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Models 2500 And 2502 Dual Photodiode Meter User`s Manual

1. Connect to INPUT LO 3 CAUTION FOR CONTINUED PROTECTION AGAINST FIRE HAZARD REPLACE FUSE WITH SAME TYPE AND RATING j Model 2500 2 10 Connections Model 2500 and 2502 User s Manual Voltage source connections Figure 2 8 shows the connecting scheme for using the Model 2500 as a stand alone volt age source Note that the DUT HI terminal is connect to the OUTPUT terminal for the voltage source while the DUT LO terminal is connected to analog common inner ring of INPUT jack The maximum voltage source output is 100V 20mA Figure 2 8 Stand alone voltage source connections Channel 1 INPUT ya WARNING NO INTERNAL OPERATOR SERVICABLE PARTS SERVICE BY QUALIFIED PERSONNEL ONLY RATINGS MAX igrat E igi KEITHLEY COMM WADEN CHANGE EEE ABDRESS MODE ote EEE INPUT DIGITAL 1 0 CHANNEL 1 CHANNEL 2 A A owe A TRIGGER LINK RS 232 CATI LINE RATING 50 60Hz C gt RATINGS MAX 60 VA MAX 100V 20mA FUSE LINE 630 mAT 100 VAG A SB 120 VAC 315 mAT 220 VAC i dammi jam ani aani aan VACTAGE SOURCE VOLTAGE SOURCE SB 240 VAC Y Pur CHANNEL 1 OUTPUT CHANNEL 2 Optional Noise Shield Con nect to IN PUT LO CAUTION FOR CONTINUED PROTECTION AGAINST FIRE HAZARD REPLACE FUSE WITH SAME TYPE AND RATING Model 2500 Triax Cable INPUT LO Inner Shield Channel 1 OUTPUT Model 2500 and 2502 User s Manual Connections 2 1
2. Figure C 1 Data flow block diagram READ FETC CALC3 DATA DATA fi CALCI DATA l Bypass if CALC1 l disabled Sample Buffer Data Store Buffer Bypass if y l l l disabled y CALC2 CALC5 DATA CALC6 DATA CALC7 DATA CALC8 DATA y TRAC DATA H CALC2 DATA i READ X FETC CALC4 DATA Models 2500 and 2502 User s Manual Data Flow C 3 SENS1 and SENS2 The SENS1 and SENS blocks represent the basic measured current readings for channel 1 and channel 2 respectively If the filter is enabled the readings will be filtered The SENSE blocks also measure time for the timestamp INIT When the INITiate command is sent the programmed number of source and measure operations are performed and the respective data is temporarily stored in a sample buffer For example if 20 source and measure operations were performed then 20 sets of data will be stored in the Buffer Data from this buffer is then routed to other enabled data flow blocks Assuming that all functions are enabled the data that is output by the read commands FETCh CALCX DATA and TRACe DATA depend on which data elements are selected With all elements selected available data will include channel 1 and channel 2 measurements as well as the timestamp and status information Note that if a channel is not enabled then either the NAN not a number value or the source value will be used instead S
3. eee 3 12 Basic measurement and voltage source commands 3 12 Measurement programming example nesses 3 13 Using the analog outputs Model 2502 only seese 3 14 Photodiode Measurements Configuring measurements oo elec eee eeeeeeeeseteeeeseeeeeeseeeees 4 2 Measurement configuration Menu eee eeeeeeeeeeeeeeeees 4 2 Configuring measurements 0 eee eeeeeseeeeeeseeeseeseeeaes 4 3 Optical POWET risers seeriana oasa saioei erorita oi 4 3 Front panel photodiode measurements sssseeseseeeseseeereeeereeeeee 4 4 Photodiode measurement circuit configuration 4 4 Front panel photodiode measurement procedure 4 4 Step 1 Configure measurement functions 0 0 4 4 Step 2 Set bias voltage source values eee eee 4 5 Step 3 Turn source outputs ON oo eee eeeeseeeeereeees 4 5 Step 4 Observe readings on the display 0 0 0 4 5 Step 5 Turn source outputs Off oe eeeeeeseeeeeees 4 5 Remote photodiode measurements 0 0 eee eeeeeeeeeeseeeeeereeeeees 4 5 Photodiode measurement commands ee eeeeeeeseeeeeeees 4 5 Photodiode measurement programming example 4 7 Measurement Concepts Source delay measure cycle eee eeeeeeeeseeeseeseeeseeseeeseeseeeaeeseeens 5 2 OVERVIEW coetir Areenaa aana EE ER E T EAE 5 2 TIIE CLUB ecakawtcecatieestdesedstasses disidaenstisveanspeelsdventerebeavtecteenans 5 2 Delay phase sic c cccc scncelesczedishoseddesaucass heed a EE 5
4. Model 2500 Maximum Maximum I range resolution reading 2nA 1fA 2 1nA 20nA 10fA 21nA 200nA 100fA 210nA 2nA IpA 2 1A 20nA 10pA 21NA 200p A 100pA 210uA 2mA InA 2 1mA 20mA 10nA 21mA Table 3 2 Voltage source ranges Model 2500 Maximum Maximum V range Resolution voltage current 10V 400u V 10V 20mA 100V 4mV 100V 20mA Models 2500 and 2502 User s Manual Basic Operation 3 3 Compliance Each voltage bias source has a maximum output level of 100V 20mA If the load resis tance is low enough so that the unit exceeds the 20mA current limit the unit is considered to be in compliance and the corresponding source display field Srcl or Src2 will blink See Section 5 Bias source operating boundaries for more information You can also use compliance for limit testing Section 10 and the unit can be programmed to generate an SRQ under compliance conditions over the GPIB Section 14 Basic circuit configuration The fundamental circuit configuration for the Model 2500 is shown in Figure 3 1 Note that the unit has two separate channels one channel shown each of which includes a feedback ammeter and a 0 10V or 0 100V voltage bias source Figure 3 1 also shows the output enable circuit which is shown enabled Section 12 and the ground connect relay see Ground connect mode page 3 8 Note that the DUT is connected between the triax INPUT jack and the SOURCE OUTPUT terminal
5. 6 58 58 1 60 dB Photodiode Voltage Bias Specifications ACCURACY MAXIMUM LOAD TEMPERATURE RANGE RESOLUTION 23 C 5 C CURRENT REGULATION COEFFICIENT 0to 10V lt 400 pV 0 15 of setting 20 mA lt 0 30 150 ppm C 5mV 0 to 20 mA 0 to 100V lt 4mV 0 3 of setting 20 mA lt 0 30 300 ppm C 50 mV 0 to 20 mA NOTES 1 Speed Normal 1 0 NPLC Filter On 2 1 year 3 Measured as AV AI at full scale and zero input currents 4 Dual channel internal trigger measure only display off Autorange off Auto Zero off source delay 0 filters off limits off CALC5 and CALC6 off 60Hz 5 Measured as AV AlI at full scale 20mA and zero load currents 6 Noise floor measured as rms 1 standard deviation 100 samples Filter off open capped input 7 Specification by design 8 Measured at input triax as AV at full scale 20mA vs zero input currents Analog Output Specifications 2502 only OUTPUT VOLTAGE RANGE OUTPUT IS INVERTING 10V out for positive full scale input 10V out for negative full scale input OUPUT IMPEDANCE 1kQ typical TEMPERATURE ACCURACY COEFFICIENT RISE TIME 23 C 5 C 0 C 18 C amp 28 C 50 C Typical RANGE output offset output offset C 10 to 90 2 000000 nA 6 0 90mV 0 30 7mV 6 1 ms 20 00000 nA 3 0 9mV 0 11 700pV 6 1 ms 200 0000 nA 6 0 90mV 0 30 4mV 395 us 2 000000 pA 3 0 9mV 0 11 400pV 395 us 20 00000 pA 6 0 90mV 0 30 4mV 1
6. Range Digits Speed and Filters Models 2500 and 2502 User s Manual Moving filter The moving average filter uses a first in first out stack When the stack filter count becomes full the readings are averaged yielding a filtered reading For each subsequent reading placed into the stack the oldest reading is discarded The stack is reaveraged yielding a new reading When the filter is first enabled the stack is empty Keep in mind that a Moving Filter read ing is not yielded until the stack is full The first reading is placed in the stack and is then copied to the other stack locations in order to fill it Therefore the first filtered reading is the same as the first reading that entered the stack Now the normal moving average filter process can continue Note that a true average is not yielded until the stack is filled with new readings no copies in stack For example in Figure 6 5 it takes ten filtered readings to fill the stack with new readings The first nine filtered readings are calculated using cop ied readings Moving filter count 10 6 10 Figure 6 5 Reading Reading Reading Reading Reading Reading 3 2 eoo 1 Moving Moving 1 Moving gt Reading Reading 1 gt Reading 1 2 1 3 1 1 1 Reading Reading 1 Reading Moving Moving gt Reading Reading 10 11 Reading Models 2500 and 2502 User s Manual Range Digits Speed and Filters 6 11 Advanced filter
7. Trigger count 10 Data store feed channel 1 readings only e Acquired data all buffer readings mean average and standard deviation NOTE See Appendix H for a complete program listing which also shows how to deter mine when the buffer is full by reading the appropriate status register bits See Section 14 for details on the status structure Table 8 2 Data store example Command Description RST Restore GPIB defaults SOURI VOLT 10 Source 10V TRAC POIN 10 Store 10 readings in data store buffer FORM ELEM TRAC CURRI Select channel 1 readings TRAC FEED CONT NEXT _ Enable buffer TRIG COUN 10 Trigger count buffer points 10 OUTP1 ON Turn on output 1 INIT Trigger readings OUTP1 OFF Turn off output TRACE DATA Request all buffer readings DISP MODE CALC3 Select channel 1 for statistics gt CALC8 FORM MEAN Select mean buffer statistic gt CALC8 DATA Request buffer mean data gt CALC8 FORM SDEV Select standard deviation statistic gt CALC8 DATA Request standard deviation data 9 Sweep Operation e Sweep types Describes the three basic sweep types Linear staircase logarithmic staircase and custom sweep Configuring and running a sweep Discusses the procedure for setting up and per forming sweeps including selecting and configuring a sweep setting the delay and performing a sweep 9 2 Sweep Operation Models 2500 and 2502 User s Manual Sweep types
8. B6 B5 B4 B3 B2 B1 Bo Enable Register Idle In idle state amp Logical AND Arm Waiting for arm event OR Logical OR Trg Waiting for trigger event Swp Sweeping Cal Calibrating 14 14 Status Structure Models 2500 and 2502 User s Manual Measurement event register The used bits of the measurement event register Figure 14 6 are described as follows Bit BO Limit 1 Summary L1 Set bit indicates Limit 1 summary information is available in the FORM ELEM STAT element see Section 17 FORMat subsystem Bit B1 Limit 2 Summary L2 Set bit indicates Limit 2 summary information is available in the FORM ELEM STAT element Bit B2 Limit 3 Summary L3 Set bit indicates Limit 3 summary information is available in the FORM ELEM STAT element Bit B3 Limit 4 Summary L4 Set bit indicates Limit 4 summary information is available in the FORM ELEM STAT element Bit B4 Limit Fail High LFH Set bit indicates that one of the high limit tests has failed Bit B5 Limits Pass LP Set bit indicates that all limit tests passed Bit B6 Reading Available RAV Set bit indicates that a reading was taken and processed Bit B7 Reading Overflow ROF Set bit indicates that the current reading exceeds the selected measurement range of the Model 2500 Bit B8 Buffer Available BAV Set bit indicates that there are at least two readings in the buffer Bit B9 Buffe
9. Figure 3 1 Basic circuit configuration To A D Converter Chassis Ground SOURCE OUTPUT O Feedback Ammeter oO Floating Channel 1 or Output Channel 2 Common On Ground Bias Source Canned 0 to 10V or Note One channel shown 0 to 100V Other channel is identical 20mA Max Chassis Ground 3 4 Basic Operation Models 2500 and 2502 User s Manual Operation considerations The following paragraphs discuss warm up period auto zero and source delay Warm up The Model 2500 must be turned on and allowed to warm up for at least one hour to achieve rated accuracies See Appendix A for specifications Auto zero Every A D conversion current reading is calculated from a series of zero reference and signal measurements With auto zero enabled all three of these measurements are per formed for each reading to achieve rated accuracy With auto zero disabled zero and refer ence are not measured Disabling auto zero increases measurement speed but zero drift will eventually degrade accuracy With auto zero disabled periodically change measure ment speed Temperature changes across components within the instrument can cause the reference and zero values for the A D converter to drift due to thermo electric effects Auto zero acts to negate the effects of drift in order to maintain measurement accuracy over time Without auto zero enabled current measurements can drift and become errone
10. The Advanced Filter is part of the Moving Filter With the Advanced Filter enabled a user programmable noise window is used with the Moving Filter The noise window which is expressed as a percentage of range 0 105 allows a faster response time to large signal step changes If the readings are within the noise window the Moving Filter operates normally as previously explained If however a reading falls out side the window the stack is flushed of old readings and filled with the new reading For example assume the window is set to 10 and the 20mA range is selected Therefore the noise window is 2mA 20mA x 10 2mA Also assume the first reading is 2mA Per normal filter operation the stack is filled with that reading As long as each subsequent reading is within 2mA of the previous reading the filter operates normally Now assume a 10mA noise spike occurs This noise window violation causes the stack to flush out the old readings and fill it with 10mA reading NOTE Ifthe Repeat or Median Filter is enabled the Moving Filter operation will not start until after the previous filter yields a reading In other words after a read ing is yielded from the Repeat or Median Filter that reading will then be sent to the Moving Filter stack Filter configuration Using Table 6 5 and Figure 6 6 as a guide configure the filter as follows NOTE The filter setting is global and affects both channels 1 Press the CONFIG key and
11. 0 105263 Now add the LogStep value to Log Start and to each subsequent result This will create a list of Log values Next take the anti log of each Log value to get the actual sweep values Il Value Logi 9 Value Sweep Value V 1 1 0000000 10 000000 2 1 0526316 11 288379 3 1 1052632 12 742751 4 1 1578948 14 384501 5 1 2105263 16 237767 6 1 2631579 18 329807 7 13157895 20 691382 8 1 3684211 23 357217 9 1 4210527 26 3665 13 10 1 4736842 29 7635 14 11 1 5263158 33 598184 12 1 5789474 37 926905 13 1 6315790 42 813329 14 1 6842105 48 329299 15 1 7368421 54 555947 16 1 7894737 61 584823 17 1 8421053 69 519286 18 1 8947369 78 416007 19 1 9473684 88 586675 20 2 0000000 100 00000 17 74 SCPI Command Reference SOURce3 Models 2500 and 2502 User s Manual The following commands are used to set the logic level of the digital output lines and con trol the pulse width of limit test output patterns that are sent to component handlers Limit tests are configured and controlled from the CALCulate7 Subsystem For details on limit testing see Section 11 Setting digital output LEVel lt NRf gt lt NDN gt SOURce3 TTL LEVel lt NRf gt lt NDN gt Parameters Query Description lt NRf gt lt NDN gt Bx Hx Qx TTL Set digital output pattern 0to7 Decimal format for 3 bit 0 to 15 Decimal format for 4 bit Binary format 3 bit x 000 to 111 4 bit x 0000 to 1111 Hexad
12. 14 19 Error queue commands 00 0 eeseeseeeeseceseeeeteeeeeeeeeecsaeeeaeers 14 21 Common Commands TEEE 488 2 common commands and queries e 15 2 OPC programming example oes eseeeesseeseeeeeeeeeeeeees 15 4 SAV RCL programming example n se 15 5 TRG programming example cee eeeeeeseceseeeeeeeeeeeeees 15 6 SCPI Signal Oriented Measurement Commands Signal oriented measurement command summary 16 2 SCPI Command Reference CALCulate command summary eeeeeseeeeeeceneeeeeeeeeeeeees 17 3 DISPlay command summary cee eeeeseeseeeseeseeeeeeneeeeeees 17 8 FORMat command summary ceceeesceeseeeeeeceneeeteeeeeeesees 17 9 OUTPut command summary eeeceeceeseeseeeeteeeeeeeneees 17 10 SENSe command summary ccesceesessneeeseeeeeeeeseeeneeeeee 17 11 SOURce command SUMMATY ceeeeeseesteeeseeeeeeeeteeeteeeees 17 13 STATus command Summary cesceesceesseeeseeeeeeeeseeeeeeeeee 17 18 SYSTem command summary eeescesseeseeeseeeeseeeeeeee 17 19 TRACe command summary 2 eeeceeseeeeseeeeeeeeteeeeeeeeaeees 17 20 TRIGger command summary 20 0 eeeeeeeeeseeeteeeeteeeeneeeaeees 17 21 B Table B 1 D Table D 1 Table D 2 Table D 3 Table D 4 Table D 5 Table D 6 E Table E 1 Table E 2 F Table F 1 Status and Error Messages Status and error MESSAGES oo eee eeeeeseeeeeeeeeaeceeeeseeeeeeaeeeees B 3 IEEE 488 Bus Overview TEEE 488 bu
13. ENABLE Enable ground connect mode CONFIG SRC2 Configure delay and ground connect mode CONFIG SRC2 Configure voltage source DELAY Set source delay 0 9999 998s AUTO DELAY Control source auto delay DISABLE Disable auto delay ENABLE Enable auto delay delay depends on current range GND CONNECT Control ground connect mode DISABLE Disable ground connect mode ENABLE Enable ground connect mode Table 1 7 Rel filter and range configuration menus Configuration menu item Description CONFIG REL CONFIG FILTER CONFIGURE FILTERING AVERAGE MODE MOVING REPEAT AVERAGE COUNT ADVANCED DISABLE ENABLE MEDIAN RANK CONFIG A RANGE CONFIG W RANGE Program REL value Configure filter Select average mode filter Moving average Repeat average Set average filter count 1 100 Enable disable advanced filter Disable advanced filter Enable advance filter set noise tolerance Select median rank 0 5 Program upper range limit Program lower range limit Model 2500 and 2502 User s Manual Table 1 8 Limit configuration menu Getting Started 1 27 Configuration menu item Description CONFIG LIMIT CONFIG LIMITS MENU DIGOUT SIZE 3 BIT 4 BIT 16 BIT 2499 DIGIO MODE GRADING IMMEDIATE END SORTING AUTO CLEAR DISABLE ENABLE H W LIMITS CONTROL DISABLE ENABLE FAIL MODE IN OUT S W LIMITS CONTROL DISABLE ENABLE LOLIM HILIM PASS FEED PASS DIGIO P
14. The acceptor controls the state of NRFD It is used to signal to the transmitting device to hold off the byte transfer sequence until the accepting device is ready NDAC Not Data Accepted NDAC is also controlled by the accepting device The state of NDAC tells the source whether or not the device has accepted the data byte The complete handshake sequence for one data byte is shown in Figure D 2 Once data is placed on the data lines the source checks to see that NRFD is high indicating that all active devices are ready At the same time NDAC should be low from the previous byte transfer If these conditions are not met the source must wait until NDAC and NRFD have the correct status If the source is a controller NRFD and NDAC must be stable for at least 100nsec after ATN is set true Because of the possibility of a bus hang up many control lers have time out routines that display messages in case the transfer sequence stops for any reason Once all NDAC and NRED are properly set the source sets DAV low indicating to accept ing devices that the byte on the data lines is now valid NRFD will then go low and NDAC will go high once all devices have accepted the data Each device will release NDAC at its own rate but NDAC will not be released to go high until all devices have accepted the data byte The sequence just described is used to transfer both data talk and listen addresses as well as multiline commands The state of th
15. Turns the unit power on or off Turns the sources on or off Pull out and rotate to desired position 1 8 Getting Started Model 2500 and 2502 User s Manual Rear panel summary The rear panel of the Model 2500 is shown in Figure 1 2 and the rear panel of the Model 2502 is shown in Figure 1 3 Figure 1 2 Model 2500 rear panel WARNING NO INTERNAL OPERATOR SERVICABLE PARTS SERVICE BY QUALIFIED PERSONNEL ONLY RATINGS MAX COMMON ed IEEE 488 MADE IN K CHANGE IEEE ADDRESS Moov Bea ITH FRONT PANEL MENU INPUT INPUT DIGITAL 1 0 CHANNEL 1 CHANNEL 2 C TRIGGER LINK RS 232 CATI LINE RATING SS 50 60Hz RATINGS MAX 60 VA MAX 100V 20mA FUSE LINE 630 mAT 100 VAC A SB 120 VAC 315 mAT 220 VAC VOLTAGE SOURCE VOLTAGE SOURCE SB 240 vac OUTPUT CHANNEL 1 OUTPUT CHANNEL 2 g CAUTION FOR CONTINUED PROTECTION AGAINST FIRE HAZARD REPLACE FUSE WITH SAME TYPE AND RATING j Model 2500 INPUT connectors INPUT CHANNEL 1 Use to measure on channel 1 INPUT CHANNEL 2 Use to measure on channel 2 Triax connector terminals Center conductor Input HI Inner shell Floating input output common Outer shell Chassis ground VOLTAGE SOURCE connectors OUTPUT CHANNEL 1 Use to output voltage bias on channel 1 OUTPUT CHANNEL 2 Use to output voltage bias on channel 2 WARNING Maximum common mode voltage voltage between INPUT common and chassis g
16. CALCulate6 Configure and control DELTA function The CALC6 commands control the delta function They perform the remote equivalents to the front panel DELTA and CONFIG DELTA configuration menu Select DELTA calculation mode FORMat lt name gt CALCulate6 FORMat lt name gt Select DELTA calculation mode Parameters lt name gt C3C4 CALC3 CALC4 C4C3 CALC4 CALC3 Query FORMat Query selected DELTA calculation Description This command selects the DELTA calculation mode With C3C4 selected the CALC4 result channel 2 REL is subtracted from the CALC3 result channel 1 REL With C4C3 selected the CALC3 result is subtracted from the CALC4 result Enable and read DELTA result STATe lt b gt CALCulate6 STATe lt b gt Control DELTA Parameters lt b gt 1 or ON Enable DELTA 0 or OFF Disable DELTA Query STATe Query state of DELTA Description This command is used to enable or disable DELTA mode When enabled the CALC6 reading will be DELTA value determined by FORMat above When disabled or if a divide by zero error occurs the CALC6 reading will return a NAN not a number value of 9 91e37 DATA CALCulate6 DATA Read DELTA result Description This query command is used to read the result of the CALCS ratio cal culation When enabled the CALCS5 reading will be ratio value deter mined by FORMat above When disabled or if a divide by zero error occurs the CALC5 reading will return a NAN not a number value of
17. OUTP1 ON Turn on output INIT Start measurements OPC Send OPC to query output queue Additional code required to test for 1 in output queue OPT option query Return list of installed options When OPT is sent Model 2500 returns a list of any installed options SAV lt NRf gt save Save present setup in memory RCL lt NRf gt recall Return to setup stored in memory Parameters 0 Memory location 0 1 Memory location 1 2 Memory location 2 3 Memory location 3 4 Memory location 4 Use the SAV command to save the present instrument setup configuration in memory for later recall Any control affected by RST can be saved by the SAV command The RCL command is used to restore the instrument to the saved setup configuration Five setup configurations can be saved and recalled The Model 2500 ships from the factory with SYSTem PRESet defaults loaded into the available setup memory If a recall error occurs the setup memory defaults to the SYSTem PRESet values Models 2500 and 2502 User s Manual Common Commands 15 5 SAV RCL programming example Table 15 3 summarizes the basic command sequence for saving and recalling a setup The present setup is stored in memory location 2 GPIB defaults are restored and the memory location 2 setup is recalled Table 15 3 SAV RCL programming example Command Description SAV 2 Save present setup in memory location 2 RST Re
18. The three basic sweep types described in the following paragraphs include e Linear staircase Logarithmic staircase e Custom Linear staircase sweep As shown in Figure 9 1 this sweep steps from a start voltage source value to an ending stop voltage source value Programmable parameters include the start stop and step source voltage levels When this sweep is triggered to start the output will go from the bias voltage level to the start source voltage level The output will then change in equal steps until the stop source level is reached With trigger delay set to zero the time duration at each step is determined by the source delay and the time it takes to perform the measurement NPLC setting Note that the delay cannot change once a sweep is configured and running and is the same for all steps Figure 9 1 Linear staircase sweep l lt Delay gt lt Stop Step k Delay gt l lt Delay gt k lt Delay gt Bias gt Measure Measure Measure Measure X Measurement Point Models 2500 and 2502 User s Manual Sweep Operation 9 3 Logarithmic staircase sweep This sweep is similar to the linear staircase sweep The steps however are done on a loga rithmic scale as shown in the example sweep in Figure 9 2 This is a 5 point log sweep from 1 to 10V As with the staircase sweep the delay period is the same for all steps Figure 9 2 Logarithmic staircase sweep example 5 point sweep from 1 to 10 volts L
