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Four Channel Digital Electrometer User Manual

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1. o o EAR LA xc VEN J o XZ Screen Guard V Bias PSU Figure 48 Guarded and screened input 22 2 Temperature Offset factors are generally exacerbated by increased temperatures Temperature fluctuation can appear as variation in the reading When very small currents need to be measured the experimental arrangement should be temperature stabilized as far as possible 22 3 Triboelectric effects When there is relative movement of insulators and conductors in signal cabling free charge is released This is particularly the case for the screen of coaxial cable The resulting potential 1404 User Manual 1404 UM 130129 Page 88 of 104 PSI System Controls and Diagnostics difference can drive small currents to the signal conductor across the high impedance of the insulator Additionally charge may leak in directly if there are any breaks in the insulator Special low noise cable is available with graphite lubrication bonded to the insulator to reduce charge generation and to conduct any released charge away harmlessly Belden low noise RG 58 9223 has been tested with Pyramid Technical Consultants Inc gated integrator products and gives good results The following figure shows triboelectric noise measured when standard RG 58 coaxial cable is flexed and the result of the same flexing on low noise RG 58 2 50E 09 2 50E 09 2 00E 09 2 00E 09 1 50E 09 1 1 50E 09
2. 3 Models I404 Four channel gated integrator electrometer with 100pF and 3300pF feedback capacitors XP30 20 10 5 2 Add positive 0 to 3000 V 2000 V 1000 V 500 V 200 V auxiliary bias output XN30 20 10 5 2 Add negative 0 to 3000 V 2000 V 1000V 500 V 200 V auxiliary bias output Cx y Change feedback capacitors to x pF and y pF default is C100 3300 Example 1404 XP10 C100 1000 1404 with 1000V positive auxiliary bias output 100 pF and 1000 pF feedback capacitors 1404 User Manual 1404 UM 130129 Page 11 of 104 PSI System Controls and Diagnostics 4 Scope of Supply 1404 model as specified in your order PSU24 40 1 Plug pack 24 VDC power supply ADAP D9F MINIDIN Adaptor cable DSub 9 pin female to mini DIN six pin male ADAP LEMO BNC Adaptor Lemo 00 coax male to BNC jack USB memory stick containing User manual PSI diagnostic software files Optional items as specified in your order OEM customers may not receive all items 1404 User Manual 1404 UM 130129 Page 12 of 104 PSI System Controls and Diagnostics 5 Optional Items All cable lengths can be customized upon request 5 1 Power supplies PSU24 40 1 24 VDC 45W PSU universal voltage input plug receptacle for standard IEC C14 three pin socket with output lead terminated in 2 1mm threaded jack 5 2 Signal cables and cable accessories CAB BNC COLN 25 BNC Cable RG 58 coaxial low noise BNC plug to
3. Monitor Monitor output output TTL Analog Figure 33 Dataflow in the I404 The two left hand blocks of figure 33 represent the process in which raw ADC values are turned into accurate currents in amps by the process of averaging and application of the calibration gain factors These currents are what you get back from the I404 via the communications link irrespective of how you set the compensation factors So when you change the compensation factors expect the position readback to change but not the currents However the values A B C D the inputs to the position algorithm can be optionally directed to the monitor outputs The output of the position algorithm is available over the communications channel and from two of the monitor outputs 1404 User Manual 1404 UM 130129 Page 54 of 104 PSI System Controls and Diagnostics 14 2 Position algorithms Now we have the compensation corrected values A B C D then the I404 can calculate the position responses and send the results over the communications interface and to the monitor outputs The two available position calculations are as shown in the following figures X A D A D Y B C B C Figure 34 Single axis readout from a pair of split sensors lg y Y A B C D A B C D X X A C B D A B C D lp lc Figure 35 Two axis readout from a quadrant sensor The position algorithms shown in figures 34 and 35 are implemented in the 1404
4. r 93 j EDUrn 97 1404 User Manual 1404 UM 130129 Page 5 of 104 PSI System Controls and Diagnostics 25 26 27 28 29 30 31 Ret rns PLOCeMULe a MM 98 SUPP OL Esse CLE 99 DSP OSA siccsisccssateoncsnsseascaassassevasousceacecessevsseasccaccesteesecoossuesiaeducsecsouacsscredassacsousdosequssvacsenseadecedsesadeunseas cessebeseascuas 100 Declaration of Conformity scscccsscscscscssscssssscssscssscssccsccsscssccssecssesssssscsscesscsssesssscssscesssssssscssscssseseoess 101 Hardware Versions eisiuscseccccaicedsscscteccsstacesssctatensescecedescdsdeuseatacecoscacsesseveosedssebsgnssasenteuceetevesastadaassntetesoastoeedsses 102 Firmware compatibility E n 103 User Manual Revision History eee eee eese esee eee ee ette etta etna etna teas tta stas tas staat en setas eas ene senes ease ense ta sess enae 104 1404 User Manual 1404 UM 130129 Page 6 of 104 PSI System Controls and Diagnostics Table of Figures Figure 1 1404 chassis end panels 17 Figure 2 1404 case side and plan views Dimensions mm 18 Figure 3 1404 block diagram 19 Figure 4 A current to be measured 20 Figure 5
5. 1404 User Manual 1404_UM_130129 Page 95 of 104 PSI System Controls and Diagnostics the current inputs output position functions Monitor frequency appear incorrect Reflections in long coaxial cable Look at monitor signal with an oscilloscope Terminate with 50 ohm at the receiving end Monitor outputs do not reflect compensation factor changes Use factors for monitor outputs bit is not set Check whether bit is set Use appropriate setting Position output inaccurate Incorrect compensation factors Determine and load the correct factors Position readout incorrect Signals are not connected to the correct inputs Connect the signals from the sensor as necessary for the position algorithms 1404 User Manual 1404_UM_130129 Page 96 of 104 PSI System Controls and Diagnostics 24 Maintenance The 1404 does not require routine maintenance There is risk of contamination which may degrade performance if the case is opened There are no user serviceable parts inside A CAUTION High voltages can be present inside the case if the HV option is fitted Do not open the case when power is applied The 1404 is fitted with a 1 1 A automatically resetting positive temperature coefficient PTC fuse in the 24 VDC input No user intervention is required if the fuse operates due to overcurrent The fuse will reset when the overcurr
6. Internal The start trigger is generated internally by the 1404 once the initiate message is received so the predefined acquisition 1404 User Manual 1404 UM 130129 Page 49 of 104 PSI System Controls and Diagnostics sequence runs at once This is like the autorun feature on an oscilloscope External Start A rising falling edge on the gate input starts the predefined acquisition sequence The external mode requires a physical signal via the gate input BNC The gate input requires a TTL level and presents a TTL gate impedance To avoid spurious signals due to noise we recommend that you fit a 50 ohm terminator to this input if you are not using it If your trigger source is able to drive a 50 ohm load we also recommend this termination if you are using the input 13 4 Calibration The 1404 contains a high precision high stability 500 nA true current source which is used for the self calibration sequence It is switched to each of the channels in turn in an automated sequence when you request a calibration The gain numbers that result reflect the factor by which the feedback capacitors differ from their nominal values The gain factors are stored in EEPROM in the 1404 microcontroller upon request and are then used to convert the ADC readings into charge in coulombs Current in amps follows directly because time difference between the start and end ADC readings is known exactly If
7. 1404 User Manual 1404 UM 130129 Page 64 of 104 PSI System Controls and Diagnostics 16 1 5 Auxiliary HV out SHV male To mate with standard SHV connector such as Radiall R317 005 High voltage on center pin 3000 VDC maximum 16 1 6 Ground lug M3 threaded stud To mate with M3 ring lug 16 2 Rear panel connectors 16 2 1 Power input 2 1 mm threaded jack To mate with Switchcraft S761K or equivalent x Center pin 24VDC Outer OV 16 2 2 RS 232 and RS 485 communications Six pin mini DIN socket PS 2 mouse keyboard type Pin 2 External view on connector solder side of mating plug 1 RS 232 Tx RS 485 Tx 4 n c 2 RS 232 Rx RS 485 Rx 5 RS 485 Tx 3 Gnd 6 RS 485 Rx 1404 User Manual 1404 UM 130129 Page 65 of 104 PSI System Controls and Diagnostics The socket incorporates a sensor switch that allows the 1404 to detect that a plug has been connected When a connection is made the RS 232 RS 485 transceiver is active and the communication mode is set by the mode switch When there is no connection the fiber optic channel is active 16 2 3 Fiber optic communications ST bayonet To mate with ST male terminated fiber optic cable Transmitter Receiver light gray dark gray E Take appropriate care when making ST connectors Do not apply excessive force or you may damage the connector Most ST plugs have
8. 1404 Four Channel Digital Electrometer User Manual Pyramid Technical Consultants Inc 1050 Waltham Street Suite 200 Lexington MA 02421 USA US TEL 781 402 1700 FAX 781 402 1750 EMAIL SUPPORT PTCUSA COM Europe TEL 44 1273 493590 PSI System Controls and Diagnostics 1 Contents 1 jU P 2 2 Safety Information eC 9 3 Models 11 4 MIeniEDNlnuig e 12 5 Optional Items 32 ni nere Pat p testae Dette eo epdoPo eU sa iss epa ps bre roiie osise eesse soeieto oaeeo Debra eS isa ina dU dpa 13 3 1 PBowersupplies za pi DE p Be Re 13 5 2 Signal cables and cable accessories eese eene teen nennen teens 13 oJ Data cables a eR ERR ERE UENIRE E ERE A ETRE Raed 13 XA Fibersoptic lo0p si S deep tense tne huis entes EUR eder RE 13 6 Intended Use and Key Features eee eee eee eese eese eese eese teneat ense tens essees s tens oran orasons s stesse eene otaota 14 DE NEUTER 14 62 Key Fedtures i ns utes mee ber e aeg e i oa o ER HER Men e EN TR ERR INE E e ee Rae e v E FRANE 14 7 Muss ein oreo nsei s0os 15 8 How the 1404 Works an Overview eese esee reete entente ent tntn sons ta tns tn tintas tn stata sons ta tasa sensns tassa tasa sin snuo 19 Sel Current measurement DrOC
9. 350 mA typical 500 mA max Controls Two rotary controls for loop address and communications mode Displays Status LEDs for power device status communications mode data traffic HV on indicator LED with auxiliary HV PSU option Case Stainless steel sheet Case protection rating The case is designed to rating IP43 protected against solid objects greater than 1mm in size protected against spraying water Weight 1 64 kg 3 6 Ib Operating environment 0 to 35 C 15 to 25 C recommended to reduce drift and offset 7096 humidity non condensing vibration 0 1g all axes 1 to 1000Hz Shipping and storage 10 to 50C environment 80 humidity non condensing vibration 2 g all axes 1 to 1000 Hz Dimensions see figures 1 and 2 1404 User Manual 1404 UM 130129 Page 16 of 104 PSI System Controls and Diagnostics SIGNAL INPUTS BNC HV OUT SHV Analog Monitor TTL Monitor GROUND LUG HV ON LED M3 GATE BNC MONITOR OUTPUTS MONITOR OUTPUTS ANALOG VOLTAGE FREQUENCY FIBER OPTIC TX RS 232 RS 485 FIBER OPTIC RX 24VDC COMMS ADDRESS POWER IN SELECTOR SELECTOR STATUS LEDs Figure 1 1404 chassis end panels 1404 User Manual 1404 UM 130129 Page 17 of 104 PSI System Controls and Diagnostics 4X 23 66 MOUNTING HOLE 2X 161 3 2X rey 1440 7 E il 8 6 2X 152 0 45 161 1 2X 10 2 170 3 Figure 2
10. SRE Program query the Service Request Enable register Not currently supported STB Read Status Byte Query Query the Status Byte Register 1404 returns decimal value TST Self Test Query Perform a checksum test on ROM and return the result 1404 returns 1 WAI Wait to Continue Command Wait until all previous commands are executed Not currently supported 20 2 3 3 IEEE 488 2 OPTIONAL COMMANDS RCL Recall instrument state from EEPROM SAV Save present instrument state to EEPROM The settings covered by RCL and SAV are CONFig CAPacitor CONFig PERiod CONFig POLarity TRIGger SOURce Note that the high voltage settings CONFigure HIVOltage are NOT included 1404 User Manual 1404 UM 130129 Page 77 of 104 PSI System Controls and Diagnostics 20 2 3 4 1404 COMMANDS ABORt Abort measurement CALIBration COMPensation ENABLE 011 Q Send query bit to enable use of sensor compensation factors for values sent to monitor outputs Note prior to device firmware release 4 1O only gain factors were supported with CALIB COMP lt float32 gt lt float32 gt lt float32 gt lt float32 gt GAIN lt float32 gt lt float32 gt lt float32 gt lt float32 gt Q Send query sensor compensation gain factors OFFset lt float32 gt lt float32 gt lt float32 gt lt float32 gt Q Send query sensor compensat
11. TT LTU Downloading program from host 17 4 7 Link Red Green LED This LED indicates a variety of communication states as follows Alternating red orange green off Unit powering up Off No connection since last power up Alternating green off Unconnected after timeout Alternating orange off Unconnected after timeout unit has gone to the safe state Green Connection made to host Red Fatal communications error ga AADA Fast alternating green orange Boot state waiting start command or code download 1404 User Manual 1404 UM 130129 Page 69 of 104 PSI System Controls and Diagnostics 18 Internal Jumpers We do not recommend that users open the 1404 case There are no user serviceable parts within and there is the risk of degrading low current performance by contaminating the circuit board The following information is provided for reference only Jumper bank JPR2 settings for revision 2 hardware 4 1H device firmware and later If you have revision 1 hardware and wish to add the high voltage option please contact Pyramid Technical Consultants Inc for detailed advice 18 1 High voltage options Set 2mm jumpers to identify the installed HV module to the device software High voltage option Jumpers made None No jumpers on HVO HV1 HV2 HV2 HV1 HVO 3000 HVO HV2 HV2 HV
12. 1404 case side and plan views Dimensions mm 1404 User Manual 1404 UM 130129 Page 18 of 104 PSI System Controls and Diagnostics 8 How the 1404 Works an Overview The 1404 is a very flexible instrument which uses a charge measurement method that may be unfamiliar to you This section gives you an overview of how incoming signal current is turned into readings and the main features of the device Full details are in the later sections of this manual ChA id D qb Comms Ch B in gt Monitor outputs voltage Ch C in p Monitor outputs Ch D gt frequency in Charge to voltage conversion Figure 3 1404 block diagram The 1404 has four parallel input channels which convert very small currents to measureable voltages The voltages are measured in quick succession by an ADC analog to digital converter The resulting binary values are converted to current readings in amps by applying calibration factors These currents can be requested over the communication link and are also used to drive the monitor outputs Let s start by looking at the measurement process in a little more detail 8 1 Current measurement process Because all four channels are identical and work in synchronization we can focus on a single channel Imagine there is a small current that you wish to measure which may be varying in time as shown on the following graph 1404 User Manual 1404 UM 130129 Page 19 of 104 PSI Sy
13. I400 PIC 4 0A hex SS prosao m E 13200 PIC4 0G_090807 hex N2400 PIC 4_0A hex PIC Boot 3_2 hex Ej S100 PIC 4 0B hex Last Error 1 11 04 AM FETCHEXTERNAL 200 NotConnected Mai Documents wr AE Filename Ji404 Pic 4_1F_090619hex z Files of type esi Device Firmware hex z Cancel ZA Figure 44 Selecting the hex file to load 1404 User Manual 1404 UM 130129 Page 85 of 104 PSI System Controls and Diagnostics PSI Loop Diagnostic v4 51 nl x Actions Options Window Help l l eo o iex 1404 3 Address 3 on COM1 Pending Upload FPGA Select fhex file Last Error 3 25 13 AM RST 335 ProgramNotLoaded Figure 45 Upload in progress 1404 User Manual 1404 UM 130129 Page 86 of 104 PSI System Controls and Diagnostics 22 Techniques for Making Low Current Measurements Measurements of currents of around 10 nA and below require some care to prevent unwanted interference that can distort the results In particular the conductor that carries the current to the 1404 input the sensitive node must be carefully isolated and guarded to ensure unwanted currents cannot flow into it When an unexpectedly high background offset current is seen the first thing to do is to check again with the signal input s disconnected from the 1404
14. Note that this only applies for PSI Diagnostic versions 4 50 and later In prior versions only the numeric data was affected Zero The PSI Diagnostic will capture the latest reading and subtract it from all subsequent readings if you click the Zero button Pressing Clear stops this Note that if you press zero when there is a real signal current this current will then be hidden The zeroing affects the numeric display the graphic display and any data that you capture Note that this only applies for PSI Diagnostic versions 4 50 and later In prior versions only the numeric data was affected Data If you have the external bias voltage option the readback of the voltage is displayed here X Y gain These are factors applied by the PSI Diagnostic to raw position data generated by the 1404 which are in the range 1 to 1 This should not be confused with the vertical and horizontal scaling of the data plot This controls the vertical scaling of the data plot It can be automatic or various fixed proportions of the full scale of the range in use 1404 User Manual 1404 UM 130129 Page 36 of 104 PSI System Controls and Diagnostics Y fAuto X This controls how fast new points are added to the data plot x Fast Fas T00ms 1s 10s This is generally limited by the speed of your PC If the averaging time has been set to a large period then this will override
