence in Fig 4 and the frequency independence in Figs 6 and 7 The data taken at 305 K have not been shown as the results are qualitatively very similar to the 77 K measurements and c
239. n configuration for the IEEE 488 connector Even though the Input A contacts are not on the J9 connector the sensor signal from Input A is routed through the 8229 Scanner COPYRIGHT 12 87 LSCI Table 8229 1 J9 8229 Scanner Conversion Option Connections V Channel V Channel V Channel V Channel V Channel V Channel V Channel V Channel Shield Shield Shield Shield 24 Digital Grnd In essence the 8229 routs the sensor signals from all five Input A channels to the Input Card The Al through A4 8229 inputs are designed for four lead measurements and have independent pairs of current and voltage leads The current leads have a make before break switching action and the voltage leads are break before make The BO through B2 outputs J9 are BCD representation of the channel selected with BO being the least Significant bit and B2 the most significant bit a 0 represents logic LO and a 1 logic HI with respect to the Digital Ground on 29 Logic 000 represents channel 0 001 channel 1 010 channel 2 011 channel A3 and 100 represents channel A4 on B2 Bl and BO respectively 8229 3 SPECIFICATIONS Specifications for the Model 8229 Scanner Conversion Option are given in Table 8229 2 8229 1 8229 Scanner Conversion Option Table 8229 2 Model 8229 Scanner Conversion Specifications Number of Channels 4 in addition to the existing Inputs A and B designated Al through A4 Contact C
240. n the Input and gently pulling on the body of the wiring harness mating connector Attach the Thermocouple Terminal Block into the Alternate Connector Slot J9 if the Card is Input A Alternate Connector Slot J11 if the Card is Input B with the wires facing the input card Slots are shown in Figure 3 2 Uncovering the Connector Slot may require the removal of a plastic cover plate If the JF mating connector on the main board interferes with installation of the Terminal Block remove it by lifting the locking tab and gently pulling the body of the connector Be sure to lock the JF mating COPYRIGHT 6 88 LSCI 5 6 9305 Thermocouple Input Card 9305 Thermocouple Input Card Temperature Ranges connector securely in place after this step is complete Connect the wiring harness from the Terminal Block to the bottom P3 Connector on the 9305 Card Also connect the J1 Input A or J2 Input B wiring harness mating connector to the top P2 Connector on the 9305 Card Make sure that the wiring harness locking tab is seated over the extended edge of the wiring harness mating connector Plug the 9305 into the appropriate Input Card Slot with the component side facing to the left of the unit as viewed from the front Make sure the card is thoroughly seated Verify that the wiring harness is in place correctly by noting that the A or p on the harness connector is facing up if it is not review
241. nce automatically ranges from to to to as the resistance increases value If the input resistance ex ceeds the resistance range for the card an overload condition is present and is indicated by OL on the display The display ranges and resolutions for the 9220 P2 and 8219 P2 9220 P3 and 8219 P3 and 9220 R1 8219 R1 are 0 00 to 299 99 ohms 0 0 to 2999 9 and 0 000 to 99 999 ohms respectively Again if a resistance exceeding full scale is applied to the input OL is indicated on the display 3 8 6 2 3 Capacitance Units The capacitance mode is allowed for the 9215 Input Card which can be configured in the 15 or 150 con figurations The display range is 0 000 to 30 000 or 150 00 nano farads respectively An input in excess of the configured maximum is indicated by OL on the display 3 8 7 Display Resolution The Model DRC 93C allows the user to set his display resolution over the range from 1 kelvin to 1 millikelvin 0 1 millikelvin for the 9317C input card The temperature is rounded to the least significant digit of the resolution range selected Since the temperature display resolution is dependent on both the sensor units voltage resistance or capacitance resolution of the Input Card as well as the sensor sensitiv ity temperature resolution is grea tly dependent on the sensor Refer to Table 3 1 for a representative summary of system resolution 3 7 Sect
242. nd the curve assigned is 4 Both channels are using the DT 470 Curve 10 the difference is that INPUT A is set for an upper limit of 325K and INPUT B is set with an upper limit of 475K 4 9 THE CONTROL COMMANDS 4 9 1 The Set Point Value The S Command The set point is sent from the controller to the DRC 93C in a free field format of which examples are given in Table 4 9 Note that the sign only has to be present if negative celsius or fahrenheit settings are desired Although COPYRIGHT 3 88 LSCI Model DRC 93C Section IV Table 4 7 DRC 93C Command Summary for Instrument Setup Command Functional Description Selection of Units Sensors Resolution and Deviation Function 0 Select Control Setpoint Units Forms of the command are FOK kelvin FOC celsius FOF fahrenheit and FOS for Sensor Units in volts ohms or nanofarads Function 1 Select Sample Units Forms of the command are F1K kelvin F1C celsius F1F fahrenheit and F1S for Sensor Units in volts ohms or nanofarads F2CC4N4 Function 2C Select Control Setpoint Sensor Forms of the command are F2CAQ 2 1 F2CA2 F2CA3 F2CA4 and F2CB or F2CBO With 8229 Scanner Card Only F2SC N Function 2S Select Sample Sensor Forms of the command are F2SAQ F2SA1 F2SA2 F2SA3 F2SA4 and F2SB or F2SBO With 8229 Scanner Card Only F3CN4 Function 3C Select the Control Setpoint Resolution N4 is
243. nding with epoxy Lake Shore Cryotronics Inc will not warranty replace any device damaged by a user designed clamp or damaged through solder mounting DT 470 LR 3 2 mm 12 19 mm The gold plated copper LR adapter is designed for insertion into a 1 8 inch diameter k hole A thin layer of Apiezon N Grease should be applied to the copper adapter before insertion This eases installation at room temperature and enhances the thermal contact anode 3 1 mm dia Cathode DT 470 CU DT 470 DI DT 470 CY The gold plated copper CU DI and CY 2 9 mm diameter 14 3 mm dia adapters serve as both sensor and thermal 0 76 mm off center anchor assembly These adapters mount to a flat surface with a 4 40 brass screw Avoid over tightening the screw use only enough force to firmly hold the sensor in place A brass screw is recommended as the differential thermal contraction between the 3 8 mm 8 mm 29 mm dia hole adapter and the screw causes the mounting thick diameter 5 1 mm centered assembly to tighten as opposed to loosen thick when the system cools Apply a thin layer of Apiezon N Grease to enhance thermal contact DT 470 CU DT 470 DI DT 470 CY between the adapter and mounting surface The CU adapter has four color coded leads Red Green V Clear V and Blue I The CY adapter has two color coded leads Yellow and Green The green lead on the DI adapter is the cathode Application Notes 11 La
244. nfiguration Table located on the first page of the Instruction Manual should updated to keep documentation current Use the following procedure for the installation of the 9305 Thermocouple Input Card WARNING To prevent shock hazard turn off the instrument and disconnect it from AC line power and all test equipment before removing cover 1 Set the POWER switch to OFF and disconnect the power cord from the unit Remove the three top panel screws and slide the panel off Note from the calibration cover the position of the Input Slot the 9305 will occupy 9305 1 9305 Thermocouple Input Card Model DRC 91C 93C Table 9305 1 Specifications Model 9305 Thermocouple Input Card Input Voltage Range Room Temperature Compensated 10 to 10 millivolts Uncompensated 15 to 15 millivolts ture Range Depends on Thermocouple type Refer to Table 9305 2 Thermocouples Ordered Separately Chromel vs Au 0 03 at Fe Chromel vs Au 0 07 at Fe Chromel vs Constantan E Chromel vs Alumel K and Copper vs Constantan T Thermocouple EMF Tables Curve tables are stored in the controller and accessed through normal curve selection The curves are normalized to zero degrees Celcius and listed in Table 9305 4 Input Resistance Greater than 109 ohms Terminal Block and Room Temperature Compensation A secondary sensor is installed in the rear panel mounted Terminal Block to measure the Reference Junction Tempe
245. nputs with a scan rate independently set between O Skip and 99 seconds for each input Setting a dwell time to zero automatically skips the channel only when in the SCAN mode If the scanner option is present inputs 1 4 are included in the SCAN func tion and each has its own dwell time which is set independently 3 8 5 The SCAN Dwell Time The dwell time for the Sensor inputs associated with the Upper and Lower Display can be displayed by pressing the t key down for more than one second The display will read dt 00 for a dwell time of 0 seconds If it is desired to change the dwell shown in the upper display the user continues to hold down the SCAN key 3 6 Model DRC 93C and presses the 44 key Both keys can then be released The dwell in the Upper Display will flash in dicating that it can be changed by the keypad 0 9 and entered into the instrument with the ENTER key Hitting the CLEAR key before the ENTER key will cancel the entry and return the instrument to normal operation To change the dwell shown in the Lower Display is the same except that the SCAN and vv keys are em ployed When the dwell is being changed in addition to using the keypad 0 9 there are two other methods to mod ify the dwell displayed The first method is to increment the dwell with the 44 key and decrement it with the vv key When the desired dwell is displayed hitting the ENTER key will store that dwell in the in strument
246. ns of 10 mK The Chebychev equation is at G where T x temperature in kelvin ti x a Chebychev polynomial and the Chebychev coefficient The parameter x is _V VL VU V ET where V voltage and VL amp VU lower and upper limit of the voltage over the fit range The Chebychev polynomials can X 2xt x t x be generated from the recursion relation 3 ty x Lf t cos ix arccos 4 The use of Chebychev polynomials is no more complicated than the use of the regular power series and they offer significant advantages in the actual fitting process The first step is to transform the measured voltage into the normalized variable using Equation 2 Equation 1 is then used in combination with equations 3 and 4 to calculate the temperature Programs 1 and 2 provide sample BASIC subroutines which will take the voltage and return the temperature T calculated from Chebychev fits The subroutines assume the values VL and VU have been input along with the degree of the fit The Chebychev coefficients are also assumed to be in any array 0 A 1 A idegree a normalized variable given by 2 Alternately these polynomials are given by An interesting property of the Chebychev fits is evident in the form of the Chebychev polynomial given in Equation 4 No term in Equation 1 will be greater than the absolute value of the coefficient This property makes it easy to determine the
247. nstalled in a DRC 91C DRC 93C to convert either the Input A or Input B or both with two options to accommodate diode sensors with a voltage output of up to 3 0000 volts 9210 3 configuration The 9210 3 is used with Lake Shore DT 500 DRC or 470 Series Sensors Calibrated DT 500 or DT 470 Series Sensors be accommodated with an 8000 Series Precision Option The 9210 6 configuration will accommodate diode sensors TG 120 series with voltages between 0 and 6 5535 volts A calibrated sensor and 8001 Precision Option is required for the DRC 91C 93C to read accurately in temperature 9210 3 can be converted to 9210 6 configuration by switch on the 9210 Diode Input Option Card This configuration will also read DT 470 and DT 500 series sensors but with reduced resolution and accuracy See Table 9210 1 9210 3 SPECIFICATIONS Specifications for the Model 9210 Diode Input Card are given in Table 9210 1 The card can be configured by the user as either a 3 volt 9210 3 or a 6 volt 9210 6 card COPYRIGHT 12 87 LSCI Table 9210 1 9210 Diode Card Sensor ordered separately 07 470 series DT 500 series and TG 120 series from LSCI as well as any other diode sensor See Lake Shore Diode Sensor brochures Temperature Range Dependent on Diode Sensor See Sensor brochure Sensor Excitation DC current source 10 microamperes 0 005 AC current noise less than 0 01 of DC current Compliance volta