19. 9 91e37 Models 2500 and 2502 User s Manual SCPI Command Reference 17 31 CALCulate7 Configure and control limit tests The following commands are used to configure and control the six limit tests Limit 1 channel 1 compliance hardware limit test Limit 2 channel 2 compliance hardware limit test e Limit 3 through Limit 6 software limits When used with a handler to provide binning operations communication between the Model 2500 and the handler is provided via the Digital I O port See Section 11 for com plete details Many control aspects of the digital output lines are performed from the SOURce3 Subsystem These control aspects include setting and clearing the digital output lines and setting pulse width See SOURce3 page 17 74 for details Select input path FEED lt name gt CALCulate7 FEED lt name gt Select input path for Limit 3 6 tests Parameters lt name gt CALCulate3 Use CALC3 result channel 1 REL CALCulate4 Use CALC4 result channel 2 REL CALCulate5 Use CALCS result ratio CALCulate6 Use CALC6 result delta Query FEED Query input path for Limit 3 6 tests Description This command is used to select the input path for the Limit 3 6 tests software limits With CALCulate3 or CALCulate4 selected the speci fied limits will be compared to the result of CALC3 channel 1 REL feed or CALC4 channel 2 REL feed With CALCulate5 selected the specified limits will be compared with the ratio
20. Connector terminals eee eseeceseeseeeeeeeeeseceeeeaeceeeeseeeeeeeeeeee 2 3 Triax INPUT connectors oo eee eseeeesseeeeeseeeceeseeeeetseeeeeeaes 2 3 OUTPUT COMMECtOTS cicssessnessssdencescessseoserosesevsteseatesonenced 2 3 Output enablers oieee tab aeai a E e viens 2 4 Photodiode connections esessesessseseseesesresesrrsrsresresersesrrsrereeresese 2 4 Typical connections siisirenieioiiininieoe siinne 2 4 Equivalent circuit 2 0 eee sseeseeseeeseceeeeaeceeeeaeeeeeeseeneeaes 2 6 Connection Considerations cceeeesseeeeseeeceeseeeeeeseeeeeeaes 2 6 Ground connect mode Connections 00 cee eeeeeeeeeeeeeeeeeee 2 7 Alternate connecting methods oo eee eeeeseceeeeseeseeeseeeeeeaees 2 9 Current measurement CONNECTIONS oe eee eeeeseeeeeeeeeeeeeee 2 9 Voltage source CONNECTIONS oo eee eeeeeeceeeeseeseeeeeeeeeaees 2 10 Analog output connections Model 2502 only 0 0 eee 2 11 Analog output connector terminals 0 0 0 lee eeeeeeeeeeeeees 2 11 Non isolated connections eee ee eeseeeeceseceeeeseteeeeeeeeeeaees 2 12 Isolated CONNECTIONS 20 lees eeeeseceeeeseceeeeeeeesetseeeaeeseeeaees 2 13 Equivalent circuits ceeesceescecescceseeeeeceeneeeeeeseeeeteeeneeeees 2 14 Basic Operation Operation OVETVICW asescessce ices caiseenssrcdentiesetesoseseienesdenscevsesoas canes 3 2 Measurement and voltage bias capabilities 0 ee 3 2 RANGES seiiet siar aa EE ETENEE a EEA 3 2 Compliance sirisniseeciiini iei eiiie ian
21. FIXed SWEep or LIST FIXed v MODE Query V Source mode v RANGe lt n gt Select fixed V Source range 100 to 100 10 or 100 10 v AUTO lt b gt Enable or disable autoranging ON Jv AUTO Query state of autoranging v RANGe Query V Source range setting v LEVel Set V Source level in volts y IMMediate Set specified voltage level immediately v AMPLitude lt n gt Specify voltage level 100 to 100 0 v AMPLitude Query voltage level y TRIGgered Set specified voltage level when triggered y AMPLitude lt n gt Specify voltage level 100 to 100 0 v AMPLitude Query voltage level y 17 16 SCPI Command Reference Table 17 6 continued SOURce command summary Models 2500 and 2502 User s Manual Command SOURce2 VOLTage STARt lt n gt STARt STOP lt n gt STOP STEP lt n gt STEP SPAN lt n gt SPAN CENTer lt n gt CENTer SWEep SPACing lt name gt SPACing POINts lt n gt POINts DIRection lt name gt DIRection RANGing lt name gt RANGing LIST VOLTage lt NRf gt APPend lt NRf gt POINts VOLTage Description Path to configure channel 2 source continued Specify start level for V sweep 100 to 100 Query start level for voltage sweep Specify stop level for V sweep 100 to 100 Query stop level for voltage sweep Specify step value for V sweep 200 to 200 Query step value for voltage sweep S
22. For Limit 3 6 it does not tell you which limit upper or lower has failed To determine which limit has failed you must read the mea surement event register See STATus subsystem page 17 78 Reading the results of a limit test does not clear the fail indication of the test A failure can be cleared by using a CLEar command Composite testing PASS SOURce3 lt NRf gt NDN CALCulate7 CLIMits PASS SOURce3 lt NRf gt lt NDN gt Specify composite pass pattern Parameters lt NRf gt 0 to 7 3 bit Decimal value 0 to 15 4 bit Decimal value Query Description lt NDN gt Oto b111 3 bit Binary value O to b1111 4 bit Binary value 0 to q7 3 bit Octal value 0 to q17 4 bit Octal value 0 to h7 3 bit Hexadecimal value 0 to hF 4 bit Hexadecimal value SOURce3 Query programmed source value This command is used to define the 3 bit or 4 bit output pattern for the digital I O port when there are no failures for any of the limit tests Note that the output value can be specified in binary octal decimal or hexa decimal format Use the table provided in SOURce3 lt NRf gt lt NDN gt Description page 17 34 to determine the parameter value for the desired decimal digital output pattern The Model 2500 can be configured to place the defined pass bit pattern on the digital output immediately when the pass condition occurs or it can wait until all testing on a device package is completed operation lea
23. For example to enable the Source Event Detector and Measure Event Detector send the fol lowing command TRIGger INPut SOURce SENSe The Delay Event Detector will be disabled since the DELay parameter is not included in the above event list NOTE To disable all the Trigger Layer event detectors the NONE parameter must be sent alone i e trigger input none If it is listed with any of the other parame ters NONE will be ignored Models 2500 and 2502 User s Manual SCPI Command Reference 17 95 ILINe lt NRf gt ARM SEQuence 1 LAYer 1 TCONfigure ILINe lt NRf gt Select input line arm layer TRIGger SEQuence 1 TCONfigure ILINe lt NRf gt Select input line trigger layer Parameters lt NRf gt 1 Line 1 2 Line 2 3 Line 3 4 Line 4 5 Line 5 6 Line 6 Query ILINe Query input trigger line Description This command is used to select input lines for the Trigger Link For nor mal operation Trigger Link input and output OLINe should not share the same line OLINe lt NRf gt ARM SEQuence 1 LAYer 1 TCONfigure OLINe lt NRf gt Select output line arm layer TRIGger SEQuence 1 TCONfigure OLINe lt NRf gt Select output line trigger layer Parameters lt NRf gt 1 Line 1 2 Line 2 3 Line 3 4 Line 4 5 Line 5 6 Line 6 Query OLINe Query output trigger line Description This command is used to select output lines for the Trigger Link For normal operation Trigger Link
24. NONE at all OUTPut Query when output trigger is going to occur Calculate subsystems There are a total of eight CALCulate subsystems e CALCI1 Channel 1 math e CALC2 Channel 2 math e CALC3 Channel 1 REL e CALC4 Channel 2 REL e CALCS Ratio e CALC6 Delta e CALC7 Limit tests e CALCS8 Buffer statistics The commands in these subsystems are summarized in Table 17 1 NOTE See Appendix C for a detailed explanation on how data flows through the vari ous CALC operation blocks of the Model 2500 It clarifies the type of readings that are acquired by the various commands to read data Models 2500 and 2502 User s Manual CALCulate 1 and CALCulate2 SCPI Command Reference 17 23 Configure and control math functions The CALC1 and CALC2 commands control math functions for channel 1 and channel 2 respectively They perform the remote equivalents to the front panel CONFIG MSR1 and CONFIG MSR2 configuration menus Select math function FORMat lt name gt CALCulate 1 FORMat lt name gt Select channel 1 math function Parameters lt name gt MXB 1 MX B COND 1 I1 V1 POWER 1 V1 I l RES 1 V1 1 OP 1 measured Idark current Responsivity Query FORMat Query selected math function Description This command selects the channel 1 math function The channel 1 cur rent reading I1 and source voltage V1 are used to calculate COND 1 conductance POWER1 and RES1 resistance while MX B and OPI parameters are pro
25. Operation model for triggering example 0 0 eee 10 13 Configure trigger Menu tree eel eee eeeereeeeeeeeeeneteee 10 16 Trigger model remote Operation 0 0 0 eee eeeeseeeeeeeeeee 10 18 Measure ACHON sccssvsessacsessiensenecosssnesessastsendosesesecteesecozecsivs 10 21 Limit Testing Linit tests 253525505 aers or A A E 11 2 Grading mode limit testing eee eeeeeeeseeeeeeeeeaeees 11 5 Immediate Dimming is scccesiiicsesceseskeseidececsssevsstevsidecdtasveceenstess 11 6 Fd TB ses 5 5 eases a cdee ts cus vse S0ceeessg edsedeaicesvaiesocaesssverscass ora 11 6 Sorting mode limit testing oo eee eeeeeeeeeeeeeeeeeeeeneeeees 11 9 Handler interface connections 0 0 eee eeeeteeseeereeeeeeneeeee 11 10 Binning system single element devices 0 0 0 cece 11 13 Binning system multiple element devices eee 11 13 Digital output auto clear timing example 0 0 0 eee 11 15 Limits configuration menu tree ee eee eeeeeeeteeeeeeeeteee 11 18 12 Digital 1 O Port Output Enable and Output Configuration Figure 12 1 Output Enable and digital I O oe eeeseeseeseeeeeeeeeeeeeeeee 12 2 Figure 12 2 DINK Operation eiscsivseveesessvaesavesvadsesscbicscetevivecUecesiativinedeeneeiesis 12 4 Figure 12 3 Source operation oo eee eee eseeseeseeseeeseceeeeaeceeeeaeseaeeaeeeeeaes 12 5 Figure 12 4 Using test fixture output oe cece eseeeeeseeeeeeeeeeeeseeeaeees 12 7 Figure 12 5 Output configuration Menu tree oe eee eeeeeeeeeereeeeeeee 12 8 13
26. RECALL CONFIG MENU EXIT ENTER Annunciators EDIT ERR REM TALK LSTN SRQ REL FILT AUTO ARM TRIG Power control POWER OUTPUT ON OFF Handle Getting Started 1 7 Select channel 1 or channel 2 measurement for display Toggle between channel 1 2 display add MSR2 to display for dual display mode Cancel remote operation Enable disable relative reading MSR1 or MSR2 function only Display digital filter status for present function and toggle filter on off Perform configured limit tests Trigger a measurement from the front panel Start configured sweep Change number of digits of display resolution Change measurement speed by selecting accuracy or specifying NPLC Set buffer size and enable reading storage Display stored readings and timestamp Press CONFIG and then appropriate key to configure function or operation Access and configure Main Menu selections When entering numeric data use to clear reading to minimum absolute value Cancels selection Use to back out of menu structures Accepts selection Instrument in edit mode Questionable reading invalid cal step Instrument in GPIB remote mode Instrument addressed to talk over GPIB Instrument addressed to listen over GPIB Service request over GPIB Relative measure reading displayed Digital filter enabled Autoranging enabled Source measure operations being performed External trigger source selected Reading being stored
27. STATe Query state of source 2 J Models 2500 and 2502 User s Manual SCPI Command Reference 17 11 Table 17 5 SENSe command summary Default Command Description parameter SCPI SENSe 1 Sense subsystem to control channel 1 measurement A CURRent DC Path to configure current v RANGe Configure measurement range v UPPer lt n gt Select range by specifying the expected 2e 4 v current reading 0 to 21e 3 UPPer Query range v AUTO lt b gt Enable or disable auto range ON y AUTO Query auto range v ULIMit lt n gt Set auto ranging upper limit 0 021 to 0 021 2e 2 v ULIMit Query auto ranging upper limit Jv LLIMit lt n gt Set auto ranging lower limit 0 021 to 0 021 2e 9 v LLIMit Query auto ranging lower limit Jv NPLCycles lt n gt Specify integration rate in line cycles 1 v 0 01 to 10 NPLCycles Query integration rate v AVERage Path to configure moving and repeat filters v COUNt lt n gt Specify filter count 1 to 100 10 Jv COUNt Query filter count v STATe lt b gt Enable or disable digital filter OFF y STATe Query state of digital filter v TCONtrol lt name gt Select filter control MOVing or REPeat REPeat TCONtrol Query filter control mode ADVanced Configure the advanced filter v NTOLerance lt NRf gt Set filter noise window in 0 to 105 5 y NTOLerance Query filter noise window setting v STATe lt b gt Enable or disable advanced filter
28. The controller reads the information and the appropriate software can be used to direct the information to the desired location D 4 IEEE 488 Bus Overview Figure D 1 Models 2500 and 2502 User s Manual IEEE 488 bus configuration Device 1 Able to Talk Listen and Control Computer Device 2 Able to Talk and Listen 2500 Device 3 Only Able to Listen Printer Device 4 Only Able to Talk To Other Devices Data Bus Data Byte Transfer Control General Interface Management DIO 1 8 Data 8 Lines DAV NRFD NDAC IFC ATN Bug Handshake SRQ Management REN EOI Models 2500 and 2502 User s Manual IEEE 488 Bus Overview D 5 Bus lines The signal lines on the IEEE 488 bus are grouped into three different categories data lines management lines and handshake lines The data lines handle bus data and com mands while the management and handshake lines ensure that proper data transfer and operation takes place Each bus line is active low with approximately zero volts represent ing a logic 1 true The following paragraphs describe the operation of these lines Data lines The IEEE 488 bus uses eight data lines that transfer data one byte at a time DIO1 Data Input Output through DIO8 Data Input Output are the eight data lines used to transmit both data and multiline commands and are bidirectional The data lines operate with low true logic Bus management lines The five bus
29. Types 11 11 Handshaking 13 18 V V 7 4 Idle 10 2 10 17 TEEE 488 bus overview D 1 IFC interface clear 13 7 Initiate 10 17 Interface Selecting 13 2 Interface function codes D 14 Key presses Simulating 17 84 Keys CHANNEL SELECT 1 14 DISPLAY TOGGLE 1 14 EDIT 1 6 LOCAL 13 10 Measurement function 1 6 Operation 1 7 OUTPUT ON OFF 12 7 Range 1 6 Voltage bias source function 1 6 Light F 8 Limit Menus 1 27 Limit 1 and 2 tests compliance 11 3 Limit 3 to 6 tests 11 3 Limit lines see Operating boundaries Limit tests 5 8 Clear results 17 38 Commands 11 20 Compliance 11 3 Composite testing 17 36 Configure and control 17 32 Configuring 11 16 Feeds 11 3 Grading mode 11 4 Modes 11 3 Pass fail information 11 2 Performing 11 18 Programming example 11 21 Read data 17 32 Sorting mode 11 8 Tolerance 11 3 Types 11 2 Line frequency 1 12 Line power connection 1 10 Line voltage selection 1 10 Linear staircase sweep 9 2 LLO local lockout 13 7 Loading effects 5 6 Logarithmic staircase sweep 9 3 Low current measurements F 2 Magnetic fields F 10 Manual ranging 6 2 Math functions 7 4 Commands 7 7 Electrical power 7 5 Enable and read result 17 26 T V 7 4 MX B 7 5 Optical power 7 5 Programming example 7 8 Selecting 17 23 V A 7 5 Measurement Capabilities 3 2 Circuit configuration 3 10 Commands 3 13 Concepts 5 1 Configuration menu 4 2 Configuring 4 3 Considerations F 1 Front panel procedure 3 11 Function configurati
30. assumes as the power on configuration as follows 1 Press the MENU key select SAVESETUP then press ENTER 2 From the SAVESETUP MENU select POWERON then press ENTER From the SET POWER ON DEFAULT menu choose the power on configuration BENCH or GPIB see below or USER SETUP NUMBER If you chose to use a user setup as the power on configuration select the user setup number then press ENTER Factory default settings As summarized in Table 1 3 there are two sets of factory defaults BENCH front panel and GPIB remote You can restore either of these default conditions as follows l Press the MENU key select SAVESETUP then press ENTER 2 From the GLOBAL SETUP MENU select RESET then press ENTER Select BENCH or GPIB defaults as desired then press ENTER to complete the process Model 2500 and 2502 User s Manual Getting Started Table 1 3 Factory default settings Setting BENCH default GPIB default A D Controls Auto zero On On Line frequency No effect No effect Data Store No effect No effect Digital output size 15 or 7 15 or 7 Display digits 5 5 5 5 Display mode Dual channel Dual channel Filter Off Off Average mode state Repeat disabled Repeat disabled Average filter count 10 10 Advanced state tol Off 5 Off 5 Median filter rank state 0 Off 0 Off GPIB address No effect No effect Ground connect Disabled Disabled Limit tests DigOut Size 4 bit 4 bit Mode Grading Grad
31. byte of data Models 2500 and 2502 User s Manual IEEE 488 Bus Overview D 3 Bus description The IEEE 488 bus which is also frequently referred to as the GPIB General Purpose Interface Bus was designed as a parallel transfer medium to optimize data transfer with out using an excessive number of bus lines In keeping with this goal the bus has only eight data lines that are used for both data and with most commands Five bus manage ment lines and three handshake lines round out the complement of bus signal lines A typical setup for controlled operation is shown in Figure D 1 Generally a system will contain one controller and a number of other instruments to which the commands are given Device operation is categorized into three operators controller talker and listener The controller does what its name implies it controls the instruments on the bus The talker sends data while a listener receives data Depending on the type of instrument any particular device can be a talker only a listener only or both a talker and listener There are two categories of controllers system controller and basic controller Both are able to control other instruments but only the system controller has the absolute authority in the system In a system with more than one controller only one controller may be active at any given time Certain protocol is used to pass control from one controller to another The IEEE 488 bus is limited to 15 devices
32. digits speed and data store configuration menus Configuration menu item Description CONFIG SWEEP Configure sweeps CONFIGURE SWEEPS TYPE Select sweep type NONE Disable sweep STAIR Staircase sweep program START STOP STEP LOG Log sweep program START STOP POINTS CUSTOM Custom sweep program parameters POINTS Program number of sweep points ADJUST POINTS Set individual point values INIT Set first point value SWEEP COUNT Set sweep count FINITE Program sweep count value INFINITE Never ending sweep SOURCE RANGING Set sweep ranging mode BEST FIXED Best fixed range based on maximum value AUTO RANGE Auto range during sweep FIXED Set fixed source range CONFIG DIGITS Set display number of digits DISPLAY DIGITS Select 3 5 4 5 5 5 or 6 5 CONFIG SPEED Set measurement speed SPEED ACCURACY MENU FAST Fast speed MED Medium speed NORMAL Normal HI ACCURACY Maximum accuracy OTHER Program NPLCs number power line cycles CONFIG STORE Configure data store timestamp STORE TIMESTAMP ABSOLUTE Absolute timestamp DELTA Delta timestamp 1 30 Getting Started Table 1 11 Model 2500 and 2502 User s Manual Output and display configuration menus Configuration menu item Description CONFIG ON OFF OUTPUT CONFIG OUTPUT AUTO OFF DISABLE ENABLE ALWAYS AFTER TRIG COUNT ENABLE DISABLE ENABLE CONFIG DISPLAY TOGGLE DISABLE DISPLAY NOW NEVER SWEEP STORE Configure output Ena
33. page 10 17 Key trigger model settings are included in the flowchart Note that the BENCH defaults are denoted by the symbol The primary actions of the trigger model are Source Delay and Measure The source action outputs the programmed voltage bias value and the programmed delay provides a settling period for the voltage bias source before the measurement is performed The trigger model consists of two layers Arm Layer and Trigger Layer to provide versa tility Programmable counters allow operations to be repeated and various input and out put trigger options are available to provide source measure synchronization between the Model 2500 and other instruments via the Trigger Link Unless otherwise noted the programmable aspects of the trigger model are performed from the CONFIGURE TRIGGER menu See Configuring triggering page 10 14 NOTE The trigger model and associated settings and commands affect both channels simultaneously The Model 2500 is in idle when it is not operating in the Arm Layer or Trigger Layer of the trigger model When in idle the ARM annunciator is off To take the Model 2500 out of idle turn the output ON The Model 2500 can be returned to idle at any time by selecting the HALT menu item of the CONFIGURE TRIGGER menu See Configuring triggering Models 2500 and 2502 User s Manual Triggering 10 3 Figure 10 1 Trigger model front panel operation Turn Output ON Idle Bypass
34. queues Table 14 1 Common and SCPI commands to reset registers and clear queues Commands Description Ref To Reset Registers CLS Reset all bits of the following event registers to 0 Note 1 Standard Event Register Operation Event Register Measurement Event Register Questionable Event Register STATus PRESet Reset all bits of the following enable registers to 0 Note 1 Operation Event Enable Register Measurement Event Enable Register Questionable Event Enable Register To Clear Error Queue CLS Clear all messages from Error Queue Note 2 STATus QUEue CLEar Clear messages from Error Queue Note 3 Notes 1 The standard event enable register is not reset by STATus PRESet or CLS Send the 0 parameter value with ESE to reset all bits of that enable register to 0 See Status byte and service request commands page 14 10 2 STATus PRESet has no effect on the error queue 3 Use either of the two clear commands to clear the error queue Models 2500 and 2502 User s Manual Status Structure 14 5 Programming and reading registers Programming enable registers The only registers that can be programmed by the user are the enable registers All other registers in the status structure are read only registers The following explains how to ascertain the parameter values for the various commands used to program enable registers The actual commands are covered later in this section Table 14 3 and Tab
35. s Manual SCPI Command Reference 17 93 source occurs immediately Subsequent arm events will then occur every 30 seconds The interval for the timer is set using the TIMer command With MANual selected the event occurs when the TRIG key is pressed With BUS selected the event occurs when a GET or TRG command is sent over the bus With NSTest selected the event occurs when the SOT start of test low pulse is received from a component handler via the digital I O port This is used for limit testing With PSTest selected the event occurs when SOT start of test high pulse is received from a component handler via the digital I O port This is used for limit testing With BSTest selected the event occurs when SOT start of test high or low pulse is received from a component handler via the digital I O port This is used for limit testing TiMer lt n gt ARM SEQuence 1 LAYer 1 TIMer lt n gt Set interval for arm layer timer Parameters lt n gt 0 001 to 9999 999 Specify timer interval in seconds 10000 00 to 99999 99 Specify timer interval in seconds Query TIMer Query programmed timer interval Description These commands are used to set the interval for the timer Note that the timer is in effect only if the timer is the selected control source DIRection lt name gt ARM SEQuence 1 LAYer 1 TCONfigure DIRection lt name gt Control arm bypass TRIGger SEQuence 1 TCONfigure DIRection lt name gt Control tr
36. the 20V source range will be used Note that the range changing process of AUTO RANGE may cause transients in the sweep If these transients cannot be tolerated use the BEST FIXED source range FIXED With this option the source remains on the range presently on when the sweep is started For sweep points that exceed the source range capability the source will output the maximum level for that range For example if the source is on the 2V range when the sweep is started it will remain on the 2V range for the entire sweep If the configured sweep points are 1V 2V 3V 4V and 5V the sweep will be 1V 2V 2 1V 2 1V and 2 1V Figure 9 5 Sweep configuration menu tree Source Ranging Setting delay Generally the time duration spent at each step or point of a sweep consists of the source delay and the time it takes to perform the measurement NPLC setting The source delay is part of the SDM cycle and is used to allow the source to settle before the measurement is made See Section 5 Source delay measure cycle for details The total time period of the source delay could include an auto delay and or a user pro grammed delay With auto delay enabled 1ms of delay is used The user programmable 9 8 Sweep Operation Models 2500 and 2502 User s Manual source delay adds 0000 0000 to 9999 9980 seconds of delay See Section 3 Source delay to set these delays Additional delay for a sweep is available b
37. value you want to set For this example set the range to LOV 3 Using either the EDIT or numeric entry keys enter the desired source value For this example set the source value to 10V 4 Press SRC2 to select the channel 2 source 5 Use the RANGE A key to select the 100V range 6 Again using either the EDIT or numeric entry keys set the bias source value to 20V Step 3 Turn source outputs on Turn both voltage source outputs on by pressing the ON OFF OUTPUT key The red OUTPUT indicator will turn on to indicate the outputs are on Step 4 Observe readings on the display Observe the current readings in display For this example press MSR1 to display the cur rent on channel 1 or use MSR2 to display channel 2 power If necessary use the RANGE A and 9 keys to manually select the current measurement range for that channel or press AUTO to select autoranging Use the DISPLAY TOGGLE or CHANNEL SELECT keys to display the desired readings Step 5 Turn source outputs off When finished making measurements turn both voltage source outputs off by pressing the ON OFF OUTPUT key The red OUTPUT indicator light will turn off Remote photodiode measurements Photodiode measurement procedures can also be performed via remote by sending appro priate commands in the right sequence The following paragraphs summarize the com mands and give a simple programming example Photodiode measurement commands Table 4 2 summarizes comma