15. SS a d ees tt tte eie aee tiere PE e re AR E RE 19 6 2 Current ranges 2 oca eR HEX RE EXE SEES TENERA NEUE RE A ERUUE NR E REN YN VER EE RT ERAS ER ERU ESEE SR Re ey 23 8 3 Resolution arid averaging ai dde dades ete idiee dee E ree dd bo PR i e ge paene adve KAS EEES 23 GU TELEN O oaa ete ptu tette ta tat eda es et e vM Aiit e edt ht tete deste os 23 6 5 3Self testing and CalibTatlon i i een quio Hb nn P Rege 24 ROME TTD Ur H ook 24 9 jUn 25 Dil Mounting iaa c eed d 8 Sie aa a a d ui qa e ee E deeds 25 1404 User Manual 1404 UM 130129 Page 2 of 104 PSI System Controls and Diagnostics 9 2 Grounding and power supply ioci ec dee eda qu e tt e I E i RE RE e ERRORES 25 93 Connection to SIONAL SOUrCO eni ceo E eee eee Poe e eue eret e et e a reet 25 0 34 TypicalsetUps n nara e tre er e re a EE Yee e ERR ER RN SOPORE Ye paneled nears 25 932 SipnabcableSus ree ERE UU biu coin teens 27 0 3 3 Signal current path dete Re RERO Rie mele Ree en 27 10 Getting Started Using ASCII Communication c eeeeee eese eese eee eene etae tn setas enses senes tas etas t tastes tenue 29 11 Getting Started using the PSI Diagnostic Host Program eeeeeeeeee eese estes eene enses etna tn sensns enses sesenta eno 32 11 1 Installing the PSI Diagnostic Program eese eee nen eene nnne eet rennen nennen eterne 32 11 2 Connecting 10 th
16. This will isolate the problem to the external measurement circuit or within the 1404 itself 22 1 Guarding and screening If the sensitive node is separated from a voltage source such as a power rail by an insulating layer then a small current will flow through the finite impedance of the insulator V Voltage source J l J Insulator V Figure 46 Offset current entering an unguarded input For example a 10 V conductor separated from the sensitive node by 1 Gohm of total resistance would drive in 10 pA of background current If the insulation is compromised by contamination then the problem is magnified A solution is to provide a guard shield around the sensitive node at the same electrical potential as the node Leakages currents across insulators now flow to the guard where they do not affect the reading 1404 User Manual 1404 UM 130129 Page 87 of 104 PSI System Controls and Diagnostics V Voltage source l OL D insulator Figure 47 Guarded input AC fields in the environment can induce AC currents in the sensitive node Depending upon the frequencies and the integration time in use these may appear as noise fluctuation in the signal An outer cable screen can be used to shield the sensitive node from external fields
17. Voltage on a capacitor that is connected at time zero 20 Figure 6 Capturing the voltage at two times 21 Figure 7 Discharging the integration capacitor and starting a new cycle 21 Figure 8 Repeated integrations to sample a continuous current signal 22 Figure 9 Multiple ADC readings on each integration 23 Figure 10 Schematic 1404 installation for PIN diode readout 26 Figure 11 Schematic 1404 installation for ionization chamber readout 26 Figure 12 Path of measured current photodiodes 28 Figure 13 Path of measured current ion chamber 28 Figure 14 RS232 connection cable from the 1404 to a PC serial port DB9 Pins are shown looking at the face of the connectors 29 Figure 15 Hyperterminal COM port setup 30 Figure 16 Hyperterminal terminal settings 30 Figure 17 Example Hyperterminal session 3l Figure 16 Direct RS 232 connection to the I404 33 Figure 19 Connection through an A300 33 Figure 20 PSI Diagnostic Search Utility 34 Figure 21 Data current tab 1404 connected via COMI and running with default settings showing background noise 35 Figure 22 Setup tab I404 connected via an A500 controller and running in Basic Mode 38 Figure 23 Setup tab 1404 running in Expert Mode 39 Figure 24 Internal calibration current routed to channel 1 histogram display format 42 Figure 25 Device tab showing firmware update utility controls 43 Figure 26 The basic gated integrator circuit 45 Figure 27 Example gated integrator timing d
18. 1404 voltages limited only by electrical breakdown can build up if the 1404 is not connected to provide the earth return path The user must ensure that a suitable earth return path is always present when the particle beam may be present The unit must not be operated unless correctly assembled in its case Protection from high voltages generated by the device will be impaired if the unit is operated without its case Only Service Personnel as defined in EN61010 1 should attempt to work on the disassembled unit and then only under specific instruction from Pyramid Technical Consultants The unit is designed to operate from 24VDC power with a maximum current requirement of 500mA A suitably rated power supply module is available as an option Users who make their own power provision should ensure that the supply cannot source more than 2000mA A safety ground must be securely connected to the ground lug on the case Some of the following symbols may be displayed on the unit and have the indicated meanings 1404 User Manual 1404 UM 130129 Page 9 of 104 PSI System Controls and Diagnostics Direct current Earth ground terminal Protective conductor terminal Frame or chassis terminal Equipotentiality Supply ON Supply OFF CAUTION RISK OF ELECTRIC SHOCK PPO 6t CAUTION RISK OF DANGER REFER TO MANUAL 1404 User Manual 1404 UM 130129 Page 10 of 104 PSI System Controls and Diagnostics
19. Address 3 on COM1 Comms piee Connected j Pending Error SYSTem Properties Utilities Device Version 44H Reset Device SAFEstate AUTORECover m Checksum Errors gt 459 FPGA Version 14 0 9 Upload Application Select hex file COMM TERM COMM CHECksum r Echo Errors 2 Hardware Version r FREQuency Upload FPGA Select fhex file co Hz SERIALnumber mlO Input Length 2 mlO Output Length 0000004213 30 Reset Counters COMM TIMEout Es Last Error 8 40 23 PM SYSTEMSERIALNUMBER 203 CommandProtected Figure 25 Device tab showing firmware update utility controls Communication The counters show details of the communications between the 1404 and its host You can click the Reset Counters button to reset the fields to zero SafeState Enabling SafeState will cause the 1404 to go to its defined safe state if there is a communications timeout In particular the HV supply will be turned off Autorecover These controls affect behavior of the I404 when in ASCII terminal mode Comm Term Comm Checksum You can ignore them when using the PSI Diagnostic Frequency This parameter sets the averaging period that will be used for calibration You should set it to the dom
20. BNC plug 3 lug 25 CAB SHV 25 SHV Cable coaxial SHV to SHV 25 CAB LEMO CO 25 LEMO Cable coaxial 50ohm Lemo 00 coax plug to Lemo 00 coax plug 235 ADAP LEMO BNC Adaptor Lemo 00 coax male to BNC jack 5 3 Data cables ADAP D9F MINIDIN Adaptor cable DSub 9 pin female to mini DIN six pin male CAB ST P 10 ST Cable fiber optic Imm plastic ST terminated 10m CAB ST HCS 10 ST Cable fiber optic Imm glass ST terminated 10m 5 4 Fiber optic loop A360 fiber optic loop controller Ethernet adaptor A500 intelligent cell controller with Ethernet interface A560 intelligent cell controller with Ethernet interface 1404 User Manual 1404 UM 130129 Page 13 of 104 PSI System Controls and Diagnostics 6 Intended Use and Key Features 6 1 Intended Use The 1404 is intended for the measurement of small charges or corresponding currents from pA to uA generated by devices such as ionization chambers in vacuum beam position monitors proportional chambers and photodiodes Four input channels make the 1404 particularly well suited to four quadrant electrode systems used for beam centering The I404 has design features which make it tolerant of electrically noisy environments but the place of use is otherwise assumed to be clean and sheltered for example a laboratory or light industrial environment The unit may be used stand alone or networked with other devices and integrated into a larger system Users are a
21. On the Device tab click the Select fhex file button and navigate to the relevant file The code will then load The process takes a few minutes You will then be prompted to reboot the device The PIC microcontroller application code may be updated periodically to add new operating features New code releases will be provided by your supplier or can be downloaded from the Pyramid Technical Consultants Inc website The hex file can be loaded using the PSI Diagnostic host without any need to access the unit The upload can be performed directly from the PC host via RS 232 USB or fiber optic or routed via an A500 controller On the Device tab click the Select hex file button and navigate to the relevant file The code will then load The process takes about 60 seconds and the I404 will start running the new code immediately 1404 User Manual 1404 UM 130129 Page 84 of 104 PSI System Controls and Diagnostics a A200 192 168 100 100 100 1404 3 Address 3 on COM1 Comms Feber Connected Pending Reset Device Upload Application Select hex file COMM CHECksum Hardwzza Marcinn Upload PIC device application code 3 xl FREQuency lookin Device gs emam PES B10 PIC 4 DA hex SERIALnumber D100 PIC 4 0A hex 3 F100 PIC 4_0C hex 0000004213 Its F3200 PIC 3_0E hex F3200 PIC 4 0A hex H10 PIC 3_0C hex H10 PIC 4 0B hex E H10 PIC 4_0C hex WS 1200 PIC 4 0A hex 5
22. a key or lug on the central body This must align with the keyway on the top of the socket on the I404 before the plug can be pushed home The outer shell of the plug can then be rotated while pushing against the spring pressure to engage the bayonet 1404 User Manual 1404 UM 130129 Page 66 of 104 PSI System Controls and Diagnostics 17 Controls and Indicators SerialMode Binary ASCII 115K 57 6K 19 2K 115K 57 6K 19 2K RS 232 msas 6 7 8 9 Optical Serial Mode yo hod NEM RENG O I SF mio Link a ee rac ue iii 24V 500 mA Figure 41 Rear panel showing controls and indicators 17 1 Front panel controls None 17 2 Rear panel controls 17 2 1 Mode switch Address This 10 position rotary switch sets the communications mode when a connection is made to the serial port It is ignored if there is no connection and the 1404 defaults to 10 Mb s binary communication on the fiber optic port Binary protocols are used by the Pyramid Technical Consultants Inc Diagnostic and other suitable host systems The ASCII protocol is provided for ease of connection to existing systems and simple terminal programs Setting Function 0 8 bit binary 115 kbps RS 232 1 8 bit binary 57 6 kbps RS 232 2 8 bit binary 19 2 kbps RS 232 3 ASCII 115 2 kbps RS 232 4 ASCII 57 6 kbps RS 232 5 ASCII 19 2 kbps RS 232 6 8 bit binary 115 kbps RS
23. and Diagnostics Measured currents or charges are inaccurate by up to 15 Unit not calibrated Calibrate Calibration was carried out while a signal current was present Internal calibration source does not measure as 500nA with all inputs disconnected Repeat calibration with no external signal present High background offset Various causes Refer to section on low current current measurements 500 nA background on a Internal calibration source has Turn off calibration source channel been turned on Compensation factors do not affect current readings This is correct behavior factors only affect values used in position calculations and optionally those sent to the monitor outputs No or incorrect response to external trigger or gate Incorrect gate polarity selected Use correct polarity 1404 not configured to respond to external gate Use correct setup No high voltage Shorted to ground in external circuit Monitor HV reading zero or very low relative to setpoint Monitor value recovers if 1404 disconnected from the external circuit Eliminate shorts to ground Cannot set high voltage Trying to set above the maximum allowed value soft limit Sets OK if a lower value is chosen If allowed increase the maximum allowed value 1404 User Manual 1404_UM_130129 Page 94 of 104 PSI System Controls and Diagnos
24. and the results can be read over the communications interface or mapped onto the monitor outputs The algorithm that is implemented depends upon your selection of the monitor output on the Setup tab as follows 1404 User Manual 1404 UM 130129 Page 55 of 104 PSI System Controls and Diagnostics Monitor output selection Algorithm Current Quadrant Quadrant Quadrant Split Split In order to convert to physical units such as mm you can multiply the result by a gain factor and add any zero offset in the host software X mm Gx X XOFF Y mm Gy Y Y OFF where Gx y are the conversion gain factors in mm per position unit and Yorr Yorr are the absolute position of the center of the position sensor in mm The PSI Diagnostic software implements conversion to mm using conversion gain factors and offsets that you enter The position algorithms assume that all four signals have the same polarity and that the values are not too small If your signals are negative rather than positive you can tell the 1404 so that the position still gets correctly calculated You can also define a percentage of full scale below which the current reading will be replaced with zero in the calculation This can prevent a noisy position value when the signals are very small If the denominator in the calculations ever becomes zero then a position of 0 0 is returned 14 3 Considerations when using split or quadrant sensors Pro
25. compliance with the Waste Electrical and Electronic Equipment Directive WEEE 2002 96 EC Please contact Pyramid Technical Consultants Inc for instructions when you wish to dispose of the device 1404 User Manual 1404 UM 130129 Page 100 of 104 PSI System Controls and Diagnostics 28 Declaration of Conformity Declaration of Conformity Issued by Pyramid Technical Consultants Inc 1050 Waltham Street Lexington MA 02421 USA The undersigned hereby declares on behalf of Pyramid Technical Consultants Inc that the referenced product conforms to the provisions as listed Refer to the document Extension of testing and analysis to the PTC product line December 10 2007 and its continuations and the 1400 Technical Construction File for detailed testing information Product 1404 Quad electrometer Year of initial manufacture 2009 Applicable Directives 73 23 EEC Low Voltage Directive Laws for electrical equipment within certain voltage limits 89 336 EEC EMC Directive Laws relating to electromagnetic compatibility Applicable Standards IEC 610101 2002 2 Edition UL 61010 1 2004 EN 61326 1997 A1 1998 A2 2001 EN 55011 1998 A2 2002 EN 61000 6 2 2001 Electromagnetic Compatibility Generic Standard Immunity for Industrial Applications Issuing Agencies Safety TUV Rheinland North America 12 Commerce Rd Newtown CT 06470 USA EMC TUV Rheinland North America 12 Commerce Rd Newtown CT 06470 USA
26. current currents generally require the smallest available feedback capacitor and the longest practicable integration time to build up a readily measurable voltage For example a 1 pA current integration on a 10 pF feedback capacitor requires 10 seconds to 1404 User Manual 1404 UM 130129 Page 89 of 104 PSI System Controls and Diagnostics develop 1 V Background offset noise is also integrated of course and cannot be distinguished from the signal This sets the ultimate detection limit The plots in figure 47 illustrate how a 5 pA signal from a small ionization chamber becomes clearly distinguishable from a reference background signal and the noise reduces as the integration period is increased from 1 msec to 100 msec to 10 000 msec 1 msec 2 0E 10 1 5E 10 1 0E 10 P Fig 50E M c se D 9 9 v ow 9 m5 o one nu o mo mn omo soon mp na m 0 08 0 64 e f 0 96 0 0E 00 50E 11 9 1 0E 10 1 5E 10 ease e he pee e e es ev eno oo EI 7 0E 12 amp 0Ed49 4 ae X9 ou a Ku dp pr eq M QA eee 5 0E 12 34 t 99 a 5 j vat LOS i t hi vo 9 t 4 0E 12 4 U OC te 3 0E 12 2 0E 12 4 1 0E 12 4 s s 0 0E 00 3 ae s fa Da au um ee 1 0E 12 0 eos s j 2 0E 12 Ch1 ionchmbr Ch2 no signal 10000 msec 20209999 5909007 909 067000 0009050020009 990090 909 0090999990949 9009940 099990900809 9090 0 9 0 i erin
27. duty cycle The monitors allow the unit to be integrated into existing systems 1404 User Manual 1404 UM 130129 Page 50 of 104 PSI System Controls and Diagnostics where ADC cards or counter cards are already available If you use these outputs exclusively for taking data then the communications interface is only needed for setting up the device By default the four analog monitors put out an analog voltage that maps the full scale bipolar current range that is being used Similarly the frequency monitors put out a frequency that maps the same full scale Since we can t generate a negative frequency the 1404 offers two options for mapping the signal current range onto the frequency range as illustrate in figure 29 Normal mode maps the full scale current range onto the 0 to 1 MHz frequency range so that the frequency will be 500 kHz for zero current Absolute mode puts out 0 Hz at zero current and maps increasing absolute current to frequencies up to 1 MHz Clearly you must be able to resolve the two valued response by other means in this case 1 MHz 1 MHz 500 kHz 500 kHz FS 0 Hz FS FS 0 Hz 4FS Figure 29 Monitor output mapping current signals Analog voltage on the left Normal and Absolute frequency mappings on the right In firmware releases prior to 4 10 Normal mode was called Bipolar mode and there were Positive and Negative modes which mapped only positive or nega