248. nstructed in step 5 5 6 1 Enter a gain and setpoint value that results in less than full power to the load If a Reset value is now entered the instru ment will try to integrate out the error With a test resistor in the control sensor input and a fixed setpoint the error signal will be constant With a constant error the Reset will continue to increase the analog output control signal until the heater display reads 100 percent If the heater output in creases to approximately 100 per cent for these conditions the reset circuit is operating To check the RESET circuit in more detail use the same set point and a GAIN of 10 Move the HI lead of the DVM to TP30 and enter a RESET of 1 0 The reading on the DVM should gradually integrate to ap proximately 7 2 volts The time required will depend on the amount COPYRIGHT 3 88 LSCI Model DRC 93C of reset with time required being the shortest for higher settings Next turn the reset off and make sure that the reading returns to 0 0 volts 5 5 7 3 Rate The operation of the Rate can not be observed without measuring voltages in the unit To check the RATE move the DVM HI lead to TP31 keep the GAIN at 10 turn the RESET off 0 0 and enter a RATE to 99 The DVM should read 0 0 volts Quickly change the set point value from approximately equal to the display value to a value 20 higher in equivalent kelvin temperature e g from 1 00 volts to 0 80 volts The DVM should sh
249. nstrument and available through an assignment as described in section 3 9 1 3 9 3 3 Editing Existing Curve Data Curve data can be modified using the same procedure described in the previous section The difference is that the temperature and voltage raw data will be shown in the Upper and Lower displays respective ly after the POINT has been select ed If it is not desired to edit the point then simply enter another point using the POINT key or press the PROG key to return to normal operation Following the editing of a data point the unit compares the temper ature and voltage entered against the existing curve to see if either match and existing point The point is matched first in temperature then voltage If a match occurs the point is edited to reflect the change If no match occurs the unit inserts the new point into the curve in the correct increasing Raw Units order 3 9 3 4 Summary of Curve Programming from the Front Panel 1 The Curve Programming routine is entered by pressing the PROG key followed by the CURVE key The PROG light will remain on while in the routine and turnoff when operation returns to normal 2 The displays have the following format during curve programming Upper Display Setpoint Display Lower Display Temperature in K Curve Point Raw Units Data 3 15 Section III 3 The Upper and Lower SENSOR win dows are blank The Upper UNITS show K and the Lower UNITS
250. nt calibration constants in all The resulting sensor voltage is converted from a differential to single ended signal and amplified by a factor of 1000 9317C or 100 9318C amplified signal is digitized by a microprocessor controlled 15 bit A D converter The microprocessor also has calibration constants stored for the gain and offset of the input amplifier As a result of the A D resolution and calibration constant manipulation of the sensor signal the sensor signal can be digitized with a resolution of 1 part in 10 000 over most of the resistance range the 9317C 9318C covers There is also a_sample and hold network on the card so that when the sensor signal is reversed for thermal correction while controll ing the correct polarity of the control signal is maintained 9317C 9318C 5 1 Thermal Correction Selection for the DRC 91C The control thermal correction function is enabled or disabled using switch 3 of the appropriate SENSOR ID located on the rear panel of the DRC 91C 9317C 9318C 3 9317C 9318C Input Cards When switch 3 of the SENSOR ID is CLOSED ON the thermal correction is enabled When switch 3 is OPEN OFF the thermal correction is disabled Pressing the LOCAL key for the appropriate channel will display either 18 C or 17 C The plus that the control thermal correction is enabled minus means the control thermal correction is disabled 9317C 9318C 5 2 Thermal Correction Sel
251. nt Panel 3 4 Table 3 1 System Resolution Versus Sensor Sensitivity 3 8 Table 3 2 Standard Curve Information e e e lt lt o 3 10 Table 3 3 Sensor Curve Table Information Precision Option Table s s e so 3 10 Table 3 4 Correlation Table for Curve from REMOTE POSITION DATA 3 13 Figure 3 2 DRC 93C Temperature Controller Rear Panel 3 18 Table 3 6 Pin Assignments for the J5 REMOTE SENSOR ID Connector 3 19 SECTION IV REMOTE OPERATION Table 4 1 Interface Functions NES 4 2 Figure 4 1 IEEE 488 Address Switch for the DRC 93C au E 4 3 Table 4 2 Allowable Address Codes for the DRC 93C 4 4 Table 4 3 IEEE 488 Bus Commands o des N 4 6 Table 4 4 DRC 93C Command Summary of Instrument Setup lige Mors ae 4 8 Table 4 5 DRC 93C Summary of Output Requests m 4 9 Table 4 6 DRC 93C Interface Setup Commands and Request Status 4 10 Table 4 7 DRC 93C Command Summary for Instrument Setup 4 13 Table 4 7 DRC 93C Request Summary for Instrument Setup 4 14 Table 4 8 and Cp in A ID and B ID the SENSOR ID s 4 14 Table 4 9 DRC 93C Command Summary for Setpoint Setup 4 15 Table 4 10 DRC 93C Command Request Summary for Control Setup 4 17 Table 4 11 DRC 93C Command Request Summary for Scanner Setup 4 18 Figure 4 2 93C Status Register MASK and Status Register Format 4 22
252. ntities it is neces sary to hold the Blue Legend key down while hitting the 44 up key or vv down key 44 key will change the entry of the Upper dis play and the vv key will change the Lower display Section III Figure 3 1 Model DRC 93C DRC 93C Temperature Controller Front Panel Figure 3 1 Model DRC 93C Temperature Controller Front Panel Description Upper and Lower Displays 10 Full Scale selection of HEATER CURRENT or HEATER POWER for 1 Sensor reading in temperature four orders of magnitude Kelvin Celsius or Fahren Includes power OFF position heit or sensor units Volt age Resistance Capacitance Keyboard 2 Sensor No A b 1 2 3 4 3 Annunciators indicating units 11 Control Data input keys Gain of Sensor K F N Rate Reset Setpoint and Manual Heater Set Point 12 Up and vv Down keys 13 PROG Programming t SCAN 4 CTRL control Arrow Annun and Sign TIME and POINT ciator indicating whether the keys sensor in the Upper or Lower 14 Decimal Keypad with Blue Legend Display is the control sensor functions of SENSOR CURVE 5 Display of Set Point in temper FILTER MATH UNITS RSLIN ature kelvin celsius or ReSoLuTioN DEV DEViation fahrenheit or sensor units CONTROL MAX MAXimum MIN voltage resistance or capaci MINimum and MAXDEV MAXimum tance in the units of the DEViation Control Sensor as indicated by 15 CLEAR
253. ntrol It is normally good practice to determine the power requirements for one s System prior to or during the first experimental run Some system manufacturers may have that information available and may possibly supply a power load curve with the system Two other aspects of temperature control should be mentioned First ON Off controllers are frequently encountered at room temperature and above As the name implies such systems have only two states power on when the temperature is below the set point and off when it is above The proportional controller with excessive loop gain approximates this mode Although ON OFF controllers perform adequately with large furnaces for example they are generally unsatisfactory for cryogenic applications because of the relatively short thermal time constants encountered at low temperatures Secondly some controllers such as the DRC 82C have a manually adjustable power output control This control can be used in either of two modes 1 open loop with a manual adjust of heater power in place of the signal from the deviation amplifier and 2 automatic where the adjustment is in addition to the controller s closed loop signal Mode 1 is extremely helpful in set up procedures and in subsequently determining the power levels associated with the desired temperatures In Mode 2 one can reduce and sometimes eliminate temperature offset by providing the required power without the need for a large error signal to dr
254. nviron mental information bench and rack mounting instructions descrip tion of interface connections and repackaging instructions 2 2 INITIAL INSPECTION This instrument was electrically mechanically and functionally in spected prior to shipment It should be free from mechanical damage and in perfect working order upon receipt To confirm this the instrument should be visually inspected for damage and tested electrically to detect any concealed damage upon receipt Be sure to inventory all components supplied before discarding any shipping materials If there is damage to the instrument in tran sit be sure to file appropriate claims promptly with the carrier and or insurance company Please advise Lake Shore Cryotronics Inc of such filings In case of parts shortages advise LSCI immediately LSCI can not be responsible for any missing parts unless notified within 60 days of shipment The standard Lake Shore Cryotronics Warranty is given on the first page of this manual Table 2 1 Line Voltage Volts Operating Range Volts Fuse A SB COPYRIGHT 3 88 LSCI 2 3 PREPARATION FOR USE 2 3 1 Power Requirements The Model DRC 93C requires a power source of 100 120 220 or 240 VAC 5 10 50 to 60 Hz single phase CAUTION Verify that the AC Line Voltage Selection Wheel Figure 3 2 Key 1 located on the rear panel of the Model DRC 93C is set to the AC voltage to be used Table 2 1 and
255. of the DRC 93C to 12 by making Switches 5 and 6 CIOSED 1 4 7 and 8 OPEN 0 and make sure Switch 1 is OPEN 0 to select CR LF as the terminating charac ters Note that this should be done prior to turning on the instru ment since the DRC 93C updates the IEEE address on power up only Confirm that the address selected is correct by holding in the REMOTE button for longer than one second and observe the IEEE address on the front panel display as follows LSCI 93C Add12 4 6 1 Commands and Requests The device dependent commands to program the DRC 93C are given in Table 4 4 The 93C must be addressed as a LISTENER to receive any instruction or string of instruct ions from the Command list The DRC 93C input data format does not require a set number or set sequence of Commands to implement proper instrument set up These Commands are processed only after the terminators TERMI TERM2 are sent across the bus The listing and explanation of the 93C commands are summarized in Table 4 4 There are commands for Interface Setup Instrument Setup Control Setup Scanner Setup Status Register and restoring Executable Programs COPYRIGHT 3 88 LSCI Section IV The Output Statement Requests are sent by the BUS CONTROLLER to the DRC 93C to tell the 93C what data to output when data output is requested These requests are listed in Table 4 5 and the data formats are described in detail in the following tables as well a
256. ohm for 1000 ohm platinum i1mV ohm for 1 3 Section I rhodium iron 100mv ohm and for capacitance units 100mV nF and 10mV nF Since the 9317C and 9318C vary over such a large range of resistance use of the 8225 with these two input cads is limitd to 10mV K The Model 8229 Scanner Table 1 1 Input Characteristics Inputs Two Sensor Inputs A and B The 8229 Scanner Conversion Option provides for four additional channels of Sensor Input Display sensor can be selected from front panel or interface or display can be set to scan between sensor inputs Dwell time per channel can be set independently from O skip to 99 seconds Input characteris tics are a function of Sensor Input Option Installed The DRC 93C can accommodate two input options which allows the A input and the B input to each be assigned their own input card This allows concurrent use of different sensor types depen dent on the user s application Sensors Ordered Separately DRC 93C will handle all types of diodes germanium carbon glass carbon etc negative temperature coefficient resistors thermistors platinum rhodium iron etc metallic resistors as well as capacitance thermometers with proper choice of input option cards See the Lake Shore Cryotronics Inc Sensor catalog for details on the above Sensors Display Readout Display 5 digit LED Display of Sensor reading in Sensor Units Volts Ohms or Nanofarads or temperat
257. om the BUS CONTROLLER the DRC 93C starts its scan of the inputs from the channel input which it is currently on The scan sequence is A 1 1 2 A2 3 A3 4 A4 A etc with any channel whose dwell COPYRIGHT 3 88 LSCI control channel be the B channel when the scanner is used If it is not it will be changed if a scanner card is present since one current source is associated with the A0 A4 inputs Section IV Model DRC 93C Table 4 11 93 Command Request Summary for Scanner Functional Description YAN NoN3 Set the AN AO 4 or BO Scanner channel dwell time or YBON gt N3 time to seconds is 00 to 99 seconds Forms After YH cmmd 000 thru YA099 YA100 thru YA199 etc Enable the S CAN function Disable or H old the SCAN kkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkk Functional A A Functional Description Scan Information C4 C2C5 C4C5 C6C7 CgCo C10C11 C12C13 14 15 22 characters plus up to 2 terminators where is the SCAN status olding or S canning 2 2 is the AO A4 and BO dwell times in seconds 14 15 is the SCAN position AO 1 2 or A4 a Cj corresponds to an alphanumeric 4 10 4 Holding the Scan Function The YH Command The Scan can be stopped any time over the IEEE 488 Bus by sending out the YH command The scanner should be in hold wh