38. 1 through Table 17 10 list the SCPI confirmed commands and the non SCPI commands implemented by the Model 2500 Models 2500 and 2502 User s Manual IEEE 488 and SCPI Conformance Information E 3 Table E 1 IEEE 488 documentation requirements Requirements Description or reference 1 IEEE 488 Interface Function Codes 2 Behavior of Model 2500 when the address is set outside the range 0 30 3 Behavior of Model 2500 when valid address is entered 4 Power On Setup Conditions 5 Message Exchange Options a Input buffer size b Queries that return more than one response message unit c Queries that generate a response when parsed d Queries that generate a response when read e Coupled commands 6 Functional elements required for SCPI commands 7 Buffer size limitations for block data 8 Syntax restrictions 9 Response syntax for every query command 10 Device to device message transfer that does not follow rules of the standard 11 Block data response size 12 Common Commands implemented by Model 2500 13 Calibration query information 14 Trigger macro for DDT 15 Macro information 16 Response to IDN identification 17 Storage area for PUD and PUD 18 Resource description for RDT and RDT 19 Effects of RST RCL and SAV 20 TST information 21 Status register structure 22 Sequential or overlapped commands 23 Ope
39. 14 Rest House Crescent Bangalore 560 001 91 80 509 1320 21 Fax 91 80 509 1322 ITALY Viale San Gimignano 38 20146 Milano 02 48 39 16 01 Fax 02 48 30 22 74 JAPAN New Pier Takeshiba North Tower 13F e 11 1 Kaigan 1 chome Minato ku Tokyo 105 0022 81 3 5733 7555 Fax 81 3 5733 7556 KOREA 2FL URI Building 2 14 Yangjae Dong Seocho Gu Seoul 137 888 82 2 574 7778 Fax 82 2 574 7838 NETHERLANDS Postbus 559 4200 AN Gorinchem 0183 635333 Fax 0183 630821 SWEDEN c o Regus Business Centre Frosundaviks All 15 4tr 169 70 Solna 08 509 04 679 Fax 08 655 26 10 SWITZERLAND Kriesbachstrasse 4 8600 D bendorf 01 821 94 44 Fax 01 820 30 81 TAIWAN 1FL 85 Po Ai Street Hsinchu Taiwan R O C 886 3 572 9077 Fax 886 3 572 9031 4 02 Models 2500 and 2502 Photodiode Meter User s Manual 2000 Keithley Instruments Inc All rights reserved Cleveland Ohio U S A Third Printing June 2002 Document Number 2500 900 01 Rev C Manual Print History The print history shown below lists the printing dates of all Revisions and Addenda created for this manual The Revision Level letter increases alphabetically as the manual undergoes subsequent updates Addenda which are released between Revisions contain important change information that the user should incorporate immediately into the manual Addenda are numbered sequentially When a new Revision is created all Addenda associated with
40. 15 4 bit Decimal value lt NDN gt Oto bi11 3 bit Binary value O to b1111 4 bit Binary value 0 to q7 3 bit Octal value 0 to q17 4 bit Octal value 0 to h7 3 bit Hexadecimal value 0 to hF 4 bit Hexadecimal value Query SOURce3 Query source value for specified limit Description These commands are used to define the digital output fail patterns for the specified tests 0 to 7 3 bit 0 to 15 4 bit Note that the fail patterns for Limits 3 6 apply only to the grading mode Tests are performed in the following order 1 Limit Test 1 2 Limit Test 2 3 Limit Test x where x 3 6 in ascending numerical order a Lower Limit x b Upper Limit x The first failure in the test sequence determines the bit pattern for the digital output port Subsequent failures in the test sequence will not change the defined digital output pattern Note that the output value can be specified as a binary octal decimal or hexadecimal value 17 34 SCPI Command Reference Models 2500 and 2502 User s Manual NOTE 16 bit I O is available with the 2499 DIGIO option The maximum 16 bit output value is 65535 Use the following table to determine the parameter value for the desired decimal digital output pattern For non decimal parameters convert the decimal value to its binary octal or hexadecimal equivalent Decimal OUT 4 OUT 3 OUT2 OUT1 value L L L L 0 L L L H 1 L L H L 2 L L H H 3 L H L L 4 L H
41. 2 While DUT 2 is being tested Ch 2 opens and Ch 3 closes Again assuming no failure a measurement is performed on DUT 3 and it is then tested Assuming that all the tests pass on all DUTs the device package is placed in the pass bin If any of the DUTs fails a test the FAIL message is displayed and the digital output infor mation for the first failure is stored in memory assuming that END binning control is selected After the sweep is completed the Model 2500 sends the output pattern stored in memory This is the output pattern for the first test failure The component handler places the DUT package into the bin assigned to that particular failure The handler selects the next DUT and the testing process is repeated Digital output clear pattern After every binning operation the digital output needs to be reset to a clear pattern which serves as a no action condition for the component handler The Model 2500 can be programmed to automatically clear the digital output after the pass or fail pattern is sent With auto clear you must specify the required pulse width delay for the pass or fail pattern When not using auto clear you must return the digital output to its clear pattern from the DIGOUT AUTO CLEAR option of the CONFIG LIMIT menu This option also sets the pass fail pattern and pulse width Enabling auto clear To enable auto clear Press CONFIG then LIMIT Select DIGOUT then press ENTER Choose AUTO CLEAR then
42. 2 Summary ROF Reading Overflow L1 Limit 1 Summary RAV Reading Available amp Logical AND OR Logical OR 14 16 Status Structure Models 2500 and 2502 User s Manual Questionable event register The used bits of the questionable event register Figure 14 7 are described as follows Bits BO through B7 Not used Bit B8 Calibration Summary Cal Set bit indicates that an invalid calibration constant was detected during the power up sequence This error will clear after suc cessful calibration of the instrument Bits B9 through B13 Not used Bit B14 Command Warning Warn Set bit indicates that a signal oriented mea surement command parameter has been ignored Bit B15 Not used Figure 14 7 Questionable event status Warn a B15 pe B13 B9 87 BO Warn a B15 B14 B13 B9 B7 BO Questionable 7 ae K stat ques cond Condition Register Questionable stat ques Event Register To QSB of Status Byte Register Figure 14 3 stat ques enab lt NRf gt stat ques enab Questionable Event Enable Register Warn CAL B15 B14 B13 B9 B8 B7 BO Warn Command Warning Logical AND Cal Calibration Summary ne Logical OR Models 2500 and 2502 User s Manual Status Structure 14 17 Condition registers As Figure 14 1 shows each status register set except the standard event register set has a condition register A condi
43. 2004A 2mA 20mA I range based auto delay 16ms 16ms 12 25ms 12 25ms 3 55ms 3 55ms 530us 530us For example with the 2A range and a voltage step size of 0 5V the total delay is Delay 12 25ms 0 5 x 3 07ms Delay 13 785ms 3 6 Basic Operation Models 2500 and 2502 User s Manual Output slew time Figure 3 2 demonstrates the effect of output slew time on overall settling Total time after changing the source value before accurate measurements can be taken includes both the slew time and the measure circuit settling time NOTE When not performing a sweep the output slew time is not part of the auto source delay Therefore for best accuracy when turning the output on or changing the voltage source value allow a delay of 3 07ms V of output change before trigger ing a reading This delay can be programmed by setting the trigger delay Section 10 Trigger model front panel operation Also while the output is slewing the compliance status bit for the channel will be set Section 14 Status Structure You can poll the compliance bit to determine when the pro grammed source value is reached and an accurate reading can be taken Figure 3 2 Output slew time Volts l mooo e o Time 1 Output Measurement s Slew Circuit Settling I Source Output Accurate readings Value Settled can be taken Changed Manual delay Manual delay for each channel can be set from 0000 00000 to 9999 9
44. 25 OUTP1 ON Turn on channel 1 output PRINT Pes 4572 INIT Trigger readings PRINT 7 7 25 OUTP1 OFF Turn off channel 1 output PRINT OUTPUT 25 CALC7 LIM3 FAIL Request Limit 3 fail status P T ENTER 25 Address 2500 to talk INPUT 2 L Input Limit 3 result IF L 0 THEN PRINT Limit 3 passed ELSE PRINT Limit 3 failed PRINT OUTPUT 25 CALC7 LIM4 FAIL Request Limit 4 fail status PRINT ENTER 25 Address 2500 to talk PUT 2 L Input Limit 4 result 0O THEN PRINT Limit 4 passed ELSE PRINT Limit 4 failed HH H 7 je Il Index Accessories 1 3 Acquiring readings 16 3 Amplitude Setting for fixed source 17 63 Annunciators 1 7 Arm layer 10 4 10 19 Auto delay period 3 5 Auto range Limits 6 3 Select 17 55 Speed limitations 6 3 Auto zero 3 4 Controlling 17 82 Front panel 3 4 Remote command 3 4 Auto clear Enabling 11 14 Timing 11 15 Baud rate 13 17 Bench defaults 10 7 Binning 11 4 11 8 Control 11 6 Multiple element devices 11 13 Single element devices 11 12 Systems 11 10 Buffer Aquire statistic 17 39 Configure and control 17 88 Considerations 8 5 Location number 8 3 Reading and clearing 17 87 Select statistic 17 39 Statistics 8 4 Bus commands D 7 Bus lines D 5 Byte order 17 51 Cables Interface 1 4 Triax 1 3 Calculate subsystems 17 22 CALCulate 1 17 23 CALCulate2 17 23 CALCulate3 17 27 CALCulate4 17 27 CALCulate5 17 29 CALCulate6 17 30 CALCulate7 1
45. 2500 and 2502 User s Manual Introduction The Model 2500 supports two GPIB protocols SCPI and 488 1 The 488 1 protocol is included to significantly increase speed over the GPIB When using the 488 1 protocol throughput is enhanced up to 10 times for data sent to the Model 2500 command messages and up to 20 times for data returned by the Model 2500 response messages The speed of readings sent over the GPIB is also increased NOTE With the 488 1 protocol selected you will still use SCPI commands to program the Model 2500 Operation differences between the two protocols are discussed in this appendix Selecting the 488 1 protocol Perform the following steps to select the 488 1 protocol 1 Press MENU to display the MAIN MENU 2 Place the cursor on COMMUNICATION and press ENTER to display the COMMUNICATIONS SETUP menu 3 Place the cursor on GPIB and press ENTER to display the present GPIB address 4 Press ENTER to display the GPIB PROTOCOL menu 5 Place the cursor on 488 1 and press ENTER 6 Use the EXIT key to back out of the menu structure When switching between the SCPI protocol and 488 1 protocol the instrument does not reset The GPIB protocol setting is saved in EEPROM and the unit will power up with that selected protocol The GPIB protocol cannot be changed over the bus However there is a query command to determine the presently selected protocol When the 488 1 protocol is selected the mes sage exc
46. 2500 and 2502 User s Manual Getting Started 1 5 Product overview NOTE This manual covers both the Model 2500 and 2502 which are virtually identical except for the addition of analog outputs on the Model 2502 All references to the Model 2500 apply to the Model 2502 unless otherwise noted The Model 2500 combines two stable DC bias voltage sources with two low noise amme ters for dual channel low current photodiode measurements The unit has 0 1 basic measurement accuracy with up to 6 2 digit resolution At 5 2 digit resolution the Model 2500 can transfer up to 475 readings per second over the GPIB and up to 900 read ings per second with 412 digit resolution Each Model 2500 channel has the following measurement and voltage bias capabilities Measure current from 1fA to 20mA Source bias voltage from 500uV to 100V Some additional capabilities of the Model 2500 include Sweep capabilities linear and logarithmic staircase and custom sweeps of up to 2500 points Two hardware limit tests and four software limit tests with a built in comparator for pass fail testing Digital I O for stand alone binning operations or interface to component handler Programming language and remote interfaces The Model 2500 uses the SCPI pro gramming language and two remote interface ports IEEE 488 GPIB and RS 232C Trigger Link interface to Keithley Series 7000 switching hardware Math functions V I I V optical power electrical powe
47. 2500 voltage bias and measurements operation for each channel can consist of a series of source delay measure SDM cycles Figure 5 1 During each SDM cycle the following occurs 1 Set the voltage bias source output level 2 Wait for the programmed delay period 3 Make the measurement Figure 5 1 Source delay measure SDM cycle End of A D Start of A D Conversion COVES Source Value j Trigger Trigger Delay gt Measure gt Latency 100s Triggering Figure 5 2 shows how the SDM cycle fits into the trigger model See Section 10 for com plete details on the trigger model When the source is turned on triggered an approxi mate 100usec trigger latency occurs before the programmed source level is output As long as the source output stays on trigger latency will not be included in subsequent SDM cycles Trigger latency only occurs when the output makes the transition from off to on See the specifications in Appendix A for definitions of trigger latency as well as other trigger specifications Models 2500 and 2502 User s Manual Measurement Concepts 5 3 Figure 5 2 Simplified trigger model Source Delay Measure See Section 10 for trigger model details Delay phase The delay phase of the SDM cycle allows the source to settle before the measurement is performed The delay period depends on how the source delay is configured The source delay can be manually set f
48. 3 Measurement function configuration menu 0 0 eee eee 7 6 Table 7 4 Math function commands 000 eee eeeseeseeeeeeseeeseeseeeeeeaeeeeeeaes 7 7 Table 7 5 Math function programming example eee eeeeeseeeeeeeee 7 8 Table 7 6 RATIO and DELTA configuration menus 0 0 0 ee eee 7 10 Table 7 7 RATIO and DELTA function commands eee 7 11 Table 7 8 RATIO and DELTA programming example eee 7 12 8 Data Store Table 8 1 Data store commands 0 eee esesteeseeeeeeeeeeeeecetaeeneeeaeeeeeaes 8 6 Table 8 2 Data store example cisiseiccocsceh kesscticcesstacetassssiveveagleasecsasceeas anes 8 7 9 Sweep Operation Table 9 1 Logarithmic sweep points ce eeeceeeecesceeeeeceseeeeeeeeeeeseeeeeeens 9 4 Table 9 2 Linear and log staircase sweep commands eeeeeeeeee 9 12 Table 9 3 Staircase sweep programming example photodiode test 9 13 Table 9 4 Custom sweep commands ee eeeceseeeeteceseeeteeeseeeeteeeteeeeee 9 14 Table 9 5 Custom sweep programming example ce eeeeeeeeereee 9 15 10 Triggering Table 10 1 Remote trigger command 000 eee es eeeeeseeeeeteeeeeeeeeeaeeeee 10 24 Table 10 2 Remote triggering example 0 0 eee eeseeeeereeeeeeeeseeeeeeees 10 25 11 Limit Testing Table 11 1 Limitcomma dS issii anoinia a 11 20 Table 11 2 Limits test programming example ssssseseseereseeresrereserresree 11 22 12 Digital I O Port Output Enable and Output Configuration Table 12 1 Digital output line set
49. 4 is controlled manually if the END OF TEST mode is set to EOT MODE Use to select GRADING or SORTING mode In GRADING mode a reading passes if it is within all of the HI LO limit tolerances enabled assuming that it has passed the compliance tests first The Digital I O will be driven with the first pattern of the first compliance HI or LO failure Otherwise the pass pattern will be output In GRADING mode you will also choose bin control modes With IMMEDIATE the testing process will stop after the first failure and place the fail pattern on the digital output If none of the limit tests fail the pass pattern will be placed on the output and the testing process will stop With END the testing pro cess will continue until the programmed sweep is completed regardless of how many failures occur This allows multi element devices to be tested After testing is finished the bit pattern for the first failure is placed on the output If all tests pass the pass pattern will instead be placed on the output In SORTING mode a reading will fail if it fails the compliance test or is not within any of the Digital I O Bands If the tests pass and only Limit 1 or 2 is enabled the associated pass pattern will be output Otherwise the first limit test band that passes will output its lower limit pattern upper limit patterns will be ignored If Limit 1 or 2 fails its failure patterns will be output If no Limit 3 to 6 passes their failure p
50. 8501 1 is 1m long the Model 8501 2 is 2m long Model 8502 trigger link adapter Lets you connect any of the six Trigger Link lines of the Model 2500 to instruments that use the standard BNC trigger connectors Model 8503 DIN to BNC trigger cable Lets you connect Trigger Link lines one Volt meter Complete and two External Trigger of the Model 2500 to instruments that use BNC trigger connectors The Model 8503 is 1m long Rack mount kits Model 4288 1 single fixed rack mount kit Mounts a single Model 2500 in a standard 19 inch rack Model 4288 2 side by side rack mount kit Mounts two instruments Models 182 428 486 487 2000 2001 2002 2010 2015 2016 2400 2410 2420 2430 2500 2510 6430 6517 7001 side by side in a standard 19 inch rack Model 4288 3 side by side rack mount kit Mounts a Model 2500 and a Model 199 side by side in a standard 19 inch rack Model 4288 4 side by side rack mount kit Mounts a Model 2500 and a 5 25 inch instrument Models 195A 196 220 224 230 263 595 614 617 705 740 775 etc side by side in a standard 19 inch rack Model 4288 5 dual fixed rack mounting kit Mounts a Model 2500 and another 34 inch high instrument Model 182 428 486 487 2000 2010 2400 2410 2420 2430 or 7001 side by side in a standard 19 inch rack Carrying case Model 1050 padded carrying case A carrying case for a Model 2500 Includes handles and a shoulder strap Model
51. 9 200nA lower range limit DISP DIG 5 5 display digits OUTP1 ON Turn on output READ Trigger and acquire reading OUTP1 OFF Turn off output The Speed Accuracy menu is used to set the integration time of the A D converter period of time the input signal is measured The integration time affects the usable digits the amount of reading noise and the ultimate reading rate of the instrument The integration time is specified in parameters based on the Number of Power Line Cycles NPLC where 1 PLC for 60Hz is 16 67msec 1 60 and 1 PLC for 50Hz is 20msec 1 50 In general the fastest integration time FAST 0 01 PLC results in increased reading noise and fewer usable digits The slowest integration time HI ACCURACY 10 PLC provides the best common mode and normal mode noise rejection In between settings are a com promise between speed and noise The default power on speed setting is NORMAL 1 PLC 6 6 Range Digits Speed and Filters Models 2500 and 2502 User s Manual Setting speed Speed is set from the SPEED ACCURACY MENU and is structured as follows Use Section 1 Rules to navigate menus to check and or change the speed setting SPEED ACCURACY MENU Press SPEED or CONFIG SPEED to display the menu Figure 6 1 FAST Sets speed to 0 01 PLC and sets display resolution to 3 digits MED Sets speed to 0 10 PLC and sets display resolution to 4 digits NORMAL Sets speed to 1 00 PLC an
52. Arm Event Immediate Detector GPIB Never Another Arm Arm Timer A Counter Layer Manual 2 1 TLink UStest 4 Tstest Na O peA Arm Out Event gt 1 On Off TUstest Trigger Layer Another Trigger Trigger On Off Source Event 2 Detector Trigger Delay 0 0 sec MEASURE Action y SOURCE Immediate Action Trigger Link Trigger Out Event gt On Off Trigger In Source Filter Process Repeat l DELAY Action n Trigger Out Event gt On Off On Off MEASURE Action Bench Default Output Trigger U ii CONV Reading Conversion Trigger Out Event On Off 10 4 Triggering Models 2500 and 2502 User s Manual Event detection In general operation is held up at an Event Detector until the programmed event occurs Note however that if an event detector has a bypass operation can be programmed to loop around the event detector Arm layer Event detector bypass As shown in Figure 10 1 there is a bypass for the Arm Event Detector This bypass can only be used if TLINK or STEST is the selected Arm In Event The bypass serves to jump start operation With the event detector bypass set to ONCE operation will loop around the Arm Event Detector when the output is turned ON The programmable arm in events for the Arm Layer are described as follows IMMEDIATE Event detection occurs immediately allowing operation to continue GPIB Event detecti
53. CONFIG MSR2 BUTTON I Current measurement I V I V measurement conductance V I V I measurement resistance MX B_UNIT MX B measurement P Electrical power measurement V X I P gt Optical power lneasured ldark current Responsivity Figure 4 1 Measurement configuration menu tree MSR1 MSR2 Models 2500 and 2502 User s Manual Photodiode Measurements 4 3 Configuring measurements Follow the steps below to configure channel 1 or channel 2 measurement functions l Press CONFIG then the MSR1 or MSR2 key to access the configuration menu for the channel you are configuring From the displayed configuration menu select the math function you wish to use on that channel I I V V I MX B P or P gt then press ENTER If you choose MX B configure the appropriate M slope and B offset parameters for that function at the display prompts After configuring all parameters press EXIT to return to normal display Optical power The Model 2500 has a built in function for converting photodiode current to optical power 1 Press CONFIG then MSR1 or MSR2 to select the configuration menu for channel 1 or channel 2 2 Select P then press ENTER 3 At the prompt enter the desired R responsivity value then press ENTER 4 At the prompt enter the desired D dark current then press ENTER 4 4 Photodiode Measurements Models 2500 and 2502 User s Manual Front panel photodiode measu
54. COdeS 5 225 nae E deeds D 11 F Measurement Considerations Figure F 1 Voltage b rden tis tsccccect disse cicteesecese edie ecacsevsee ssbesscnuvediereseesesus F 6 Figure F 2 Power line ground lOOPS eeeeeeeeseeeeeeeeeeeeseesseeeeeaeeseeess F 7 Figure F 3 Eliminating ground 1OOpS 0 eee eeseeseeseeeeeeeeeeeeseeeeeeaeeaes F 8 List of Tables 1 Table 1 1 Table 1 2 Table 1 3 Table 1 4 Table 1 5 Table 1 6 Table 1 7 Table 1 8 Table 1 9 Table 1 10 Table 1 11 3 Table 3 1 Table 3 2 Table 3 3 Table 3 4 Table 3 5 Table 3 6 Table 3 7 Table 3 8 4 Table 4 1 Table 4 2 Table 4 3 6 Table 6 1 Table 6 2 Table 6 3 Table 6 4 Table 6 5 Table 6 6 Table 6 7 Getting Started Line fuse Sks ennn iina a a n 1 13 Basic display commands ce eeeeseeseeeseeseeeseeseeeeeeeeeaeees 1 15 Factory default settings 0 eee cece eseeeeeseeeseeseeeeeeseeeaeens 1 17 Main MENU 4 22603 sasisestavesvasecoseosedscensstssnsdeoveovaescestgsrdsesetonsance 1 20 Measurement configuration MENUS 00 0 0 eee eeeeeeeeeereeeeeeee 1 25 Source configuration MENUS 0 0 eee eeeeseeeeeeeeeeeeeeeeeeaee 1 26 Rel filter and range configuration Menus Le eee 1 26 Limit configuration MENU ieee eseeeseeseeeeeeeeeeeeeeeeaeees 1 27 Trigger configuration Menu 0 0 eee eeeeeseeeeeeeeeeeeeeeeeees 1 28 Sweep digits speed and data store configuration menus 1 29 Output and display configuration Menus 0 0 0 1 30 Basi
55. Command Description RST Restore GPIB defaults FORM ELEM CURRI Select channel 1 reading data SOUR1 VOLT 10 Output 10V on channel 1 OUTP ENAB ON Activate output enable SOUR1 CLE AUTO ON Enable auto off mode READ Trigger and acquire readings Connect pins 8 and 9 of digital I O port to simulate closed output enable switch 13 Remote Operations Differences remote vs local operation Summarizes remote operation enhance ments and local to remote and remote to local transitions Selecting an interface Describes how to select between the GPIB and RS 232 interfaces GPIB operation Covers GPIB bus standards bus connections and primary address selection General bus commands Describes general bus commands used for fundamental GPIB control Front panel GPIB operation Summarizes GPIB error messages status indicators and using the LOCAL key Programming syntax Describes the basic programming syntax for both common and SCPI commands RS 232 interface operation Outlines use of the RS 232 interface to control the Model 2500 via remote 13 2 Remote Operations Models 2500 and 2502 User s Manual Differences remote vs local operation Local to remote transition When changing from local to remote operation the following takes place The Model 2500 stops taking readings and is placed into the IDLE layer of the Trigger Model All menus are exited All pending front panel c