28. handled by hardware in the original IEEE 488 1 specification The I404 provides a simple mechanism for making any device on the loop the listener The device will remain the listener until another device is selected address Make device address 1 to 15 the listener Query which device is listener 20 2 3 2 IEEE 488 2 MANDATORY COMMANDS Commands which have a query equivalent for readback are marked with in the following tables Parameters are generally passed to the 1404 with the set version of the command but no parameters are passed for the query version For example ESE 3 set the Event Status Enable register to 0000011 ESE query the Event Status Enable register 1404 User Manual 1404 UM 130129 Page 76 of 104 PSI System Controls and Diagnostics CLS Clear Status Command Clear all event registers and the error queue ESE Program query the state of the Event Status Enable register 8 bits 1404 returns decimal value ESR Standard Event Status Register Query Query the state of the Event Status register 1404 returns decimal value IDN Identification Query 1404 returns manufacturer model number serial number firmware version OPC Set query the Operation Complete bit in the Standard Event Status Register after all pending commands have been executed Not currently supported RST Reset Command Return the device to the RST default conditions
29. kHz 50 kHz effective per channel Built in averaging gives up to 20 bit effective resolution Linearity Deviation from best fit line of individual readings lt 0 1 of maximum current or charge reading for given feedback capacitor and integration time setting Drift lt 0 5 over 12 hours External accuracy Better than 0 5 of full scale in use integration time 500 us to 1 sec after calibration with built in source with cable capacitance not exceeding 750 pF Integration time User selectable 100 usec to 65 sec Averaging modes Multiple integrations Multiple conversions per integration Trigger modes Internal autorun external start triggered Position calculation Difference over sum algorithm with compensation factors for non uniform sensor response Quadrant or split sensor Position values can be read by host computer and sent to monitor output connectors Auxiliary HV PSU option 0 to 3000 V programmable 14 bit resolution 1 watt max Noise and ripple lt 0 001 of full scale at full load options up to 2 kV lt 0 1 of full scale at full load 3 kV option Output filter R kohm 3 3 nF where R 33 2k for 3 kV 2 kV 10k for 1 kV 4k7 for 500V Ok for 200V 1404 User Manual 1404 UM 130129 Page 15 of 104 PSI System Controls and Diagnostics External gate 0 5 V TTL level 10 kohm input impedance Power input 24 VDC 4 2 V
30. noise offset current Mitigation Typical noise after mitigation Triboelectric effects in cable 10 A Reduce cable lengths Keep cable from moving Use low noise cable 10 A Current across 10 to 109 A Guard the sensitive node 10 A insulators from voltage ssinsdalesble sources AC interference 10 to 109 A Used screened triaxial cable 10 A AC AC interference 10 to 109 A Use integration periods that 10 A AC are an integer multiple of the dominant noise frequency Contaminated insulators 10 A Clean insulating surfaces with 10 A solvent Use air insulation where possible Keep humidity low Piezoelectric effects 10 to 10 A Avoid mechanical stresses and Negligible vibration in the sensor and cable Resistor Johnson noise 107A None fundamental limit set by signal source resistance Temperature fluctuation 10 to 10 A Temperature stabilize the 10 to 107 A 1404 User Manual 1404 UM_130129 Page 91 of 104 PSI System Controls and Diagnostics fluctuation whole measurement apparatus fluctuation Elevated temperature 10P to 10 A Reduce temperature of the whole measurement apparatus 10 A 1404 User Manual 1404 UM 130129 Page 92 of 104 PSI System Controls and Diagnostics 23 Fault finding Symptom Possible Cause Confirmation Solution High background current Resistiv
31. or the readouts of photodiodes 14 1 How compensation factors are used The 1404 is designed to measure current or charge accurately and report the values it sees However the response of the sensors may not be completely uniform and they may have offset currents and as a result the position readback is not zero when the beam is centered This is particularly the case for photodiodes To handle this the 1404 allows the user to define gain and offset compensation values Compensation Factors Gain Offset A 1 1 0570 2 000e 009 2 0 9870 1 300e 009 3 11200 6 540e 010 4 4 0030 5 300e 010 Iv Map Compensated Values to Freq Analog Figure 32 Sensor compensation value fields as shown in the PSI Diagnostic With no illumination of the sensor you can observe any offset currents and enter these directly as offsets in amps The value you enter O is added to the measured current so you should enter the negative of the offset you observe Deciding how to set the gain compensation factors G will depend upon the nature of your system If the sensors are photodiodes the simplest method can be to provide a uniform illumination and note the resulting currents Then calculate the compensation factors that would be necessary to make the values A B C and D equal One of the factors can remain as 1 00 of course Alternatively if you have a beam that you know is at exactly X Y 0 then you can tune the relevant compensation facto
32. protected functions The default is 12345 SAFEstate 011 2 Set query whether the 1404 goes to the safe state when unconnected 0 do not go to safe state 1 go to safe state Safe state is HV off SERIALnumber lt serial gt Q Set query the serial number serial of the I404 max 10 alphanumeric characters Password protected 1404 User Manual 1404 UM 130129 Page 81 of 104 PSI System Controls and Diagnostics VERSion Q Query the SCPI standard version TRIGger COUNt Query the trigger count since the last INITiate DELAY uint16 Q Set query the trigger delay for message trigger mode This parameter permits all devices on a loop to start an acquisition at the same time despite message propagation delays around the loop SOURce source Q Set query the trigger source to source The options are internal external start 1404 User Manual 1404 UM 130129 Page 82 of 104 PSI System Controls and Diagnostics 20 3 Terminal Mode SCPI is not ideal for a user trying to control the 1404 from a terminal program A more interactive terminal mode can be turned on by sending the command SYSTem COMMunication TERMinal 1 After this command is executed the I404 will provide a response to every command Valid query commands will get their normal reply
33. protocol The first and last bytes of the entire command or reply have the eighth bit set and contain the address All other bytes in the messages are broken into two bytes encoded into the low nibble 4 bits thus never having the top bit set c A nine bit binary protocol Synchronization is done with the ninth bit The first and last byte of each message have the ninth bit set and contain the address and all other bytes are unmodified binary with the ninth bit clear ASCII messaging is provided for users who wish to use existing host software systems that provide convenient support for ASCII communications An example is EPICS which can support the 1404 via the StreamDevice module All the capabilities of the 1404 are available through a familiar virtual instrument model and message structure A simple terminal program such as Windows Hyperterminal is sufficient to establish communication with the device This is no longer supplied as part of Microsoft Windows but you can use shareware equivalents such as puTTY and Realterm The binary messaging is more efficient in its use of communications bandwidth It is fully deterministic with embedded addressing in the messages and immediate responses including error reports from the devices Pyramid Technical Consultants Inc provides software drivers and diagnostic host programs for users who wish to use binary communication protocols Eight bit binary is primarily intended for direct host to devi
34. supply then 24 VDC power should be provided with the following minimum performance Output voltage 24 0 5 VDC Output current 500 mA minimum 2000 mA maximum Ripple and noise lt 100 mV pk pk 1 Hz to 1 MHz Line regulation lt 240 mV Connector 2 1 mm jack 24 V on center conductor The 1404 includes an internal automatically re setting PTC fuse rated at 1 1 A However the external supply should in no circumstances be rated higher than the 1404 connector limit of 5 A and a maximum of 2 A is recommended 9 3 Connection to signal source 9 3 1 Typical setup Figure 10 shows one typical installation in schematic form Four PIN diodes operated in photovoltaic mode self biased are connected to the four inputs of the I404 The diodes are physically arranged in a quadrant pattern so that beam position information can be obtained by the relative sizes of the four signals The measured current returns to the diodes via the signal 1404 User Manual 1404 UM 130129 Page 25 of 104 PSI System Controls and Diagnostics cable screens The example shows data taken out to a control system as TTL pulse rate but it could also be taken as analog voltages or as data on the communications link Photodiode array i Signals Low noise coax Ws y Serial comms 24V in Monitor outputs 0 1
35. the update rate you set here Data buffer The PSI Diagnostic collects data coming from the I404 as fast as it can into a buffer If the I404 rate set by the integration time and the communications channel bandwidth is relatively low then every data point is logged At high rates some readings will be lost but you can see this because every reading gets a trigger count and missing values are evident Spooling data into the buffer can be halted with the slider mw The plot can be cleared with the Clear Plot button EI The data can be written to a nominated csv file with the File button fal The buffer is cleared by a new initiate command The kB and Buffer indicator show how much data is currently in the buffer Couple Selecting AC coupling removes any DC component from the graphic display only Display mode There are various ways to plot the data There are strip chart le or bar chart histogram ti In histogram mode you can place a cursor on any channel by clicking on it Click again to clear the cursor Scope mode Z is a variant of the strip chart One full screen of data is displayed at a time rather than the continuous scrolling of the strip chart The derivative button KA displays the difference between successive values and is useful if you are looking for sudden changes in the signal It 1404 User Manual 1404_UM_130129 Page 37 of 104 PSI System Controls and Diagnostics only affects t
36. there is no stored calibration you will still get data back but default factors of 1 000 will be used so the accuracy of the results is limited When you do a calibration it is important that no spurious signal current or excess noise is present at the I404 inputs The simplest way to ensure this is to disconnect any signal leads before doing the calibration If you want to check your calibration accuracy you should use an independent current source If you simply measure the internal current source the same source that is used to do the calibration you will of course see the expected 500 nA even if the calibration is incorrect Note that there is no offset parameter in the calibrations The integration method of the I404 with its start and end ADC readings ensures that any internal offsets are removed Any other offsets are due to real currents at the signal inputs which may be of interest so we do not hide them However it is a simple matter to zero any such offsets in the host software if you are confident that they are stable The PSI Diagnostic software provides a zero function like this 13 5 Monitor outputs 13 5 1 Current monitoring The 1404 puts out signals on the monitor outputs that represent the inputs or a function of the inputs The monitor signals are provided as analog voltages and as a frequency and both types are available simultaneously The frequency output takes the form of a TTL 0 to 5 V square wave with 5096
37. to use COMI or other available port on your PC as shown in the following figures A suitable Hyperterminal file is provided on the I404 software CD ROM Unfortunately Hyperterminal is not included with Windows Vista or Windows 7 You can copy the relevant files hypertrm dll and hypertrm exe from an XP machine to your Vista or Windows 7 machine or use one of many free terminal programs that are available such as PuTTY or RealTerm 1404 User Manual 1404 UM 130129 Page 29 of 104 PSI System Controls and Diagnostics COM Properties x Port Settings Bits per second 115200 v Data bits 8 ha Parity None Stop bits 1 zi Flow control None xi Restore Defaults Figure 15 Hyperterminal COM port setup 1404 mode3 Properties 3 x Connect To Settings Function arrow and ctr keys act as E Terminal keys Windows keys ASCII Setup 2 x Backspace key sends 34 ASCII Sending Ir Cti H C Del 9 Cti H Space Cti H v Send line ends with line feeds Echo typed characters locally Emulation auto detect eon Line delay 0 milliseconds p m Telnet terminal ID pw Character delay milliseconds Backscroll buffer lines po zd Play sound when connecting or disconnecting ASCII Receiving Append line feeds to incoming line ends Force incoming data to 7 bit ASCII v Tensen rout Translation 0 Sap v W
38. 1 HVO 2000 HV2 HV2 HV1 HVO 1000 HVO HV1 HV2 HV1 HVO 500 HV1 HV2 HV1 HVO 200 HVO HV2 HV1 HVO 3000 HVO HV2 HV2 HV1 HVO 2000 HV2 HV2 HV1 LLL HVO i 1000 HVO HV1 HV2 HV1 HVO 500 HV1 HV2 HV1 HVO 1404 User Manual 1404_UM_130129 Page 70 of 104 PSI System Controls and Diagnostics HV2 O O e e 200 HVO avi Hvo E The remaining jumper stations RG1 2 and OP1 2 are reserved for future options 1404 User Manual 1404 UM 130129 Page 71 of 104 PSI System Controls and Diagnostics 19 Communications Interfaces 19 1 1404 Interfaces The 1404 is a member of the PSI range of devices More details of PSI device interfacing options can be found in document Pyramid Technical Consultants document PSI_AN_060505 Versatile Communications and Control for Scientific and Engineering Applications The unit is provided with three hardware interfaces RS 232 RS 485 and fiber optic The RS 232 interface is intended for simple direct connection to PCs with no other equipment necessary The RS 485 interface is used primarily as an RS 232
39. 1 00E 09 1 1 00E 09 5 00E 10 5 00E 10 0 00E 00 0 00E 00 5 00E 10 5 00E 10 5 10 15 20 25 3p 1 00E 09 j 1 00E 09 J 1 50E 09 1 50E 09 2 00E 09 i 2 00E 09 2 50E 09 2 50E 09 Figure 49 Triboelectric noise from flexing conventional RG 58 cable left compared to low noise RG 56 right Cables from other suppliers with similar specifications will be suitable Other mitigations include keeping the signal cables short and motionless 22 4 Battery Effects Ionic contamination such as salt from fingerprints which connects to the sensitive node can give battery effects particularly in the presence of moisture which can drive unwanted currents Any insulating surfaces in contact with the sensitive node must be clean Humidity levels should be such that there is no moisture condensation Wherever possible the sensitive node should be insulated by vacuum or air 22 5 Piezoelectric Effects Ceramic and plastic insulators can release charge when under mechanical stress which may be collected on the sensitive node The effect is generally small less than 10 pA and can be avoided by eliminating stresses in cables and connections 22 6 Integration Period and Synchronization The 1404 provides considerable flexibility in setting the integration time interval and synchronizing the integration to external events The integration method is inherently good at averaging noise Very low
40. 128 5 50 2 7 52 8 5 Rev 2 4 1Q 14 0 21 4 130 5 50 2 7 52 8 5 Versions 4 11 14 0 11 introduced compensation factors Versions 4 1 14 0 19 made changes to how compensation factors were used and applied to monitor outputs This required changes to the A500 loop controller also for customers who use the 1404 on a fiber optic loop 4 1Q made minor bug fixes to ASCII commands 1404 User Manual 1404 UM 130129 Page 103 of 104 PSI System Controls and Diagnostics 31 User Manual Revision History The release date of a Pyramid Technical Consultants Inc user manual can be determined from the document file name where it is encoded yymmdd For example M10_UM_080105 would be a M10 manual released on 5 January 2008 Version Changes 1404_UM_090625 First general release 1404_UM_091028 Changed PSI Diagnostic screen shots to version 4 51 Added information about 2 kV and 3 kV HV options and HV filter 1404_UM_091202 Added description of compensation factors introduced in firmware 4 11 14 0 11 Updated screen shots to show compensation factors Updated ASCII commands table to show command to set and read compensation factors 1404_UM_100414 New screen images and descriptions for position readout to reflect improvements in 4 58 PSI Diagnostic Corrected description of response to ASCII read command Added section on disposal Removed loop controller from firmware compa