258. ommonly used in sizes 32 or 36 AWG These wires have a fairly poor thermal conductivity yet the resistivities are not so large as to create any problems in four wire measurements Lead wires should also be thermally anchored at several temperatures between room temperature and cryogenic temperatures to guarantee that heat is not being conducted through the leads to the sensor A final thermal anchor at the sample itself is a good practice to assure thermal equilibrium between the sample and temperature sensor Note that the CU CY BO and DI mounting adapters serve as their own sample thermal anchor If the connecting leads have only a thin insulation such as Formvar or other varnish type coating a simple thermal anchor cn be made by winding the wires around a copper post or other thermal mass and bonding them in place with a thin layer of GE 7031 varnish There are a variety of other ways in which thermal anchors can be fabricated and a number of guidelines which may be found in detail in the references given below SENSOR MOUNTING General Comments Before installing the DT 470 sensor identify which lead is the anode and which lead is the cathode by referring to the accompanying device drawings Be sure that the lead identification remains clear even after installation of the sensor and record the serial number and location The procedure used to solder the connecting leads to the sensor leads is not very critical and there is very little danger
259. onfiguration 4 pole 2 current poles make before break 2 voltage poles break before make Maximum Input Voltage or peak AC Maximum Current 32 volts DC 10 milliamperes Thermal Offset Less than 3 micro volts per contact on break before make poles less than 50 microvolts on others Contact Resistance Iess than 1 f Open Channel Isolation gt 1010 ohms Input Output 24 pin D style connector mate supplied Channel Selection Front panel SENSOR A key increments AO A1 A2 A3 A4 AO etc each time it is pressed or automatically in the SCAN mode All front panel operations can be duplicated over the remote interfaces Switch Contact Life 109 operations at rated load Configuration Channels AO through A4 are configured as Remote Position A00 through A04 with respect to Sensor Curve selection with 8229 present Channel Selected Data Chnnl selected present in BCD form on J9 connector 8229 4 INSTALLATION The 8229 Scanner Conversion is factory installed if ordered with an DRC 91C Temperature Controller 8229 2 Model DRC 91C 93C or can be field installed at a later date If field installation is required use the following procedure WARNING To prevent shock hazard turn off instrument and disconnect it from AC line power and all test equip ment before removing cover 1 Set the POWER switch to OFF and disconnect the power cord from the unit Remove the three top panel
260. ontrol Resolutions 4 Setpoint 5 Gain Rate and Reset 6 Manual Heater Power 7 Heater Range 8 Program Timer 9 Filtering on off Section VI 0 Null 1 Dwell 2 Dwell 3 Ramp Up 4 Ramp Down 5 Ramp 8 Jump 9 Exit 6 2 Model DRC 93C TABLE 6 2 PROGRAMMING COMMANDS 0 REPEAT COUNT Does nothing but enter a REPEAT CO into the REPEAT COUNTER associated with Command 2 and move to the EE eno Step No front panel parameters can be changed with the Null Command This command is used in conjunction with Command 2 EAD to establish a do loop The REPEAT COUNT number establishes the number of times a given set of operations will be repeated Step 1 JUMP VECTOR Dwell Soak for the time given set with Time key with the front panel parameters set in the program step format After this dwell time jump to the Program Step 4 specified by the JUMP VECTOR 2 JUMP VECTOR Dwell Soak with Conditional Jump Same as Programming Command 1 except that when the Dwell is completed the PEAT COUNTER set b Command _0 is decremented If the value of the REPEAT COUNTER 15 non zero operation continues at the EOD specified by the VECTOR If the REPEAT COUNTER is zero then oper ation continues at the next Program Step Step 3 RAMP COUNT Ramp the Setpoint Up The setpoint is incremented by the value given in the setpoint of that Program Step set with SETPOINT key The setpoin is incremen
261. op This output is now the only drive to the power stage since the proportional error signal has been forced to zero No overshoot will occur since zero thermal resistance eliminates the thermal lag which is the cause of overshoot The zero thermal time constant also means that any amount of reset will eventually force the system to zero error Before we switch the discussion back to real systems let us deal with the nomenclature and units involved in integral control Automatic reset action can be expressed in terms of a time constant minutes or its inverse reset rate repeats per minute The reset time constant is the time required measured in minutes for the reset circuit to integrate to full output with an input signal which is constant and equal to the proportional band error signal The amount of reset action can also be measured in repeats per minute or the number of times which the integrator can integrate between zero and full output in a time period of one minute for the constant proportional band error signal Thus if the time constant were say two minutes this is the same as saying that the reset circuitry repeats the proportional action in two minutes or 72 repeats per minute The term reset windup refers to a condition occurring in reset controller when an offset persists for a sufficiently long time The integration of the error with time will cause the integrator to saturate or windup at maximum output and remain so unti
262. or 9220 Option diode configurations 3 6 give buffered output of diode sensor for 6 configuration buffer is 0 458 times sensor voltage for 9220 Option positive temperature coefficient config urations P2 P3 R1 buffer is sensor voltage output times 10 For 9215 signal is proportional to capacitance value for 9317C or 9318C monitor not of use Response time electronics Less than 1 second to rated accuracy for non Lagrangian calculations Lagrangian curves result in update times between one and two seconds Three readings on channel change or range change to reach rated accuracy IEEE 488 Interface Allows remote control of set point gain rate reset units and heater power range Provides output of display in units chosen units and all front panel functions except power on off Allows input of curve data for calibrated sensors and internal ramping programs Dimensions Weight 432mm wide x 102mm high x 330mm deep 17in x 4in x 13in Style L full rack package Net weight 8kg 17 lb Power 90 110 105 125 or 210 250 VAC selected via rear panel with instrument off 50 or 60 Hz 75 watts Accessories connector connector Supplied Mating for sensor monitor instruction manual SECTION II INSTALLATION 2 1 INTRODUCTION This Section contains information and instructions pertaining to instrument set up Included are inspection procedures power and grounding requirements e
263. ow a positive transient whose peak value will lie between 0 1 and 7 volts depending on the rate at which you change the set point the amount of gain the speed at which you change the volt age as well as when the reading is read by the DVM For the change from 80 to 1 00 the reading will be negative in value The GAIN RATE and RESET values are summed together before the heater drive circuit with the GAIN being multiplied by two signal strength before summation The sum of the three terms can be measured at TP28 ANA OUT 5 5 8 Checking the Heater Ranges 5 5 8 1 Standard 50 Watt output Set up the unit so that 100 percent is output to the heater load At full power out on the Max scale 1 amp should be through the resistor as long as the resistor is 50 ohms or less heater circuit has compliance voltage limit of 50 volts so a resistor larger than 50 ohms will limit the current to 50 divided by the load s Resistance If the next lower range 1 is COPYRIGHT 3 88 Section V selected then the heater will put 0 33 amperes through the resistor at 100 percent 2 range will output 0 10 amperes at full scale output At the 3 range the output will be 0 033 amperes full scale and at the 4 range the output will be 0 001 amperes 5 5 8 2 W60 Watt Option If the unit has a W60 output option the Max scale has a 1 55 amp 40 volt limit If a 25 ohm resistor is used the controller will supply 60 watts to
264. oy a controller cooling loop but this type of system will not be discussed Most of the difficulties in cryogenic control applications are associated with factors 4 and 5 where changes in parameters are involved Application Notes 1 Lake Shore Cryotronics Inc II PROPORTIONAL CONTROL The block diagram in Figure 1 shows a systems in which only proportional control is being used In this system the desired control temperature setting set point is being compared to the sensor signal and the difference or error signal including polarity is amplified within the controller When the sensor temperature corresponds to the set point temperature in voltage for a diode or resistance for a resistor the sensor signal will be equal to but opposite in polarity to the set point signal and the error signal will be zero In older instruments the set point is normally calibrated in millivolts or volts or resistance corresponding to the sensor output signal Most modern controllers have stored within them the appropriate voltage temperature or resistance temperature sensor characteristic so that the set point can be calibrated directly in temperature However as discussed in Section VII this convenience feature can compromise the resolution and accuracy of the controller The output of the controller is dc power to a resistive heater the output magnitude of which depends on the size and sign of the error signal as well as on the gain o
265. peak to peak variation in temperature which exceeds 1 kelvin at a nominal 3 Hz frequency That variation represents an inherent disadvantage which is difficult for the all digital system to overcome since the sampling rate is lower than the frequency of the temperature variation The Sampling Theorem of Electrical Engineering implies that no sampled data control system can be stable unless it is sampled at a rate which exceeds at least twice the highest frequency variation within the system Some designers of all digital controllers for cryogenic temperatures appear to have overlooked this sampling rate problem There are also examples of digital controller which fail to achieve optimum performance because of the design of their output stage heater power is varied on a cyclical time proportioning ON OFF basis This often introduces noise within the system which may interfere with the cryogenic experiment An advantage that the microprocessor and its read only memory provides for users of digital controllers is that of a direct reading in temperature set point and sensor readout However as noted in Section Ill this feature may exact a price In the real world there is always an error due to lack of perfect conformity between the true sensor voltage or resistance temperature characteristic and the value actually stored in memory This error will depend on the degree of non linearity of the characteristic and on the amount of storage available It is
266. perature Coefficient is Negative 9215 6 2 Selection of Temperature Coefficient Sign on the DRC 93C When a 9215 Capacitance Input Card is installed pressing the SENSOR key will display for the propriate channel either 15 15 or 15 50 the 15 for the 9215 15 configuration or 50 for the 9215 150 configuration The sign indicates whether the Temperature Coefficient is positive or nega tive The plus means that the Temperature Coefficient is posi tive The minus means that the Temperature Coefficient is nega tive Select the Temperature Coefficient sign from the front panel by using a combination of the SENSOR key SCAN t key and the a4 key and vv key as follows 1 Press and hold the SENSOR key 2 While holding down the SENSOR key press the SCAN tt key You may now let up on the SENSOR key 3 To change the sign if in the COPYRIGHT 2 88 LSCI 9215 Capacitance Input Card upper display hit the 44 key while still holding down the SCAN 11 key Similarly to change the sign if in the lower display hit the vv key while still holding down the SCAN 11 key 4 Now let up on the 44 key or vv key and then the SCAN t1 key You should press the SENSOR key to make sure that the sign is as desired 9215 6 3 Selection of the Sign of the Temperature Coefficient via the Computer Interface To select the sign of the tempera ture coefficient via the IEEE interface check the 2