56. Floating Output V Common p On Bias Source Ground Connect Note One channel shown Relay Closed Other channel is identical Chassis Ground Figure 3 4 Ground connect disabled Triax INPUT HI To Ammeter LO gsr Chassis Ground SOURCE OUTPUT Output Common Ground On Bias Source Connect 7 Relay Note One channel shown Open Other channel is identical Chassis Ground 3 10 Basic Operation Models 2500 and 2502 User s Manual Basic measurement procedure NOTE The following procedures outline measurements on a generic DUT See Section 4 Photodiode Measurements for procedures specific to photodiodes Output control Use the ON OFF OUTPUT key to turn both Model 2500 outputs on or off simultaneously for basic source measure situations With either channel 1 or channel 2 output on the red ON OFF OUTPUT indicator light will be on The indicator light turns off when the out puts are turned off WARNING To prevent electric shock do not make or break connections to the Model 2500 while it is on Basic measurement circuit configuration The circuit configuration for the basic measurement procedures that follow is shown in Figure 3 5 In this example channel 1 connections are shown but channel 2 connections are similar See Section 2 Connections for detailed connection information Figure 3 5 Circuit configuration for basic measurements i et eee CHANNEL 1 Floating
57. Limit 1 and Limit 2 are the compliance limits for channel and channel 2 respectively while the data source for Limit 3 through Limit 6 depends on the selected FEED MSR1 MSR2 RATIO or DELTA e Set up PASS conditions for Digital I O bit pattern Ifusing 3 bit port size program the Digital I O Line 4 EOT MODE for EOT or BUSY as appropriate Step 4 Turn output on Press the ON OFF key to turn the output on red OUTPUT indicator turns on The Model 2500 will output the programmed bias voltage level Step 5 Start testing process To enable the limit tests press the LIMIT key If the SOT line of the Digital I O is being used by a handler the testing process will not start until the handler sends a low going pulse Otherwise the testing process will start when LIMIT is pressed Step 6 Stop testing process The testing process can be terminated at any time by again pressing LIMIT When using a handler the testing process will stop after the last DUT is tested 11 20 Limit Testing Remote limit testing Limit commands Models 2500 and 2502 User s Manual Table 11 1 summarizes remote commands to control limit testing Note that LIMitX refers to identical software limits LIMit3 through LIMit6 See Section 17 CALCulate7 and SOURce3 for more details on these commands Table 11 1 Limit commands Command Description CALCulate7 LIMit 1 COMPliance FAIL lt name gt CALCulate7 LIMit 1 COMPliance
58. OFF y STATe Query state of advanced filter v MEDian Configure and control the median filter RANK lt NRf gt Specify median filter rank 1 to 5 1 RANK Query median filter rank STATe lt b gt Enable or disable median filter OFF STATe Query state of median filter 17 12 Table 17 5 continued SENSe command summary SCPI Command Reference Models 2500 and 2502 User s Manual Default Command Description parameter SCPI SENSe2 Sense 2 subsystem to control channel 2 measurement v CURRent DC Path to configure current y RANGe Configure measurement range v UPPer lt n gt Select range by specifying the expected 2e 4 v current reading 0 to 21e 3 UPPer Query range v AUTO lt b gt Enable or disable auto range ON v AUTO Query auto range v ULIMit lt n gt Set auto ranging upper limit 0 021 to 0 021 2e 2 v ULIMit Query auto ranging upper limit v LLIMit lt n gt Set auto ranging lower limit 0 021 to 0 021 2e 9 v LLIMit Query auto ranging lower limit v NPLCycles lt n gt Specify integration rate in line cycles 0 01 1 v to 10 NPLCycles Query integration rate v AVERage Path to configure moving and repeat filters v COUNt lt n gt Specify filter count 1 to 100 10 v COUNt Query filter count v STATe lt b gt Enable or disable digital filter OFF y STATe Query state of digital filter v TCONtrol lt name gt Select filter control
59. OR IMPLIED INCLUD ING ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE THE REMEDIES PROVIDED HEREIN ARE BUYER S SOLE AND EXCLUSIVE REMEDIES NEITHER KEITHLEY INSTRUMENTS INC NOR ANY OF ITS EMPLOYEES SHALL BE LIABLE FOR ANY DIRECT INDIRECT SPECIAL INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OF ITS INSTRUMENTS AND SOFTWARE EVEN IF KEITHLEY INSTRUMENTS INC HAS BEEN ADVISED IN ADVANCE OF THE POSSIBILITY OF SUCH DAMAGES SUCH EXCLUDED DAM AGES SHALL INCLUDE BUT ARE NOT LIMITED TO COSTS OF REMOVAL AND INSTALLATION LOSSES SUSTAINED AS THE RESULT OF INJURY TO ANY PERSON OR DAMAGE TO PROPERTY KEITHLEY Keithley Instruments Inc 28775 Aurora Road Cleveland Ohio 44139 440 248 0400 Fax 440 248 6168 1 888 KEITHLEY 534 8453 e www keithley com Sales Offices BELGIUM Bergensesteenweg 709 B 1600 Sint Pieters Leeuw 02 363 00 40 Fax 02 363 00 64 CHINA Yuan Chen Xin Building Room 705 12 Yumin Road Dewai Madian Beijing 100029 8610 6202 2886 Fax 8610 6202 2892 FINLAND Tiet j ntie 2 02130 Espoo Phone 09 54 75 08 10 Fax 09 25 10 51 00 FRANCE 3 all e des Garays 91127 Palaiseau C dex 01 64 53 20 20 Fax 01 60 11 77 26 GERMANY Landsberger Strasse 65 82110 Germering 089 84 93 07 40 Fax 089 84 93 07 34 GREAT BRITAIN Unit 2 Commerce Park Brunel Road Theale Berkshire RG7 4AB 0118 929 7500 Fax 0118 929 7519 INDIA Flat 2B Willocrissa
60. REMOTE 25 T r OUTPUT 257 RST Restore GPIB defaults T OUTPUT 25 FORM ELEM CURR2 Select channel 2 measure data T OUTPUT 25 SENS2 CURR RANG 20e 3 Enable 20mA measure range T OUTPUT 25 SOUR2 VOLT START 1 1V Ch 2 start voltage T OUTPUT 25 SOUR2 VOLT STOP 10 10V Ch 2 stop voltage T OUTPUT 25 SOUR2 VOLT STEP 1 1V Ch 2 step voltage T OUTPUT 25 SOUR2 VOLT MODE SWE Select Ch 2 source sweep mode T OUTPUT 25 SOUR2 SWE RANG AUTO Ch 2 auto source range mode T OUTPUT 25 SOUR2 SWE SPAC LIN Ch 2 linear sweep mode T OUTPUT 25 TRIG COUN 10 Trigger count sweep points T OUTPUT 25 SOUR2 DEL 0 1 Source delay 0 1s iT OUTPUT 25 OUTP2 ON Turn on channel 2 output T OUTPUT 25 READ Trigger and acquire readings T ENTER 25 Address 2500 to talk INPUT 2 R Input sweep reading string T Sweep data R Print reading string ay OUTPUT 25 OUTP2 OFF Turn off channel 2 output Models 2500 and 2502 User s Manual Example Programs H 7 Limit test program The program listing below performs a limits test as covered in Section 11 This program sets up the following operating modes e Source and measure channel channel 1 e Source voltage 1V e Source delay 100ms e Limit 3 upper value 10mA e Limit 3 lower value 4mA e Limit 4 upper value 8mA Limit 4 lower value 6mA Limit Test Program OPEN IEEE FOR OUTPU
61. Remote Operations Figure 13 1 TEEE 488 COnmector 0 0 eee eeeseeeeseseeeeseeeeeeseeseeeaeeseeeaeeeeeas 13 4 Figure 13 2 TEEE 488 connections oo cee eeeeseseeeeseeeeeeseeseeeaeeseeeaeeeeeas 13 4 Figure 13 3 TEEE 488 and RS 232 connector location eee 13 5 Figure 13 4 RS 232 interface Connector oo eee eeeeeseeeceeeeeeeeeeeeeeeaes 13 18 14 Status Structure Figure 14 1 Model 2500 status register structure 1 ee eee eeeeeeeeee 14 3 Figure 14 2 16 bit status register 22 c ec5cisdesseeedd iecaesecteavsisessegesseragecededees 14 5 Figure 14 3 Status byte and service request SRQ ooo eeeseesceesneeeneeeeees 14 7 Figure 14 4 Standard event status 0 eee eseeeseceeeeseceeeeseeeeeeeeeneesees 14 11 Figure 14 5 Operation event Status eee eeeesecseeereesseeaeeeeeeseenseeaes 14 13 Figure 14 6 Measurement event Status 0 elec eseeeseesseeeeeeeeneesseeaes 14 15 Figure 14 7 Questionable event Status 1 eee eeeeeseeeseereceeeeneeeeeeees 14 16 17 SCPI Command Reference Figure 17 1 ASCII data format 00 eceeeeseesecesecseeeeeeeeeaeseeeeeeeeeeaes 17 44 Figure 17 2 TEEE 754 single precision data format 32 data bits 17 45 C Data Flow Figure C 1 Data flow block diagram 0 eee eee eseeseeseeeeeseeeaeenseeaeenes C 2 D IEEE 488 Bus Overview Figure D 1 TEEE 488 bus configuration eee eeeeseeseeeseeeeeeeeeeseeaeenee D 4 Figure D 2 TEEE 488 handshake sequence eee eeseseeseeeeeeseeeseeaeeeee D 6 Figure D 3 Command
62. SOURce3 lt NRf gt lt NDN gt CALCulate7 LIMit 1 STATe lt state gt CALCulate7 LIMit 1 FAIL CALCulate7 LIMit2 COMPliance FAIL lt name gt CALCulate7 LIMit2 COMPliance SOURce3 lt NRf gt lt NDN gt CALCulate7 LIMit2 STATe lt state gt CALCulate7 LIMit2 FAIL CALCulate7 FEED lt name gt CALCulate7 LIMitX LOWer lt n gt CALCulate7 LIMitX UPPer lt n gt CALCulate7 LIMitX LOWer SOURce3 lt NRf gt lt NDN gt CALCulate7 LIMitX UPPer SOURce3 lt NRf gt lt NDN gt CALCulate7 LIMitX PASS SOURce3 lt NRf gt lt NDN gt gt CALCulate7 LIMitX STATe lt state gt CALCulate7 LIMitX FAIL Set Limit 1 fail condition Name IN fail into compliance or OUT fail out of compliance Specify Limit 1 fail bit pattern NRf NDN pattern Enable disable Limit 1 test state ON or OFF Query Limit 1 test result 0 pass 1 fail Set Limit 2 fail condition Name IN fail into compliance or OUT fail out of compliance Specify Limit 2 fail bit pattern NRf NDN pattern Enable disable Limit 2 test state ON or OFF Query Limit 2 test result 0 pass 1 fail Select Limit 3 6 tests input path name CALC3 CALC4 CALCS or CALC6 Specify lower Limit X 3 Specify upper Limit X Specify lower Limit X fail bit pattern for grading mode NRf NDN bit pattern Specify upper Limit X fail bit pattern for grading mode NRf bit pattern Specify pass pattern for sorting m
63. STATe lt b gt SENSe 1 AVERage ADVanced STATe lt b gt Enable disable advanced filter SENSe2 AVERage ADVanced STATe lt b gt Enable disable advanced filter Parameters lt b gt 0 or OFF Disable advanced filter 1 or ON Enable advanced filter Query STATe Query state of advanced filter Description This command is used to enable or disable the advanced filter When enabled the noise window is used with the averaging filter When dis abled the noise window is not used Models 2500 and 2502 User s Manual SCPI Command Reference 17 59 Median filter commands MEDian RANK lt NRf gt SENSe 1 MEDian RANK lt n gt Set median filter rank SENSe2 MEDian RANK lt n gt Set median filter rank Parameters lt n gt 0to5 Specify rank value for median filter DEFault 1 MINimum 0 MAXimum 5 Query RANK Query median filter rank Description The median filter is used to pass the middle most reading from a group of readings that are arranged according to size This command is used to specify the rank which determines the number of reading samples for the filter process The number of reading samples are determined as follows Sample readings 2n 1 Where n is the selected rank 1 to 5 MEDian STATe lt b gt SENSe 1 MEDian STATe lt b gt Enable disable channel 1 median filter SENSe2 MEDian STATe lt b gt Enable disable channel 2 median filter Parameters lt b gt 0 or OFF Disable repeat filter 1 or ON Enabl
64. Select trigger layer output events Event list SOURce DELay SENSe or NONE Trigger Model 2500 if BUS source selected Models 2500 and 2502 User s Manual Remote trigger example Triggering 10 25 Table 10 2 summarizes the command sequence for basic trigger operation These com mands set up Model 2500 triggering as follows e Arm layer source bus e Arm layer count 2 e Trigger layer delay 0 1s Trigger layer count 10 Trigger layer output events source and sense Trigger layer trigger link output line 1 After the unit is set up INIT is sent to take the unit out of idle TRG is sent to trigger the unit after which it cycles 10 times through the trigger layer A second TRG is required to trigger the unit the second time and it then completes the second cycle through the trigger layer NOTE You must allow sufficient time between the first and second TRG commands or the second trigger will be ignored Table 10 2 Remote triggering example Command Description RST Restore GPIB defaults SOURI VOLT 10 Source 10V on channel 1 ARM SOUR BUS Select bus arm layer source TRG command ARM COUN 2 Arm layer count 2 TRIG DEL 0 1 0 1s trigger layer delay TRIG COUN 10 Trigger layer count 10 TRIG OUTP SOUR SENS Source sense output trigger events TRIG OLIN 1 Trigger output line 1 OUTP1 ON Turn on channel output INIT Take unit out of idle TRG Trigger first sequence
65. Set moving count to 20 AVER ON Enable average filter AVER ADV OFF Disable advanced filter AVER ADV NTOL 10 Set filter tolerance to 10 7 Relative Math Ratio and Delta e Relative Discusses the relative REL mode that can be used to null offsets or sub tract a baseline value from readings e Measurement Math Functions Provides detailed information on the following math functions I V V I MX B electrical power V x I and optical power e RATIO and DELTA Discusses the ratio and delta functions which can be used to calculate the ratio or difference between channel and channel 2 measurement func tion results 7 2 Relative Math Ratio and Delta Models 2500 and 2502 User s Manual Relative The rel relative feature can be used to null offsets or subtract a baseline reading from present and future readings With REL enabled subsequent readings will be the difference between the actual input value and the rel value as follows Displayed Reading Actual Input Rel Value Once a rel value is established for a measurement the value is the same for all ranges For example if ImA is set as a rel value on the 20mA range the rel value is also mA on the 2mA range Selecting a range that cannot accommodate the rel value does not cause an overflow condi tion but it also does not increase the maximum allowable input for that range For exam ple on 2mA range the Model 2500 still over
66. Standard fuses with applicable national safety ap provals may be used if the rating and type are the same Other components that are not safety related may be purchased from other suppliers as long as they are equivalent to the original component Note that selected parts should be purchased only through Keithley Instruments to maintain accuracy and functionality of the product If you are unsure about the applicability of a replacement component call a Keithley Instruments office for information To clean an instrument use a damp cloth or mild water based cleaner Clean the exterior of the instrument only Do not apply cleaner directly to the instrument or allow liquids to enter or spill on the instrument Products that consist of a circuit board with no case or chassis e g data acquisition board for installation into a computer should never require cleaning if handled accord ing to instructions If the board becomes contaminated and operation is affected the board should be returned to the factory for proper cleaning servicing Table of Contents 1 Getting Started General information ssssssssessseesesreressesrssesrertrrrstesrerrsreresesrereens 1 2 Warranty information s sessssesssesessessesesresterestrsreresrerreresrerenrs 1 2 Contact information sssesssseseeeseeseseesesrestsrestrsrsresrsreeesrsresre 1 2 Man al addenda ci scsscieccescsavssvenssageiencetecstsosaetonsenreseasageesereaes 1 2 Safety symbols and terms
67. TRG Trigger second sequence OUTP1 OFF Turn off output 1 FETC Request readings 11 Limit Testing Types of limits Discusses the two types of limits hardware limits and software lim its Also summarizes the two operating modes grading and sorting Operation overview Covers binning control and pass fail conditions Binning systems Details the handler interface as well as single element and multiple element binning Digital output clear pattern Details the digital output bit pattern that occurs after a binning operation Configuring and performing limit tests Describes how to configure the Model 2500 for limit testing and summarizes a typical test procedure Remote limit testing Summarizes limit commands and provides a basic program ming example 11 2 Limit Testing Models 2500 and 2502 User s Manual Types of limits As shown in Figure 11 1 there are six limit tests that can be performed on a DUT Limit 1 channel 1 hardware compliance limit test Limit 2 channel 2 hardware compliance limit test Limits 3 to 6 software limits for channel 1 channel 2 ratio and delta A test is only performed if it is enabled Thus you can perform one two or all six tests The tests are always performed in the order shown in the drawing Figure 11 1 Limit tests Limit 1 or Pass or Fail on Compliance Limit 2 Test Compliance Limit 3 Test Coarse Limits Limit 4 6 Tes
68. When disabled the front panel LOCAL key is operational in remote Removing the instrument from remote LOCal restores front panel keys operation Reset timestamp RESet SYSTem TIME RESet Reset timestamp Description This action command is used to reset the absolute timestamp to 0 sec onds The timestamp also resets to 0 seconds every time the Model 2500 is turned on Models 2500 and 2502 User s Manual SCPI Command Reference 17 87 TRACe subsystem The commands in this subsystem are used to configure and control data storage into the buffer The commands are summarized in Table 17 9 TRACel DATA The bar I indicates that TRACe or DATA can be used as the root command for this sub system From this point on the documentation in this manual uses TRACe If you prefer to use DATA simply replace all the TRACe command words with DATA Read and clear buffer DATA TRACe DATA Read contents of buffer Description When this command is sent and the Model 2500 is addressed to talk all the readings stored in the data store are sent to the computer The format used to send readings over the bus is controlled from the FORMat subsystem NOTE See Appendix C for a detailed explanation on how data flows through the vari ous operation blocks of the Model 2500 It clarifies the types of readings that are acquired by the various commands to read data CLEar TRACe CLEar Clear buffer Description This action command is used
69. a command or query do not attempt to read data from the Model 2500 until the terminator has been sent usually Line Feed with EOI Otherwise a DCL or IFC must be sent to reset the input parser When receiving data all data up to and including the terminator LF with EOD must be accepted Otherwise a DCL or IFC must be sent to reset the output task Empty command strings terminator only should not be sent Using SCPI based programs In general an existing SCPI based program will run properly and faster in the 488 1 pro tocol as long as it meets the above guidelines and limitations G 4 GPIB 488 1 Protocol Models 2500 and 2502 User s Manual Bus hold off OPC OPC and WAI are still functional but are not needed for the 488 1 protocol When sending commands the GPIB is automatically held off when it detects a terminator The hold off is released when all the commands have finished executing or if there is some parser or command error An exception is an initiate command which releases the hold off immediately and does not wait for all of the readings to be acquired This imme diate release of bus hold off is done to support GET SDC IFC TRG RCL RST SYSTem PRESet and ABORt during data acquisition Trigger on talk Trigger on talk functionality has been added for the 488 1 protocol If a query has not been received by the instrument the Model 2500 will automatically assume a READ command has been sent when it is a
70. ai aa E E a ESR 3 3 Basic circuit configuration eeseseseeseereeeeresesreererrerrereresrese 3 3 Operation considerations seeesseeseseeresssrerrsreresrrrrsrrerrsrerrsreseee 3 4 AET e no m Li o EE EE E 3 4 ALO ZETO ariasi EENE E E TAER EREA 3 4 Front panel auto Zero sesssessesessesessesreresrrrsrsrsrrsrrresrrseees 3 4 Remote command auto Zero eee eeeeseeseeereeseeeaees 3 4 Source delay asiveccasitaasscizetenaavcncesoeccedionsvecsebausanddedaeosondbeengeteed 3 5 Auto delay period sessies 3 5 O tp t slew Me sssrini 3 6 Manntial delay sissiissieiiceisesiiiheoranini iii 3 6 Front panel source delay sessseeseeeeeeeesresesrsrrsrererrrerrees 3 7 Remote command source delay 0 0 eeeeseseeeseeeeeeees 3 7 Ground connect mode oo eeecccccscscscceeeseceseseeseseessseessneeeees 3 8 Front panel ground connect 0 0 eee eeeeeeeseeeeereeeeees 3 8 Remote command ground connect ce eeeeeeeeeeeees 3 8 Basic measurement Procedure 0 0 es eeeeseeeeeeeeeeeeseeeeeeeeeneeeaes 3 10 OUTPUT control oriretur i 3 10 Basic measurement circuit configuration 0 0 eee 3 10 Front panel measurement procedure n se 3 11 Step 1 Select measurement channel and range 3 11 Step 2 Select source channel and set source level 3 11 Step 3 Turn source outputs ON oo eeeeeeeeeeeeeees 3 12 Step 4 Observe readings on the display 0 0 0 3 12 Step 5 Turn source output Off neeesser 3 12 Remote command measurement procedure
71. are separated by semicolons A common command can be executed at any com mand level and will not affect the path pointer Example stat oper enab lt NRf gt ESE lt NRf gt Program message terminator PMT Each program message must be terminated with an LF line feed EOI end or identify or an LF EOI The bus will hang if your computer does not provide this termination The following example shows how a multiple command program message must be terminated outpl on lt PMT gt Command execution rules e Commands execute in the order that they are presented in the program message An invalid command generates an error and of course is not executed Valid commands that precede an invalid command in a multiple command program message are executed Valid commands that follow an invalid command in a multiple command program message are ignored 13 16 Remote Operations Models 2500 and 2502 User s Manual Response messages A response message is the message sent by the instrument to the computer in response to a query command program message Sending a response message After sending a query command the response message is placed in the Output Queue When the Model 2500 is addressed to talk the response message is sent from the Output Queue to the computer Multiple response messages If you send more than one query command in the same program message Multiple com mand messages the multiple response me
72. as one or more ASCII characters that tell the device to perform a particular operation such as setting a range or closing a relay The IEEE 488 bus treats these commands as data in that ATN is false when the commands are transmitted Command codes Command codes for the various commands that use the data lines are summarized in Figure D 3 Hexadecimal and the decimal values for the various commands are listed in Table D 2 Table D 2 Hexadecimal and decimal command codes Command GTL SDC GET LLO DCL SPE SPD LAG TAG SCG UNL UNT Hex value Decimal value 01 04 08 11 14 18 19 20 3F 40 5F 60 7F 3F 5F D 11 IEEE 488 Bus Overview Models 2500 and 2502 User s Manual Figure D 3 Command codes Oas dNOND aNYWWOD AYVGNODAS aA 99d dNOUD GNVWWOD AYVWIad aed 1 U0q X 801A 4G LOLG 9d 30N 0067 JPPOW Aq pajyuatuajdu 70u JOALNOD JAAVL LOL pue NDIANODNN T1Od TATIVYVd Add UYNDIANOD 110d TATIWAVd Ddd E Jf gt oh OVD dNOND ssIAAaAY XIYL ao nr a gt BK gt NY seQv0ToY wc nx ECO a s aOeXnNED gt ESEX gt N v sS SL tl EL a LL OL 6 8 4 9 S v c L 0 jw gt I F oa az Ov dNOND SsIAAAY NILS Ln oE 6c 87 Le 9 SC ve ET AA IZ oz 6l 81 ZL OL d S SSgpanaT H T OrFNMTNON DH OF NMTNON lt noOwn ON 99V dNOND d
73. avoid applying voltages greater than a few volts to insulators being used for sensitive current measure ments In cases where this practice is unavoidable it may take minutes or even hours in some cases for the current caused by dielectric absorption to dissipate Voltage burden The input resistance of the ammeter causes a small voltage drop across the input terminals This voltage is known as the voltage burden If the voltage burden is large in relation to the voltage of the measured circuit then significant measurement errors will occur Refer to Figure F 1 to see how voltage burden affects current measurements Assume Vg is set to output 5mV and R is 5kQ An ideal ammeter with zero voltage burden would mea sure the current source as follows Iq Vs Rs 5mV 5kQ 1 In practice however every ammeter has a voltage burden If the voltage burden Vp is ImV the current will be measured as follows Vs Vp Rs 5mV ImV 5kQ 12 ll IM The ImV voltage burden caused a 20 measurement error Figure F 1 Voltage burden Model 2500 Models 2500 and 2502 User s Manual Measurement Considerations F 7 General measurement considerations The following measurement considerations apply to all precision measurements Ground loops Ground loops that occur in multiple instrument test setups can create error signals that cause erratic or erroneous measurements The configuration shown in Figure F 2 intro duces errors i