41. 129 Page 44 of 104 PSI System Controls and Diagnostics 12 Principle of Operation 12 1 Gated Integrators The 1404 uses the gated integrator method This is a particularly effective technique for measuring small amounts of electrical charge The input signal current builds up charge on a small low leakage capacitor in the feedback loop of an operational amplifier with the result that the voltage at the amplifier output is the integral of the current that flows into the input FET Sw2 o o Cr P MUT iem t t Q 0 FET 1 Swi V poa fb Figure 26 The basic gated integrator circuit Integration starts when FET switch Sw2 is opened The current into the input can be negative or positive The voltage at the output of the amplifier is sampled and digitized by an ADC at the beginning of the integrator ramp then again near the end Calibration with a stable accurately known test current allows variables such as the exact size of the feedback capacitor buffer amplifier gain and ADC gain to be compensated in a single gain factor At any time t after the start of the integration the accumulated charge is thus given by d meas K ADC T ADC par where k is the gain factor The data can also be presented as an average current in the time interval between the readings because that interval is known accurately k ADC ADC sar t meas As the integration proceeds this
42. 13 Type rst lt CR gt to reset the 1404 Your unit is functioning correctly and is ready to be integrated into your system Com5 STE HyperTerminal File Edit View Cal Transfer Help Dae o5 sms H calib gain 0K calib g 15 9 Sgain 01 9 2038e 01 9 1294e 01 9 3443e 01 1 0113e 00 1 0193e 00 1 0215e 00 1 0298e 00 read curr p 2 00e d i S 4 1179e 10 8 3 3600e 10 A 7 5789e 11 8 0 0000e 41 A B read cur 7 5500e 04 2 9810e 10 8 3 3600e 10 8 2 9305e 10 8 1 5158e 10 A B Br range 1e 6 calib source 1 OK read curr 1 5500e 04 5 0092e 07 8 3 3600e 10 8 5 5578e 10 8 4 9010e 10 A B Connected 0 01 14 Auto detect 57600 8 N 1 Figure 17 Example Hyperterminal session 14 If you wish to explore the ASCII communication capabilities of the I404 more fully refer to the commands list in section 19 You may also wish to try out the terminal mode which provides feedback from the I404 to every message you send not just query messages and is therefore more user friendly 1404 User Manual 1404 UM 130129 Page 31 of 104 PSI System Controls and Diagnostics 11 Getting Started using the PSI Diagnostic Host Program 11 1 Installing the PSI Diagnostic Program The 1404 is supplied with software programs and drivers on a USB memory stick We recommend that you copy the files into a directory on your host PC The PSI Diagnostic Host program runs under the Microsoft Windows operating system with the 2 0 NET framewor
43. 1404 UM 130129 Page 21 of 104 PSI System Controls and Diagnostics reading In the figure the blue bars indicate the readings each is the final ADC value minus the starting ADC value for that integration Current Voltage Reading A WAAN 1300 1800 Time Figure 8 Repeated integrations to sample a continuous current signal There are some points to note Firstly notice that the readings are very clearly linked to the time of their integration Because of the resets there is no influence at all from earlier integrations Next notice also that we get no information about how the current may have varied within each integration we see only the average Finally notice that we are not measuring at all during the resets If you choose the shortest available integration times the reset time might be a noticeable fraction of the overall time Why would you choose any particular integration time The first consideration is the size of current you expect to measure For a given charge integrating capacitor the longer the integration the smaller is the maximum current you can measure and the more sensitive the 1404 is to very small currents The next consideration is timing If the current you are measuring is only present in a short pulse there is little point in integrating longer than this because you will simply be measuring extra noise If the current is continuous but has variations that you wi
44. 4 is connected to the controller via a fiber optic loop In this case the loop controller is identified at the first level the loops at the sublevel below and then 1404 as a device on a loop The illustrations in the rest of this section are for the case of connecting through a COM port The 1404 screens will look the same for any other connection arrangement aside from the connection details in the title bar Start the PSI Diagnostic It will search the available ports on your PC and present a search list for device discovery Figure 20 shows a case where three COM ports have been found plus a selection of previously entered IP addresses When you press Start the program will search for loops and devices on all checked options 1404 User Manual 1404 UM 130129 Page 33 of 104 PSI System Controls and Diagnostics Pra ID Technical Consultants Inc Y PSI Diagnostic v4 51 Select Ports for Autodetect Below IP 192 168 100 202 100 i IP 192 168 100 100 100 C LAN Broadcast Add IP Remove IP Figure 20 PSI Diagnostic Search Utility 11 3 Data screen A few seconds after you click the Start button the program should find the 1404 plus any other devices Clicking on the 1404 entry in the explorer list in the System window will open the 1404 window In the following screenshot an 1404 has been found on RS 232 port COMI The address switch on the I404 was read as 3 but this has no rel
45. 485 7 8 bit binary 57 6 kbps RS 485 8 ASCII 115 2 kbps RS 485 9 ASCII 57 6 kbps RS 485 1404 User Manual 1404 UM 130129 Page 67 of 104 PSI System Controls and Diagnostics 17 2 2 Address switch This 16 position rotary switch sets the device address Choice of address is arbitrary but each device in a fiber optic loop system must have a unique address Setting Function 0 Reserved to loop controller 1 15 Available address settings 17 3 Front panel indicators 17 3 1 HV active Orange LED The optional HV supply is enabled 17 4 Rear panel indicators 17 4 4 Power Green LED 24VDC power is present 5V DC DC converter is running 17 4 2 Serial Green LED The RS 232 RS 485 communication port is active 17 4 3 Optical Green LED Fiber optic communication port is active 17 4 4 Rev Green LED Data being received by the unit two second timeout before the LED goes off 17 4 5 Xmit Green LED Data being transmitted from the unit two second timeout before the LED goes off 17 4 6 Status Red Green LED This LED indicates a variety of internal states as follows 1404 User Manual 1404 UM 130129 Page 68 of 104 PSI System Controls and Diagnostics Alternating red orange green off Unit powering up Off Unit idle not measuring Orange Waiting for trigger or resetting integrators Green Measuring Red Error Alternating green orange
46. ADD T aT fer aTe 200 400 600 800 Chi ion chmbr Ch2 no signal Figure 50 Separation ofa 5 pA signal from background Where there are known dominant noise frequencies in current measurements for example line voltage interference these can be suppressed by choosing an integration periods that is an integer multiple of the noise period For example 50 Hz or 60 Hz noise from the power line is present in most environments This can be completely removed in the 1404 by selecting the integration period as follows 1404 User Manual 1404 UM 130129 Page 90 of 104 PSI System Controls and Diagnostics Noise frequency Integration period choices to eliminate noise 50 Hz 20 00 40 00 60 00 80 00 100 00 K x 20 00 msec 60 Hz 16 67 33 33 50 00 66 67 83 33 100 00 K x 16 67 msec The 100 msec value is the smallest period common to both line frequencies and is used for the startup default current range of the device Very small charge package measurements should be optimized by synchronizing the integration carefully around the arrival of the charge This minimizes the amount of background offset current that is included in the reading Often the arrival of the charge is associated with an event in the system which can be used to drive the external gate input of the 1404 to obtain the required synchronization 22 7 Summary Factor Typical
47. Applicable Markings TUV FCC CE Authorized by 2 CLA President Pyramid Technical Consultants Inc Date a4 jc Ine dd F The Technical Construction File required by theses Directives are maintained at the offices of Pyramid Technical Consultants Inc 1050 Waltham Street Lexington MA 02421 USA A copy of this file is available within the EU at the offices of Pyramid Technical Consultants Europe Ltd 2 Chanctonbury View Henfield BN5 9TW United Kingdom 1404 User Manual 1404 UM 130129 Page 101 of 104 PSI System Controls and Diagnostics 29 Hardware Versions This user manual refers specifically to the 1404 at hardware revision 1 Major differences between versions that are or have been in regular production are summarized below Revision Changes Rev 1 First production version Rev 2 Added 2 kV and 3 kV HV supply options Added HV filter 1404 User Manual 1404_UM_130129 Page 102 of 104 PSI System Controls and Diagnostics 30 Firmware compatibility The following combinations are compatible with the highlighted combinations the recommended ones that take most advantage of software improvements Hardware 1404 device 1404 FPGA PTC Diagnostic A500 loop controller revision version Rev 1 4 1F 14 0 8 4 30 Rev 1 4 11 14 0 11 4 51 Rev 1 4 1K 14 0 11 4 58 Rev 2 4 1H 14 0 9 4 51 Rev 2 4 1K 14 0 11 4 58 Rev 2 4 10 14 0 19 4
48. MHz frequency Figure 10 Schematic 404 installation for PIN diode readout Figure 11 shows an alternative installation to illustrate some other options The 1404 is reading out quadrant ionization chamber electrodes and also provides the bias voltage for the chamber The biased electrode is shown schematically behind the readout electrodes it will be the anode or cathode of the chamber depending upon the bias polarity A gate input is shown which could provide a trigger to synchronize measurements to an external event Monitoring is from the analog outputs In this case the measured current loop is completed through the bias voltage lead and the bias power supply module in the 1404 lonization chamber Signals Low noise coax Serial comms Trei e eee ee te ee el i Monitor outputs 10V Bias voltage 24V in Gate in Figure 11 Schematic 404 installation for ionization chamber readout 1404 User Manual 1404 UM 130129 Page 26 of 104 PSI System Controls and Diagnostics Refer to section 21 in this manual for general guidance on making low current measurements The 1404 should be located as close to the source of the signal as possible Long signal cables increase the chances of seeing unwanted signals and noise A maximum length of five metres is advised Longer cables may be used but th
49. Other commands will generate an OK response if they were interpreted without errors or an error message if they could not be interpreted The non printing ACK and BEL characters are not sent 1404 User Manual 1404 UM 130129 Page 83 of 104 PSI System Controls and Diagnostics 21 Software updates The 1404 has three embedded firmware releases Firmware Function FPGA pof file General logic loop message passthrough ADC reading and averaging PIC Boot hex file Boot up code upload PIC Application hex file Main application calibration conversion to floating point values range control HV PSU control I O readback host communications SCPI instrument model The PIC microcontroller boot code should never need updating Changing it requires access to the circuit board and dedicated programming tools to load new code If the boot code does need to be updated your supplier will contact you and make arrangements either to return the unit for upgrade or to have an engineer call The FPGA code handles the low level timing and control of the I404 It is unlikely to require updating but if it does it can be uploaded using the PSI Diagnostic host New code releases will be provided by your supplier or can be downloaded from the Pyramid Technical Consultants Inc website The upload can be performed directly from the PC host via RS 232 RS 485 or fiber optic or routed via an A300 or A500 controller
50. Temm s 2 NEEGINE score Read Avg IE oi NETTEN ETZIM Ea 1 Max 2000V to OV 20 Monitors Position E Output Monitor misru Set Value Current Y 00 of 0 0 0 o ERE Freq Mapping Negative r Absolute M Input Figure 22 Setup tab 1404 connected via an A500 controller and running in Basic Mode 1404 User Manual 1404 UM 130129 Page 38 of 104 PSI System Controls and Diagnostics A 1404 3 Address 3 on Loop 5 on ASOORSTS 192 168 100 213 100 oe Error ES Comms FEEH EEEHEEEHE Connected j Pending Setup CONFIGURATION TRIGGER Calibration Compensation Range Integr Period PNE Internal v Calibrate 2 1 000E 008 A 7 837E 002 s Clear Cal Current 500 nA Gate Polarity Channel Capacitor H 6 W Load 1 x C 2 J 100 pF Save Gain Factors Resolution Integration Avg Valid 100 pF 3300 pF a m 0 9252 1 16 x Bits 1 External Bias EE CUM S Read Avg o o EEM ETH 9 4 0 9206 e 4 0 9997 1 Max 2000V to OV 20 V RESET 5 Monitors Position T uS Cmd 100pF 3300p Output Monitor Set Value Reset 20 Threshold i Current M 00 0 o Settl EM ES a Setup EH Freq Mapping Negative Absolute Input SW1 1 EM i Time 5 m Width Figure 23 Setup tab 1404 running in Expert Mode You can investigate all the screen controls and displays Range There are eight pre d
51. ansients to die away A further time associated with the reset called the setup time is necessary to allow all the ADC conversions to be completed at the end of the integration The following timing plot shows an example in which there are two integrations Integration Avg 2 each with two ADC readings Read Avg 2 EN L ES Swi Sw2 Voltage 400 450 100 50 Time Figure 27 Example gated integrator timing diagram Tl integration period T2 setup T3 reset T4 settle T5 Swl width The Swl opening transition is displaced from the Sw2 closing transition by the Swl offset 12 2 1404 Circuit Overview The signal inputs are protected by back to back diodes and spark gaps Four identical gated integrator channels operate under switch control from an FPGA A single control line to switches on every channel allows a second feedback capacitor to be added in parallel to give the large capacitor option A precision 500 nA current source can be switched into any of the four channels 1404 User Manual 1404 UM 130129 Page 46 of 104 PSI System Controls and Diagnostics The ADC reads out the four integrator outputs via a multiplexer at four microsecond intervals All four channels are thus read out in 12 usec The integration cycles are similarly offset by four microseconds from each other to compensate for this The FPGA field programmable gate array controls the ADC timing and collects the readi
52. ce communication for example via RS 232 or RS 485 links Nine bit binary is reserved for the 10 Mbit s fiber optic channel and is highly recommended for larger systems with multiple addressable devices in a loop 1404 User Manual 1404 UM 130129 Page 74 of 104 PSI System Controls and Diagnostics 20 2 ASCII Protocol SCPI Standard Commands for Programmable Instruments SCPI is an extension of the IEEE 488 2 standard This was originally developed by Hewlett Packard for the HP IB later GP IB interface before being adopted by the IEEE and is widely used by manufacturers of measurement equipment The I404 implements the 1999 0 revision of SCPI O 1999 SCPI Consortium 20 2 1 Messages The first bit of every eight bit group in a message is the start bit followed by seven bits encoding a character from the ASCII character set A full command from the host to the I404 comprises as many ASCII characters as needed to form the message terminated by the LF 0x0A ctrl J character The 1404 will not start to process a command until the OxOA character is received The list of valid commands is listed in the next section If the communications is being handled in a terminal session the terminal program should send CR 0x0d before the LF to get a legible display The CR is ignored by the command interpreter in the I404 The 1404 generates a reply to every message from the host when it is the listener The first byte of its reply wil
53. ce with this button and control which channel it is directed to This provides a useful diagnostic function Compensation i oa A separate sub tab Compensation iios you access to the sensor compensation gain and offset parameters These factors can be entered by the user to compensate uneven sensor response in applications where the I404 is reading out position See section 14 for more details Reset Expert Mode only You can alter the gated integrator reset settle and setup times away from their default values These controls are for expert use only and the values have to be set subject to constraints of the averaging settings Refer to section 12 to learn more about these parameters As an exercise do the following Clear the calibration then click the calibration button and observe that the gain factors change Store this new calibration in the user memory Click the calibration current button to turn on the source and select channel 1 Select the 1 uA range 16 bit resolution and internal triggering Now if you return to the data tab and initiate data acquisition you should see the 500 nA calibration current on channel 1 Try displaying the data in histogram mode Setting 10046 vertical scale should show the calibration at half of full scale 1404 User Manual 1404 UM 130129 Page 41 of 104 PSI System Controls and Diagnostics 1404 3 Address 3 on COM1 Comms Perea Connected j Pending j Err