267. position number the REMOTE POSITION DATA This can be done by attaching a Scanner and sel ecting a position 3 Select the Curve Number desired for that position from the front panel as described in section 3 9 1 4 The GAIN or RESET win dow must have the REMOTE POSITION DATA to show that the function is enabled 4 When the ENTER key is pressed the Curve Number will be stored in the Correlation Table in the Position indicated by the REMOTE POSITION DATA in the GAIN window if the Curve in the Upper Display was altered or in the RESET win dow if the Curves in the Lower Display was altered COPYRIGHT 3 88 Model DRC 93C Table 3 4 Correlation Table for Curve 4 from REMOTE POSITION DATA REMOTE Curve Curve POSITION for for Input A DATA Input B Front Panel This section describes how the user can enter his own sensor calibration via the front panel Section IV covers entry over the IEEE 488 or RS 232C interfaces The curve is stored battery back up non volatile RAM NOVRAM which can be read and written an unlimited number of times The number of data points stored per curve can be between 2 and 99 two being the lower limit which defines a straight line COPYRIGHT 3 88 Section III 3 9 3 1 Accessing Stored Curve Data In order to access stored curve data hit the PROG Programming key The PROG indicator will turn on and flash Next hit the CURVE key The PROG indicator will stop flash in
268. put as a curve description When all 18 characters are input the last 6 are used in the Sensor Curve table in the 8000 Series Precision Option curves these 6 characters are used to indicate the sensor serial no The 18 characters must be immediately followed by a comma The data is input in units temperature pairs with the units in the form of Voltage Requiy or LogR Data points must be entered in ascending units order The character terminates the Sensor Curve input Edit Sensor Curve The point is either inserted in its proper position in the curve or it is added to the curve as a new data point XKN1N5 Erases kills Sensor Curve and repacks all curve data Standard Curves 00 thru 05 cannot be erased XR amp I Command sent five times will delete all Precision Options and any curves stored in unit by user e a Assignment of Curve to Position in Correlation Tables Assign the Input A or Input B Remote Position C1C2 to Sensor Curve number is the Remote Position 00 thru 1 N41N5 is the Sensor Curve number 00 thru 31 This Command modifies the Remote Position to Sensor Curve Correlation Table 3 3 and XDT output data XEN4N5 X XXXXX TTT T NOTE added to the end of the 1 2 1 2 XCN4N5 1 and XK commands is required for the command to operate properly Due to the length of some of the data strings appropriate computer ti
269. put in table form consisting of voltage and temperature points with the voltage in ascending voltage order Refer to Section 4 of this manual for a discussion of how the data must be formatted for entry into the unit over the remote interfaces and to Appendix B for a discussion of Precision Option curves examples of curves that would be used with the 9210 9210 8 REPLACEABLE PARTS Included in this section is Figure 9210 1 It includes the Model 9210 Diode Input Schematics replaceable parts list and illustrated component layout Refer to the manual for ordering information 9210 3 Model DRC 91C 93C 9215 Capacitance Input Card 9215 CAPACITANCE INPUT CARD OPTION 9215 1 INTRODUCTION This section contains information pertaining to the Model 9215 15 9215 150 Capacitance Input Card Configurations Specifications installation and operating instruc tions a description of the principle of operation and Maintenance information are included Section 9215 3 describes some characteristics of Capacitance sensors 9215 2 DESCRIPTION AND SPECIFI CATIONS The Model 9215 Capacitance Input Card is designed to be installed in a DRC 91C or DRC 93C to convert either Input or Input B to accommodate Capacitance sensors When used to control temperature in magnetic fields the capacitance sensor is superior to other sensors since the displacement current in a capacitor is magnetic field independent Accurate temperat
270. put SCIT 50 DISP FILETABLE 1 16 Bytes Free 60 DISP FILETABLES 17 38 Next Loc 70 DISP FILETABLE 39 56 Curve 00 80 DISP FILETABLE 57 74 Curve 01 90 DISP FILETABLE 75 92 Curve 02 100 DISP FILETABLE 93 110 Curve 03 110 DISP FILETABIES 111 128 Curve 04 110 DISP 129 152 120 DISP 153 176 130 DISP FILETABLES 177 200 140 DISP FILETABLES 201 224 Thru 1 150 DISP FILETABLE 225 248 160 DISP FILETABLES 249 272 170 DISP FILETABLES 273 296 180 DISP FILETABLES 297 319 thru 190 END 1 00 BOO Note that the last character to be displayed is number 319 since the Terminators CR LF have to be input but not displayed This program results in the following output of the Sensor Curve Information Table 3584 BYTES FREE 0200 IS NEXT LOCATION 00 31 1D40 DRC D 01 31 1DFO DRC E1 02 31 1EA0 CRV 10 03 31 1F50 DIN PT 04 31 2000 CRV 10 COPYRIGHT 3 88 LSCI Section IV 05 31 20BO0 RESVRD 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 4 16 2 The XDNjN5 Command The XDN N5 command is used to output a particular Sensor Curve rather than all the curves stored within the instrument as in the XDA command with being the curve number OO thru 31 The format of the Sensor Curve output is
271. r Aborting the Programming Mode Q N P COO WWW NAOH 4 I gt PS bb P gt Q P DAAAO Oi Ut Ol aoa o vi COPYRIGHT 3 88 LSCI TABLE OF CONTENTS CONT D 6 6 RUNNING THE PROGRAM e o e o 6 7 CLEARING ALL INTERNAL PROGRAM MEMORY 6 8 EXAMPLES 6 1 Example 6 8 2 Example 6 8 3 Example 6 8 4 Example 1 2 3 T Ramp and Soak e o Ramp and Soak Repeated Setpoint Ramp Up and Ramp Down with Gain Ramping Repeat of Example 3 with a Limit of 10 Cycles SECTION VII ACCESSORIES INPUT CARDS AND OPTIONS APPENDIX Standard Curve Data APPENDIX B Sensor Curve Information APPENDIX C Error Code Summary COPYRIGHT 3 88 LSCI vii LIST OF TABLES AND ILLUSTRATIONS SECTION I GENERAL INFORMATION Table 1 1 Specifications Model DRC 91C Temperature Controller 1 4 SECTION II INSTALLATION Table 2 1 Line Voltage Selection e s e eo 2 1 Figure 2 1 Typical Rack Configuration s s e 2 2 Table 2 2 INPUT Connections for 21 INPUT A and J2 INPUT B 2 2 Figure 2 2 Sensor Connections e e e e e e e s e so 2 2 Table 2 3 J3 MONITORS Connections Set we bod eS 2 3 Table 2 4 REMOTE SENSOR ID Connector Assignments m 2 4 SECTION III OPERATING INSTRUCTIONS Figure 3 1 DRC 93C Temperature Controller Fro
272. r in the Lower Display The three keys MAX MIN and MAXDEV on the keypad digits 9 6 and 3 COPYRIGHT 3 88 tion have been zeroed Section III respectively allow the user to observe the MAXimum and MINimum temperature and MAXimum DEViation from the Setpoint When one of these keys is depressed the Upper and Lower Displays will contain the se lected Math Function These Math Functions are enabled using the MATH key decimal point on the keypad and the 44 key or vv key In combination with the MATH key the CLEAR key restarts the process When the MATH key is depressed the Upper display shows OFF or When OFF is displayed the Math Functions are inhibited When On is displayed the Math Functions are enabled To change from OFF to On and vice versa hold the MATH key down and hit the 44 key or vv key to toggle between On and When the MATH key is releas ed operation returns to normal If the On was left in the Upper Display when the MATH key was re leased then the instrument will begin calculating the Math Func tions If OFF was left in the Upper Dis play when the MATH key was released then the instrument freezes the contents of the Math Functions The MAX MIN and MAXDEV keys can be used to observe the last readings of the Math Functions If it is desired to restart the calculation of the Math Functions the MATH key is held down and the CLEAR key hit the Lower Disp
273. r under these conditions 3 2 3 Dual Input Cards When two input cards are present in the unit the input card that oc cupies the INPUT CARD 1 slot is routed to the Sensor A input and the input card that occupies the INPUT CARD 2 slot is routed to the Sensor B input Consequently both sensors are energized at all times The second input card allows the instrument to mix sensor types COPYRIGHT 3 88 i II INSTRUCTIONS e g both a diode thermometer and a resistance thermometer can be used on the two inputs Another possibil ity with the 9318C and 9220 Options would be the presence of a GR 200A Series Germanium Sensor as well as a PT 100 Series Platinum Resistance Sensor Both inputs are updated independently which allows them both to be displayed or queried under IEEE 488 or RS 232C control The addition of an optional 8229 Sensor Scanner Card adds capability for 4 additional inputs to the A channel resulting in up to 5 sensors of the same type being allowed using the A input card 3 2 4 Old Version Input Cards The 8210 8211 diode input cards can be used in the 93C as well as the 8219 series resistance input card The installation of these cards is covered in Section 7 3 of this manual Note that there are Dip Switch settings on the main board which must be set in order for these older cards to work properly 3 3 CURVE ENTRY The DRC 93C allows the user to enter his own sensor calibration via the front pane
274. ram Steps of the internal programming feature are very powerful A single Program Step contains information to enable the instrument to ramp the setpoint to a given value with control parameters selected for that ramping function A single Program Step is all that is necessary to provide a soak with all parameters desired A simple ramp and soak requires only two Program Steps one to ramp and one to soak There are provisions for 99 Program Steps Since typical programs are COPYRIGHT 12 87 LSCI Section VI Vi INSTRUCTIONS three to four Programs Steps in length this provides storage for many programs The Programmer Specifications are summarized in Table 6 1 Table 6 1 Programmer Summary Number of Stored Programs limited by a total of 99 steps for example 49 Ramp and Dwells Steps per Program Up to 99 Programming Commands 8 different commands Ramp Formats Total of 3 ramp setpoint up ramp Setpoint Down and ramp setpoint gain rate and reset to a final value Ramp Time 0 to 30 days specified in days hours minutes and seconds Repeat Cycles 99 per step can be multiplied by using additional steps 6 3 PROGRAM STEP FORMAT Each Program Step contains the Step Command and JUMP VECTOR REPEAT COUNT or RAMP COUNT as well as a full description as indicated by the front panel These are listed below 1 Sample and Control Sensors 2 Sample and Control Units 3 Sample and C
275. rature Compensation can be enabled or disabled Offset Adjustment One point hardware adjustment built into the Terminal Block Electronic Resolution 1 microvolt Electronic Accuracy 3 uV for 10 to 10 millivolts 5 uV up to the 15 and 15 millivolt full scales Overall Accuracy Depends on conformity of the thermocouple to it s standard curve and system configuration Controllability Typically 0 2K in a properly designed system Display Resolution 5 digits Compensated and uncompensated voltage in millivolts from 0 000 to 15 000 or temperature in Celcius Fahrenheit and Kelvin Note When displaying millivolts the unit V is shown Temperature Control Signal Card processes an analog voltage output signal 200 times the thermocouple voltage The instrument generates setpoint voltage based on the voltage or temperature entered by the user If compensation is enabled the setpoint voltage is modified to reflect the compensation required Real time analog comparison of these two voltages provides the required control error signal 9305 2 COPYRIGHT 6 88 LSCI Model DRC 91C 93C Table 9305 2 Chromel vs Au 0 03 at Fe Chromel vs Au 0 07 at Fe Remove the four screws that secure the calibration cover to its clips and remove the cover If the 9305 is to replace an existing Input Card unplug the Input Card which is to be replaced Disconnect the wiring harness mating connector by lifting the locking tab o
276. rd address Output Data Command If the user were to monitor the IEEE 488 Bus when the computer sent its command string over the Bus the following IEEE 488 Format would be observed L 123 4P45130D25R4W3 CR LF The Universal Unlisten Command is sent so that no other instruments on the Bus will eavesdrop on the Bus and assume that the data being sent is for their attention The DRC 93C s Talk Address L is sent to unaddress any existing TALKER Note that the BUS CONTROLLER could have designated another instrument as the TALKER Therefore to keep the format consistent it must send a Talk Address even when the DRC 93C is going to be that TALKER The Listen Address must be sent to tell which instrument on the Bus is to receive the Data String Note that TERM1 TERM2 have been indicated to be CR LF carriage return line feed these are the correct terminators for the HP computer example Note that the string P45130P40 would result in a gain of 40 and an integral value of 30 i e only the last value sent over the bus for that command will be entered after the appropriate terminators have been sent over the bus 4 14 OUTPUT DATA STATEMENTS The DRC 93C s Output Requests for Data Statements are summarized in The DRC 93C will always respond when asked to talk with the last command sent to it i e if WO is sent once then the 93C will always output the WO information whenever it is asked to talk as lon