74. between the channel 1 measurement function MSR1 and the channel 2 measurement function MSR2 RATIO MSR1 MSR2 where MSR1 channel 1 measurement function MSR2 channel 2 measurement function Models 2500 and 2502 User s Manual Relative Math Ratio and Delta 7 9 MSR2 MSR1 This function computes the ratio between the channel 2 measurement function and the channel measurement function RATIO MSR2 MSR1 where MSRI channel 1 measurement function MSR2 channel 2 measurement function DELTA functions The Model 2500 has built in RATIO functions to calculate the following e MSRI MSR2 e MSR2 MSRI1 MSR1 MSR2 This function computes the difference between the channel 1 measurement function and the channel 2 measurement function DELTA MSR1 MSR2 where MSRI channel 1 measurement function MSR2 channel 2 measurement function MSR2 MSR1 This function computes the difference between the channel 2 measurement function and the channel measurement function DELTA MSR2 MSRI1 where MSRI channel 1 measurement function MSR2 channel 2 measurement function 7 10 Relative Math Ratio and Delta Models 2500 and 2502 User s Manual Front panel RATIO and DELTA configuration Using Table 7 6 as a guide configure RATIO and DELTA functions as follows 1 Press CONFIG then RATIO or DELTA to select the function to be configured 2 Using the EDIT keys place the cursor on the desired function then pres
75. bias source capa bilities ranges compliance and fundamental measurement and voltage bias circuit configuration Operation considerations Covers warm up auto zero and source delay Basic measurement procedure Describes the basic procedure for setting up the Model 2500 for measurement and voltage bias operation including choosing the mea surement channel and range selecting the source channel and setting output values and turning the output on and off Using the analog outputs Model 2502 only Covers basic characteristics of the analog outputs 3 2 Basic Operation Models 2500 and 2502 User s Manual Operation overview Measurement and voltage bias capabilities The Model 2500 has the following measurement and voltage bias capabilities e Measure Current Each Model 2500 channel can measure DC currents from 1fA to 20mA Each channel has eight current ranges 2nA 20nA 200nA 2A 20nA 200nA 2mA and 20mA e Source Voltage Each Model 2500 channel can output DC voltage from 500yV to 100V Each channel has two ranges 10V and 100V NOTE Both channel 1 and channel 2 are floating and independent of one another Ranges Table 3 1 summarizes current measurement ranges resolutions and maximum readings while Table 3 2 lists voltage bias source ranges resolutions and maximum voltage and current See Section 6 for more details on ranging Table 3 1 Current measurement ranges
76. calculations drive the digital I O lines In GRADing mode a reading passes if it is within all of the hi low limit tolerances enabled assuming that it has passed Limit 1 or Limit 2 compliance test first The digital I O lines will be driven with the first pattern of the first compliance hi or low failure Otherwise the CALC7 CLIM PASS SOUR3 pattern will be output In SORTing mode a reading will fail if it fails the compliance test or is not within any of the digital I O bands If the tests pass and only Limit 1 or Limit 2 is enabled the CALC7 CLIM PASS SOUR7 pattern will be output Otherwise the first limit test band that passes will output its LOW SOUR3 pattern UPP SOUR3 patterns will be ignored If Limit 1 or Limit 2 fails its SOUR3 pattern will be output If no Limit 3 6 limit passes the CALC7 CLIM FAIL SOUR3 pattern will be output Clear test results IMMediate CALCulate7 CLIMits CLEar IMMediate Clears test results and resets digital O port Description This command clears the test results pass or fail of the limit tests and resets the output lines of the digital I O port back to the SOURce3 TTL settings See SOURce3 page 17 74 AUTO lt b gt CALCulate7 CLIMits CLEar AUTO lt b gt Control auto clear for test results Parameters lt b gt 1 or ON Enable auto clear 0 or OFF Disable auto clear Query AUTO Query state of auto clear Description With auto clear enabled test results will clear and the ou
77. can also be programmed to output a trig ger when operation leaves the Trigger Layer and enters into the Arm Layer This output trigger is typically sent to another instrument to signal the end of a scan or sweep Models 2500 and 2502 User s Manual Triggering 10 7 Bench defaults The bench defaults are listed as follows They are also denoted in Figure 10 1 by the symbol Arm In Event Immediate Trigger In Source Immediate Arm Count 1 Trigger Count 1 Trigger Delay 0 0 sec e Delay Action 0 0005 sec Source Trigger In Event On Delay Trigger In Event Off e Measure Trigger In Event Off Trigger Out Events All Trigger Out Events are disabled off Arm Out Events Off Event Detection Bypasses Never both layers When the output is turned ON the Model 2500 will run in a continuous loop around the trigger model After each Measure Action operation will continue at the top of the trigger model The Model 2500 can be returned to idle by turning the output OFF Operation summary The trigger model is designed to offer versatility for the various source and measure appli cations Typically it allows you to perform a specified number of measurements at various source levels For example assume you want to perform three measurements each at two different chan nel voltage bias source levels 1V and 2V To do this set the arm count to two the trig ger count to three
78. cceseeeeeeeneeseeeeeeeeseeeeneeeeeees 1 2 INSpECHON sirier eie ooe ar a E Eei 1 3 Options and accessories essseessessesesreeersretrsrerrsssreresreresee 1 3 Manuals sssrinin aa aiea 1 3 Triax cables and adapters 0 eee eeeeeeeeeeeseeeeeeseeeeees 1 3 Interface Cables 22 c c6 ccccseaesesslecaacesnesbaseteasseuertenessose 1 4 Rack mount Kits oo eee eeeeeeeeeceeeeeeseeeeaeeseeeaeeeees 1 4 CANT YINS CASE serere sirr rose NE EEATT REESE 1 4 Product OVEIVICW coscecire taenia iir as 1 5 Front and rear panel familiarization seeseseeeeeeeeeeeesrerereereereeee 1 6 Front panel summary sssssessereseersseeseseserreserersresesrreseseeresrs 1 6 Rear panel summary sssssissriorisissreserscionseianscirevusreavsras tsisa 1 8 PowerUp soiirci i es AEREA E EENE 1 10 Line voltage Selection eee eeeeeceeseeeeeeeeresetseeeaeeseeeaees 1 10 Lime power connection 0 0 eee eeseeeeeeeeeeeeeereeeeaeeeeeeseeenees 1 10 Power up sequence cea ceeseediisvenssasecaisnesteactevussteaserpeseapesveiages 1 11 System identification 2 0 eeeeeeeesseeeseeceneesseeeeeeeseeesneeeeees 1 11 Line frequency Setting see eee eeeeseeeeeeseseeeeaeeneeeeeeaees 1 12 Front panel line frequency 0 0 eee eeeeeeeseeeeeeeeeeeeeee 1 12 Remote command line frequency sses 1 12 Fuse replacement c0s20 cccfisscccccdsiasedenvassseceveevesnsbessdolecivens 1 12 Display sierran a dgeagacene e a Ea EERS 1 13 Display format ssresrseisiiieiiieiiiiriiciiiai iiai 1 13 CHAN
79. commands to define and con trol the execution of the list SWEep In this mode the source will perform a voltage sweep See Configure sweeps page 17 66 for commands to define the sweep NOTE The sourcing mode will default to FIXed whenever the Model 2500 goes to the local state Select range RANGe lt n gt SOURce 1 VOLTage RANGe lt n gt SOURce2 VOLTage RANGe lt n gt Select range for channel 1 source Select range for channel 2 source Parameters lt n gt 100 to 100 Specify source level volts DEFault 10V range MINimum 10V range MAXimum 100V range UP Select next higher range DOWN Select next lower range Query RANGe Query range for specified source RANGe DEFault Query RST default source range RANGe MINimum Query lowest source range RANGe MAXimum Query highest source range 17 62 SCPI Command Reference Description AUTO lt b gt Models 2500 and 2502 User s Manual These commands are used to manually select the range for the specified source Range is selected by specifying the approximate source magni tude that you will be using The instrument will then go to the lowest range that can accommodate that level For example if you expect to source levels around 3V send the following command SOURce1 VOLTage RANGe 3 The above command will select the 10V range for the channel source As listed in Parameters page 17 61 you can also use the MINimum MAXimum an
80. csccsebes ieii iia Ri 5 7 Data flow front panel eile eeesseeseeseeeeceseceeeaeeseeeaeeeeeeaes 5 9 CALC block data flOW 0 eee eceeeeeeseeseeeseeseeeaeeneeeaeeseeeatees 5 10 Range Digits Speed and Filters Speed configuration Menu tree oo eee eee eeeeereteeeereeeeeeaees 6 6 D Stape MMMM inneni io E E AE 6 7 Repeat filter count 10 ssesessesssesesessessssesersessesrrsesresrereseserees 6 8 Median filter rank 5 2 ci25 ssc0ceeesccesdsecdsscsecedenticceesccsstacaverncs 6 9 Moving filter count 10 oo eee eeeeeeteeeneeeteeeeeeeteeesteeeneeeeee 6 10 Configure filtering menu tree oo lees ee eseeereeeeeeaeees 6 12 Sweep Operation Linear staircase SWEEP eeeeceesceeseesceeseeseeesecaeenaeeseeeseseneeaes 9 2 Logarithmic staircase sweep example 5 point sweep from 1 to LO Volts cc ciceies iscsi sue cedbesaetecsceesseceaneteeasebes 9 3 Custom pulse SWEEP cee eeeeeeeseeeeesceeseeeeesecaneeaeeneeeaeseneeaes 9 5 Custom sweep with different pulse widths oe 9 5 Sweep configuration Menu tree oo ee eee eeeeeeeeseeereeeeeeaees 9 7 Triggering Trigger model front panel operation ce eee eeeeeereeee 10 3 Rear panel pinout cece ee eeeceeecseceseeseeeseeseeeseeeeeseeseeeatees 10 8 Trigger link input pulse specifications 2 0 eee eect 10 8 Trigger link output pulse specifications elec 10 9 DUT test Systema enna a OR E 10 9 Trigger link connections ssesseseseesesseseesesrrseerrsresrsresreresreee 10 10
81. default conditions Default conditions are listed in the SCPI tables Table 17 1 through Table 17 10 With the SAVO 4 parameters specified the instrument powers on to the setup that is saved in the specified location using the SAV command 17 82 SCPI Command Reference Models 2500 and 2502 User s Manual Control auto zero STATe lt name gt SYSTem AZERo STATe lt name gt Control auto zero Parameters lt name gt ON Enable auto zero OFF Disable auto zero Query STATe Query state of auto zero Description This command is used to enable or disable auto zero or to force an immediate one time auto zero update if auto zero is disabled When auto zero is enabled accuracy is optimized When auto zero is disabled speed is increased at the expense of accuracy Note that both channels are affected by this command Select power line frequency setting LFRequency lt freq gt SYSTem LFRequency lt freq gt Select line frequency Parameters lt freq gt 50 50Hz setting 60 60Hz setting Query LFRequency Query line frequency selection Description Use this command to manually select the line frequency setting 50 or 60Hz Error queue NOTE See Section 14 for details on the error queue NEXT SYSTem ERRor NEXT Read oldest error code and message Description As error and status messages occur they are placed in the error queue The error queue is a first in first out FIFO register that can hold up to 10 messages Afte
82. delay to the desired value then press ENTER Press EXIT to return to normal display Step 4 Turn output on Press the ON OFF OUTPUT key to turn the output on red OUTPUT indicator turns on The Model 2500 will output the programmed bias level Step 5 Run sweep To run the sweep press the SWEEP key After the sweep is completed turn the output off by pressing the ON OFF OUTPUT key 9 12 Sweep Operation Remote sweep operation Models 2500 and 2502 User s Manual Staircase sweep commands Table 9 2 summarizes remote commands used for linear and log staircase sweep opera tion See Section 17 Configure sweeps for more details on these commands Table 9 2 Linear and log staircase sweep commands Command Description SOURce SOURce SOURce SOURce SOURce SOURce SOURce SOURce 1 VOLTage MODE SWEep 1 VOLTage STARt lt n gt 1 VOLTage STOP lt n gt 1 VOLTage STEP lt n gt 1 VOLTage CENTer lt n gt 1 VOLTage SPAN lt n gt 1 SWEep RANGing lt name gt 1 SWEep SPACing lt name gt F eee Be Dl eB ee ee SOURce 1 SWEep POINts lt n gt SOURce 1 SWEep DIRection lt name gt SOURce2 VOLTage MODE SWEep SOURce2 VOLTage STARt lt n gt SOURce2 VOLTage STOP lt n gt SOURce2 VOLTage STEP lt n gt SOURce2 VOLTage CENTer lt n gt SOURce2 VOLTage SPAN lt n gt SOURce2 SWEep RANGing lt name gt SOURce2 SWEep SPACing lt name gt SOURce2 SWEep POINts
83. event detectors one for each action Source Delay and Measure Event Detector Bypass As shown in Figure 10 9 there is a bypass TRIGger DIRection for the Source Event Detector This bypass is in effect only if TLINK is the selected Trigger In Source With this event detector bypass set to SOURce operation will proceed around the Source Event Detector The programmable trigger in sources for the Trigger Layer are described as follows IMMediate With Immediate selected event detection for the three detectors is satisfied immediately Operation proceeds through the Trigger Layer to perform the Source Delay and Measure actions TLINk With TLINk selected event detection at each enabled detector occurs when an input trigger via the Trigger Link input line is received A detector is enabled by including its parameter name with the TRIGger INPut command For example to enable the Delay Event Detector and Measure Event Detector the follow ing command must be sent TRIGger INPut DELay SENSe The above command disables the Source Event Detector since its parameter name SOURCce is not included in the parameter list With the Source Event Detector disabled operation will not hold up It will simply con tinue and perform the Source Action Operation will hold up at the Delay Event Detector until an input trigger is received and then it will hold up at the Measure Event Detector until another input trigger is received
84. every 10 mea surement conversions will yield a single reading Figure 6 3 illustrates the Repeat Filter process The maximum count stack size for the Repeat Filter is 100 Note that setting the count to one disables the Repeat Filter Choose the Repeat Filter for sweeping so readings for other source levels are not averaged with the present source level Figure 6 3 Repeat filter count 10 Conversion 10 Conversion 20 Conversion 30 9 19 29 8 18 28 F 7 Repeat 17 27 Repeat 6 Reading 16 26 Reading 5 1 15 25 3 4 14 24 3 13 23 2 12 22 Conversion 1 Conversion 11 Conversion 21 Median filter The Median Filter is used to pass the middle most reading from a group of readings that are arranged according to size For example assume the following readings 2mA InA 3nA The readings are placed in a stack rearranged in ascending order as follows InA 3nA 2mA From the above readings it can be plainly seen that 3nA is the median middle most reading Therefore the 3nA reading is allowed to pass while the other two readings are discarded filtered out The Median Filter provides a good method to reject noise spikes Models 2500 and 2502 User s Manual Range Digits Speed and Filters 6 9 The number of reading samples stack size for the Median Filter is determined by the selected rank 0 to 5 as follows Sample readings 2n 1 Where n is the selected rank
85. has built in math functions to calculate the following I V e V I e MX B Electrical power e Optical power NOTE Math function uses the current and voltage from the same channel for calculations I V This math function computes the ratio between the selected channel current measurement and the voltage bias source value Reading I V where I channel 1 or channel 2 current V channel or channel 2 voltage bias Models 2500 and 2502 User s Manual Relative Math Ratio and Delta 7 5 v i This math function computes the ratio between the selected channel voltage bias source value and the current measurement Reading V I where V channel or channel 2 voltage bias I channel 1 or channel 2 current MX B This math function multiplies the measured current by an offset factor and adds an offset value as follows Reading MX B where M gain slope factor X channel 1 or channel 2 measured current B offset value Electrical power This math function calculates power using the bias voltage and measured current values as follows Reading V x I where V channel or channel 2 voltage I channel 1 or channel 2 current Optical power Optical power is calculated from the responsivity measured current and photodiode dark current as follows Optical power limeasured ldark current Responsivity where I measured photodiode current amps measured Idark current Photodiode dark cu
86. iisisti iss a 17 89 Select timestamp format esesseeseseesesresrsreresrrsrrrrsrerreseser 17 89 FORMat lt name gt oe eee eecceseeeeeeeeseeeseeseeeseeeaeenees 17 89 Trigger SUDSYStOM1 2 0cecceecie ceeeceeseies caer sesssesdeeesecveseevaaaceetbestens 17 90 Initiate source measure cycle oo eee eeseeseeeeseeeteeeeeeeeees 17 90 INI Tate eiaeiiio ta each tanec 17 90 Abort source measure cycle oo eeeeeeeeeeseeeeeneeeeeeeneeneees 17 90 ABORT nespis 17 90 Program trigger model seseeseeseereeeerrerrrrerrsresreresreresreee 17 91 COUN aserria suei 17 91 DELAY Sm naiera aeoe e 17 92 SOURCE lt name gt iinr 17 92 MEUM Gi Stn sininen errre ion oae E EE OS 17 93 DIRection lt name gt scissioni 17 93 INP t lt eVent USC cictcasccestecetsssencsiscevanseneisaaseeaus eeass 17 94 ILINe lt NRiS 0c oiiae lah aa ele 17 95 OLTING lt NR ES ission e eaten Dodi ceesciesy 17 95 Specifications Status and Error Messages TinthOGUCt OM 25 2223 seestecise don Meds i sade esd eheeeeiag E B 2 Status and error Messages oo eee eee eeeeeeeeeeeeeeeeeaeeeaeeaeeeaeeseees B 2 Eliminating common SCPI errors oe eeeeseeeeeseeeeeeeeeeeeeaeeees B 8 113 Undefined header 0 ccccccsseseeeeeessseeeeeeeees B 8 420 Query UNTERMINATED ceceeseeceeteeeeees B 9 Data Flow Introducti seese Cando Oebendeteses Senne EEREN C 2 SENS Land SENS 2 sprene A C 3 NE eee sce ssctcest vest stnessantess AA C 3 BET CR neh noe ees C 3 READ Virren REE deus AEA
87. in detail Basic readings With data store and limit tests disabled Figure 5 6A the Model 2500 simply displays the selected measurement function readings MSR1 MSR2 RATIO or DELTA No data storage or limit test is performed when those two functions are disabled Data storage enabled With data store enabled Figure 5 6B all readings are stored in the data store buffer as processed regardless of the selected measurement function before or during storage The type of recalled reading or statistic depends on the selected measurement function during recall MSR1 MSR2 RATIO or DELTA Limit test enabled With a limit test enabled Figure 5 6C the selected limit feed MSR1 MSR2 RATIO or DELTA is used for Limit 3 through Limit 6 tests Pass Fail P or F information is dis played on the front panel along with the readings If data store is performed with a limit test already enabled pass fail status information is also displayed with the readings during data recall Models 2500 and 2502 User s Manual Measurement Concepts 5 9 Figure 5 6 Data flow front panel MSR1 MSR2 Display Readings RATIO Displayed readings DELTA depend on selected function A Data store and limit tests disabled MSR1 CH Data Store Buffer All functions stored when Recalled Readings data store Recalled readings enabled DELTA depend on selected function B Data store enabled MSR1 MSR2 Re
88. in the off 0 position 2 Connect the female end of the supplied power cord to the AC receptacle on the rear panel WARNING The power cord supplied with the Model 2500 contains a separate ground for use with grounded outlets When proper connections are made instrument chassis is connected to power line ground through the ground wire in the power cord Failure to use a grounded outlet may result in personal injury or death due to electric shock 3 Turn on the instrument by pressing the front panel power switch to the on 1 position Model 2500 and 2502 User s Manual Getting Started 1 11 Power up sequence On power up the Model 2500 performs self tests on its EPROM and RAM and momentarily lights all segments and annunciators If a failure is detected the instrument momentarily displays an error message and the ERR annunciator turns on Error messages are listed in Appendix B NOTE lfa problem develops while the instrument is under warranty return it to Keithley Instruments Inc for repair If the instrument passes the self tests the firmware revision levels are displayed For example REV A01 A02 where AO1 is the main board ROM revision A02 is the display board ROM revision Also displayed is the line frequency 50 or 60Hz If the wrong frequency is displayed it can be manually set as covered below The communication interface status is briefly dis played If the IEEE 488 bus is the presently selected interfac
89. including the controller Thus any number of talkers and listeners up to that limit may be present on the bus at one time Although sev eral devices may be commanded to listen simultaneously the bus can have only one active talker or communications would be scrambled A device is placed in the talk or listen state by sending an appropriate talk or listen com mand These talk and listen commands are derived from an instrument s primary address The primary address may have any value between 0 and 31 and is generally set by rear panel DIP switches or programmed from the front panel of the instrument The actual lis ten address value sent out over the bus is obtained by ORing the primary address with H20 For example if the primary address is H16 the actual listen address is H36 H36 H16 H20 In a similar manner the talk address is obtained by ORing the pri mary address with H40 With the present example the talk address derived from a pri mary address of 16 decimal would be H56 H56 H16 H40 The IEEE 488 standards also include another addressing mode called secondary address ing Secondary addresses lie in the range of H60 H7F Note however that many devices including the Model 2500 do not use secondary addressing Once a device is addressed to talk or listen the appropriate bus transactions take place For example if the instrument is addressed to talk it places its data string on the bus one byte at a time
90. input and output ILINe should not share the same line 17 96 SCPI Command Reference Models 2500 and 2502 User s Manual OUTPut lt event list gt ARM SEQuence 1 LAYer 1 TCONfigure OUTPut lt event list gt Arm layer event TRIGger SEQuence 1 TCONfigure OUTPut lt event list gt Trigger layer events Parameters Arm Layer Trigger lt event list gt TRIGger Trigger on exiting trigger layer NONE Disable arm layer output trigger Trigger Layer Triggers lt event list gt SOURce Output trigger after source level is set DELay Output trigger after delay period SENSe Output Trigger after measurement NONE Disable trigger layer triggers NOTE Each event in the list must be separated by a comma i e arm output source delay sense Query Description OUTPut Query output trigger event s This command is used to specify when trigger pulses occur on the spec ified output trigger line of the Trigger Link OLINe Arm Layer Trigger With TRIGger selected an output trigger will occur when exiting the trigger layer With NONE selected the arm layer output trigger is disabled Trigger Layer Triggers You can specify from one to all three events Each event in the list must be separated by a comma The SOURce DELay and MEASure events refer to the Source Delay Measure SDM cycle This is the Device Action in the Trigger Model See Figure 10 7 and Figure 10 8 With SOURce specified an ou
91. is implied optional and does not have to be used Thus the above command can be sent in one of two ways INITiate or INITiate MMediate Notice that the optional command is used without the brackets When using optional com mand words in your program do not include the brackets Parameter types The following are some of the more common parameter types lt b gt lt name gt lt NRf gt lt n gt lt numlist gt Boolean Used to enable or disable an instrument operation 0 or OFF disables the operation and or ON enables the operation Example CALCulatel STATe ON Enable Calc 1 math Name parameter Select a parameter name from a listed group Example lt name gt NEVer NEXt TRACe FEED CONTrol NEXt Numeric representation format This parameter is a number that can be expressed as an integer e g 8 a real number e g 23 6 or an ex ponent 2 3E6 Example SYSTem KEY 11 Press EXIT key from over the bus Numeric value A numeric value parameter can consist of an NRf number or one of the following name parameters DEFault MINimum MAXimum When the DEFault parameter is used the instrument is pro grammed to the RST default value When the MINimum parameter is used the instrument is programmed to the lowest allowable value When the MAXimum parameter is used the instrument is programmed to the largest allowable value Examples ARM TIMer 0 1 Sets timer to 100 msec A
92. lt NRf list gt NRf NRf NRf NRf 100 to 100 Source value volts Query VOLTage Query source list Description These commands are used to define a list of source values up to 100 for the list sourcing mode of operation When operation is started the instrument will sequentially source each voltage value in the list A cur rent measurement is performed at each source level The following command shows the proper format for defining a list using source values of 10V 13V and 5V SOURce 1 LIST VOLTage 10 13 5 If using manual source ranging you can use auto range for source val ues that are not within a single range NOTE _ In order to execute a source list the selected source must be in the list sourcing mode and the product of the arm and trigger count should be at least the same as the number of source points in the list Use the VOLTage MODE command to select the LIST sourcing mode See Select sourcing mode page 17 61 The trigger count is set using the TRIGger COUNt command See Trigger subsystem page 17 90 17 72 SCPI Command Reference Models 2500 and 2502 User s Manual APPend lt NkRf list gt SOURce 1 LIST VOLTage APPend lt NRf list gt Add value s to source 1 list SOURce 2 LIST VOLTage APPend lt NRf list gt Add value s to source 2 list Parameters lt NRf list gt NRf NRf NRf NRf 100 to 1000 Source value volts Description These commands are used to add one or more values up