54. d averaging them Firstly you can take multiple ADC readings in the same integration Voltage zd 100 50 0 50 100 150 200 250 300 350 400 Time Figure 9 Multiple ADC readings on each integration Secondly you can average the data from several integrations which themselves may have one pair or several pairs of ADC readings For example each group of four integrations in figure 8 could be averaged together to form a single reading Both of these two techniques effectively increase the digital resolution of the results and the use of multiple integrations in particular will improve the signal to noise ratio As always the trade off is less time resolution 8 4 Triggering In many cases you will need to coordinate the 1404 measurements with external events You can preset the 1404 with all the measurement parameters such as range integration time and capacitor selection averaging settings and so on then initiate it ready to respond to a trigger signal Measurements will start as soon as the trigger arrives 1404 User Manual 1404 UM 130129 Page 23 of 104 PSI System Controls and Diagnostics 8 5 Self testing and calibration The 1404 can calibrate itself on all channels fully automatically and it stores the resulting factors so that it can provide results in physical units amps or coulombs You can also turn on the calibration current at any time and send it to any channel to check that
55. d and screened input amp 8 Figure 49 Triboelectric noise from flexing conventional RG 56 cable left compared to low noise RG 58 right 89 Figure 50 Separation of a 5 pA signal from background 90 1404 User Manual 1404 UM 130129 Page 8 of 104 PSI System Controls and Diagnostics 2 Safety Information This unit is designed for compliance with harmonized electrical safety standard EN61010 1 2000 It must be used in accordance with its specifications and operating instructions Operators of the unit are expected to be qualified personnel who are aware of electrical safety issues The customer s Responsible Body as defined in the standard must ensure that operators are provided with the appropriate equipment and training The unit is designed to make measurements in Measurement Category I as defined in the standard A CAUTION The 1404 can generate high voltages as follows according to the selected high voltage option or 3000 VDC at 330 uA maximum or 2000 VDC at 500 uA maximum or 1000 VDC at 1 mA maximum or 500 VDC at 2 mA maximum or 200 VDC at 5 mA maximum Present on the central conductor of the SHV connector The user must therefore exercise appropriate caution when using the device and when connecting cables Power should be turned off before making any connections In applications where high energy charged particle beams can strike electrodes which are normally connected to the
56. djusted at any time independent of what measurements are in progress Positive supplies source conventional current and negative supplies sink conventional current Any valid setpoint apart from zero volts enables the supply The HV active LED illuminates when the supply is enabled 15 1 High voltage filter The output of the supply is passed through a low pass passive RC filter configured according to the HV rating This reduces the level residual ripple from the high voltage power supply This is most important for the 3 kV HV option where the basic ripple specification of the HV supply is lower Note that there is some voltage drop across the filter if current is drawn from the supply so that the actual voltage will differ slightly from the set voltage You will see this on the readback which measures after the filter The full load voltage drops for the various HV options are as follows HV option 3kV 2kV IkV 500V 200V Filter resistor 32 2 kohm 32 2 kohm 10 kohm 4 7 kohm 0 ohm Max voltage drop 11V 17V 5V 9v OV The difference will be of no significance for most applications and it unlikely that full load current will be drawn in typical applications 15 2 High voltage readback High voltage is read directly from the I404 output using a voltage divider and ADC The divider has an impedance of 60 Mohm to ground This is always present as a small load on the supply The readback provides a useful diagnostic if
57. e 1404 e qu HO PR RR ues 32 11 3 Idcm P X 34 11 4 Ania ag 38 11 5 DDOVICE SCTCON T M 42 12 wvnteintar adjacet son tsa 45 12 1 Gated Integrators 4 o e ed aer er he pe ei Baad e IE AU ERES 45 12 2 1404 Circuit OVeFVIOW i ais ett itte etd tte RO IR e sa deviste sateua PRESE E A TE d EORR edd 46 13 Making Current Measurements e eeee censere eene ee seen stas tta sense ta senses stas tas etas e tassa sess testae etas e tastes setas eaae 48 13 1 Current RONG OS io ia e t e gl ate n I E Seem ete 48 13 2 AVerdging statt a att ee ome editam ou 49 13 3 TME ROVING slicers EE TE 49 13 4 COLD TATION IPTE 50 13 5 MOnitoF OUIDUIS 4h ette Adeste elt cited desee ed ees ati e ve e eere e Pe ee Pe ee etch 50 13 5 1 Current monitorinp 4nd ea Ie RB DP RE 50 13 5 2 Position momtortng certe E rere Eb te tere a dete dedit tle eed a 52 14 Beam position readout 4 e eeeee eee eese eese esee essen eene tasto stat tns etas esses sts etse ense ease enses senes e sesta setae tastes s eoae 53 14 1 How compensation factors are used eese ener enne ee nennen nennen enne 53 14 2 POSULON GIB OTUNIMS IMEEE 55 14 3 Considerations when using split or quadrant sensors eese eene e
58. e PSI Diagnostic uses the concepts of ports and loops to organize the connected devices A port is a communications channel from your PC such as a COM port or an Ethernet port Each port can be a channel to one or more loops and each loop may contain up to 15 devices Connect 24 V DC power but no other connections The power LED should illuminate when the power is applied and link and status LEDs will go through a power up cycle It is simplest to connect the I404 directly to the PC via its RS 232 port figure 18 assuming you are lucky enough to have a PC with a serial port Set the mode switch to position 0 RS 232 115 kbps binary If you don t have a host computer with a serial port then a basic fiber optic loop controller like the Pyramid Technical Consultants Inc A300 will allow you to connect via Ethernet The address switch can be set to anything between 1 and 15 1404 User Manual 1404 UM 130129 Page 32 of 104 PSI System Controls and Diagnostics Mode switch setting 0 24V in s Mode switch setting don t care 24V in 24V in Figure 19 Connection through an A300 The Diagnostic will see the simple configuration in figure 18 as a COM port with just the 1404 on it The direct RS 232 connection does not allow more than one device to be seen through that port Contrast this to the situation where you have a loop controller such as the A300 or A500 and the 140
59. e lowest detectable current will be increased If the length is greater than five metres the accuracy of the measurement can be affected under some circumstances Contact Pyramid Technical Consultants Inc for detailed guidance 9 3 2 Signal cables Coaxial cable should be used and we strongly recommend a low noise cable to prevent spurious signals arising from cable flexing or vibration A suitable type is Belden low noise RG 58 9223 Other types with equivalent specification can be used 9 3 3 Signal current path The current you are measuring passes along the cable inner conductor to the 1404 input It flows to the local circuit ground via the amplifier power supply due to the operational amplifier action The necessary return path then depends upon the energy source that originally drove the measured current If there is no return path you will see no current This is quite a common fault in current measurement set ups Always think about the path the measured current must follow It is not essential that you understand the details of the I404 input amplifier circuit in the figures below the important point is that you can assume that current from a source following into the amplifier must be balanced by a current from the amplifier ground back to the original source Figure 12 shows the situation for photodiodes where the loop is simply completed via the coaxial screen If the screen was not continuous and the diode cathode was common t
60. e path to signal input due to missing or broken guard Disconnect input background should reduce to specification levels Ensure good guard integrity all the way to the signal source High humidity Problem varies with relative humidity Ensure there are no water absorbent insulators Reduce the humidity levels Internal contamination Background current remains high with inputs disconnected Contact your 1404 supplier for advice or to organize a return for cleaning High noise levels Integration time too short for signal being measured Noise level reduces with integration period Use an appropriate integration time for the signal level RF pickup Noise varies with cable position status of neighboring equipment Check integrity of outer screens of signal cables Line voltage pickup Noise level drops sharply if integration period is 16 7 msec 60 Hz or 20 msec 50 Hz Keep 1404 and signal cables clear of unscreened high current mains voltage Use integration periods N line frequency No signal Small signal lost in noise Use longer integration time Signal does not vary as expected Integrators are overrange Overrange flags are set signal recovers if integration period is reduced Reduce the integration period or use the larger feedback capacitor 1404 User Manual 1404 UM 130129 Page 93 of 104 PSI System Controls
61. ed by time The time interval is called the integration period We cannot allow the voltage on the capacitor to simply increase for ever The ADC has a specified input voltage range and there is little point in exceeding it Therefore we must discharge the capacitor periodically and this takes some time typically 20 usec Then we can restart the cycle Current Voltage ae 100 50 0 50 100 150 200 250 300 350 400 Time Figure 7 Discharging the integration capacitor and starting a new cycle The process of charging the capacitor and discharging to reset is called gated integration The length of the integration can be controlled in the 1404 in the range 100 usec up to 65 seconds and typical working values are in the range 100 usec to 1 sec Notice that the first ADC conversion does not take place immediately when the integration starts This is because the signal is unstable just after the reset so we wait a time called the settle time before making the first conversion This time is normally set to 25 usec The settle time can be adjusted but it is a detailed parameter that doesn t usually need to be worried about We can get a running measure of the current by simply repeating the integration cycle as many times as we want Each time we can divide the measurement of charge that is the difference between the ending and starting ADC values by the time interval between them to get the current 1404 User Manual
62. efined current ranges that cover the full dynamic range of the I404 The 8 nA range is included because it has a 100 msec integration period and is thus immune to mains voltage interference This is the range that the 1404 measures on after it has powered up Resolution This controls the averaging that is done by the I404 As you increase the requested resolution from 16 up to 20 bits the number of ADC conversions per integration and the number of integrations per current reading is increased Monitors The Output Monitor selection lets you choose whether the monitor outputs map the input currents or a position function calculated from the input currents There are two position calculation options Split means that there are two independent calculations such as you would need if you have two independent one dimensional sensors Quadrant means the X and Y values are both calculated from all four inputs such as you would need if you have a quadrant sensor Freq Input Range determines in detail how the frequency monitor output is mapped if you have selected to map input currents Bipolar causes the absolute value of the currents to be mapped to the frequency range Positive causes only positive currents to be mapped negative currents 1404 User Manual 1404 UM 130129 Page 39 of 104 PSI System Controls and Diagnostics are set to zero and negative causes only negative currents to be map
63. ent condition ends 1404 User Manual 1404 UM 130129 Page 97 of 104 PSI System Controls and Diagnostics 25 Returns procedure Damaged or faulty units cannot be returned unless a Returns Material Authorization RMA number has been issued by Pyramid Technical Consultants Inc If you need to return a unit contact Pyramid Technical Consultants at support ptcusa com stating model serial number nature of fault An RMA will be issued including details of which service center to return the unit to 1404 User Manual 1404 UM 130129 Page 98 of 104 PSI System Controls and Diagnostics 26 Support Manual and software driver updates are available for download from the Pyramid Technical Consultants website at www ptcusa com Technical support is available by email from support ptcusa com Please provide the model number and serial number of your unit plus relevant details of your application 1404 User Manual 1404 UM 130129 Page 99 of 104 PSI System Controls and Diagnostics 27 Disposal We hope that the 1404 gives you long and reliable service The 1404 is manufactured to be compliance with the European Union RoHS Directive 2002 95 EC and as such should not present any health hazard Nevertheless when your 1400 has reached the end of its working life you must dispose of it in accordance with local regulations in force If you are disposing of the product in the European Union this includes
64. evance for a connection via the serial port 1404 User Manual 1404 UM 130129 Page 34 of 104 PSI System Controls and Diagnostics PSI Loop Diagnostic v4 51 Actions Options Window Help ted Comms js 1 1 1 1 Connected Pending Measuring Triggering Low Pass Filter Reset 1x 13 429 0 008 1 n 11 85 10 XIY Gain x 1000 Buffer 135kB dmm Zero rcm ae e zal Ls Lo Figure 21 Data current tab 1404 connected via COMI and running with default settings showing background noise The device should be collecting data with default settings and you will see a strip chart display of the four current readings reading background noise and auto scaled to full scale Now you can explore the screen controls and readbacks to get acquainted with the I404 Initiate This button starts the I404 measuring with the parameters set on the setup tab If you are in internal trigger mode then the acquisition will start at once Otherwise the acquisitions will start when the external starting trigger is detected on the gate input connector The number of readings in the initiate in progress is displayed in the Triggers box Note that after the I404 powers up it starts measuring continuously on its 8 nA range with internal triggering The LEDs indicate whether measurements are in progress whether triggers are being de
65. extender Because it uses differential lines you can transmit data reliably over hundreds of meters using the RS 485 interface rather than a few metres with RS 232 RS 485 is not generally provided on PC motherboards but RS 232 to RS 485 adaptors are widely available and cost effective The fiber optic interface provides greater speed excellent noise immunity and allows multiple devices to be connected in a looped topology It requires a fiber optic adaptor or loop controller device to connect to the host computer The fiber optic interface is well suited to large systems Only one interface is in use at any time Selection of the active interface is according to the cables that are connected and the mode switch setting 19 2 RS 485 connection example Figure 42 shows a typical configuration where RS 485 is used to extend a 115 kbps ASCII RS 232 connection over a long distance An RS 232 to RS 485 converter is used at the host PC end The built in RS 485 of the 1404 allows a direct connection at its end Mode switch setting 8 RS 485 RS 232 to Figure 42 Using RS 485 as an RS 232 extender A commonly used converter for the beam position monitor application is the MOXA TC100 The Moxa TCC 80 is a low cost alternative for less critical applications The converter should be configured for four wire full duplex RS 485 operation The 1404 provides parallel termination for transmit and receive It is the
66. faces leere ee esee eene senten statua tn oantins nekk Nnnna senes enata esos e 72 19 1 1404 Interfaces o4 ti o aste c deti e tet t e at m ice aate een 72 19 2 RS 485 connection example a WR e e ORO pur ED PEOR 72 20 Communications protocols eeeeee esee eene eene en etnia tna tn sens tn senses sesenta sens enses ees ses sensns ens to stessa essen suae 74 20 1 QVGEVIOM ts REEF E EE RE e a ete ett peti AN 74 20 2 ASCH PEOlOCOL eS CRE ueneno miei eo UR Ye tee ert eive ven 75 20 2 1 M SSage crt etate o patte aenean ede re iter 75 20 2 2 Status TeglStefs 3o ihe tee lect rede e ee tee edes md eie p edere et t deed 75 20 2 3 Host Commands e 855 domW es EEUU Ae acts ee ge SE es 76 20 3 Terminal Mode iiec eere o E HOS ER E D E CU ERRARE aA i ERE 63 ZV Soft Ware Updates D 84 22 Techniques for Making Low Current Measurements csscsssscssssssessessssessessesesssssssesssssssessessssessesessess 87 22 1 Guarding and screening a at e aoa op e RO RO ieee ae hs 67 22 2 LOMPOC Gre AEE EN EEE AE E ENE EE EE A E 68 22 3 Triboeleciric effects i ce i eerie e aee reti eee e Env EE EAE D se Ae e XE PRSE Vd 68 22 4 Battery Tf CES UCM G H 89 22 9 Piezoelectric Effects ene eed meu 89 22 6 Integration Period and Synchronization eese nennen een eene nennen rennen 89 22 7 AUI een is ata ai os a a wea ae a ees RA aoe 91 PA MEM OPTICS C CL Tp