277. re measurement errors These results can be used in estimating the accuracy and performance of a temperature measurement system Several of the more common problems which introduce noise into diode circuitry are described INTRODUCTION Current technological uses of temperature sensors require better calibration accuracies and better device performance than ever before However the assurance of an accurate temperature measurement does not stop with simply the sensor specifications Just as critical is the instrumentation used with the sensor and the manner in which the instrumentation is used This paper concentrates on identifying verifying and eliminating an often overlooked instrumentation or system induced error in the use of diode temperature sensors I PROBLEM DEFINITION Semiconductor diode temperature sensors have been in use for over 20 years and with the advantages they offer over resistance sensors or thermocouples for many applications their popularity continues to increase Diodes are operated at a constant current typically 1 10 or 100 while the voltage variation with temperature V T is monitored The diode sensor has a useful temperature range from above room temperature to as low as 1 K with reproducibilities to better than 50 mK Figure 1 shows the voltage variation with temperature for a typical silicon diode temperature sensor VOLTAGE V N o o a o a An error arises in diode thermometry if
278. re the same as for WO see Table 4 15 COPYRIGHT 3 88 LSCI 4 15 Section IV Note Although limitations on the range of the set point are set within the software when in temper ature units these limits are not possible for sensor units due to the different characteristics for each sensor Since the set point is soft the transition from REMOTE to LOCAL does not result in a change in the set point 4 9 2 The WP Request Data String This request is a subset of the WO command the WP command giving the set point value by itself 4 9 3 Setting the GAIN Proportional The P Command The gain is a multiplier between 0 1 and 99 a range of 990 i e 99 0 1 990 A gain of 0 0 is not allowed The format is free field with examples of the command being P 1 0 1 P9 9 P9 0 P99 P99 etc The string P987 12 will be inter preted as P87 i e the first valid combination will be retained P transmitted by itself is equiva lent to PO or P0 0 and sets the gain to 0 1 4 9 4 Setting the RESET Integral The I Command The reset is set from 0 1 through 99 1 to 990 seconds Like the gain command it is free field with the same characteristics and format A setting of 0 0 turns the reset off 4 9 5 Setting the RATE Derivative The D Command The rate is also set in seconds 10 from 0 1 to 99 It handles its input format exactly the same as both gain and reset commands A setting of 0 0
279. rection is inactive a thermal value of 0 is used The resultant voltage is then sent to the main board of the controller as the set point voltage or equivalent resistance for control The 9317C 9318C input card then determines if the control sensor resistance is above or below the equivalent set point resistance If the actual resistance is less than the set point resistance an over temperature condition exists and the heater power should be off The 9317C 9318C changes the current it applies to the sensor in order to maintain between 0 8 and 1 0 9317C or 8 and 10 9318c millivolts across it until the set point current range and value have been reached In this way the heater remains off until the actual sensor resistance approaches the set point resistance Once the final control sensor current value has been reached the 9317C 9318C allows the sensor voltage to range as high as 1 3 9317C or 13 9318C millivolts If the sensor voltage and the equivalent resistance continues to increase an under temperature condition exists the 9317C 9318C then reduces the current to maintain between 1 1 and 1 3 9317C or 11 and 13 9318C millivolts across the sensor The heater power remains Even though this operation takes the sensor voltage away from the optimum signal until it reaches the control point the resulting error in the resistance determination is small If the new COPYRIGHT 12 87 LSCI 9317C 9318C
280. rent from the way a DMM would measure resistance Most DMMs force a large enough signal across the device being measured to make any thermal offset negligible Using this method in a cryogenic environment could add a significant amount of power in the form of sensor self heating to the test system The 9317C 9318C Input Card limits the amount of power added to the system by limiting the voltage across the sensor to 1 9317C or 10 millivolts 9318C The 9317C 9318C can also reverse the current polarity in order to correct for thermal EMFs in the sensor connections and leads The 9317C 9318C current source has four ranges 0 1 to 1 microamperes Range 1 1 to 10 microamperes Range 2 10 to 100 microamperes Range 3 and 100 to 1000 microamp COPYRIGHT 12 87 LSCI value 9317C 9318C Input Cards eres Range 4 Each range has 64 independent current values The ranges overlap each other for example Range 1 Value 60 is equivalent to Range 2 Value 6 so that a smooth transition from range to range can be made The current as well as direction is controlled by a 16 bit bipolar D A converter This current resolution is required to maintain as close to 1 05 9317C or 10 5 9318C millivolts across the sensor as possible on card microproces sor stores calibration constants for each of the four ranges at the end point values of 6 and 60 for both the positive and negative directions a total of 16 curre
281. repaired parts will be warranted for only the unexpired portion of the original warranty All products are thoroughly tested and calibrated to published specifications prior to shipment Calibration Certifications are offered for six month periods only Where such documentation must be updated a re certification service is offered by Lake Shore Cryotronics Inc reasonable cost LIMITATION OF WARRANTY This warranty does not apply to defects resulting from improper or inadequate maintenance unauthorized modification or misuse operation outside of the environmental specifications for any product or part or buyer supplied software or interfacing THIS WARRANTY IS IN LIEU OF ANY OTHER WARRANTIES EXPRESSED OR IMPLIED INCLUDING MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE WHICH ARE EXPRESSLY EXCLUDED THE OWNER AGREES THAT LAKE SHORE S LIABILITY WITH RESPECT TO THIS PRODUCT SHALL BE SET FORTH IN THIS WARRANTY AND INCIDENTAL OR CONSEQUENTIAL DAMAGES ARE EXPRESSLY EXCLUDED CERTIFICATION Lake Shore Cryotronics Inc certifies that this product has been inspected and tested in accordance with its published specifications and that this product met its published specifications at the time of shipment The accuracy and calibration of this product at the time of shipment are traceable to the United States National Bureau of Standards COPYRIGHT 3 88 LSCI TABLE OF CONTENTS Model DRC 93C Temperature SECTION I GENERAL INF
282. roller capablty Open Collector Electronics COPYRIGHT 3 88 LSCI Model DRC 93C 4 4 DRC 93C 488 ADDRESS SWITCH The 488 Address Switch is located on the instrument s rear panel see Figure 3 2 Key No 7 Refer to Figure 4 1 for the following discussion 4 4 1 Terminating Characters delimiters Switch 1 is used to define the instrument s terminating characters delimiters The OPEN 0 position selects the ASCII characters CR and LF Carriage Return and Line Feed as the terminating characters for input and output data For the output data from the DRC 93C back to the computer over the Bus the EOI line is set by the DRC 93C with the output of the Line Feed LF This setting 0 for switch 1 is the setting for all Hewlett Packard computers Figure 4 1 D D T L 16 8 4 2 1 00000000 Section IV When Switch 1 is CLOSED 1 a variable terminating character format may be selected for the input and output data In this configuration the power up default terminating characters are LF and CR with the EOI line being set with the output of the Carriage Return CR How ever the two terminating characters can be changed via input data to the DRC 93C as detailed in Table 4 6 If the terminating characters are changed by the user these are only in effect until the instrument is turned off 4 4 2 TALKER and or LISTENER Con figuration Since the DRC 93C is both a TALKER and a LISTENE
283. s ohms or nano farads are selected automatically by the input card type Consequent ly the command for selecting sensor units for control is FOS Temperature units are selected with the same command with K C or F substituted for S Note that only one choice of sensor units volts ohms or nanofarads is available which is dependent on the input card type selected COPYRIGHT 3 88 LSCI Section IV 4 8 2 Units for Sample Display The F1C Command The sample units may be set indepen dently by the command F1C4 The commands for selecting sensor units are F1K F1C F1F and 1 4 8 3 Control Sensor Selection The F2CC N4 Command The sensor to be selected for the control display can be changed by the F2CC N command The quantity C4N is 1 A2 A4 or BO Examples F2CAO F2CBO F2CA4 4 8 4 Sample Sensor Selection The F2SC N Command The sensor to be selected for the sample display can be changed by the F2SC N command The quantity C N is AO Al A2 4 or BO Examples F2SAO F2SBO F2SA4 Caution is advised when using this command if the control sensor is not on Channel B since this command may then be switching the control sensor 4 8 5 Resolution for the Control and Sample The F3CN and F3SN Commands The resolution for the control and sample displays can be set indepen dently with the F3CN and F3SN commands respectively The quantity N4 is a number O thru 4 where
284. s the adjoining text associated with those tables 4 7 INSTRUMENT SETUP COMMANDS AND REQUESTS 4 7 1 EOI Status The ZN Command When EOI end or identify is enabled 20 Table 4 6 the EOI line is set active concurrent with the last byte of a transfer Use of EOI identifies the last byte allowing for variable length data transmissions EOI can be disabled Z1 Table 4 6 4 7 2 Interface Mode Command The MN4 4 7 2 1 Local This message MO Table 4 6 clears the remote opera tion of the DRC 93C and enables front panel operation Pressing the front panel IOCAL button also sets the instrument to local provided the button has not been disabled by the Local Lockout Message see Section 4 7 2 3 See Section 4 5 6 for a discussion of the DRC 93C under local operation while acting as a TALKER 4 7 2 2 Remote The DRC 93C is the local front panel mode when first turned on A remote message 1 see Table 4 6 allows the 93C to be controlled over the IEEE 488 interface In Remote the front panel controls are disabled except the LOCAL button and are then controllable over the IEEE Bus The instrument s initial set up is determined by the front panel settings at the time when the 4 7 Section IV Model DRC 93C instrument is placed into Remote button on the front panel or ad The DRC 93C may also be placed into dressed to talk by the BUS CON remote by pressing the REMOTE TROLLER Table 4 4
285. se of Stycast epoxy can replace the use of Apieson N Grease In all cases the mounting of the sensor should be periodically inspected to verify that good thermal contact to the mounting surface is maintained 10 Application Notes Lake Shore Cryotronics Inc DT 470 SD The SD version is the basic package for the DT 470 sensor line from which all 216mm other configurations are made using the appropriate adapter The base of the 0 98 mm 1 4mm device has a gold metallized surface and is the largest flat surface on the Anode sensor The base is electrically isolated from the sensing element and leads 1 84 all thermal contact to the sensor must made through the base thin braze joint around the sides of the SD package is electrically connected to the k Cathode sensing element Contact to the sides with any electrically conductive material 3 mm must be avoided When viewed with the base down and with leads towards the observer the positive lead anode is on the right For a removable mount the Sd sensor can be3 held against the mounting surface with the CO adapter see below or similar clamping mechanism Any method of clamping the sensor must avoid excessive pressure and should be designed so that thermal contractions or expansions do not loosen contact with the sensor For uses restricted to below 325 K a thin layer of Apiezon N Grease should be used between the sensor and sample to enhance the therm