93. menus to check and or change menu options Figure 1 4 shows the main menu tree Table 1 4 Main menu Menu item Description Parameters SAVESETUP Configure setup conditions SAVE Save present Model 2500 setup to memory location O to 4 RESTORE Return the Model 2500 to setup saved in memory 0 to4 POWERON Select the power on default setup BENCH Powers on to BENCH defaults See Table 1 3 GPIB Powers on to GPIB defaults See Table 1 3 USER SETUP NUMBER __ Powers on to user setup 0 to4 RESET Returns unit to BENCH or GPIB defaults See Table 1 3 COMMUNICATION Select and configure remote interface GPIB Select GPIB IEEE 488 Bus set primary address 0 to 30 GPIB protocol Appendix G Default 25 RS 232 Select the RS 232 interface set parameters BAUD Select baud rate 57600 38400 19200 9600 4800 2400 1200 600 300 BITS Select number of data bits 7 or8 PARITY Select parity NONE ODD EVEN TERMINATOR Select terminator CR CR LF LF or LF CR FLOW CTRL Select flow control NONE or XON XOFF Model 2500 and 2502 User s Manual Table 1 4 continued Getting Started 1 21 Main menu Menu item Description Parameters CAL Calibrate Model 2500 TEST Perform tests on Model 2500 DISPLAY TESTS Test front panel keys and display digits KEYS Test front panel keys DISPLAY PATTERNS Test display pixels and annunciators CHAR SET Test special display characters A D CTRL Control auto zero li
94. mnemonic too long EE Standard Event 5 111 Header separator error EE Standard Event 5 110 Command header error EE Standard Event 5 109 Missing parameter EE Standard Event 5 108 Parameter not allowed EE Standard Event 5 105 GET not allowed EE Standard Event 5 104 Data type error EE Standard Event 5 103 Invalid separator EE Standard Event 5 102 Syntax error EE Standard Event 5 101 Invalid character EE Standard Event 5 100 Command error EE Standard Event 5 Models 2500 and 2502 User s Manual Status and Error Messages B 5 Table B 1 continued Status and error messages Number Error message Event Status register Bit 000 No error SE Measurement events 100 Limit 1 failed SE Measurement Event 0 101 Low limit 2 failed SE Measurement Event 1 102 High limit 2 failed SE Measurement Event 2 103 Low limit 3 failed SE Measurement Event 3 104 High limit 3 failed SE Measurement Event 4 105 Active limit tests passed SE Measurement Event 5 106 Reading available SE Measurement Event 6 107 Reading overflow SE Measurement Event 7 108 Buffer available SE Measurement Event 8 109 Buffer full SE Measurement Event 9 111 OUTPUT enable asserted SE Measurement Event 11 114 Source in compliance SE Measurement Event 14 Standard events 200 Operation complete SE Standard Event 0 Operation events 300 Device calibrating SE Operation Event 0 303 Device sweeping SE Operation Event 3 305 W
95. n gt Select fixed V Source range 100 to 100 10 or 100 10 v AUTO lt b gt Enable or disable autoranging ON Jv AUTO Query state of autoranging v RANGe Query V Source range setting v LEVel Set V Source level in volts y IMMediate Set specified voltage level immediately v AMPLitude lt n gt Specify voltage level 100 to 100 0 v AMPLitude Query voltage level y TRIGgered Set specified voltage level when triggered y AMPLitude lt n gt Specify voltage level 100 to 100 0 v AMPLitude Query voltage level y 17 14 SCPI Command Reference Table 17 6 continued SOURce command summary Models 2500 and 2502 User s Manual Command SOURce 1 VOLTage STARt lt n gt STARt STOP lt n gt STOP STEP lt n gt STEP SPAN lt n gt SPAN CENTer lt n gt CENTer SWEep SPACing lt name gt SPACing POINts lt n gt POINts DIRection lt name gt DIRection RANGing lt name gt RANGing LIST VOLTage lt NRf gt APPend lt NRf gt POINts VOLTage Description Path to configure channel 1 source continued Specify start level for V sweep 100 to 100 Query start level for voltage sweep Specify stop level for V sweep 100 to 100 Query stop level for voltage sweep Specify step value for V sweep 200 to 200 Query step value for voltage sweep Specify span 200 to 200 Query span Specify center point 100 to 100
96. n gt Specify lower Limit x x 3 6 CALCulate7 LIMitx UPPer DATA lt n gt Specify upper Limit x x 3 6 Parameters lt n gt 9 999999e20 to Specify limit value 9 999999e20 DEFault Set specified lower limit to 1 Set specified upper limit to 1 MINimum Set specified limit to 9 999999e20 MAXimum Set specified limit to 9 999999e20 Models 2500 and 2502 User s Manual SCPI Command Reference 17 33 Query UPPer Query specified upper limit UPPer DEFault Query RST default upper limit UPPer MINimum Query lowest allowable upper limit UPPer MAXimum Query largest allowable upper limit LOWer Query specified lower limit LOWer DEFault Query RST default lower limit LOWer MINimum Query lowest allowable lower limit LOWer MAXimum Query largest allowable lower limit Description These commands are used to set the upper and lower limits for the Limit 3 through Limit 6 tests software limits SOURce3 lt NRf gt lt NDN gt CALCulate7 LIMit 1 COMPliance sOURce3 lt NRf gt I lt NDN gt Specify pattern Limit 1 failure CALCulate7 LIMit2 COMPliance SOURce3 lt NRf gt I lt NDN gt Specify pattern Limit 2 failure CALCulate7 LIMitx LOWer SOURce3 lt NRf gt I lt NDN gt Specify pattern for grading mode lower Limit x failure x 3 6 CALCulate7 LIMitx UPPer SOURce3 lt NRf gt I lt NDN gt Specify pattern for grading mode upper Limit x failure x 3 6 Parameters lt NRf gt 0 to 7 3 bit Decimal value 0 to
97. name MOVing or REPeat Enable disable Ch 1 filter state ON or OFF Set Ch 1 advanced filter noise window in NRf noise window 0 to 105 Enable disable Ch 1 advanced filter state ON or OFF Set Ch 2 average filter count n count 1 to 100 Select Ch 2 filter type name MOVing or REPeat Enable disable Ch 2 filter state ON or OFF Set Ch 2 advanced filter noise window in NRf noise window 0 to 105 Enable disable Ch 2 advanced filter state ON or OFF Set Ch 1 median filter rank NRf rank 0 to 5 Enable disable Ch 1 median filter state ON or OFF Set Ch 2 median filter rank NRf rank 0 to 5 Enable disable Ch 2 median filter state ON or OFF Since filter commands are global SENSe 1 channel 1 commands also affect equivalent SENSe2 channel 2 settings 6 13 6 14 Range Digits Speed and Filters Filter programming example Models 2500 and 2502 User s Manual Table 6 7 summarizes the command sequence to program channel filter aspects as follows Average filter off Median filter state on Median filter rank 5 Average filter state on Average filter type moving Average filter count 20 Advanced filter state on Advance filter tolerance 10 Table 6 7 Filter programming example Command Description MED RANK 5 Set median rank to 5 MED ON Enable median filter AVER TCON MOV Select moving filter type AVER COUN 20
98. number of measurement points in the sweep and the voltage source level at each point When this sweep is started the output goes from the bias level to the first voltage bias and measure point in the sweep The sweep will continue through the points in the order they were programmed and stop after the last voltage bias and measure point With trigger delay set to zero the time duration at each step is determined by the source delay and the time it takes to perform the measurement NPLC setting This delay is the same for all sweep points Models 2500 and 2502 User s Manual Sweep Operation 9 5 Custom sweep examples The custom sweep can be configured to provide a 50 duty cycle pulse sweep Figure 9 3 shows a pulse sweep that provides three 1V pulses on a OV bias level This pulse sweep is configured by specifying six points for the custom sweep The specified voltage levels at points PO P2 and P4 are 1V and the specified voltage levels at points P1 P3 and P5 are OV Six measurements are performed for this sweep three at 1V and three at OV Figure 9 3 Custom pulse sweep PO P2 P4 X 1V Bias OV Bias Measure Measure Measure Measure Measure Measure 1 2 3 4 5 6 Figure 9 4 shows a custom sweep example with different pulse widths In this example the first two points are configured with the same source value so that the duration of the first pulse is effectively doubled Figure 9 4 Custom sweep with different pul
99. of SCPI s ERRor Path to read messages in error queue y NEXT Return and clear oldest error code and message ALL Return and clear all errors codes and messages COUNt Return the number of errors CODE Path to return error code numbers only NEXT Return and clear oldest error code only ALL Return and clear all errors codes only CLEar Clears messages from error queue KEY lt n gt Simulate key press 1 to 31 s KEY Query the last pressed key v AZERo Control auto zero STATe lt name gt Control auto zero ON or OFF ON y STATe Query state of auto zero y LFRequency lt freq gt Select line frequency 50 or 60 Hz LFRequency Query line frequency TIME Timestamp RESet Reset timestamp to zero seconds LOCal Take unit out of remote cancel remote RS 232 REMote Put unit in remote RS 232 RWLock Enable local lockout RS 232 1 Clearing error queue Power up and CLS clears the error queue RST SYSTem PRESet and STATus PRESet have no effect 17 20 SCPI Command Reference Models 2500 and 2502 User s Manual Table 17 9 TRACe command summary Default Command Description parameter SCPI TRACel DATA Use TRACe or DATA as root command Note v DATA Read the contents of the buffer data store v CLEar Clear readings from buffer FREE Query bytes available and bytes in use v POINts lt NRf gt Specify size of buffer 1 to 3000 v ACTual Quer
100. on present digital output size SOURce3 BSIZe lt n gt 3 bit default is 7 4 bit default is 15 16 bit default is 65535 16 bit available only with 2499 DIGIO option 2 The format ASCII hexadecimal octal or binary for the returned value is set by FORMat SOURce3 lt name gt 17 6 SCPI Command Reference Table 17 1 continued CALCulate command summary Models 2500 and 2502 User s Manual Default Command Description parameter SCPI CALCulate7 CALC7 limit tests continues LIMitX Path to software limits LIMitX LIMit3 LIMit6 v UPPer Configure upper limit v DATA lt n gt Specify upper limit 9 999999e20 1 v to 9 999999e20 DATA Query upper limit v SOURce3 lt NRf gt I lt NDN gt Specify grading mode fail pattern 0 to 7 15 150or7 SOURce3 Query fail bit pattern LOWer Configure lower limit v DATA lt n gt Specify lower limit 9 999999e20 to 1 v 9 999999e20 DATA Query lower limit y SOURce3 lt NRf gt I lt NDN gt Specify grading mode fail pattern 0 to 7 15 15 or 7 SOURce3 Query fail bit pattern PASS Path to sorting mode pass SOURce3 lt NRf gt I lt NDN gt Specify output pass pattern 0 to 7 15 15 or 7 v SOURce3 Query pass bit pattern STATe lt b gt Enable or disable Limit X test OFF v STATe Query state of Limit X test v FAIL Return result of Limit X test 0 pass or 1 fail y CLIMits Composite limits for Limit 1 through Limit 6 BCONtro
101. operation See Section 17 TRACe subsystem DISPlay subsystem FORMat subsystem and CALCulate8 for more detailed information on these commands Table 8 1 Data store commands Command Description TRACe DATA Read contents of buffer TRACe CLEar Clear buffer TRACe FREE Read buffer memory status TRACe POINts lt n gt Specify buffer size n buffer size TRACe POINts ACTual TRACe FEED CONTrol lt name gt TRACe TSTamp FOR Mat lt name gt CALCulate8 FOR Mat lt name gt CALCulate8 DATA FORMat ELEMents TRACe lt name gt DISPlay MODE lt name gt Query number of stored readings Start or stop buffer Name NEXT fill buffer and stop or NEVer disable buffer Select timestamp format Name ABSolute reference to first buffer reading or DELTa time between buffer readings Select buffer statistic name MEAN SDEViation MAXimum MINimum or PKPK Read buffer statistic data Select buffer data elements Name CURRent 1 CURRent2 CALCulatel or CALCulate2 CALCulate3 CALCulate4 CALCulate5 CALCulate6 CALCulate7 TIME STATus ALL or DEFault CURRent 1 or CURRent2 Select CALC8 DATA source Name CALC3 CALC4 CALCS or CALC6 Models 2500 and 2502 User s Manual Data Store 8 7 Data store programming example Table 8 2 summarizes the commands for basic data store operation These commands set up the Model 2500 as follows e Number of points 10
102. output when first failure occurs END Update output after sweep is completed Query BCONtrol Query when digital output will update Description This command is used to control when the digital output will update to the pass or fail bit pattern The pass or fail bit pattern tells the handler to stop the testing process and place the DUT in the appropriate bin With IMMediate selected the digital output will update immediately to the bit pattern for the first failure in the testing process If all the tests pass the output will update to the pass bit pattern With END selected the digital output will not update to the pass or fail bit pattern until the Model 2500 completes the sweep or list operation This allows multiple test cycles to be performed on DUT With the use of a scanner card multi element devices can be tested If for example you did not use END and the first element in the device package passed the pass bit pattern will be output The testing process will stop and the DUT will be binned As a consequence the other elements in the device package are not tested 17 38 SCPI Command Reference Models 2500 and 2502 User s Manual MODE lt name gt CALCulate7 CLIMits MODE lt name gt Control digital I O port pass fail output Parameters lt name gt GRADing Output graded pass fail pattern SORTing Output sorted pass fail pattern Query MODE Query digital I O pass fail mode Description This command controls how limit
103. reading string PRINT All buffer readings R Print reading string PRINT 1 OUTPUT 25 DISP MODE CALC3 Select channel 1 for stats PRINT 1 OUTPUT 25 CALC8 FORM MEAN Select mean buffer statistic PRINT 1 OUTPUT 25 CALC8 DATA Request mean reading PRINT 1 ENTER 25 Address 2500 to talk LINE INPUT 2 R Input mean reading PRINT Buffer mean R Print mean reading PRINT 1 OUTPUT 25 CALC8 FORM SDEV Standard deviation statistic PRINT 1 OUTPUT 25 CALC8 DATA Request standard deviation PRINT 1 ENTER 25 Address 2500 to talk LINE INPUT 2 R Input standard deviation PRINT Buffer standard deviation R Print standard deviation END H 6 Example Programs Linear sweep program Models 2500 and 2502 User s Manual The program listing below performs a linear sweep as covered in Section 9 This program sets up the following operating modes e Source and measure channel channel 2 e Source mode sweep Current range 20mA e Start voltage 1V e Stop voltage 10V e Step voltage 1V OPEN OPEN p U ADA AHAADADAAAAAAAE Zz U wD U po l A iw U ADD Z 3 J Source delay 100ms Linear Sweep Program IEEE FOR OUTPUT AS 1 Open IEEE 488 output path IEEE FOR INPUT AS 2 Open IEEE 488 input path T INTERM CRLF Set input terminator OUTTERM LE Set output terminator T
104. recalled buffer readings Remote command data store Summarizes the commands to control the data store and provides a programming example 8 2 Data Store Models 2500 and 2502 User s Manual Data store overview The Model 2500 has a data store buffer to store from 1 to 3000 voltage bias source val ues and measurement readings for both channels Each reading includes the buffer loca tion number and a timestamp The data store buffer also provides statistical data on the measured readings stored in the buffer These include minimum maximum mean and standard deviation NOTE Fora sweep that has a finite sweep count the readings are automatically stored in the buffer Front panel data store Storing readings Perform the following steps to store readings 1 Select the desired measurement configuration using the MSR1 MSR2 RATIO or DELTA keys NOTE Data storage cannot be performed when the dual channel display mode is selected 2 Set the source value s using the SRC1 and SRC2 keys and turn on the output 3 Press the STORE key 4 Use the EDIT A V lt and gt keys to specify the number of readings to store in the buffer 5 Press ENTER The asterisk annunciator turns on to indicate data storage operation is in process It will turn off when the storage is finished at which point you can turn off the output Recalling readings Readings stored in the buffer are displayed by pressing the RECALL key The
105. result With CALCulate6 selected the specified limits will be compared with the delta result 17 32 SCPI Command Reference Models 2500 and 2502 User s Manual Read limits data DATA2 CALCulate7 DATA Read limits data Description This command is used to acquire all the readings used for the CALC7 limit tests At least one of the limit tests must be enabled to acquire limit test readings See Configure and control limit tests STATe lt b gt page 17 35 LATest CALCulate7 DATA LATest Read latest CALC7 data Description This command works exactly like CALC7 DATA except it returns only the latest limit result Configure and control limit tests COMpPliance FAIL lt name gt CALCulate7 LIMit 1 COMPliance FAIL lt name gt Set channel 1 compliance fail mode CALCulate7 LIMit2 COMPliance FAIL lt name gt Set channel 2 compliance fail mode Parameters lt name gt IN Fail Limit 1 2 test when unit goes into compliance OUT Fail Limit 1 2 test when unit comes out of compliance Query FAIL Query when Limit 1 2 test failure occurs Description These commands are used to specify the condition that will cause the Limit 1 and Limit 2 tests to fail With IN specified the test will fail when the Model 2500 goes into compliance fixed 20mA current limit for each voltage source With OUT specified the test will fail when the Model 2500 comes out of compliance DATA lt n gt CALCulate7 LIMitx LOWer DATA lt
106. result of the CALCI through CALC7 calculations If no value is available the NAN not a number value of 9 91e37 is used TIME This element includes the timestamp value See Data ele ments page 17 46 for complete description STATus This element includes the 24 bit status word See Data ele ments page 17 46 for a complete description ALL This parameter includes all CURR CALC TIME and STAT elements DEFault This parameter includes only the CURRent 1 and CURRent2 elements Models 2500 and 2502 User s Manual SCPI Command Reference 17 51 Byte order BORDer lt name gt FORMat BORDer lt name gt Specify binary byte order Parameters lt name gt NORMal Normal byte order for binary formats SWAPped Reverse byte order for binary formats Query BORDer Query byte order Description This command is used to control the byte order for the IEEE 754 binary formats For normal byte order the data format for each element is sent as follows Byte 1 Byte2 Byte3 Byte4 Single precision For reverse byte order the data format for each element is sent as fol lows Byte4 Byte3 Byte2 Byte 1 Single precision The 0 header is not affected by this command The header is always sent at the beginning of the data string for each measurement conversion The ASCII data format can only be sent in the normal byte order The SWAPped selection is simply ignored when the ASCII format is selected NOTE T
107. return Flow control signal handshaking Signal handshaking between the controller and the instrument lets the two devices com municate with each other about readiness to receive data The Model 2500 does not sup port hardware handshaking flow control Software flow control is in the form of XON and XOFF characters and is enabled when XON XOFF is selected from the RS 232 FLOW CONTROL menu When the input queue of the unit becomes more than 3 4 full the instrument issues an XOFF command The control program should respond to this and stop sending characters until the Model 2500 issues the XON which it will do once its input buffer has dropped below half full The Model 2500 recognizes XON and XOFF sent from the controller An XOFF will cause the instrument to stop outputting characters until it sees an XON Incoming commands are processed after the lt CR gt character is received from the controller If NONE is the selected flow control there will be no signal handshaking between the controller and the Model 2500 Data will be lost if transmitted before the receiving device is ready RS 232 connections The RS 232 serial port Figure 13 3 is connected to the serial port of a computer using a straight through RS 232 cable terminated with DB 9 connectors Do not use a null modem cable The serial port uses the transmit TXD receive RXD and signal ground GND lines of the RS 232 standard Figure 13 4 shows the rear panel connector fo
108. select SRC1 and use a 6 point Custom Sweep configured as follows P0000 1V P0001 1V P0002 1V P0003 2V P0004 2V P0005 2V When the sweep is started operation falls into the Trigger Layer and performs three mea surements at the 1V source level Operation then loops back into the Trigger Layer to per form three measurements at the 2V source level The six readings are stored in the buffer Note that after the sweep is finished the Model 2500 does not return to idle Operation continues at the top of the trigger model Subsequent measurements are performed at the 2V level and are not stored in the buffer For details on the Custom Sweep see Section 9 10 8 Triggering Models 2500 and 2502 User s Manual Trigger link Input and output triggers are received and sent via the rear panel TRIGGER LINK connec tor The trigger link has four lines At the factory line 2 is selected for output triggers and line 1 is selected for input triggers These input output line assignments can be changed from the CONFIGURE TRIGGER menu See Configuring triggering page 10 14 The connector pinout is shown in Figure 10 2 Figure 10 2 Rear panel pinout Rear Panel Pinout Pin Number Description 1 Trigger Link 1 2 Trigger Link 2 00 3 Trigger Link 3 ooe 4 Trigger Link 4 5 Trigger Link 5 6 Trigger Link 6 7 Ground 8 Ground Input trigger requirements An input trigger is used to satisfy event detection for a trigger model
109. size for 10 When ENTER is pressed the asterisk annunciator will turn on to indicate the buffer is enabled See Section 8 for details 2 Turn the Model 2500 OUTPUT ON The Model 2500 waits for an external trigger from the switching mainframe 3 Press STEP on the Model 7001 7002 to take it out of idle and start the scan The scan ner s output pulse triggers the Model 2500 to take a reading and store it The Model 2500 then sends a trigger pulse to the switching mainframe to close the next channel This process continues until all 10 channels are scanned measured and stored Details of this testing process are explained in the following paragraphs and are referenced to the operation model shown in Figure 10 7 Models 2500 and 2502 User s Manual Triggering 10 13 Figure 10 7 Operation model for triggering example 7001 or 7002 Press STEP to start scan Model 2500 Wait for Trigger pera gt Trigger Link Trigger Scan i Channel ros Make i Measurement EE E EE Output ra Trigger Scanned Channels A Turning the Model 2500 OUTPUT ON places it at point A in the flowchart where it waits for an external trigger B Pressing STEP takes the Model 7001 2 out of the idle state and places operation at point B in the flowchart C For the first pass through the model the scanner does not wait at point B Instead it closes the first channel point C D After the relay settles the Model 7001 2 outputs
110. size n 3 or 4 Set I O port bit pattern NRf NDN pattern Query bit pattern on digital output port Set Digital I O line 4 mode name EOTest or BUSY Set BUSY and EOT polarity HI or LO Clear digital output lines Enable disable I O port auto clear state ON or OFF Set auto clear delay n delay Limit test programming example Diode current test is an example that readily lends itself to pass fail analysis This test ver ifies the forward currents at various voltages The test is performed by sourcing a specified voltage level and then measuring the current The current is then compared with one set of limits to determine if the diode passes or fails and should be discarded A marginal diode determined by a second set of narrower limits can be sent to Q A for further analysis Test parameters for this test include e Source and measure channel channel 1 e Source voltage 1V e Source delay 100ms e Limit 3 upper value 10mA Limit 3 lower value 4mA e Limit 4 upper value 8mA Limit 4 lower value 6mA 11 22 Limit Testing Models 2500 and 2502 User s Manual Table 11 2 summarizes the basic SCPI command sequence for performing a limit test for the diode current test NOTE See Appendix H for a complete program listing that includes additional pro gramming steps necessary to test the values returned by the CALC7 LIM3 FAIL and CALC7 LIM4 FAIL queries Table 11 2 Limits test program