67. he effect of sensor compensation factors Analog voltage on the left Normal and Absolute frequency mappings on the right 13 5 2 Position monitoring The monitor outputs are generated in real time by the FPGA in the 1404 and this FPGA is able to do very fast calculations on the incoming data This gives us flexibility to map other data onto the monitors As standard the 1404 can be switched to output X and Y position functions calculated from the input currents These are output to A and B monitor outputs with C and D not used See section 14 for more details of the position functions The functions always return values in the range 1 to 1 and are mapped onto the monitors as shown below 1 MHz 5090 kHz 1 00 41 00 0 Hz Figure 31 Monitor output mapping position functions 1404 User Manual 1404 UM 130129 Page 52 of 104 PSI System Controls and Diagnostics 14 Beam position readout A common application for the 1404 is readout of beam position monitors BPMs These can take the form of dual sensors for one axis position readout the axes may or may not be orthogonal or quadrant sensors for simultaneous two axis readout at a single plane transverse to the beam direction The sensors may intercept the beam directly for example blades that emit electrons when struck by a high energy photon beam or the interaction may be indirect for example electrodes in an ionization chamber
68. he graphic not the numeric or logged data The AC DC toggle oc is similar to zero subtraction but only affects the graphic When AC is selected the average of all the display values for a channel is subtracted from the values before they are plotted It is thus like a rolling offset removal or high pass filter Notice that there are three subsidiary tabs under the Data tab You have been looking at the default labeled current The other subsidiary tabs display beam position monitor readout data This will be described in more detail in section 14 11 4 Setup screen Click on the Setup tab Here you can adjust measurement parameters such as integration period feedback capacitor averaging set the high voltage and use the built in calibration facility When you first launch the PSI Diagnostic it will not be in Expert Mode and you will see some boxes are grayed out If you want to switch modes go to the Options menu and check Expert A 1404 3 Address 3 on Loop 5 on A500R5T5 192 168 100 213 100 Comms eter sd 4 Connected j Pending j Error Setup CONFIGURATION TRIGGER Calibration Compensation r Range Integr Period pee Calibrate 1000E 008 A 7 837E 002 s jj DE Cal Current 500 nA Gate Polarity ciama Capacitor 5 4 Hi Load 1 3 Q 3 oo pF Save Gain Factors Resolution Integration Avg Valid 100 3300 16 Bits 1 dis 1
69. he number of integrations to average per reading 1 to 15 MONitor 11213 Q Set query the position function that is performed internally by the 1404 and thus the signals that are put out on the analog voltage and frequency monitor outputs no position calculation monitor outputs map the input currents 2 quadrant mode calculation monitor outputs A and B map X and Y positions 3 split mode calculation monitor outputs A and B map X and Y positions PERiod lt float32 gt Q Set query integration period in seconds POLarity 011 Q Set query external gate polarity external trigger only 0 rising edge 1 falling edge POSition lt uint16 gt 0l1 Q Set query the threshold value of full current scale in use for data to be included in position calculations and the polarity of the current readings being used in the calculations 0 ve currents 1 ve currents RANGe lt float32 gt Set query a full scale current range in amps Integration period and capacitor selection are calculated by the 1404 READavg lt uint8 gt Q Set query the number of ADC readings to be taken in each integration period 0 to 15 RESolution lt uint8 gt Q Set query the number of bits of effective resolution 16 to 20 The I404 calculates the number of integration periods and ADC readings per integration SWITch lt uint16 uint16
70. iagram Tl integration period T2 setup T3 reset T4 settle T5 Swl width The Swl opening transition is displaced from the Sw2 closing transition by the Sw1 offset 46 Figure 26 1404 block schematic 47 Figure 29 Monitor output mapping current signals Analog voltage on the left Normal and Absolute frequency mappings on the right 5I Figure 30 Example of the effect of sensor compensation factors Analog voltage on the left Normal and Absolute frequency mappings on the right 52 Figure 31 Monitor output mapping position functions 52 Figure 32 Sensor compensation value fields as shown in the PSI Diagnostic 53 Figure 33 Dataflow in the 1404 54 Figure 34 Single axis readout from a pair of split sensors 55 Figure 35 Two axis readout from a quadrant sensor 55 Figure 36 Position response from a split sensor 57 Figure 37 Position data sub tab 58 Figure 38 XY data sub tab for quadrant calculation mode 59 Figure 39 XY position data sub tab for split calculation mode 59 Figure 40 X amp Y position data sub tab 60 Figure 41 Rear panel showing controls and indicators 67 Figure 42 Using RS 485 as an RS 232 extender 72 Figure 43 RS 485 cable 1404 to TC100 73 Figure 44 Selecting the hex file to load 85 Figure 45 Upload in progress 86 Figure 46 Offset current entering an unguarded input 87 Figure 47 Guarded input 88 1404 User Manual 1404 UM 130129 Page 7 of 104 PSI System Controls and Diagnostics Figure 48 Guarde
71. inant electronic noise frequency in your environment normally the line frequency SerialNumber This is the manufacturing serial number of your device and should be left unchanged Comm Timeout This field can be used to control how the I404 behaves if the communication link to its host is lost Entering any non zero integer value sets the number of seconds that the I404 will continue what it is doing if communications are lost After that it will go to its defined safe state 1404 User Manual 1404 UM 130129 Page 43 of 104 PSI System Controls and Diagnostics Properties The most important fields are the first two where you can check the installed device firmware and Reset Device This button causes a full warm reset of the 1404 Any acquisition in progress will be lost Select hex file This button starts the 1404 firmware update process It opens a file selection dialog When you select a hex file it will start uploading to the 1404 immediately Upon completion the 1404 will restart automatically and you will see the new Device Version number displayed Select fhex file This button starts the 1404 FPGA update process It opens a file selection dialog When you select a fhex file it will start uploading to the 1404 immediately Upon completion the I404 will restart automatically and you will see the new Device Version number displayed 1404 User Manual 1404 UM 130
72. int8 Q Set query the reset settle Sw1 offset Sw1 width in usec 1404 User Manual 1404 UM 130129 Page 79 of 104 PSI System Controls and Diagnostics int8 gt FETCh CHArge Return the last measured charge data in coulombs Returns integration time charge over range flags CURRent Return the last measured current data in amps Returns integration time charge over range flags DIGital Fetch digitals bitO measuring bit waiting trigger bit2 calibrated bit3 HV enabled bit4 external gate present HIVOltage Read HV output sense POSition Perform position calculation and return results in configured calculation mode INITiate Initiate readings on valid trigger READ CHArge Forces a measurement initiates the I404 and returns the measured charge data in coulombs Returns integration time charge over range flags CURRent Forces a measurement initiates the I404 and returns the measured current data in amps Returns integration time current over range flags DIGital Read digitals bitO measuring bit waiting trigger bit2 calibrated bit3 HV enabled bit4 external gate present HIVOltage Read HV output sense POSition Perform position calculation and return results in configured calculation mode READ Do same READ command as p
73. ion offsets in amps exponential format GAIn Q Calibrate query current measurement calibration gain for each channel or reset stored gains to nominal RCL Recalls the stored calibration and compensation factors SAV Saves the active calibration and compensation factors to EEPROM SOURce 011121314 Q Set query internal calibration source state 0 off OFF 1 4 on directed to designated channel CONFigure CAPacitor 0l1 Q Set query feedback capacitor 0 2 small capacitor 100 pF by default 1 large capacitor 3300 pF by default FREQuency 01112 Q Set query the mapping of the frequency monitor outputs when they are showing current 0 Absolute mode The absolute value of the selected signal is mapped to the frequency monitor output range with gain and offset applied if compensation factors are enabled 1 or 2 Normal mode The bipolar signal range is mapped onto the frequency range with gain and offset applied if 1404 User Manual 1404 UM 130129 Page 78 of 104 PSI System Controls and Diagnostics compensation factors are enabled HIVOltage MAXvalue lt intl6 gt Q Set query maximum allowable external high voltage setting in volts password protected SET lt intl6 gt Q Set query the auxiliary external high voltage in volts INTavg lt uint8 gt Q Set query t
74. k It has been tested with Windows XP Windows Vista and Windows 7 The NET framework has to be installed before the PSI Diagnostic Most new PCs have NET already installed It can be downloaded from the Microsoft web site at no charge The installer will alert you if the NET framework needs to be installed Install the PSI Diagnostic by running the PTCDiagnosticSetup msi installer and following the screen prompts Once the program has installed you can run it at once If you wish to view the files that have been installed navigate to Program Files Pyramid Technical Consultants Inc PTCDiagnostic The screenshots in this user manual were taken from PSI Diagnostic versions 4 51 and 4 55 The screens you see may differ slightly if you are running a different version The first version to support the 1404 was 4 30 Do not attempt to use an earlier version 11 2 Connecting to the 1404 The PSI Diagnostic is a stand alone program which allows you to read graph and log data from the I404 and set all the important acquisition control parameters It supports communication via any of the interfaces and uses the binary protocol as opposed to the ASCII protocol for higher performance For some applications it may be adequate for all of your data acquisition needs Once the program has installed you can run it at once It will allow you to connect to the I404 and depending upon your interface setup multiple additional devices at the same time Th
75. l always be a single non printing character The first character is ACK 0x06 when the command has been successfully executed with no errors Responses to host commands with a will then have the required data terminated with the CR LF sequence If the host is not requesting data no no other bytes will be transmitted after the ACK If the 1404 generates an error when executing the host command it will transmit a single BELL 0x07 as its response A computer running a terminal program will therefore beep when the I404 cannot execute a command for example due to incorrect syntax A more interactive terminal mode can be selected which modifies this behavior to make the I404 more user friendly when it is being driven from a terminal program Device addressing is performed using the special command Addressing is only necessary for devices linked by a fiber optic loop but a device is made the listener when the host sends ADDRESS For example 4 will make the device with address 4 the listener You must ensure that all devices on the same communications channel have unique addresses AII subsequent commands sent without address will be listened and responded to by device 4 only The host message asks who the listener is The command can be sent as a compound message such as 3 IDN 20 2 2 Status registers The 1404 implements the IEEE 488 2 status register method Each of the registers is masked by a corresp
76. l triggering like autorun on an oscilloscope or external triggering In the latter case if you initiate an acquisition it will not start until the 1404 sees a TTL transition on the gate input You can set the 404 to respond to a rising or falling trigger edge External Bias If your 1404 has the auxiliary external high voltage option you can set the output voltage with the Set Value box The Max box allows you to constrain the settings to a particular maximum for example to protect sensitive equipment that cannot sustain the maximum voltage of the supply The feedback value is not generally as accurate as the setpoint but does allow you to see if the supply is being overloaded Note that your setpoint entry must have the correct polarity to set a 1000 V supply to 600 V you must enter 600 Calibrate Clicking the calibrate button causes the I404 to execute its automatic self calibration routine using the precision 500 nA internal current source The gain factors will be displayed upon completion You can save the calibration to 1404 EEPROM memory load a previously stored calibration 1404 User Manual 1404 UM 130129 Page 40 of 104 PSI System Controls and Diagnostics or clear to the uncalibrated state The green LEDs alongside the gain factors indicate that the calibration is within allowed tolerance bands Cal Current You can toggle the built in 500 nA calibration sour
77. measure of the average current achieves increasing signal to noise ratio as more charge is accumulated and the low pass filtering roll off due to the increasing integration time moves to lower frequency The inherent integration is very effective in reducing noise being in effect a rectangular low pass filter with 3dB response at 0 44 t Hz and zero response at N t Hz N21 2 3 Known 1404 User Manual 1404 UM 130129 Page 45 of 104 PSI System Controls and Diagnostics dominant noise frequencies for example line voltage interference at 50 Hz or 60 Hz can be completely suppressed by choosing tper 1 50 or 1 60 seconds or integer multiples thereof Integration cannot proceed indefinitely because the charge amplifier output voltage cannot exceed its voltage supply rails and because the voltage would exceed the range of the ADC that follows It is therefore necessary to reset the integrator periodically After the defined integration period switch Sw2 closes to short the feedback capacitor and release the charge so zeroing the integrator ready for the next cycle Sw1 is opened briefly while Sw2 is closing to inhibit transients The reset time needs to be sufficient to completely clear the accumulated charge through the switch FET on resistance and thus depends upon the size of the feedback capacitor There is also a settle time allowed after opening Sw2 to start the integration before the start ADC reading is taken to allow tr
78. mmunications eeesessesseseeeeeneeee nennen ren eren enn rennret eene 65 16 2 3 Fiber optic communications ape Gl OO I HG CR RERO EC HE HR EIER EHE 66 IEMM UPrnr 67 17 1 Front panel controls siei ei tente ag itii EACH Ee LR tte vans de Reuse ee bee EENES 67 17 2 Re t PANEL CONT OIS sence et etti eese gen edet deant a ed 67 17 2 1 Mode switch iulio eet ce i mede he dee e esie ed 67 17 2 2 Address SWitchi ieu seem eee eie eee et e ee edet tee eene 68 17 3 Front panel indicators ioa ne uua dida Er 68 17 3 1 ITV active ziii eet HORROR Eten iie DU OD avis eases ei guste tms 68 17 4 Rear panel indic ors s t e Me eet rtt en dedii tti e e tette det 68 17 4 1 POWe gc e MY 68 17 4 2 NLIET e DOE eet eet 68 17 4 3 Optical 5e beetle oer mete epe de a eat d OE Een 68 1404 User Manual 1404 UM 130129 Page 4 of 104 PSI System Controls and Diagnostics 17 4 4 po M 68 17 4 5 AIDIU ii tines o e n Ain ae faf e reta eoi nat m EET 68 17 4 6 StAtUs MC 68 17 4 7 Inc 69 18 Mmternal nnns C R 70 18 1 High voltageOoplions i peer E AERE E RR EET P UNE E ee d ERR PEEU US 70 19 Communications Inter
79. n directly select the numbers of each averaging method it is most convenient to simply select the number of resolution bits then let the 1404 select the number of averages It will also make the necessary adjustments to the integrator reset timing If you do wish to make your own direct selections of integration averages and read averages then you must be aware of the following constraints all values in usec Integration Period gt Read Avg 16 Setup gt Read Avg 1 4 Setup Reset gt Read Avg 16 log Integration Avg logg Read Avg lt 4 The 1404 will adjust the reset and setup times as needed to accommodate your settings and you can read the values it has used from the screen or query them if you are using the ASCII protocol The rate at which new readings on all four channels are generated is given by tdata Integration Period Reset Settle Setup The exception to this is when you have selected Integration_Avg greater than 1 Then you must wait Integration Avg taata for the first reading to allow the average to be formed After that the current readings come at the normal rate because the averaging is done on a rolling basis the oldest value is removed and replaced with the latest value 13 3 Triggering When you initiate a measurement the 1404 prepares to make the reading with the selected setup parameters However the integration cycle does not start until a trigger is seen There are two trigger modes