286. seldom cost effective to keep the conformity error as small as the useful resolution of the controller system Thus in the 14 bit system referred to earlier in this section its 4 mK resolution would be swamped by e g a conformity limited 100 mK Fortunately in a controller such as the DRC 82C the user can select either a temperature or voltage resistance set point and readout The choice between analog and digital controllers turns out to be not a choice at all but an optimum combination of the best features of each True analog control provides a heater output that is a continuous function of the sensor signal and so eliminates the sampled data problem This analog control may be combined with digital circuitry for readout of sensors and power output for setting the PID control parameters and for deriving the set point signal This approach is used in most of the Lake Shore Cryotronics Inc controllers 6 Application Notes Lake Shore Cryotronics Inc For Further Reading 1 E M Forgan On the Use of Temperature Controllers in Cryogenics Cryogenics 14 1974 pp 207 214 This is a cogent discussion of the interaction between the electrical and thermal response times in a typical cryogenic control system The mathematical analyses are straightforward and relatively easy to follow A series on process Control published in the journal Measurement amp Control Part 3 On Off and Proportional Control September 1984 pp 165
287. t in 10 000 and an accuracy of 0 05 of reading for resistances from 10 to 10 000 ohms and 0 25 of range for resistances less than 10 ohms and from 10 000 to 100 000 ohms Sensor Excitation Current range is from 0 1 microampere to 1 milliampere The current is varied automatically to maintain the voltage across the sensor at 1 millivolt for the 9317C and 10 milli volts for the 9318C Current polarity is periodically reversed to allow for automatic digital correction for thermal EMFs in the sensor connections and leads Temperature Range Depends on sensor type used Sensor resistance scales from 1 to 10 000 ohms 9317C or 100 000 ohms iiu can be accommodated Sensors Ordered Separately Card optimized for CGR Series Carbon Glass or GR Series Germanium Resistance Thermometers Other negative temperature coefficient resistors such as thermistors can also be used Sensor Response Curve The DRC 91C 93C display resistance in ohms directly A calibrated sensor and an 8001 Precision Option curve generated using Lake Shore s proprietary Polynomial Interpolation Algorithm are required for the unit to display temperature accurately Input Resistance Greater than 109 ohms sensor voltage measurement Maximum Sensor Power Dissipation Depends on sensor resistance Voltage applied is 1 millivolt for the 9317C power is 1 R in micro watts or 10 millivolts for the 9318C power is 100 R in microwatts Display Resolution 5 digits Displ
288. t performs Lagrangian calculations on the data Any other character Unit performs Straight Line interpolation on the data Temperature Range Setpoint Limit 0 Up to 324 9 K 1 Up to 374 9 K 2 Up to 474 9 K 3 Up to 799 9 K 4 Up to 999 9 K Sensor type used for front panel curve entry here alphanumerics cannot be entered with the standard numeric keypad 0 DT 470 Series Silicon Diode Sensors 1 DT 500 Silicon Diode Sensors 2 TG 100 TG 200GaAs and GaA As 3 100 Ohm Platinum Resistance Thermometers PRT s 4 1000 Ohm Platinum Resistance Thermometers PRT s 5 Rhodium Iron Resistance Sensors 6 Germanium Resistance Sensors 7 Carbon Glass Resistance Sensors 8 Capacitance Sensors 9 Reserved for Thermocouples COPYRIGHT 5 88 B 1 13 thru 18 Stored in the Sensor Curve Information Table typically where the sensor serial number is stored in Precision Options The sensor serial number formats are as follows where is used to indicate a 0 9 numeric Sensor Type rmat DIHHHHE PHHH No S N ODN AU b O N F O B 2 COPYRIGHT 5 88 APPENDIX c DRC 93C Error Code Summary The error codes for the DRC 93C are separated into categories The ErrOx codes are for mainframe error conditions the Errlx codes are for Input Card error condit
289. t point units The IEEE 488 bus actually treats these commands as data in that ATN is high when these device dependent commands are transmitted 4 5 6 TALKER and LISTENER Status For the DRC 93C to be a LISTENER it has to be in REMOTE and can be returned to LOCAL with the MO device dependent command or GTL addressed command as desired For most but not all computers the DRC 93C as a TALKER does not have to be placed in REMOTE operation but can remain under LOCAL control This allows the user to collect data while maintaining front panel control The HP computers will allow this mode of operation If your computer automatically places the DRC 93C in remote and keeps it in remote after the transmission is over sending the additional command MO after the request for data will return the DRC 93C to IOCAL 488 Bus Commands IEEE 488 PG Sus Format REMOTE712 1107 clr7 CLEAR712 LOCAL712 S SPOLL 712 Talk Address Address 21 COPYRIGHT 3 88 LSCI Model DRC 93C 4 6 PROGRAMMING INSTRUCTIONS The following discussion references the DRC 93C at address 12 The allowable address codes are given in Table 4 2 Therefore its Talk ASCII Code is L and its LISTENER ASCII Code is comma The controller referred to in the following discussion is the BUS CONTROLLER and is normally a digital computer It should not be confused with the temperature controller on the bus DRC 93C Set the IEEE Address
290. t the External Scanner has been selected by indicating the REMOTE POSITION DATA in the GAIN window for the Upper and in the RESET window for the Lower Display The instrument uses the REMOTE POSITION DATA the signal applied to the REMOTE SENSOR ID Connector from the Scanner in conjunction with the Correlation Table of Table 3 4 to obtain the Curve Number If the REMOTE POSITION DATA is zero then instrument uses the same Curve Number assigned to the input without the Scanner When there is an 8229 Scanner Option present there are 5 Curve Number assignments for Input A one each for AO A1 A2 A3 and 4 If the REMOTE POSITION DATA is non zero then the Curve Number is selected from the row of the Cor relation Table corresponding to the value of the REMOTE POSITION DATA When there is an 8229 Scanner Option present there is only one Curve Number assignment for Input A A0 3 12 Model DRC 93C Al A2 A3 and A4 all use the Curve Number from the A column of the correlation table 3 9 2 3 Modifying the Correlation Table from the Front Panel The DRC 93C is shipped from the factory with curve 02 stored in all positions of the Correlation Table The Correlation Table is modified by using the CURVE and 44 key and vv key as follows 1 Use the procedure described in the previous section to put the instrument in the External Scan ner mode 2 Apply a signal on the REMOTE SEN SOR ID Connector to indicate a
291. ted the number of times specified by the RAMP COUNT given in the last two digits of the Upper Display The time for each increment is specified by the timer in the Program Step set with TIME key After the specified number of times cone by the RAMP COUNT operation continues at the next Program Step All other parameters change to the displayed values on entering this command during program operation at the beginning of the ramp This command is normally used for rapid warmup where ramp times exceed 0 1K second Yek ninute Step 4 RAMP COUNT Ramp the Setpoint Down Same as Program Command 3 except that the setpoint is ramped down that is the setpoint is decremented by the quantity specified in the setpoint display After ram ang the specified number of times given the OUNT operation continues at the next Program Step This command is normally used for rapid Cooldown where ramp times exceed 0 1 6K minute Step 5 JUMP VECTOR Setpoint Gain Rate and Reset Up or Down The Setpoint Gain Rate and Reset are ramped in this Command The setpoint is incremented decremented in its least significant bit at a rate given in the timer of the Program Step The setpoint begins at the value given in the previous Program Step and increments or decrements to the value specified in this Program Step Similarly the gain rate and reset are decremented or in cremented as required to ramp from the value giv
292. that varies from 0 7 3 volts as the gain setpoint or reset values are changed then the circuit is probably operating cor rectly Now measure the voltage across from TP19 to 21 The voltage should vary from 0 to 1 volt as the analog out signal var ies from 0 to 7 3 volts As the gain or manual heater is increased the analog signal will increase and the voltage between TP19 and TP21 will in crease If the voltage stays at 0 Volts then U45 or U46 is probably bad as long as the raw V TP21 to TP6 is close to 28 volts for the 10 25 Ohm Heater Range 37 and 53 volts for the 25 35 and 35 50 Ohm Heater Ranges respectively The V can be checked by measuring approximately 28V from TP21 to 1 The V value is 50 Volts if a W50 watt option is installed in a DRC 91C or if the resistor setting is 50 ohms on the DRC 93C If a W60 Watt option is 5 7 Section V installed the V voltage should be approximately 44 volts NOTE DO NOT CHANGE the Heater Range switch when the unit is on Changing this switch with the unit on WILL DAMAGE the unit If the Voltage from TP19 to TP21 is correct and there is no heater power on any range than U47 or U48 are probably bad and both should be replaced Before it is decided that U47 and U48 are bad be sure the relays K4 K8 are working If they can be heard clicking as they are turned off and on then they are probably operating properly They are turned off and on by se lecting different h
293. the unit as viewed from the front Gently thread the RS 232C internal cable along the inside edge of the rear panel so that it will not interfere with the installation of the calibration cover or top cover 6 Position the 25 RS 232C Interface connector in the J10 opening on the back panel and secure it in place using the screws provided 7 Install the calibration cover by reversing procedure 3 8 Install the top panel 8223 6 OPERATION The 8223 RS 232C Interface has 256 character FIFO buffer for input commands The interface accepts commands the same as for the IEEE 488 Interface until it sees the End of Line EOL sequence The 8223 requires a carriage return line feed CR LF or just line feed LF as its input EOL and transmits carriage return line feed CR LF as its output EOL Following the EOL Sequence the command string is processed Operation of the Interface link is initiated by the computer The computer will transmit either a Program Code or an Output Request to the 8223 Interface The DRC 91C 93C will respond to the Output Request with the appropriate response or with the response and an error message if an error was 8223 4 considered the Model DRC 91C 93C detected The interface responds to Program Code Commands by storing the variables input The Programming Codes given in Tables 4 4 4 7 and 4 8 are input only and do not result in a response from the interface The
294. the Upper display will begin flashing Use the keypad to enter the temperature of the point in kelvin The decimal point can be used but the resolution will be limited to If the entry is begun but not as desired the CLEAR key can be used to clear the display to restart The first and last points entered are determined by the temperature coefficient of the curve being en tered For a negative temperature coefficient N curve the first data point 01 is 499 9K and 0 0000 volts For a positive temp erature coefficient P curve the first data point is 0 0K and 0 0000 volts The quantity is accepted for the temperature when the ENTER key is pressed NOTE You cannot use the 4 key or Y key when entering curve data Only the keypad 0 9 and and the CLEAR key are active After the temperature is entered the Lower Display will begin to flash The keypad is used to enter the Raw Units Data for the point as described in Table 4 14 The entry is accepted when the ENTER key is pressed Another point can be added by press ing the POINT key After the curve has been entered the last data point to enter is 0 0K and 6 5536 volts for N type and 999 9K and 6 5536 volts for P type curves COPYRIGHT 3 88 Section III NOTE Failure to enter the correct curve end points will result in unpredictable results Pressing the PROG key will return operation to normal with the curve being entered into the memory of the i
295. the excitation current is not a 0 0 gt true dc current but has an ac component superimposed on the dc 300 Although the ac component can be due to a poorly designed current supply a more common source of the ac is noise induced in the FIGURE 1 Voltage temperature curve for a typical measurement circuit This noise can be introduced through improper silicon diode temperature sensor at a constant current shielding improper electrical grounds or ground loops Currently of 10 uA available voltmeters have sufficient normal mode rejection capabilities their dc measurement modes that these noise effects can go completely unnoticed if they are not explicitly checked The equivalent temperature error which may be caused by this problem is typically a few tenths of a kelvin although an extreme case with a 4 K aa SEAIN pasas Cay error has been observed IV CURVE The effect of the ac noise appears as a shift in the dc voltage measurement due to the nonlinear current voltage characteristics of the diode An illustration of this effect is shown in Fig 2 where an exaggerated IV curve is given An induced ac noise current superimposed on the dc operating current lac is shown along the current axis The resulting voltage seen by the voltmeter is shown along the voltage axis The nonlinear IV characteristics of the diode have caused a distortion in the ac voltage signal making it asymmetrical with respect to the voltage