111. source and measure readings are positioned at the left side of the display while the buffer location number and timestamp are positioned at the right side NOTE RECALL cannot be used with the dual channel display mode RECALL will dis play buffer data of the presently selected function MSR1I MSR2 RATIO or DELTA You can display these different functions while the recall mode is active by pressing the appropriate function key Models 2500 and 2502 User s Manual Data Store 8 3 Buffer location number The buffer location number indicates the memory location of the source measure reading Location 0000 indicates that the displayed source measure reading is stored at the first memory location If limit testing was performed a P or an F will precede the buffer location number to indicate the pass fail result of the test Limit testing is covered in Section 11 Timestamp The first source measure reading stored in the buffer 0000 is timestamped at 0000000 000 seconds Subsequent readings can be recalled in absolute or DELTA timestamp format For the absolute format the timestamp references readings to zero seconds For the DELTA format the timestamp indicates the time between the displayed reading and the reading before it To set the timestamp format see Timestamp format page 8 5 Displaying other buffer readings To display the other readings stored in the buffer display the desired memory location number T
112. sweep Sweep voltage points 7V 1V 3V 8V 2V Source delay 100ms Table 9 5 summarizes the basic remote command sequence for performing the custom sweep described above Table 9 5 Custom sweep programming example Command Description RST Restore GPIB default conditions FORM ELEM CURR1 Select channel 1 measurement data SOUR1 VOLT MODE LIST SOURI LIST VOLT 7 1 3 8 2 TRIG COUN 5 SOURI1 DEL 0 1 OUTP1 ON READ OUTP1 OFF Channel 1 list volts sweep mode TV 1V 3V 8V 2V Ch 1 sweep points Trigger count sweep points 100ms Ch 1 source delay Turn on Ch 1 source output Trigger sweep request data Output 1 off 10 Triggering Trigger model Discusses the trigger model including various layers event detec tion delay and device action Trigger link Discusses the trigger link including input triggers output triggers and external triggering example Configuring triggering Details how to configure the various triggering aspects Remote triggering Details the remote trigger model summarizes trigger com mands and gives a basic triggering example 10 2 Triggering Models 2500 and 2502 User s Manual Trigger model front panel operation Idle The flowchart in Figure 10 1 summarizes triggering for front panel operation The trigger model is modeled after the remote commands used to control triggering Refer to Trigger model remote operation
113. terminator Set output terminator Restore GPIB defaults Select 2uA Ch range 2 measure Select channel 2 reading Select 10V Ch 2 source Output 10V on channel 2 Turn on channel 2 output Trigger and request reading Address 2500 to talk Input reading string Print reading string Turn off channel 2 output H 4 Example Programs Models 2500 and 2502 User s Manual Photodiode measurement program The program listing below performs photodiode measurements as covered in Section 4 This program sets up the following operating modes e Channel 1 measurement current measurement auto range e Channel 2 measurement optical power R 1 D 0 e Channel 2 MX B units M 8 33333 B 0 e Channel 1 source 10V range 10V amplitude Channel 2 source 100V 20V amplitude Photodiode Measurement Program OPEN IEEE FOR OUTPUT AS 1 Open IEEE 488 output path OPEN IEEE FOR INPUT AS 2 Open IEEE 488 input path PRINT INTERM CRLF Set input terminator PRINT OUTTERM LF Set output terminator PRINT REMOTE 25 CLS PRINT r OUTPUT 257 RSI Restore GPIB defaults PRINT OUTPUT 25 FORM ELEM CURR1 Select channel 1 for READ PRINT OUTPUT 25 CALC2 FORM OP2 Select optical power PRINT OUTPUT 25 CALC2 KMAT RESP 1 R 1 PRINT 7 OUTPUT 25 CALC2 KMAT DC 0 D 0 PRINT OUTPUT 25 SOUR1 VOLT RANG 10 Select
114. the number of points 9 14 Sweep Operation Models 2500 and 2502 User s Manual Custom sweep commands Table 9 4 summarizes remote commands used for custom sweep operation See Section 17 Configure list for more details on these commands Table 9 4 Custom sweep commands Command Description SOURce 1 VOLTage MODE LIST Select channel 1 voltage list custom sweep mode SOURce 1 LIST VOLTage lt list gt Define Ch 1 V source list list V1 V2 Vn SOURce 1 LIST VOLTage APPend lt list gt Add Ch 1 V source list value s list V1 V2 Vn SOURce 1 LIST VOLTage POINts Query length of Ch 1 V source list SOURce 1 SWEep RANGing lt name gt Select Ch 1 source ranging name BEST AUTO or FIXed SOURce2 VOLTage MODE LIST Select channel 2 voltage list custom sweep mode SOURce2 LIST VOLTage lt list gt Define Ch 2 V source list list V1 V2 Vn SOURce2 LIST VOLTage APPend lt list gt Add Ch 2 V source list value s list V 1 V2 Vn SOURce2 LIST VOLTage POINts Query length of Ch 2 V source list SOURce2 SWEep RANGing lt name gt Select Ch 2 source ranging name BEST AUTO or FIXed Models 2500 and 2502 User s Manual Sweep Operation 9 15 Custom sweep programming example As an example of custom sweep operation assume a five point sweep with the following parameters Source and measure channel channel 1 Voltage sweep mode list Custom
115. to 100 to a source list that already exists The source values are appended to the end of the list By using multiple appended lists up to 3000 points can be in a list POINts SOURce 1 LIST VOLTage POINts Query length of source 1 list SOURce2 LIST VOLTage POINts Query length of source 2 list Description These commands are used to determine the length of the specified source list The response message indicates the number of source values in the list Sweep and list program examples Linear voltage sweep Linear source 1 voltage sweep from 1V to 10V in 1V increments RST SOUR1 SWE SPAC LIN SOURI VOLT STAR 1 SOUR1 VOLT STOP 10 SOURI VOLT STEP 1 SOURI1 SWE POIN returns 10 TRIG COUN 10 SOURI VOLT MODE SWE OUTP1 ON INIT List sweep The previous linear sweep can instead be performed using a voltage list as follows RST SOURI LIST VOLT 1 2 3 4 5 6 7 8 9 10 SOUR1 LIST VOLT POIN returns 10 TRIG COUN 10 SOURI VOLT MODE LIST OUTP1 ON INIT Models 2500 and 2502 User s Manual SCPI Command Reference 17 73 Logarithmic sweep Logarithmic sweep from 10V to 100V in 20 points RST SOURI1 SWE SPAC LOG SOURI VOLT STAR 1 SOURI VOLT STOP 100 SOURI SWE POIN 20 TRIG COUN 20 SOUR1 VOLT MODE SWE OUTP1 ON INIT To determine the source values that will be generated Start 10 Logjg Start 1 Stop 100 Logj Stop 2 LogStep Log 0 Start Log 9 Stop SWE POIN 1 2 1 20 1 1 19
116. to clear the buffer of readings If you do not clear the buffer a subsequent store will overwrite the old readings 17 88 SCPI Command Reference Models 2500 and 2502 User s Manual Configure and control buffer FREE TRACe FREE Read status of memory Description This command is used to read the status of storage memory After send ing this command and addressing the Model 2500 to talk two values separated by commas are sent to the computer The first value indicates how many bytes of memory are available and the second value indi cates how many bytes are reserved to store readings POINts lt n gt TRACe POINts lt n gt Specify buffer size Parameters lt n gt 1 to 3000 Specify buffer size MINimum 1 MAXimum 3000 DEFault 100 Query POINts Query buffer size POINts MINimum Query smallest allowable buffer size POINts MAXimum Query largest allowable buffer size POINts DEFault Query RST default buffer size Description This command is used to specify the size of the buffer ACTual TRACe POINts ACTual Query number of stored readings Description This query command is used to determine how many stored readings are in the buffer After sending this command and addressing the unit to talk the number of readings stored in the buffer will be sent to the com puter Models 2500 and 2502 User s Manual CONTrol lt name gt TRACe FEED CONTrol lt name gt SCPI Command Reference 17 89 Start or stop buffer Pa
117. two channels Table 7 1 summarizes rel commands See Section 17 for additional information Table 7 1 Rel commands Command Description 7 3 CALCulate3 NULL OFFSet lt n gt CALCulate3 NULL STATe lt state gt CALCulate3 NULL ACQuire CALCulate3 FEED lt name gt CALCulate4 NULL OFFSet lt n gt CALCulate4 NULL STATe lt state gt CALCulate4 NULL ACQuire CALCulate4 FEED lt name gt Define Ch 1 null rel value n rel value Enable disable Ch 1 rel state ON or OFF Acquire Ch 1 rel value Select input feed name SENS1 or CALC1 Define Ch 2 null rel value n rel value Enable disable Ch 2 rel state ON or OFF Acquire Ch 2 rel value Select input feed name SENS2 or CALC2 7 4 Relative Math Ratio and Delta Models 2500 and 2502 User s Manual Rel programming example Table 7 2 lists commands for setting up and enabling rel These commands set up the Model 2500 as follows e Channel 1 rel value le 3 e Channel 1 feed SENS1 current function block e Channel 1 rel state enabled Table 7 2 Rel programming example Command Description gt CALC3 NULL OFFS le 3 Rel value le 3 CALC3 FEED SENS 1 Current measure feed gt CALC3 NULL STAT ON Enable rel OUTP1 ON Output on INIT Trigger reading gt CALC3 DATA Get reading OUTP1 OFF Turn off output Measurement math functions Math functions Each Model 2500 channel
118. voltage or current value and the programmed delay pro vides a settling period for the source before the measurement is performed The trigger model consists of two layers Arm Layer and Trigger Layer to provide versa tility Programmable counters allow operations to be repeated and various input and out put trigger options are available to provide source measure synchronization between the Model 2500 and other instruments via the Trigger Link Idle and initiate The instrument is considered to be in the idle state ARM annunciator off when it is not operating within the trigger model layers While in the idle state the instrument cannot perform any measurements An initiate command is required to take the instrument out of idle The following commands perform an initiate operation e INITiate e READ e MEASure Conversely if the unit is taking readings most commands except DCL SDC IFC and ABORt are queued up and will not be executed until the unit returns to idle The MEASure command will automatically turn the output on Note that after the instru ment returns to the idle state the output will remain on When auto output off is enabled SOURce 1 1 CLEar AUTO ON or SOURce2 CLEar AUTO ON any of the above three commands can be used to initiate operation The source output will automatically turn on at the beginning of each SDM source delay measure cycle and turn off after each measurement is completed 10 18 T
119. will be placed in the bit assigned to that pulsed line Category register component handler When using this type of handler the Model 2500 sends a bit pattern to three handler lines when a pass or fail condition occurs This bit pattern determines the bin assignment for the DUT With the pass fail pattern on the output line 4 is then pulsed This end of test EOT pulse latches the bit pattern into the register of the handler which places the DUT in the assigned bin When interfacing to this type of handler a maximum of eight compo nent handler bins are supported If the handler requires a high going or low going EOT pulse program Model 2500 for 3 bit operation and appropriate EOT mode NOTE The EOT and 3 bit modes are configured from the CONFIG LIMIT MENU See Configuring limit tests page 11 16 Basic binning systems Two basic binning systems are shown in Figure 11 7 and Figure 11 8 Both systems require a handler to physically place the device packages in the appropriate bins The han dler is controlled by the Model 2500 via the Digital I O port Single element device binning Figure 11 7 shows a basic binning system for single element devices After all pro grammed testing on the DUT is completed the appropriate digital output information is sent to the component handler which then places the DUT in the appropriate bin The component handler selects the next DUT and the testing process is repeated Models 2500 and
120. 0 to 5 From the above equation it can be seen that the minimum number of sample readings is 1 n 0 and the maximum number is 11 n 5 The following table shows the number of sample readings for each rank setting Rank of Sample setting readings 0 1 1 3 2 5 3 7 4 9 5 11 The first in first out stack for the Median Filter operates as a moving type after it fills For example if the Median Filter is configured to sample 11 readings Rank 5 as shown in Figure 6 4 the first filtered reading will be calculated and displayed after 11 readings are acquired and placed in its filter stack Each subsequent reading will then be added to the stack oldest reading discarded and another Median Filter reading will be calculated and displayed NOTE With auto range enabled a range change cannot occur until a reading is yielded by the median filter process Therefore auto ranging could be very slow when the median filter is enabled If the Repeat Filter is enabled the Median Filter operation will not start until after the Repeat Filter operation yields a reading In other words after a Repeat Filter reading is yielded that reading will then be sent to the Median Filter stack Figure 6 4 Median filter rank 5 Reading 11 Reading Reading 13 10 12 9 11 e 8 Median Median 10 Median 7 Reading Reading 9 Reading e 6 1 2 8 3 5 7 4 6 3 5 2 4 Reading 1 Reading Reading 3
121. 1 Analog output connections Model 2502 only Analog output connector terminals Figure 2 9 shows the terminal configuration of each triax ANALOG OUT connector Output terminals are as follows e Center conductor analog output HI e Inner shield analog output LO floating analog common e Outer shield chassis ground WARNING Analog output low can float up to 100V Use care to avoid a shock hazard when using the analog outputs Figure 2 9 Analog output connector terminals Analog Output HI Analog Output LO Analog Common Chassis Ground ANALOG OUT Triax Connector 2 12 Connections Model 2500 and 2502 User s Manual Non isolated connections Figure 2 10 shows typical non isolated analog output connections Note that analog output HI center conductor is connected to INPUT HI of the measurement instrument while analog output LO inner shield is connected to INPUT LO CAUTION With the ground connect mode enabled analog output LO can float up to 100V above chassis ground depending on the voltage bias source setting Connecting the analog outputs to external equipment that does not allow analog output low to float up to 100V may result in damage to the Model 2502 voltage bias sources when the ground connect mode is enabled Figure 2 10 Non isolated analog output connections Center INPUT Conductor HI Model 2502 Measuring Instrument R D ya KEITHLEY ai ema varar 10 pe a
122. 1 stop bit and no parity Make sure the device you connect to the Model 2500 also uses these settings You can break data transmissions by sending a C decimal 3 or X decimal 18 charac ter string to the instrument or by sending an RS 232 break condition holding the transmit line low for gt 11 bits This clears any pending operation discards any pending output and returns a DCL Baud rate The baud rate is the rate at which the Model 2500 and the programming terminal commu nicate Choose one these available rates e 57600 e 38400 e 19200 e 9600 4800 e 2400 e 1200 e 600 e 300 The factory selected baud rate is 9600 When you choose a baud rate make sure the programming terminal or printer that you are connecting to the Model 2500 can support the baud rate you selected Both the Model 2500 and the other device must be configured for the same baud rate Data bits and parity The RS 232 interface can be configured to send receive data that is 7 or 8 bits long using even odd or no parity No parity is only valid when using 8 data bits 13 18 Remote Operations Models 2500 and 2502 User s Manual Terminator The Model 2500 can be configured to terminate each program message that it transmits to the controller with any of the following combinations of lt CR gt and lt LF gt lt CR gt Carriage return lt CR LF gt Carriage return and line feed lt LF gt Line feed lt LF CR gt Line feed and carriage
123. 10 21 Source delay and measure actions ceeeeeeeeeeeeeeeee 10 21 COUTET S icies EEr ed AEE E 10 22 Output TIS BETS siesati sinai riai EK 10 22 GPIBdefa lis serron ree ore eng ernea En anA ENE REA 10 23 Operation SUMMATY sssssssssseesrsteresreresesrsresrertrrrstrsreresrerese 10 23 Remote trigger commands ee eeeeseeseeeseeseeeeeseeeneees 10 24 Remote trigger example 0 0 eee eeeeseeseeeeeseeeaeereeeneees 10 25 11 Limit Testing Types OF Minit kongsi ennn e e isuecavs cos NER e T 11 2 Pass fail information ee eeeeeeseceeceeeseeseeaeeaeeseeaseaseeees 11 2 Data HOW asocia esaa aa r RETHA 11 3 Limittestfeedg 5 55 caes decayed stastveidi seesaw tistheeedaeiesd teats beets 11 3 Limit 1 and 2 tests Compliance 0 cece eeeeeeeeeeneeeeeeeeee 11 3 Limit 310 GA Sts iiao ea E A N 11 3 Limit test MOdeS 0 ee eee eeeeeseeseeeseeseeeseesseeaeeneeeneeeaes 11 3 BUMS eepo ee eaei dite Ea EE e ada ees 11 4 Operation OVervVieW ou ceeccesecesceeeeceseeeesecesceceaeeeeeseaeessaeeeaeenses 11 4 Gradine MOE srecen rrera enen ea EE hisedvesedescnenis 11 4 Binning control s ssssessesseeseessesssesresessessereresesreressesessse 11 6 Pass condition sscsssosiisiuceini ei a 11 7 Fail condition oe eee eeeeeeeceeeeseeeseeseeeseeseeeaeesaeens 11 7 SOMME MOE 6s ssissseeveetesdacevaccesadiveseecceiuaredascesacdbisecueveeitnvs 11 8 BUTS aeng nee deena marseanes arate 11 8 Binning SYStEMS sonreir e a ER N 11 10 Handler i
124. 10V Ch 1 source range PRINT OUTPUT 25 SOUR1 VOLT 10 Output 10V on channel 1 PRINT OUTPUT 25 SOUR2 VOLT RANG 100 Select 100V Ch 2 source range PRINT OUTPUT 25 SOUR2 VOLT 20 Output 20V on channel 2 PRINT OUTPUT 25 OUTP1 ON Turn on channel 1 output PRINT OUTPUT 25 OUTP2 ON Turn on channel 2 output PRINT OUTPUT 25 SENS1 CURR RANG AUTO ON Ch 1 auto measure range PRINT OUTPUT 25 SENS2 CURR RANG AUTO ON Ch 2 auto measure range PRINT OUTPUT 25 READ Trigger and request Ch 1 reading PRINT ENTER 25 Address 2500 to talk LINE INPUT 2 R Input Ch 1 reading string PRINT Channel 1 reading R Print Ch 1 reading string PRINT OUTPUT 25 CALC2 STAT ON Enable Ch 2 math PRINT OUTPUT 25 INIT Trigger Ch 2 math reading PRINT OUTPUT 25 CALC2 DATA Trigger request Ch 2 math reading PRINT ENTER 25 Address 2500 to talk LINE INPUT 2 R Input Ch 2 reading string PRINT Channel 2 reading R Print Ch 2 reading string PRINT OUTPUT 25 OUTP1 OFF Turn off channel 1 output PRINT OUTPUT 25 O0UTP2 OFF Turn off channel 2 output END Models 2500 and 2502 User s Manual Example Programs H 5 Data store program The program listing below performs data storage as covered in Section 8 and it also dem onstrates how to use SRQs to determine when storage is complete This program sets up the following
125. 16 bit HILIM Use to set the high limit and for the grading mode specify the fail bit pattern 0 to 7 3 bit 0 to 15 4 bit 0 to 65535 16 bit PASS Use to specify the pass bit pattern for the sorting mode software limit tests FEED Use to select the data source for the Limit 3 through Limit 6 tests Spec ify MSR1 or MSR2 channel 1 or channel 2 measurement function RATIO or DELTA e PASS Use this menu item to dictate actions upon a PASS condition DIGIO PATTERN Use this option item to define the digital output bit pattern 0 to 7 3 bit 0 to 15 4 bit 0 to 65535 16 bit For the grading mode it is the pass pattern for the all tests pass condition For the sorting mode it is the pass pattern for Limit 1 or Limit 2 compliance when all other software limit tests are disabled 0 to 7 3 bit 0 to 15 4 bit 0 to 65535 16 bit EOT MODE Use this menu item to control the operation of Digital I O line 4 to act as an EOT end of test or BUSY signal EOT In 3 bit mode automatically output a HI pulse on Digital I O line 4 at end of test In 4 bit mode EOT is not automatically controlled EOT In 3 bit mode automatically output a LO pulse on Digital I O line 4 at end of test In 4 bit mode this option is not available BUSY Set Digital I O line 4 HI while unit is busy With BUSY selected the unit behaves as if it is in 3 bit mode BUSY Set Digital I O line 4 LO while unit is bus
126. 21 External triggering example 10 9 Front panel operation model 10 2 Input specifications 10 8 Layer 10 5 10 20 Link 10 8 Menus 1 28 Operation summary 10 7 10 23 Output 10 6 10 22 Output specifications 10 9 Remote example 10 25 Remote operation model 10 17 Trigger subsystem 17 90 Turn source on or off 17 52 V I 7 5 Voltage measurement 3 10 Voltage bias Capabilities 3 2 Compliance 3 3 Editing values 1 24 Voltage source Commands 3 13 Warm up 3 4 Warranty 1 2 Waveforms Sweep 5 4 Service Form Model No Serial No Date Name and Telephone No ____ _ _ gt S Company List all control settings describe problem and check boxes that apply to problem Q Intermittent Q Analog output follows display Particular range or function bad specify IEEE failure Q Obvious problem on power up U Batteries and fuses are OK Front panel operational U All ranges or functions are bad Q Checked all cables Display or output check one Drifts Unable to zero Unstable Overload Will not read applied input Q Calibration only Q Certificate of calibration required Data required attach any additional sheets as necessary Show a block diagram of your measurement including all instruments connected whether power is turned on or not Also describe signal source Where is the measurement being performed factory controlled laboratory out of doors etc What power line vol
127. 2502 User s Manual Limit Testing 11 13 Figure 11 7 Binning system single element devices Handler OUTPUT INPUT Model 2500 Figure 11 8 Binning system multiple element devices Switching Mainframe Handler Trigger Link Scanner Card OUTPUT INPUT Trigger Dig Link O Model 2500 Trigger layer configured to output trigger pulse after each measurement 11 14 Limit Testing Models 2500 and 2502 User s Manual Multiple element device binning Figure 11 8 shows a basic binning system to test multiple DUTs Note that this system requires a scanner card that is installed in a switching mainframe Scanner card switching is controlled through the Trigger Link End binning control is required for this test system therefore the grading mode must be used Trigger operations for the scanner and Model 2500 must be configured appropriately for this test In general the scanner must be configured to scan three channels and the Model 2500 must be configured to perform a 3 point sweep and output a trigger to the scanner after each measurement See Section 10 for details When the testing process is started Ch 1 of the scanner card closes and DUT 1 is mea sured Two events occur concurrently after the measurement is completed DUT 2 is tested and the Model 2500 sends a trigger pulse to the switching mainframe causing Ch 1 to open and Ch 2 to close Assuming there is no failure a measurement is then performed on DUT
128. 3 Measurement ime sisii 5 3 Sweep WavefotMS sissisotaan desiere piii 5 4 Staircas SWEEPS sicesvicticscis cbse dageevesbvas cass saavedesosetenaceeces 5 4 CUSTOMS WEED tscch cscvcsiesessaicsiicessssecancdseaessenaecensedacscdeanoaiecanes 5 4 SDM cycle during sweeps 0 eee eeeseeseeeeceeeeeeeeeeeeeeeaeenees 5 5 Typical sweep applications 0 ee eeeeseeeeseceeeeseeeeeeeeeeeeaes 5 5 SWEEP dala StOLA GS csc ceeseesascascavesescesnsevenscegesenced i eai 5 5 Bias source operating boundaries 0 0 eee eee eeeeeeeeeteeeereeteeeaees 5 6 Limit lines cae esasectasicsasehegslevapsayissuceiedboedancdshanienaiecacoconsbeeseicess 5 6 Loading effects sic csct aeseeseivceeeiieses send eiiis 5 6 Data TOW serieren seinne a E RR 5 8 Basic teddings srnpsnssniriceirioeiesi ihoa 5 8 Data storage enabled sssorssesscissesirsesrssesessiessscissasarssserervs 5 8 Limit test enabled 0 ccccecsc cesses ease cieeecasesedesestarmcvenestes 5 8 Range Digits Speed and Filters Ran Se aNd ISIS sc yvsr3 ceoriveetssashenteee ceed ieissar reesen 6 2 Measurement fange sccciviscvssscveseedeecascdvs is vahesseaeseeasvetaventartevs 6 2 Available ranges ceeceesceseeceseceseeeeseceseeeeaeceneeeeaeeeaees 6 2 Maximum readings cceeseescceeeeceseeeeeeceseeceeeeseeeeaees 6 2 Manual ranging oo eeeeecceesccesceeeeceeseeeeeeeeseecseeeneeeeaees 6 2 AULO TAN SINE erreso aiaa aii 6 3 Auto range limits 0 eee eseeseeeeeseeeeeeeeeneesseeseeeaes 6 3 A
129. 35 ps 200 0000 pA 2 5 9MV 0 11 400pV 135 ps 2 000000 mA 6 0 90mV 0 30 4mV 21 us 20 00000 mA 2 5 9MV 0 11 400pV 21 us 1 The analog output voltage for each channel is referenced to that channel s floating ground GENERAL Typical Noise Floor Measurement Specification TYPICAL NOISE FLOOR RMS 1 STDEV 100 SAMPLES 0 01NPLC 0 1NPLC 1 0NPLC 10NPLC 2 000000 nA 20 00000 nA 200 0000 nA 2 000000 pA 20 00000 pA 200 0000 pA 2 000000 mA 20 00000 mA SOURCE CAPACITANCE Stable to 10 0nF typical INPUT BIAS CURRENT 50fA max 23 C INPUT VOLTAGE BURDEN 4 0mV max VOLTAGE SOURCE SLEW RATE 3 0ms V typical COMMON MODE VOLTAGE 200VDC COMMON MODE ISOLATION Typically 10 Q in parallel with 150nE OVERRANGE 105 of measurement range MEMORY BUFFER 6000 readings two 3000 point buffers Includes selected measured value s and time stamp PROGRAMMABILITY IEEE 488 SCPI 1995 0 RS 232 five user definable power up states plus factory default and RST DIGITAL INTERFACE Enable Active low input Handler Interface Start of test end of test 3 category bits 5V 300mA supply Digital I O 1 trigger input 4 TTL Relay Drive outputs 33V 500mA diode clamped POWER SUPPLY 100V 120V 220V 240V 10 LINE FREQUENCY 50 60Hz POWER DISSIPATION 60VA WARRANTY 1 year EMC Complies with European Union Directive 89 336 EEC VIBRATION MIL T 28800F Random Class 3 SAFETY Complies with Europea