80. nd that you familiarize yourself with its operation on the bench using the ASCII communications You can check the unit powers up correctly establish communications run the internal calibration procedure and read the internal calibration current 1 Inspect the unit carefully to ensure there is no evidence of shipping damage If there appears to be damage or you are in doubt contact your supplier before proceeding 2 Connect the 24 V DC power supply but no other connections The power LED should illuminate when the power is applied and the link and status LEDs will go through a power up cycle 3 Make a connection to a PC serial port A three wire lead terminated in a six pin mini DIN male connector PS 2 mouse type and a nine pin D female is required A suitable adaptor cable is available from Pyramid Technical Consultants Inc When the connector is pushed home in the 1404 the optical LED should extinguish and the RS232 485 should illuminate 6 pin mini DIN male in D P RX 9 pin D female TX TX RX GND 5 9 3 9 o o0 o o9 Figure 14 RS232 connection cable from the 1404 to a PC serial port DB9 Pins are shown looking at the face of the connectors 4 Set the address rotary switch to position 4 address 4 this is an arbitrary selection for this exercise and the mode rotary switch to position 3 RS 232 ASCII communication 115 kbps 5 Configure a Windows Hyperterminal session
81. ngs It performs any necessary accumulations for averaging It puts out the monitor frequency outputs via line driving buffers and the analog voltage monitor outputs via 16 bit DACs and output buffers The FPGA is also responsible for the low level communications control The microcontroller handles higher level communications including parsing the ASCII command strings and generating the responses It also monitors the readback of HV if the optional high voltage module is fitted Cal current Calibration source A 4x switchable large feedback capacitor DC DC x 24V DC in 4x gated integrator Pwr 15 5 3 3 2 5 1 2 VDC CI Ch 1 e Gate 5 Xmit Rcv O Serial RS232 Rs485 D Serial Ch2 Fiber in oO Ba T H gt FPGA Fiber optic RX lt lo CT i Quad R k Monitor outputs DAC Analog voltage X 8 HV divider Monitor outputs Frequency HV out Micro controller D Status Link Figure 28 1404 block schematic 1404 User Manual 1404 UM 130129 Page 47 of 104 PSI System Controls and Diagnostics 13 Making Current Measurements 13 1 Current Ranges The 1404 powers up measuring on its 8 nA range which uses an integration period of 100 msec which suppresses mains interference almost completely However it is very likely tha
82. nne nennen 56 1404 User Manual 1404 UM 130129 Page 3 of 104 PSI System Controls and Diagnostics 14 4 Position readout screens in the PSI Diagnostic essere een eene eene 57 14 4 1 Position SUD t b 5 cote eee aq efotete atto ice ted ase 57 14 4 2 Medus 58 14 4 3 XC amp Y subta Dco e eie ote e d i HU EHE THE EROR 60 15 High Voltage Option P 61 15 1 High voltage filter erinnere ee ERN vey i IR REA ER ERRARE ERES ORT RE RT ERE 61 15 2 High voltage re dbacks i ene tti DR ROS 61 15 3 High voltage protection features eese nennen enne eene n SAE DEOISE ERESSE OSISE EEEE 62 O 9 64 16 1 Front Panel COnhnectoTs iu c a PR HR RESI ERR o ee d 64 16 1 1 Signal PUG Sys ect et pete de eed ten t e e tet e te Ne nd 64 16 1 2 Analog monitor o tputs 5 o eo re den te e d E a te ERE P Ep Re 64 16 1 3 Frequency monitor Outputs ee eR AV a A eas mee ee ee 64 16 1 4 Gate Input eben mediata team autetn e ehe 64 16 1 5 Auxiliary HV OUN 8 sei ites pete uie ete p trae e ted eiue 65 16 1 6 Ground TU Sees setae SR Sei ERIS ERRORES UR SEO Se ET 65 16 2 R r Panel COnnectors 5 ne t DU EE REESE E RR eages Dena A 65 16 2 1 Power inputs 2 teer atento emaeite mee ert 65 16 2 2 RS 232 and RS 485 co
83. o beamline system ground then an alternative path would be via general ground and the I404 chassis Figure 13 shows the situation for an ion chamber biased by the I404 auxiliary supply Here the return current must flow through the high voltage supply If you use an independent bias supply instead of the I404 internal supply then the situation is similar except that the connection from the ground point of the supply to the internal ground of the I404 must be made by an external link generally from the chassis of the supply to the chassis of the I404 This can be a discrete wire link or they can both be connected to laboratory ground 1404 User Manual 1404 UM 130129 Page 27 of 104 PSI System Controls and Diagnostics Photodiode current source Coax screen pReuaeed 1404 Alternative return if outer screen is broken and diode cathode is connected to beamline neuem LUN Figure 12 Path of measured current photodiodes lon chamber current source Coax screen sew 5 1404 o nal Bias EE Auxiliary HV PSU Figure 13 Path of measured current ion chamber 1404 User Manual 1404 UM 130129 Page 28 of 104 PSI System Controls and Diagnostics 10 Getting Started Using ASCII Communication Before installing the 1404 in its final location and if it is the first time you have used an 1404 we recomme
84. onding enable register It is recommended that you set all the enable registers to all 1 s The host software should use the STB command to watch for changes to the status of the I404 and then ESR STATus OPERation CONDition or STATus QUESTionable CONDition as appropriate to recover the details from the relevant register 1404 User Manual 1404 UM 130129 Page 75 of 104 PSI System Controls and Diagnostics 20 2 3 Host Commands The 1404 responds to the mandatory commands prescribed by SCPI and IEEE 488 2 plus specific commands as required by the operation of the device The commands are grouped with a hierarchical structure with the levels separated by the colon character For example CONFigure PERiod 1e 2 This command configures the integration period to have a length of 10 milliseconds SCPI provides for a long and short form for each command The short forms are indicated by the capitalized part of the command denotes a required argument denotes an optional argument A number of commands are password protected to reduce the chance of changing them accidentally These commands are only effective after the device has been rebooted if they have been enabled by first sending SYSTem PASS word 12345 Sending any other number as the argument of this command disables the protected commands again 20 2 3 1 ADDRESSING DEVICES SCPI does not provide specific commands for addressing multiple devices because this was
85. or Current Position Quadrant Split Initiate Measuring Ext Bias V Abort Triggering mE Channel 1 500 9 9 cated 800 600 Current nA v 400 200 0 200 400 Triggers 1910471 800 IDEE LE Low Pass Filter 1000 Ease T 4x XIY Gain 1 X 1 000 Buffer 65535kB _ lt 209 Y 1 000 100 rast oc ss e e fia cul st cear 600 Figure 24 Internal calibration current routed to channel 1 histogram display format If you have suitable cables and test equipment available you can look at the monitor output for channel 1 channel A You should see close to 5 V on the analog voltage output and close to 500 kHz on the frequency output Try other channels and investigate the effect of changing the range and of changing the display from current to charge If the calibration current is overrange the current reading is shown in red text 11 5 Device screen The final major tab in the 1404 window is the Device tab You can check the communication link status and verify the versions of the hardware and firmware On the right is the firmware update utility You can use this to download firmware updates hex files downloaded from the Pyramid Technical Consultants Inc web site 1404 User Manual 1404 UM 130129 Page 42 of 104 PSI System Controls and Diagnostics Communication Messages Sent 616807 lt T404 3
86. orithm that is used You should always use the algorithm that is most appropriate to your sensor configuration The selected mode is shown at the lower left corner of the I404 Data tab 14 4 1 Position sub tab The position tab simply displays the calculated X and Y positions instead of currents The controls are otherwise the same as the current tab Low pass filtering works on the position readings but zero does not Changing the X Y gain or X Y offset 1404 User Manual 1404 UM 130129 Page 57 of 104 PSI System Controls and Diagnostics 1404 3 Address 3 on COM1 Comms FHEHEHEEHEMR 7 Connected Pending Error Data Current Position xv x amp v Initiate Measuring Ext Bias V Abort Triggering 9 casa Current uA X Y Gain x 2 000 Triggers 218238 Y 5 000 z Low Pass Filter XIY Offset Reset 10x 7971 1 D 1 E 1 000 658 62 659 660 661 qmm Y 3 000 Buffer 36025kB Iz meus uL e SplitXY Y 10076 zl zx A z efu z L Figure 37 Position data sub tab Note that setting the graph to display positive values only may not be appropriate for position signals which are typically bipolar even though the measured currents are all unipolar 14 4 2 XY sub tab The XY screen plots X against Y as a moving crosshair The readings shown on the graphic are the current readings multiplied by the compensation factors that you have entered on the Set
87. pacitor values in your calculation and adding the settle and setup time to the integration period Selected capacitor Value used for range calculation 100 pF 80 pF 3300 pF 3050 pF When the 1404 is choosing capacitor and integration period for a selected full scale range it first selects the capacitor using 100 pF for currents of 1 uA and less and 3300 pF for higher currents Optimized reset settle and setup times are used based on the capacitor and averaging selection Finally the I404 calculates the integration period using the effective capacitor values given above Because the 1404 calculates range using conservative values you will often be able to measure currents higher than the nominal full scale However note that the monitors give their maximum 1404 User Manual 1404 UM 130129 Page 48 of 104 PSI System Controls and Diagnostics defined outputs 10 V or 1 MHz at the defined full scale and will not respond linearly above that 13 2 Averaging The 1404 gives you great flexibility in the tradeoff between speed of measurement and resolution and signal to noise ratio You can choose the number of integrations that are averaged to give one reading from to 16 You can also choose the number of ADC reading pairs that are made in each integration also from 1 to 16 The resulting effective resolution in bits is given by Resolution 16 int log Integration Avg int log Read Avg Although you ca
88. ped These selections only affect the monitor outputs They do not affect what the 1404 measures or what you can see via the communications link Integration period Expert Mode only You can set the integration period directly The resulting current range will be displayed Capacitor Expert Mode only You can select the small or large feedback capacitor The resulting current range will be range will be displayed Integration Avg Expert Mode only You can select the number of integrations that are averaged into each current reading The resulting effective resolution will be displayed Read Avg Expert Mode only You can select the number of ADC data points that are averaged into each current reading The resulting effective resolution will be displayed There are constraints on the combination of Integation Avg and Read Avg due to timing limitations If you exceed the constraints the 1404 will use the nearest available combination Position The position Threshold allows you to specify the percentage of full scale that a signal current must have before it gets included in a position calculation Below the threshold it gets set to zero This is to prevent the position function becoming very noisy when the currents are very small The Negative Input checkbox should be set if the signal currents going into the position calculation are negative rather than positive Trigger You can select interna
89. rap lines that exceed terminal width Figure 16 Hyperterminal terminal settings 6 Type lt CR gt to query the active listener You should get the response 4 You are communicating successfully with the 1404 set at address 4 If you hear your computer s bell sound when you send the string the 1404 did not understand it probably because there was a typing error If you make any errors while typing use the backspace key and re type from the error 7 Type calib gain lt CR gt The characters can be upper or lower case The 1404 will perform its internal calibration sequence 8 Type calib gain lt CR gt The 1404 will return the gain factors for the four channels 9 Type read curr lt CR gt The 1404 will do a measurement and return the integration period it used the measured current values for each of the four channels and a byte which says if any of 1404 User Manual 1404 UM 130129 Page 30 of 104 PSI System Controls and Diagnostics the channels went overrange The current values should be close to background If you repeat read curr lt CR gt a few times you should see the readings change due to background noise 10 Type conf range 1e 6 to set a 1 microamp full scale range 11 Type calib source 1 to turn on the internal 500 nA calibration source to channel 1 channel A 12 Type read curr lt CR gt You should see a reading close to 5e 7 A on channel 1
90. refore optional whether you also terminate at the TC100 end but there is no harm if you do The recommended Dip switch setting for the TC100 is 1404 User Manual 1404 UM 130129 Page 72 of 104 PSI System Controls and Diagnostics Swl Sw2 Sw3 OFF ON ON The recommended Dip switch setting for the TCC 80 is Swl Sw2 Sw3 ON OFF ON LEA ee FP 1 Tx a Tx A 2 Rx xo It Rx B 3 Gnd L e Rx A 4 n c Z I 5 Tx NS 1O 6 Rx I A I 1 Q SGnd 1404 TC100 Figure 43 RS 485 cable 1404 to TC100 In order to enable the RS 485 interface on the I404 you must have a physical connection to the serial port and you must select one of the relevant modes modes 6 through 9 If you have trouble getting the RS 485 connection to work check carefully to ensure that you have all the transmit and receive lines connected as shown 1404 User Manual 1404 UM 130129 Page 73 of 104 PSI System Controls and Diagnostics 20 Communications protocols 20 1 Overview The 1404 supports three types of communication protocol selected according to the setting of the mode switch a An eight bit ASCII protocol messages compliant with SCPI The low seven bits are used to encode the ASCII character The eighth bit is only set for synchronization when the lt ACK gt lt BELL gt lt CR gt lt LF gt and lt ESC gt characters are transmitted b An eight bit binary
91. revious defaults to charge if no previous 1404 User Manual 1404 UM 130129 Page 80 of 104 PSI System Controls and Diagnostics STATus OPERation CONDition Query operation register status condition bit ENABle Set query operation register status enable bit EVENC Query operation register status event bit QUEStionable CONDition Query questionable register status condition bit ENABle Set query questionable register status enable bit EVENC Query questionable register status event bit SYSTem COMMunication CHECKsum 011 Set appending checksum to all replies password protected 0 off l on TERMinal 011 Set query terminal mode password protected 0 terminal mode off 1 terminal mode on In terminal mode ACK and NACK are not sent and OK or error response is sent for all valid commands that do not otherwise generate a response TIMEout lt timeout gt Set query timeout in seconds password protected 0 timeout disabled 1404 will go to unconnected state if no valid message is received in the timeout period ERRor Query the next error in the error event queue FREQuency Hz Q Set query the dominant noise frequency Hz to be suppressed in the calibration routine This will generally be the line frequency 50 or 60 PASS word pass Q Set query the administrator password pass to allow access to
92. rs so that the readout is also X Y 0 The values A B C D used in the difference over sum position algorithms by the I404 are therefore A GA IA Oa 1404 User Manual 1404 UM 130129 Page 53 of 104 PSI System Controls and Diagnostics B Gg Igt Oa C Gc Ic OA D Gp p OA where IA p c p are the signals from inputs labeled A through D and GA p c p Oap cp are the corresponding compensation factors Do not confuse these sensor compensation factors with the gain factors that are generated by the 1404 s automatic calibration routine to convert raw data to accurate currents in amps nor with the gain and offset factors that are used in the PSI Diagnostic to convert position algorithm output to physical positions Figure 33 illustrates the overall flow of data in the I404 Compensation Gain factors from factors amp offsets automatic calibration Ga Gg Gc Gp O4 Og Mode quad split HL HH ChA raw gt c A 5 gt ChB raw gt ES I Apply gt Apply C gt Position gt XY 1 to 1 ChC raw gng L calibration compensation D algorithm via comms ChD raw LL gt la lg lc Ip amps Compensated la ls lc lp 4 l lg lc Ip amps via comms lt i vvvy vy TTL absolute y n Saleen lees ree current current comp position THREE