296. the temperature measurement depends directly onf the specifications of the current source and the voltmeter A current source operating at the level of 10 0 01 microamperes 40 1 gives a nominal temperature uncertainty of 10 millikelvin 0 01 K which is probably suitable for most applications The voltmeter resolution required can be estimated from the sensitivity dV Dt of the DT 470 Temperature K Sensitivity mV K 305 2 4 77 1 9 4 2 33 Multiplying the above sensitivity by the desired temperature resolution in kelvin will give the required voltage resolution in millivolts The static impedance of the DT 470 sensor operating at 10 microampere current is on the order of 100 000 8 Therefore the input impedance of the voltmeter must be significantly larger than this to avoid measurement errors Voltmeters with input impedances of greater than 109 or 1010 ohms should be used Good quality instrumentation must be used and all instrumentation and wiring should be properly grounded and shielded Temperature measurement errors will result if there is excessive AC noise or ripple in the circuitry Further details can be found in the article by Krause and Dodrill given in the references NOTE All materials mentioned which are used in sensor installation are available from Lake Shore Cryotronics Inc References Krause J K and Swinehart P R 1985 Demystifying Cryogenic Temperature Sensors Photonics Spectra August 61 68 Av
297. these voltage values If Reference Junction Compensation is desired the thermocouple curve must be normalized to zero degrees Celcius Compensation also limits the practical range of the card by approximately the room temperature voltage of the thermocouple used The controllers are designed to operate on sensor curve data in the range of 0 00000 to 3 00000 volts so thermocouple voltage must be converted to this range before it is entered into a curve table To obtain the proper table value from a thermocouple voltage it must be summed with 15 millivolts to make it positive and multiplied by one hundred to shift resolution 100 VTHERMOCOUPLE mV 15 mV A 15 0000 millivolt thermocouple voltage will result in a 0 00000 volt table value and 15 0000 millivolts will result in 3 00000 volts Once the Thermocouple Curve has been converted carefully read and follow the instructions in DRC 91C Manual Section 4 14 or DRC 93C Manual Section 4 16 on how to enter the data into a controller 9305 8 EQUIPMENT CALIBRATION SCHEDULE AND The design of the 9305 Thermocouple Input Card is such that calibration should not be required more often than every six to twelve months in order to keep the card within its accuracy specification However if calibration is required the following equipment is needed 9305 8 Model DRC 91C 93C 1 Digital Voltmeter DVM 5 1 2 digit resolution or better 2 Pre
298. thin the instrument is available which aver ages up to ten readings This read ing mode eliminates noise within the cryogenic system analogous to aver aging within a digital voltmeter This function can be examined and selected or deselected by the FILTER key and the 44 key and vv key When the FILTER key is pressed the words On filter on and OFF filter off are presented in the Upper and Lower Displays To toggle the fil ter of the input of the Sensor shown in the upper display hold down the FILTER key and press the 44 key Similarly holding the FILTER key and pressing the vv key toggles the filter of the input of the Sensor shown in the Lower Display from On to OFF In operation an indicator will appear in the upper left hand corner of the sign digit in the Upper and or Lower Displays to flag Filter on for that input If the averaging algorithm is used displayed temperature is the average of between 1 and ten readings de pending on the temperature varia tion If an abrupt change in tem perature is observed averaging is disabled and the last calculated reading is displayed As the dis turbance is reduced in value the averaging gradually increases until a total of ten readings are con sidered 3 8 9 Math Functions The DRC 93C has three built in Math Functions to retain the maximum and minimum temperatures as well as the maximum deviation from the setpoint for the Sensor in the Upper Display and the Senso
299. this primer is to address this problem by presenting some fundamental and practical concepts of control at low temperatures The so called three mode or PID controller utilizing Proportional gain Integral reset and Derivative rate functions will be discussed and examples given of its operation and adjustment While the emphasis will be placed on analog control systems the advantages and disadvantages of digital versus analog control will also be presented CHARACTERISTICS OF CRYOGENIC TEMPERATURE CONTROL SYSTEMS The adjective cryogenic as applied to temperature control systems defines a set of conditions that distinguishes such systems from those for which the great majority of applications exist i e industrial processes in which temperatures are above and often well above room temperature There are at least five factors which crucially affect temperature control performance when one compares a cryogenic system with that existing inside a furnace for example 1 The values of heat capacity lower Cp and thermal conductivity often higher x are such that much shorter thermal time constants are the rule at low temperatures 2 The temperature sensor used in a furnace is almost always one of a variety of thermocouples with sensitivities in the 10 100uV C range In the cryogenic regime resistance thermometers both metallic and semi conductive diode and capacitance thermometers provide from one to three ord
300. three different dc operating currents with a 60 Hz signal superimposed Equivalent temperature errors are indicated along the right edge Application Notes Lake Shore Cryotronics Inc The utilization of the small signal model has the advantage of being analytically simple However the model does not contain the nonlinearity inherent in the forward biased IV characteristics of a p n junction In an attempt to retain the non linear characteristics V lac lac cos t was expanded in a Fourier series The first term constant term is just the average dc voltage in Eq 3 and is not seen by the voltmeter operating in an ac measurement mode The remaining terms in the Fourier series can then be used to calculate the rms voltage which will be read by the voltmeter 2 semet dt 7 n 1 m 1 2 _1 Vs ze zl a cosnat where an and bm are the Fourier coefficients In order to evaluate the Fourier coefficients V I was expanded a power series around lac Sufficient terms were maintained in both the power series expansion and in Eq 7 to give a second order correction to Eq 5 2 Lim z em T J li RT 8 tls lac 15 Substitution of this result into Eq 4 gives the 77 offset voltages shown Fig 4 by the dashed line Slightly better agreement with the experimental data is seen at the higher rms voltages At 305 K the two calculation methods are in even better agreement and a plot similar to Fig 4 would show
301. ting service The SPD command ends the polling sequence 4 5 Section IV 4 5 4 The Unaddress Commands The Unaddress Commands in Table 4 3 are used by the BUS CONTROLLER to remove any TALKERS or LISTENERS from the bus The ATN line is asserted low when these commands are asserted UNL Unlisten LISTENERS are placed in the listener idle state by the UNL command UNT Untalk Previous TALKERS will be placed in the TALKER idle state by the UNT command Table 4 3 summarizes the IEEE 488 Bus Commands acknowledged by the DRC 93C 4 5 5 Device Dependent Commands The DRC 93C supports a variety of device dependent commands to allow the user to program the instrument remotely from a digital computer and to transfer measurements to the computer These commands are sent from the computer BUS CONTROLLER to the DRC 93C as one or more ASCII characters that tell the device to Table 4 3 Message HP9825A HP86 YE co ANNI LL COMMA 1 Tietz Commands Remote REN Interface Clear IFC Universal Commands Local Lock Out LLO Device Clear DCL Addressed Command Selected Device Clear SDC Go to Local GTL Serial Poll Enable SPE Unaddress Commands Unlisten UNL Untalk UNT U is the controller computer 4 6 clr712 1c1712 rds 712 S Model 93 perform a specific function For example the command sequence FOK sent by the BUS CONTROLLER to the DRC 93C is used to select kelvin as the se
302. tion Set s ts 3 8 3 8 8 Filtering the A and B Inputs s e o 3 9 3 8 9 Math Functions lt x lt e v w sw 4 2 3 9 3 9 SENSOR CURVE SELECTION NC E EU 3 10 3 9 1 Standard and Precision Option Curves AY 3 10 3 9 1 1 The Precision Option a Gy tu de 3 10 3 9 1 2 Display of Accessed Curve Number A Em 3 10 3 9 1 3 Addition of 8229 Scanner Option 3 11 3 9 1 4 Changing the Curve used by a Sensor 3 11 3 9 2 External Scanners Models 8085 RC hips tue of 3 9 2 1 Selection of the REMOTE POSITION DATA wet CBS LL 3 9 2 2 Correlation Table E 3 9 2 3 Modifying the Correlation Table from the Front Panel Suk fel ven ES eub 3 9 3 Programming Curves from the Front Panel eae 3 13 3 9 3 1 Accessing Stored Curve Data 3 13 3 9 3 2 Entering New Curves Ww uo 3 14 3 9 3 3 Editing Existing Curve Data iis 2 3 15 3 9 3 4 Summary of Curve Programming from the Front Panel ey Ra We ew 3 15 li COPYRIGHT 3 88 LSCI TABLE OF CONTENTS CONT D 3 10 SET POINT AND CONTROL BLOCK e lt 3 10 1 SETPOINT e s lt o n 3 11 2 3 11 3 RATE 3 11 4 RESET Soe Mey 3 11 5 MANUAL HEATER POWER oe 3 11 HEATER POWER e s oo 3 11 1 HEAT
303. ts see the Application Note enclosed as an Appendix to this manual To change the Rate press the RATE key and use methods 1 2 and or 3 described above 3 10 4 RESET Adjusts reset integral time con stant of integrator Effectively sets time constant between 1 second and 990 seconds These are dis played as 0 1 to 99 To change the RESET press the RESET key and use methods 1 2 and or 3 described above 3 10 5 MANUAL HEATER POWER The DRC 93C provides a feature in which the heater power can be set manually The Manual Heater Power value is indicated on the Bar Graph by a blinking segment at the percent at which it is set To change the Manual Heater Power press the MANUAL HEATER key and use methods 1 2 and or 3 described above If the decimal number 5 is entered the Bar Graph will blink the segment at 5 If a zero is entered immediately after the 5 thus entering 50 the Bar Graph will blink the segment at 50 The CLEAR key cancels anything entered and returns the instrument to normal operation The ENTER key inserts the new Manual Heater Power and then returns to normal operation COPYRIGHT 3 88 Section III 3 11 HEATER POWER 3 11 1 HEATER The Bar Graph displays the magnitude of the heater power in percent of full scale Full scale is defined as the product of the maximum heater current of one ampere squared times the heater resistance times the range setting The DRC 93C Tempera ture Controll
304. turns the rate off 4 16 Model DRC 93C 4 9 6 Heater Range The R Command The heater range can be changed over the bus with the RN command R6 and up are equivalent to the RO command see Table 4 10 4 9 7 Manual Heater Power The H Command The Per Cent Manual Heater Power can be set between 00 and 99 with this command Total power can be greater or less than this setting dependent on control settings and actual control sensor temperature 4 9 8 The W3 Data String The settings for the gain rate reset manual heater power heater range as well as the instantaneous of Heater Power can be transmitted from the DRC 93C with the W3 command The command SPIDR or any combina tion without a value following the letter sets the chosen parameters to O e g SP sets the set point and gain to O 4 10 THE SCANNER INPUT CARD 4 10 1 SCAN Programming Instructions NOTE The YA YB Table 4 11 and Y2S Table 4 7 commands should be issued when the SCAN mode is Holding Changing a SCAN time or Scanner Channel while the unit is actively scanning may cause unpredictable results 4 10 2 Setting the Dwell Time The YAN41N9N4 and YBON N4 Commands The time spent on a given scanner channel can be varied between 0 and 99 seconds by setting the dwell time for that channel This can be done over the IEEE 488 Bus with these commands or from the front panel Setting the dwell time to O skips that channel COPYRIGHT
305. uced by a factor of 20 short term controllability is better than 2 mK With diodes there is no need for a sensor pre amplifier which would precede the set point control and deviation amplifier However in the case of resistance thermometers including both semiconductor and metal types a pre amplifier becomes necessary In a dc measurement system such as is used in the DRC 82C it is sometimes possible to obtain temperature control stability with resistance thermometers superior to that obtainable with diodes This requires a highly stable and adjustable constant current source in addition to a pre amplifier designed for very low noise and drift The choice of sensor is not at all obvious it depends on many factors besides sensitivity including sensor size time response power dissipation magnetic field dependence and temperature range In the less common case of cryogenic thermocouples the very low sensitivity 10uV K requires quite large pre amplifier gains and a stable reference junction arrangement Thermocouples are sometimes used when sensor size or time response are more important than temperature stability and accuracy At cryogenic temperatures thermocouple accuracy does not approach that of a semiconductor diode or resistance thermometer when either are properly installed VII ANALOG VERSUS DIGITAL CONTROL In this day of computers designing digital instrumentation with a microprocessor is definitely in vogue In a digital control
306. ument interfacing The IEEE 488 INTERFACE of the DRC 93C fully complies with the IEEE 488 1978 standard and incor porates the functional electrical and mechanical specifications of the standard It also follows the supplement to that standard titled Code and Format Conventions for use with IEEE Standard 488 1978 This section contains general bus information Model DRC 93C interface capabilities addressing and the programming instructions that control the DRC 93C functions 4 2 GENERAL IEEE SPECIFICATIONS AND OPERATION The following discussion covers the general operation of the IEEE 488 interface For a more detailed description of signal level and interaction refer to the IEEE Standard 488 1978 publication IEEE Standard Digital Interface for Programmable Instrumentation All instruments on the interface bus must be able to perform one or more of the interface functions of TALKER LISTENER or BUS CONTROLLER A TALKER transmits data onto the bus to other devices A LISTENER receives data from other devices through the bus The BUS CONTROLLER designates to the devices on the bus which function to perform The DRC 93C performs the functions of TALKER and LISTENER but cannot be BUS CONTROLLER The BUS CONTROLLER is your Digital Computer which tells the DRC 93C which COPYRIGHT 3 88 LSCI IV OPERATION functions to perform The interface works on a party line basis with all devices on the bus connecte
307. ure K C or shown with annunciators Model DRC 93C Option provides four additional channels of sensor input to the A input The A input is channel A with the additional inputs desig nated 1 4 with the selection indicated on the display Specifications Model DRC 93C Temperature Controller Resolution Display resolution is 0 001K below 100K 0 01 above 100K 0 0001K below 10K for 9317C Resistance Sensor Input Card Resolution can be user limited to 1K 0 1K or 0 01K Same resolution considerations apply for C and F Changes made by front panel keys or over interface Temperature Accuracy Dependent on Sensor Input Card and Sensor See Input Options available Temperature Range Dependent of Sensor Input Card and Sensor Temperature Control Set Point Keypad selection as a numeric value as a step change from prior value or incrementally via up down counter All keypad operations can be duplicated with optional interfaces Set Point Resolution Selection in kelvin celsius fahrenheit or Sensor Units Temperature to 0 1 in corresponding units in Sensor Units O 1mV in voltage 0 01 ohms but limited to five digits in resistance and 0 001 nanofarads out of 15 nanofarads 0 01 nanofarads out of 150 nanofarads for second scale in capacitance May also be set over the interface Typical Controllability Dependent on Sensor its temperature and the resultant Sensor gain i e sensitivit
308. ure reading requires the use of another type of sensor in zero magnetic field This accurate sensor can be placed in the other Input Slot of the DRC 91C DRC 93C The 9215 15 configuration is used with Capacitance sensors with a maximum of 30 nanofarads for example Lake Shore 5 401 Series Sensors The 9215 150 configuration will accommodate Capacitance sensors of up to 150 nanofarads for example Lake Shore CS 501 Series The card can be configured by the user as either a 15 nanofard 9215 15 or 150 nanofarad 9215 150 card by switches on the card Specifications for the Model 9215 COPYRIGHT 2 88 LSCI Capacitance Input Card Configura tions are given in Table 9215 1 Table 9215 1 Specifications of the Capacitance Input Card Display Resolution 5 digits Display Units Capacitance in nanofarads Temperature Accuracy A function of sensor sensitiv ity See Table 9215 2 Unit supports capacitance only Sign of Temperature Coefficient User Selectable by Switch on on DRC 91C Keys on DRC 93C or via Computer Interface Magnetic Field Sensitivity 0 15 for B 19 Tesla and T 4 2K See Section 9215 3 9215 15 Sensor Excitation 5 kilohertz charging current Capacitance Range O to 15 nF 0 30 nF with reduced accuracy Sensor ordered separately CS 401 Series from ISCI or or other Capacitance Sensor Resolution 0 001 nF Accuracy 10 25 of Full Scale Range 0 000 to 29 999 nF Analog O
309. ust PWR VREF until the DVM reads 1 0000 volts 5 Repeat 3 and 4 until they do not change Note TP 24 CNT V is the control voltage For the 9210 20 3 it is the voltage across the sensor for the 9210 20 6 it is 0 45 times the voltage across the sensor TP 25 is the set point voltage and is of opposite sign from TP 24 These two voltages Rigebraically sum to the error signal 5 7 TROUBLESHOOTING Information on troubleshooting the Model DRC 93C controller is con tained in this Section 5 7 1 Sensor Current If the sensor current is not within specifications Section 5 5 3 then adjust the current trimpot on the input card Section VII COPYRIGHT 3 88 LSCI Model DRC 93C 5 7 1 Monitor Voltage Display Voltage or Resistance The display reading in volts or resistance should match the monitor reading and the voltage across the sensor except for the 9215 9305 9317C and 9318C input cards and the 6 configuration If the readings do not match then the input card should be calibrated If the moni tor reading is incorrect and can not be adjusted then the following IC s may need to be replaced Old Input cards 1 8210 8211 cards replace 05 2 8219 8220 cards replace U5 If that does not solve the problem then replace U4 New Input Cards 1 9210 9220 cards replace U5 2 For the 9318C the monitor volt age should be approximately 10mV If it is not between 5 16mV then U16 U13 or U10 could be ba
310. utput Signal 0 1 times capacitance nF in volts 9215 150 Sensor Excitation 1 kilohertz charging current Capacitance Range 0 to 150 nF Sensor ordered separately CS 501 Series from LSCI or other Capacitance Sensor Resolution 0 01 nF Accuracy 0 25 of Full Scale Range 0 00 to 149 99 nF Analog Output Signal 0 02 times capacitance nF in volts 9215 1 9215 Capacitance Input Card DRC 91C 93C Table 9215 2 Typical Temperature Ranges and Sensitivities CS 401GR A1 1184 CS 401GR B1 1186 CS 4011G Cl 11 1972 12 9423 1248 15 3912 14 9303 9 3561 5 9762 4 3180 3 9989 5 5012 6 5884 7 1334 10002 9 0452 10 1940 14 0355 21 7233 91 0746 130 140 Notes 1 9215 15 configuration 2 9215 150 configuration 3 No Calibration Data Available 9215 2 COPYRIGHT 2 88 LSCI Model DRC 91C 93C 9215 3 NOTES ON 5 501 CAPACITANCE SENSORS 9215 3 1 Short Term Stability The capacitance sensor provides very stable temperature control over long periods of time However since an operational aging phenomenon exists some care must be exercised in their use The short term minutes to hours capacitance temperature drift is initiated by a thermal perturbation of the sensor In order to minimize this short term drift it is recommended that approximately one hour be allowed for the sensor to stabilize after the initial cooldown short term drift is then on th
311. vin and in the case of the 9317C resistance card to 0 0001 kelvin 0 1 millikelvin below 1 kelvin Please note that this is display capability and neit her system resolution nor necessari ly accuracy of the reading Also note that if the sensitivity of the sensor is too low to support this resolution i e one bit cor responds to greater than the above resolution some temperatures may be skipped This will be true for a silicon diode sensor between 30 kelvin and 100 kelvin where the sensitivity is approximately 2 5 millivolts per kelvin and the volt age resolution is 0 046 millivolts For this case the resulting temp erature resolution is 0 046 2 5 0 018 kelvin However below 30 kelvin the silicon diode sensitivity is approximately 25 millivolts per kelvin which results in an approxi mate resolution of 0 002 kelvin 0 046 25 System Resolution Versus Sensor Sensitivity Sensor Maximum Temperature Sensitivity Resolution in kelvin 9317C 9318C 9220 P2 P3 R12 0 001 0 1 to 0 01 0 01 0 01 to 0 001 0 1 0 001 to 0 0001 1 0 0001 to 0 00001 The input resolution is 0 05 millivolts for the 9210 9220 3 and is 0 1 millivolts for the 9210 9220 6 Note 2 varies between 107 This assumes_an ability to resolve between 1 part in 104 and 1 part 10 where and 10 1 dR dT and 4R R COPYRIGHT 3 88 Model DRC 93C 3 8 8 Filtering the A and B Inputs An averaging algorithm wi
312. y 4 tit vtile 2 52 5200 92 2 6 lt ag gt gt V p S z tu eo 8 3 T HT pp Trtrtrr FL 2 _ PEREEEEEEELE TEL m enc eee Ie RCN 51252 RS RE GRR AY ELI isi a ME S ah T s LEER 8 a SHEET 1 OF 3 PIN 7 GND 8 498 67 B81 4 T6K NOTE 014 PIN 14 VCC NO z S a lt 1N4SSA Ril 47 6 LAKE SHORE CRYOTRONICS INC i i 24 U14 A 7406 8 DECDR Sy CREER 74 8138 22 28 99 13 13 45 SSCDD81 cre L 1N4SSA CR3 1N469A 33 47 5K 4 V c ev ll ILTLLLLLLLLLLLLI ant L 6581 1 rr Q 288887 DOOO EEEE TITE nna 42 i E 8 m E Zee p Q PAK 2 28 27 24 22 21 8 Figure 93C 2e Schematic DRC 93C Display Driver Board 1 Digital Section 4 12 0 RR EEE EE EE S yrs gt oS oe ru gio AMS p sn 5 ER ex He tt LAKE SHORE CRYOTRONICS INC DRC 99C DISPLAY DRIVER BOARD BAR GRAPH DRIVE SECTION ana O
313. y Typically better than 1mK in a properly designed system below 30K and 5mK above 30K using a COPYRIGHT 3 88 LSCI Model DRC 93C Diode Sensor But for example a thermistor due to its large sensitivity may result in a controllability approaching 0 5mK above 200K over a narrow tempera ture range in certain systems and a germanium below 10K may control to 0 in another system Control Modes GAIN integral derivative RATE Set numerically 0 0 to 99 of internally es tablished range or incremented via front panel keypad Continuous two digit display of each mode Manual Mode allows 0 to 100 of available heater power to be selected via keypad Auto and Manual modes can be used concur rently All keypad operations can be duplicated thru interfaces Proportional RESET and Heater output Up to 50 watts 1A 50V standard Five output ranges can be selected either from front panel interface provide approximate decade step reductions of maximum power output Optional 60 watt output available Rear panel maximum current limit for MAX scale Heater output Monitor BAR display continuously shows heater current or power output as a percentage of range with a resolution of 1 Control Sensor Either Sensor Input selected from front panel or remote interfaces General Sensor Voltage Monitor For 9210 Option buffered output of each COPYRIGHT 3 88 LSCI Section I diode sensor voltage F
314. y or decrement the quantity with the vv key The operation is completed with the ENTER key or cancelled with the CLEAR key 3 The quantity can be incremented or decremented by any amount as follows Enter the digits of the increment or decrement desired via the keyboard The decimal point can be entered as desired Pressing the 44 key will add the quantity and the YY key will subtract the quantity The opera tion is completed with the ENTER key or cancelled with the CLEAR key Methods 2 and 3 can be used together in any combination This same pro cedure is also used to enter the dwell except that the minus sign and decimal point are not permitted See section 3 8 5 3 10 1 SETPOINT To change the Setpoint press the SETPOINT key an then use methods 1 2 and or 3 described above If in degrees celsius or degrees fahrenheit the key can be used to change the sign of the setpoint 3 10 2 GAIN Variable gain proportional allows adjustment of overall controller gain over a range from 0 1 to 99 To change the Gain press the GAIN key and use methods 1 2 and or 3 described above 3 10 3 RATE Adjusts rate time constant of dif ferentiator Effectively sets time _ constant between 1 and 990 seconds COPYRIGHT 3 88 Model DRC 93C These are displayed as 0 1 to 99 which means that the displayed num ber is multiplied by ten to get the rate in seconds For a discussion of beats per second and time con stan

Model DRC-93C - Lake Shore Cryotronics, Inc.

Contents

Download Pdf Manuals

Related Search

Related Contents