93. sh to measure then you must have integrations short enough to be sensitive to the variations rather than smoothing them out The final consideration is filtering A given integration time used repeatedly to measure a continuous current acts as rectangular low pass filter This has the property of completely suppressing frequencies in the signal which correspond to the integration period If you are troubled by 60 Hz noise for example then using an integration period of 1 60 seconds will eliminate the problem So will any integer multiple of that period A good choice is 100 msec as this is five times the 50 Hz period and six times the 60 Hz period The 1404 provides a lot of flexibility in how measurements are made Let s look at some of the parameters 1404 User Manual 1404 UM 130129 Page 22 of 104 PSI System Controls and Diagnostics 8 2 Current ranges If you use the PSI Diagnostic host program to control the I404 you will see that we have pre defined some useful current ranges to choose from to cover the whole dynamic range In Expert Mode you can directly set the parameters that affect current range yourself These are the integration time and the selection of integration capacitors The 1404 calculates the resulting full scale range making allowance for component tolerances and other factors 8 3 Resolution and averaging The 1404 has features that improve the precision of the data by taking multiple readings an
94. ssumed to be experienced in the general use of precision electronic circuits for sensitive measurements and to be aware of the dangers that can arise in high voltage circuits 6 2 Key Features Highly sensitive charge and current measuring system Four gated integrator signal input channels External gate input Analog and frequency monitor outputs with configurable mapping Dynamic range pA to 100 uA with standard capacitors Built in calibration check current source RS 232 RS 485 and fast fiber optic serial interfaces built in Selectable baud rates Can be operated in a fiber optic serial communication loop with up to thirteen other devices 100BaseT Ethernet available through the A300 and A500 interfaces ASCII and binary serial data formats Auxiliary HV output option up to or 3000 VDC 1404 User Manual 1404 UM 130129 Page 14 of 104 PSI System Controls and Diagnostics 7 Specification Inputs Four Integration time Adjustable 100 us minimum 10 s maximum Input noise current 100 fA rms 1 fA rms per pF input load up to 100 pF 1 second integration 100 pF capacitor Input offset current 10 pA 15 to25 C Offset can be removed by zero subtraction excluding external background current sources Stability Output drift 200 fA C hour 100 pF feedback Digitization 16 bit ADC multiplexing four integrator signals over 10 V integrator output range 200
95. stem Controls and Diagnostics Current 1p0 50 0 50 100 150 200 250 300 350 400 Time Figure 4 A current to be measured A conventional current to voltage conversion method would convert this current into an equivalent voltage and this voltage would be converted to a number by an ADC analog to digital converter However this method is less suitable for measuring very small currents because of signal to noise limitations The 1404 therefore uses a method called gated integration instead Imagine that at some point in time zero on the graph you start accumulating integrating this current on a capacitor The capacitor will charge up and an increasing voltage will therefore appear across the capacitor Current Voltage ipo 50 0 50 100 150 200 250 300 350 400 Time Figure 5 Voltage on a capacitor that is connected at time zero If we measure this voltage with an ADC we will know the charge on the capacitor at the time of the conversion If we measure the voltage at two defined times we will know the increase in charge over a known time interval 1404 User Manual 1404 UM 130129 Page 20 of 104 PSI System Controls and Diagnostics Current Voltage 100 50 0 50 100 150 200 250 300 350 Time Figure 6 Capturing the voltage at two times From this we know the average current during that time interval because average current is simply charge divid
96. t you will need to use other ranges The correct selection of current range is important for getting the best data quality You don t want to run the risk of overranging and thus loosing data nor on the other hand do you want to measure a very small current on a relatively high current range where you will have poor resolution The 1404 full scale current is determined by several factors The size of the feedback capacitor You can choose one of two capacitors a nominal 100 pF or a nominal 3300 pF Other values are available to special order The integration period You can adjust this from 100 usec to 65 seconds The span of the ADC This is fixed at 10 V The level at which the 1404 flags an overrange condition This is fixed at 98 of the ADC span in either direction The settle and setup times Although you are not using any data from the integrator ramp during the settle and setup times the ADC span is nevertheless being consumed If you are working in expert mode and want to predict roughly what a full scale will be for a given selection of integration period and feedback capacitor then the approximate full scale is given by ir ens 9 8C p LR where C is the selected feedback capacitor and tper is the integration period The range calculated by the I404 uses a more complete expression which takes account of worst case capacitor tolerances and settle time You can do a similar calculation by using the following ca
97. tected and the state of the external gate input it displays the state of the input irrespective of whether it is being used to trigger 1404 User Manual 1404 UM 130129 Page 35 of 104 PSI System Controls and Diagnostics measurements Abort This stops an acquisition sequence in progress Current charge You can display the 1404 reading in pA nA uA or amps or pC nC uC or coulombs The check boxes determine how the data is displayed T The integration time in use is displayed in seconds X Y If you have set up the I404 to measure the output of a quadrant or dual electrode beam position monitor the positions results will be displayed Low pass filtering You can set up data filtering by the PSI Diagnostic to make a fluctuating value easier to read The filter type is a single pole IIR infinite impulse response digital filter The number in the drop down list is the parameter A in the filter equation Y Xi A 1 1 A Yi1 where Y is the latest output of the filter Y is the prior output of the filter and Xi is the latest reading from the I404 Low Pass Filter Reset 1x Zero 10x Set 100x l 1000x Note that this filtering by the PSI Diagnostic is in addition to the data averaging done in the 1404 itself The Reset button clears past readings from the filter The filtering affects the numeric display the graphic display and any data that you capture
98. the built in supply away from the voltage it is trying to regulate or you may cause damage to the 1404 gt CAUTION Do not connect the 1404 high voltage output to electrodes in a system that will be subject to direct strike by high energy high current charged particle beams that will drive the built in supplies above the voltages they are trying to regulate or you may cause damage to the 1404 gt 1404 User Manual 1404 UM 130129 Page 62 of 104 PSI System Controls and Diagnostics CAUTION BNC connectors are only rated up to 500 VDC They are not suitable for high voltage and should not be used for this purpose The 1404 is fitted with an SHV connector which is rated for the maximum voltage You should use the appropriate corresponding cable 1404 User Manual 1404 UM 130129 Page 63 of 104 PSI System Controls and Diagnostics 16 Connectors 16 1 Front panel connectors 16 1 1 Signal inputs Four BNC female socket To mate with standard signal BNC plug Input A Input C Input B Input D On the PSI Diagnostic host program inputs A B C D are labelled as channels 1 2 3 4 16 1 2 Analog monitor outputs Four Lemo 00 coaxial female socket Signal on center pin 10 VDC 16 1 3 Frequency monitor outputs Four Lemo 00 coaxial socket Signal on center pin TTL levels 16 1 4 Gate input BNC socket female To mate with standard signal BNC Input signal on center pin TTL levels
99. the device is working correctly 8 6 Monitor outputs The 1404 has monitor outputs both analog voltage and frequency TTL pulses These correspond to the currents being measured on each channel relative to the full scale in use However you can also ask the I404 to put out X and Y position values on two of the monitor outputs instead 1404 User Manual 1404 UM 130129 Page 24 of 104 PSI System Controls and Diagnostics 9 Installation 9 1 Mounting The 1404 may be mounted in any orientation or may be simply placed on a level surface A fixed mounting to a secure frame is recommended in a permanent installation for best low current performance as this can be degraded by movement and vibration Four M3 through holes are provided in the base on a 152 mm by 144 mm rectangular pattern see figure 2 The mounting position should allow sufficient access to connectors and cable bend radii 100 mm minimum clearance is recommended at either end of the device Best performance will be achieved if the I404 is in a temperature controlled environment No forced air cooling is required but free convection should be allowed around the case 9 2 Grounding and power supply A secure connection should be made using a ring lug from the M3 ground lug to local chassis potential This is the return path for any high voltage discharge passing via the 1404 The 1404 is usually supplied with a suitable power supply If you wish to use your own power
100. the high voltage is being shorted or overloaded If you notice that the readback is significantly lower than the setpoint then this indicates excessive current drain due to a low impedance to ground Shut down and investigate Similarly if you notice that the readback is significantly higher than the setpoint this indicates that an external 1404 User Manual 1404 UM 130129 Page 61 of 104 PSI System Controls and Diagnostics voltage source is driving the 1404 HV output This may damage the supply and you should shut down and investigate 15 3 High voltage protection features The 1404 processor will automatically shut down the supply to avoid overcurrent damage if the feedback differs from the setpoint by 20 of setpoint 5 of full scale voltage for more than fifteen seconds The supply is limited by a software high voltage limit which is password protected and stored in EEPROM in the 1404 The 1404 will reject any attempts to set the voltage higher than the limit This allows sensitive detector systems or experiments which may be damaged by excessive voltage to be protected Note that there is an overshoot when the HV supply starts up to low settings gt CAUTION Do not use the 1404 HV supply if your application requires a small fraction of its full voltage rating and could be damaged by a short term overvoltage gt CAUTION Do not connect external power supplies to the 1404 high voltage output that will drive
101. tibility table 1404_UM_100505 Corrected error in RS 485 pinouts 1404_UM_121121 Describe changes to compensation factor handling device 4 10 and later New ASCII commands added for compensation parameters and fetch data 1404 UM 130129 Minor corrections to ASCII commands table 1404 User Manual 1404 UM 130129 Page 104 of 104
102. tics 1404 stops measuring Communication link timeout Investigate and fix communications issue Use a longer timeout setting Unable to communicate with 1404 Wrong mode switch or address setting Check mode switch setting Use correct switch settings Switches can be changed while the unit is operating Unable to connect on fiber loop Connector still fitted to serial port Remove serial connector Tx and Rx fibers are swapped Connect fibers correctly Communications interruptions Other processes on PC host interfering with comms ports Use a dedicated PC with simple configuration and minimum number of processes running Unable to connect on RS232 Another program is using the COM port Try to access the required port with Windows Hyperterminal Choose another port or close down the other program Incorrect port settings Try to connect with the htm file supplied with the unit Correct the settings Incorrect cable Make up a suitable cable Unable to connect on RS485 Incorrect cable Make up a suitable cable Incorrect port settings Correct the settings Remote converter not set for four wire RS 485 Correct converter settings Remote converter not powered Turn on power Mode switch set for RS 232 Use correct mode setting Monitor outputs do not map Monitors have been set to Set the correct mode
103. tive currents onto the output frequency range It is still possible to emulate these legacy modes using the compensation parameters You have considerable flexibility to change the monitor mappings of measured current using the sensor gain and offset compensation parameters see section 14 This allows you to compensate for differences between sensors for example The factors only affect the monitor outputs if you select this to happen for example by checking the relevant box in the PSI Diagnostic program Mv Map Compensated Values to Freq Analo9 Otherwise they only affect the values that feed into the position calculations If you choose to let the compensation factors affect the monitor outputs then the analog voltage V normal mode frequency Fy and absolute mode frequency Fa are given by I V i0 G4 meas ga O I O F 5e5 Gra tO i FS 1404 User Manual 1404 UM 130129 Page 51 of 104 PSI System Controls and Diagnostics I O F 1e6 G ABS U meas 0 FS Imeas is the measured uncompensated current G and O are the compensation gain and offset FS is the full scale current and ABS is the absolute value function The responses in figure 30 illustrate this for an example with gain of 0 5 and an offset of 20 of full scale 10 V 6v9 800 kHz P d P A 600 kHz 1V 550 kHz FS FS 400 kHz N 300 kHz 100 kHz 10V FS 4FS FS FS Figure 30 Example of t
104. u have two independent sensor pairs each pair encoding an individual axis There is no requirement that the sensing axes be orthogonal or coupled 1404 3 Address 3 on COM1 E anl x Comms j connected j Pending j Error Current Position XY X amp Y Initiate 9 Measuring Abort Triggering Ext Bias V XIY Gain X 2 000 N 5 000 Low Pass Filter C XIY Offset Reset 10x X X 1 000 Zero Y 300 set Clear SplitXY Figure 40 X amp Y position data sub tab 1404 User Manual 1404 UM 130129 Page 60 of 104 PSI System Controls and Diagnostics 15 High Voltage Option The range and polarity of the high voltage supplies is fixed and must be specified at time of purchase Units may be returned to the factory to alter the high voltage modules if necessary The supplies have a maximum power rating at full voltage output of 1 watt Higher voltage supply options can therefore deliver less current than the lower voltage options The maximum current compliance in amps is given by 1 V where V is the rated output in volts Note that the supplies are not designed to operate at a small fraction of their full voltage rating The current compliance reduces at lower settings and there may be overshoot on starting up if the set value is low You should specify a supply option with appropriate voltage rating for your application The set voltage can be a
105. up tab If you have set quadrant calculation mode then the channel indicators and readings are arranged around the graphic in the pattern that is assumed by that calculation If you have selected split mode then this graphic may not be physically meaningful depending on the actual arrangement of your sensors The channel indicators and readings are moved on the graphic to indicate that the quadrant layout may not apply 1404 User Manual 1404 UM 130129 Page 58 of 104 TOIETTTTEEUS ni x Quad Amplifier C 3 3 Initiate Measuring Abort Triggering 9 Gated E Current Position XY Ext Bias V B x amp v X Y Gain x 2 000 Triggers Y 5 000 Low Pass Filter XIY Offset Reset 10x X 1 000 Y 3 000 ae Set Clear d QuadrantXY Figure 38 XY data sub tab for quadrant calculation mode 1404 Quad Amplifier iniiai 3 3 Data Current Position XY x amp v Measuring Ext Bias V Triggering um zd 9 caca _ XIY Gain X 2 000 Triggers 4888 Y 5 000 Low Pass Filter XIN Offset 10x X 1 000 Y 3 000 SplitXY Figure 39 XY position data sub tab for split calculation mode PSI System Controls and Diagnostics 14 4 3 X amp Y sub tab The X amp Y screen presents the positions as two independent markers that move along the span of the position range This display would be most appropriate if yo
106. vided that the beam dimensions are not too small or large relative to the sensor dimensions then the position functions will be linear with actual beam position over a reasonable range Figure 36 shows an example position response curve for a Gaussian current distribution moving across a split sensor system The physical width over which there is an approximately linear response depends upon the width of the current distribution If it is too broad however the gradient will be small and the position function becomes noise prone particularly if the gap between the sensors is large 1404 User Manual 1404 UM 130129 Page 56 of 104 PSI System Controls and Diagnostics Figure 36 Position response from a split sensor Normally you work only in the linear region The slope of the linear region is the conversion gain factor Gx y mentioned above The working range can be increased if you can measure a calibration curve and fit a higher order polynomial However the noise problem of low gradient once more applies and there is risk of placing undue faith in the quality of the result as you move towards the positive and negative limits of the response curve 14 4 Position readout screens in the PSI Diagnostic The PSI Diagnostic software provides special screens to display position values generated by the device Note that the way you display the X Y positions is a separate consideration from the position alg

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