130. 38 20146 Milano 02 48 39 16 01 Fax 02 48 30 22 74 JAPAN New Pier Takeshiba North Tower 13F 11 1 Kaigan 1 chome Minato ku Tokyo 105 0022 81 3 5733 7555 Fax 81 3 5733 7556 KOREA 2FL URI Building 2 14 Yangjae Dong Seocho Gu Seoul 137 888 82 2 574 7778 Fax 82 2 574 7838 NETHERLANDS Postbus 559 4200 AN Gorinchem 0183 635333 Fax 0183 630821 SWEDEN c o Regus Business Centre Frosundaviks All 15 4tr 169 70 Solna 08 509 04 679 e Fax 08 655 26 10 SWITZERLAND Kriesbachstrasse 4 8600 D bendorf 01 821 94 44 Fax 01 820 30 81 TAIWAN 1FL 85 Po Ai Street Hsinchu Taiwan R O C e 886 3 572 9077 Fax 886 3 572 9031 Copyright 2001 Keithley Instruments Inc Printed in the U S A 4 02
131. 4 Digital output lines 11 10 12 3 Controlling 12 5 Settings 12 6 Digits 6 4 Commands 6 4 Menus 1 29 Programming example 6 5 Remote programming 6 4 Setting display resolution 6 4 Display 1 13 Basic commands 1 15 Controlling 17 40 Disabling 1 14 Format 1 13 1 14 Menus 1 30 Readings 8 3 17 42 Remote programming 1 15 Resolution 6 4 DISPlay subsystem 17 40 Electrical power 7 5 Electromagnetic Interference EMI F 10 Electrostatic interference F 9 EOT BUSY line 12 3 Event detection 10 4 10 19 Event enable registers Programming 17 78 Event registers Reading 17 78 Examples OPC programming example 15 4 SAV RCL programming example 15 5 TRG programming example 15 6 Custom sweep examples 9 5 Custom sweep programming example 9 15 Data store programming example 8 7 External triggering example 10 9 Filter programming example 6 14 Limit test programming example 11 21 Math function programming example 7 8 Measurement programming example 3 13 Output configuration programming example 12 10 Photodiode measurement programmimg example 4 7 Program and read register set programming example 14 19 Programming example 13 20 Programs H 1 Range and digits programming example 6 5 RATIO and DELTA function programming example 7 12 Read error queue programming example 14 21 Rel programming example 7 4 Remote command line frequency programming example 1 12 Remote trigger example 10 25 Set MSS B6 when error oc
132. 488 1 Protocol IntrOGUCtlON sissi668 s csi eis cecestees as as Gees averted G 2 Selecting the 488 1 protocol eee eeeeeeseeseeeseeeeeeeeeeeeeaeesees G 2 Protocol differences iriso ceee e a eE G 3 Message exchange protocol MEP ssssessssseseerreeerrerrse G 3 Using SCPI based programs seesseeeseseesessesersesrrererrsrrsrsres G 3 Bus hold off eee eeceeseeesseceseeceaceeseeeeaeesseeceaeeeeeeseaeeeseeeeaes G 4 Triggeron talk arcis nani G 4 Message available ossesseeseeessesseeessreresrsresrrsessesrssesrrsersrsees G 4 General operation notes s ssesssseesesrerrseeresrrsesresrsesresresrsees G 4 Example Programs TRtOGUCTION MP E E cance sbesedtebweveees H 2 Hardware requirements cecccesceeeeecesceeeeeeeeeeseeceeeeeees H 2 Software requirements 0 eeeeeeseeeeeeeeceeseeeeaeeeteeeeaeeeeees H 2 General program instructions ceeeeesceeeneeeeeeeeeeceneeeeees H 2 Basic measurement program ee eeeeeeseeeeeseeeeeseeeseeeeeeeeesees H 3 Photodiode measurement program cesceesceeeeeeeseeeseeeeneeeenees H 4 Data Store program 00 eee eeeeseesseeeceeeeaececeeaeeesesseeeseseenseesees H 5 Linear sweep program 00 0 eee eeeeseeeeeeecececaecesecseeeseeseeeseesees H 6 Limit t st PLO STAM 6 5 cceccessisseocsccasscesessesdacsesaeavecesesezesenvureesndevens ce H 7 List of Illustrations 1 Figure 1 1 Figure 1 2 Figure 1 3 Figure 1 4 2 Figure 2 1 Figure 2 2 Figure 2 3 Fi
133. 50Hz operation iSYST LFR 50 Fuse replacement A rear panel fuse protects the power line input of the Model 2500 If the line fuse needs to be replaced perform the steps below WARNING Disconnect the line cord and all cables and test leads from the instru ment before changing the line fuse 1 The fuse is located in a holder in the power module adjacent to the AC receptacle Figure 1 2 At the right of the fuse holder is a small tab At this location use a small bladed screwdriver to release the fuse holder 2 Slide the fuse holder out to gain access to the fuse carrier and fuse Model 2500 and 2502 User s Manual Getting Started 1 13 3 Remove the carrier with blown fuse and replace the fuse with the correct type listed in Table 1 1 CAUTION For continued protection against fire or instrument damage replace the fuse only with the type and rating listed If the instrument repeat edly blows fuses locate and correct the cause of the problem before replacing the fuse 4 Install the fuse carrier in the fuse holder then insert the fuse holder in the power module Table 1 1 Line fuses Line voltage Fuse rating Keithley part no 100V 120V 0 630A slow blow 250V 5 x 20mm FU 106 630 220V 240V 0 315A slow blow 250V 5 x 20mm FU 106 315 Display Display format The Model 2500 display is used primarily to display measured readings and voltage bias source values The top line displays measurement
134. 7 Operation Summary OSB Set summary bit indicates that an enabled operation event has occurred Depending on how it is used Bit B6 of the Status Byte Register is either the Request for Service RQS bit or the Master Summary Status MSS bit When using the serial poll sequence of the Model 2500 to obtain the status byte a k a serial poll byte B6 is the RQS bit See Serial polling and SRQ for details on using the serial poll sequence When using the STB command Table 14 3 to read the status byte B6 is the MSS bit Models 2500 and 2502 User s Manual Status Structure 14 9 Service request enable register The generation of a service request is controlled by the service request enable register This register is programmed by you and is used to enable or disable the setting of bit B6 RQS MSS by the status summary message bits BO B2 B3 B4 B5 and B7 of the sta tus byte register As shown in Figure 14 3 the summary bits are logically ANDed amp with the corresponding enable bits of the service request enable register When a set 1 sum mary bit is ANDed with an enabled 1 bit of the enable register the logic 1 output is applied to the input of the OR gate and therefore sets the MSS RQS bit in the status byte register The individual bits of the service request enable register can be set or cleared by using the SRE common command To read the service request enable register use the SRE query comma
135. 7 31 CALCulate8 17 39 Circuit configuration 3 3 Basic 3 3 Photodiode measurement 4 4 Clearing registers and queues 14 4 Command reference 15 3 Command summary 15 2 16 2 Command words 13 10 Commands Average filter 17 57 Bus D 7 Condition register 14 17 Custom sweep 9 14 Data store 8 6 DELTA 7 11 Digits 6 4 Error queue 14 21 Event enable register 14 18 Event register 14 17 Filter 6 13 General bus 13 6 Ground connect 3 8 Limit 11 20 Math functions 7 7 Measurement 3 13 Median filter 17 59 Output configuration 12 9 Photodiode measurement 4 6 Range 6 4 RATIO 7 11 Reading status registers 14 6 Rel 7 3 Reset registers and clear queues 14 4 SCPI signal oriented measurement 16 1 Source delay 3 7 Speed 6 7 Staircase sweep 9 12 Status byte and SRQ 14 10 Status byte and SRQ enable register 14 10 Trigger 10 24 Voltage source 3 13 Common commands 15 1 CLS 14 4 ESE 14 18 ESE 14 18 ESR 14 17 IDN 15 3 OPC 15 3 OPC 15 3 OPT 15 4 RCL 15 4 RST 15 5 SAV 15 4 SRE 14 10 SRE 14 10 STB 14 10 TRG 15 5 TST 15 6 WAI 15 6 Compliance Limit tests 11 3 Voltage bias source 3 3 Condition registers Reading 17 79 Configuration Buffer 17 88 Circuit 3 3 Digital I O port 12 2 Digital output 12 4 Filter 6 11 17 57 IEEE 488 bus D 4 Limit tests 11 16 17 32 List 17 71 Measurement 3 10 4 3 Measurement function 16 2 Output Commands 12 9 Front panel 12 8 Programming example 12 10 Remote 12 9 OUTPUT men
136. 7 46 ELEMents lt item list 0 0 cecescecssscessseeeesseeeeeseees 17 46 SOURCE3 lt NaMe gt ce eeeccessseessseeeesseeessneeessseeeess 17 49 CALC data elements 0 ccscccssssecesseeesseesssseeesssseessees 17 49 CALCulate lt item listo ceeeeesseeeeseeessteeesseeeess 17 49 TRACE data elements cccccessecessseeeesseeessneeeesnneeesees 17 50 TRACE lt item List 200 ceceeesseeesseeeeeseeessseeessseeeess 17 50 Byt ordet oianean 17 51 BORDer lt name gt ssssssossesesiesssessseessrerseressrrssreessree 17 51 Status register format esessessseesesreresrrersrrsrrrrsrrrrrsrnresreee 17 51 SREGister lt name gt sesesseresserrsseesseeesseressersssensseenes 17 51 OUTPu t subsystem sisirsrissssscirisisiiessoviaeiaiiiyse eies 17 52 Turn source on OF off ssesseessessessssesssserserereresssrersssensee 17 52 STATE lt b gt n AIN 17 52 Output enable control sesssceeriesiirssssrcsesorisavirsisssaoissisass 17 53 ENABle STATe lt b gt nnana 17 53 TRIPE c tases ccccatesasasbssotecsevsseveasslugssenssenettessvivetoicas 17 53 SENSe subsystem sericsson iiaia 17 54 Select measurement range ssssesessesrseresssesrssrrsstesessees 17 54 SUPP et n gt a S 17 54 Select AULO TANGLE ivssssesisccsessenessnseisauctsseesvseucoesiecacsconsbeeses 17 55 AUTO lt 0 gt sc ein ae eee eile 17 55 DIM 10 gt sesiis haat ot aas 17 55 ULI lt n eestieest e pE 17 55 Set measurement speed sssesesseeeseeees
137. 9800 seconds Man ually setting the delay disables auto delay Models 2500 and 2502 User s Manual Basic Operation 3 7 Front panel source delay To set the manual source delay from the front panel 1 Press CONFIG then SRC1 or SRC2 2 Select DELAY from the displayed choices then press ENTER 3 Enter the desired DELAY value then press ENTER 4 Press EXIT to return to normal display To set the auto source delay state from the front panel 1 Press CONFIG then SRC1 or SRC2 2 Select AUTO DELAY from the displayed choices then press ENTER 3 Select ENABLE or DISABLE as desired then press ENTER 4 Press EXIT to return to normal display NOTE The delay period is the same for both sources If you change the delay on one channel the delay period on the other source will change to the same value Remote command source delay Use the appropriate command shown in Table 3 4 to program the source delay via remote See Section 17 for details For example the following command sets the source delay to 50ms SOUR1 DEL 0 05 Table 3 4 Source delay commands Command Description SOURce 1 DELay lt Delay gt Set source delay SOURce 1 DELay AUTO lt State gt Enable disable auto delay ON or OFF SOURce2 DELay lt Delay gt Set source delay SOURce2 DELay AUTO lt State gt Enable disable auto delay ON or OFF 3 8 Basic Operation Models 2500 and 2502 User s Manual Ground connect mode The VOLTAGE S
138. AC CAUTION For CONTINUED PROTECTION AGAINST FIRE HAZARD REPLACE FUSE WITH SAME TYPE AND RATING Model 2502 1 10 Getting Started Model 2500 and 2502 User s Manual Power up Line voltage selection The Model 2500 operates from a line voltage in the range of 100V 120V 220V 240V 10 at a frequency of 50 or 60Hz Before plugging in the unit make sure the line voltage setting seen through the small window in the power module Figure 1 2 is correct for the line voltage in your area CAUTION Operating the instrument on an incorrect line voltage may cause dam age possibly voiding the warranty If the voltage setting is not correct change it as outlined below WARNING Disconnect the line cord and all cables and test leads from the instru ment before changing the line voltage setting 1 Pry the small tab that secures the fuse holder to the power module then remove the fuse holder 2 Pull out and rotate the fuse carrier to the correct line voltage setting then install it in the fuse holder Make sure the line voltage shown in the window is correct Also make sure the fuse rating for the expected line voltage is correct See Fuse replacement 3 Reinstall the fuse holder in the power module making sure it is seated fully Line power connection Perform the following steps to connect the Model 2500 to line power and turn it on 1 Before plugging in the power cord make sure the front panel power switch is
139. ATTERN EOT MODE BUSY EOT EOT Configure limit tests Program Digital I O bit patterns for pass fail Select I O number of bits 3 bit size 4 bit size 16 bit size 2499 DIGIO option only Select Digital I O mode Pass if within HI LO limits Stop test after first failure Stop test at end of sweep Fail if outside limits program fail pattern Enable disable auto clear Disable auto clear Enable auto clear program pass fail pattern Control and set fail mode for Limit 1 Limit 2 tests Control Limit 1 or 2 test Disable Limit 1 or 2 test Enable Limit 1 or 2 test Select Limit 1 or 2 fail mode Fail when in compliance program bit pattern Fail when out of compliance program bit pattern Control Limit 3 to Limit 6 tests Enable disable Limit 3 6 tests Disable test Enable test Set low limit Set high limit Set pass Digital I O bit pattern Select input path MSR1 MSR2 RATIO or DELTA Set limit test pass conditions Set pass conditions Digital I O bit pattern Set Digital I O line 4 to act as EOT or BUSY signal Set line 4 LO while unit is busy 3 bit mode Output line 4 HI pulse at end of test 3 bit mode Output line 4 LO pulse at end of test 3 bit mode Getting Started Model 2500 and 2502 User s Manual Table 1 9 Trigger configuration menu Configuration menu item Description CONFIG TRIG Configure triggering CONFIGURE TRIGGER ARM LAYER Configure t
140. Analog Common VOLTAGE SOURCE OUTPUT CHANNEL 1 See Section 2 for detailed connections Models 2500 and 2502 User s Manual Basic Operation 3 11 Front panel measurement procedure Step 1 Select measurement channel and range Select the desired measurement channel by pressing MSR1 channel 1 or MSR2 channel 2 With autoranging turned off use the RANGE A and W keys to manually select the cur rent measurement range for that channel You can also press AUTO to select autoranging Step 2 Select source channel and set source level The source level is the voltage setting of the selected source channel 1 or channel 2 NOTE The Model 2500 must be in the edit mode EDIT annunciator ON to set source values The edit mode is selected by pressing the SRCI or SRC2 key The flash ing digit for the source value in the Srcl or Src2 display field indicates that the Model 2500 is in the edit mode for that channel If no editing operation is per formed within six seconds the edit mode times out and is cancelled The EDIT A 4 and keys also enable the edit mode They choose the last edited source field channel When editing the source value the source is updated immediately allowing you to adjust the source value while the output is on The source value cannot be changed while the Model 2500 is performing a sweep which occurs with the Output ON and after the SWEEP key is pressed Perform the following steps to edit
141. DIGITAL 10 an TRIGGER LINK RS 22 cca sa 100V 20MA FUSE LINE k CAUTION FOR CONTINUED PROTECTION AGAINST FIRE HAZARD REPLACE FUSE WITH SAME TYPE AND RATING j Model 2500 7011 MUX Card 10 10 Triggering Models 2500 and 2502 User s Manual The Trigger Link connections for this test system are shown in Figure 10 6 Trigger Link of the Model 2500 is connected to Trigger Link IN or OUT of the switching mainframe Note that with the default trigger settings of the switching mainframe line 1 is an input and line 2 is an output Figure 10 6 Trigger link connections 7001 or 7002 Switch System WARNING NO INTERNAL OPERATOR SERVICABLE PARTS SERVICE BY QUALIFIED PERSONNEL ONLY a MADE IN USA 4 1 CAUTION FOR CONTINUED PROTECTION AGAINST FIRE HAZARD REPLACE FUS WITH SIME TYPE AND RATING j Trigger Link Trigger Link Cable Trigger 8501 Link WARNIN no INTERNAL OPERATOR SERVICABLE PARTS SERVICE BY QUALIFIED PERSONNEL ONLY am RATINGS MAX QS Q RomA Tas G es ADDRESS z omme eiis DIGITAL 1 0 CHANNEL 1 CHANNEL 2 A owo ce TRIGGER LINK RS 232 CATI LINE RATING 50 60Hz RATINGS MAX cs 100V 20mA FUSE UNE 630 mAT 100 VAG SB 120 VAC A ees VOLTAGE SOURCE VOLTAGE SOURCE SB 240 VAC OUTPUT CHANNEL 1 OUTPUT CHANNEL 2 4 i CAUTION FOR CONTINUED PROTECTION AGAINST FIRE HAZARD REPLACE FUSE WITH SAME TYPE A
142. Dow2 Path to locate message to bottom display TEXT Control user test message Note 2 s DATA lt a gt Define ASCII message a up to 32 characters v DATA Query text message y STATe lt b gt Enable or disable message mode Note 3 v STATe Query text message state v DATA Query data on bottom portion of display s ATTRibutes Query attributes of message characters blinking 1 or not blinking 0 DIGits lt n gt Specify display resolution 4 to 7 6 DIGits Query display resolution Notes 1 RST and SYSTem PRESet has no effect on the display circuitry Pressing LOCAL or cycling power enables ON the display circuit 2 RST and SYSTem PRESet has no effect on a user defined message Pressing LOCAL or cycling power cancels all user defined messages 3 RST and SYSTem PRESet has no effect on the state of the message mode Pressing LOCAL or cycling power disables OFF the message mode Models 2500 and 2502 User s Manual SCPI Command Reference 17 9 Table 17 3 FORMat command summary Default Command Description parameter SCPI FORMat SREGister lt name gt Select data format for reading status event registers ASCii v ASCii HEXadecimal OCTal or BINary SREGister Query format for reading status event registers DATA lt type gt lt length gt Specify data format ASCii REAL 32 or SREal ASCii y DATA Query data format y BORDer lt name gt Specify byte o
143. EAV and B6 MSS of the status byte register set to 1 The last command reads the status byte register using the binary format which directly indicates which bits are set The command to select format FORMat SREGister is documented in Table 14 2 To determine the exact nature of the error you will have to read the error queue Refer to Queues Table 14 4 Status byte programming example Command Description CLS Clear error queue SRE 4 Enable EAV FORM SREG BIN Select binary format XYZ Generate error STB Read status byte register Models 2500 and 2502 User s Manual Status Structure 14 11 Status register sets As shown in Figure 14 1 there are four status register sets in the status structure of the Model 2500 Standard Event Status Operation Event Status Measurement Event Status and Questionable Event Status NOTE See Appendix B for details on which register bits are set by specific error and status conditions Register bit descriptions Standard event register The used bits of the standard event register shown in Figure 14 4 are described as follows Figure 14 4 Standard event status Standard Event Status Register Standard QYE OPC Event Status B2 B1 BO Enable Register stron aie ESB of Status ESE B15 B8 B7 B6 B5 B4 B3 Byte Register Figure 14 3 PON Power On DDE Device Dependent Error URQ User Request QYE Que
144. EE C 3 CALCulate 1 DATA and CALCulate2 DATA C 4 CALCulate3 DATA and CALCulate4 DATA C 4 CALCulate5 DATA and CALCulate6 DATA C 4 CAL Culate7 DATA c cccecscccssscesseesseeeseessseeeeeeseesseeeseees C 4 TRACE DATA eta E E ETEN C 4 CAL Culate8 DATA oo cececccccssecesseeseeeseessseeeeesseessseeeeees C 4 IEEE 488 Bus Overview TritrOG ctl Om seien a a a E EE Eiai D 2 Bus description ssesseiessssesossisseseseessssiesssonsossasoeseusesssreeosisseosssss D 3 Bu NES 5 sieiiscsdcedodseeedediacsedier seach a a PEE E EEEE EE D 5 Data INES assener ee e a e ie iee D 5 Bus management lines oo ee eeeeeeeeseeeeeeseeeeeeaeeeeeaeenes D 5 Handshake lines c eeeseccsessceeesceeeseecsseeeesseeeesseeessneeens D 5 Bus Command sssri esir oerien EEE E ies D 7 Uniline commands ssseseeessssessseeseetereressssessseeseressseessseesee D 8 Universal multiline commands cccssceeesseeesteeessneeees D 8 Addressed multiline commands cccscecessseeessteesereeees D 9 Address commands sissiescrsscircirssn risiini oireisiin D 9 Unaddress commands cccccsscecesseecseneeeeeseeeessneeessneeees D 9 Common commands eessceessseeeeeseeeesseeecsseeessteeessaees D 10 SCPI commands eesscccssseceesseeeesseeessseeeesseeeesseeesseeess D 10 Command codes 4s ssicsiiisssetidctshentnciinnietiieasey D 10 Typical command sequences 0 0 0 ceeeseeeeseceeceseeeeeeseeeee
145. FIG and then ON OFF OUTPUT to display the menu which is also shown in Figure 12 5 AUTO OFF Use to ENABLE or DISABLE auto output off With ENABLE and ALWAYS enabled the OUTPUT will turn off after the measurement phase of every SDM cycle The OUTPUT turns back on at the beginning of the next SDM cycle With ENABLE and AFTER TRIG COUNT the output will remain on until the trigger count expires When disabled the OUTPUT stays on as long as the Model 2500 is operating within the trigger model ARM annunciator on With the OUTPUT enabled pressing the ON OFF key will disable the OUTPUT and disable auto output off ENABLE Use to ENABLE or DISABLE the output enable line of the Digital out put This line is used as an output enable for a test fixture See Output enable page 12 6 Figure 12 5 Output configuration menu tree Auto Off After Trig Count Models 2500 and 2502 User s Manual Digital I O Port Output Enable and Output Configuration 12 9 Remote output configuration Output configuration commands Table 12 2 summarizes output configuration commands These commands include those to enable and disable the output enable line as well as commands to control output off states See Section 17 OUTPut subsystem and SOURce subsystem for more information NOTE Output enable and source clear are global and affect both channels simultaneously Table 12 2 Output configuration commands Comm
146. I O 1 5 6 9 1 Digital Output 1 IEEE 488 2 OFO J s ee OLS st RR 2 Digital Output 2 CHANNEL 1 CHANNEL 2 ai 3 Digital Output 3 ce 4 Digital Output 4 A TRIGGER LINK BOSA EOT EOT B USY B USY cATI LINE RATING 5 Ground C RATINGS MAX 60 VA MAX 100V 20mA Fuse UNE 6 Trigger Input SOT A SRB 120 VAG 7 4 5V 315 mAT 220 VAC REOPEN RROPE SSMS oe some 8 Output Enable 9 Ground Model 2500 Models 2500 and 2502 User s Manual Digital I O Port Output Enable and Output Configuration 12 3 Digital output lines The port provides four output lines and one input line Each open collector output can be set high 5V or low OV Each output line can source up to 2mA or sink up to 500mA When using a category register handler for limit testing output line 4 is typically used for the end of test EOT or BUSY pulse This pulse from the Model 2500 signals the handler to perform the binning operation or indicates a busy condition See Section 11 Config uring limit tests SOT line The input line SOT is used by the handler to start limit testing With the STEST arm event selected the handler must pulse SOT low in order to provide event detection which starts the testing process With the TSTEST arm event selected the handler must pulse SOT high in order to provide event detection and start the testing process With the TLSTEST a
147. I V measurement Ch 21 Ch 2V V I Resistance V I measurement Ch 2V Ch 21 MX B_UNIT MX B measurement PY Electrical power V x I measurement Ch 2V x Ch 21 P gt Optical power measured Idark current Responsivity Models 2500 and 2502 User s Manual Remote math functions Relative Math Ratio and Delta 7 7 Table 7 4 summarizes commands to control the measurement math functions by remote See the CALC1 and CALC2 subsystems in Section 17 for detailed information Table 7 4 Math function commands Command CALCulate 1 DATA CALCulate 1 FORMat lt name gt CALCulate CALCulate CALCulate CALCulate CALCulate CALCulate 1 KMATh MBFactor lt n gt 1 KMATh MMFactor lt n gt 1 KMATh DC lt n gt 1 KMATh RESP lt n gt 1 STATe lt state gt m eB ee eB ee CALCulate2 DATA CALCulate2 FOR Mat lt name gt CALCulate2 K MATh MBFactor lt n gt CALCulate2 KMATh MM Factor lt n gt CALCulate2 KMATh MUNits lt string gt CALCulate2 KMATh DC lt n gt gt CALCulate2 K MATh RESP lt n gt CALCulate2 STATe lt state gt FORMat ELEMents CALCulate lt name gt INIT 1 KMATh MUNits lt string gt Description Request Ch 1 math reading Set Ch 1 math function Name MXB 1 MX B COND 1 I1 V1 POWER 1 I1 V1 RES 1 V1 11 or OP 1 Ch MX B offset n B Ch 1 MX B slope n M Ch 1 MX B units String unit
148. II only with RS 232 EE Standard Event 3 Additional command execution errors 800 Ilegal with storage active EE Standard Event 4 801 Insufficient vector data EE Standard Event 4 802 OUTPUT blocked by output enable EE Standard Event 4 803 Not permitted with OUTPUT off EE Standard Event 4 Models 2500 and 2502 User s Manual Table B 1 continued Status and error messages Status and Error Messages B 7 Number Error message Event Status register Bit 822 Too small for sense range EE Standard Event 4 824 Cannot exceed compliance range EE Standard Event 4 830 Invalid with INF ARM COUNT EE Standard Event 4 900 Internal System Error EE Standard Event 3 RE Error Event SE Status Event SYS System Error Event 2Use following queries to read status registers Standard Event ESR Operation Event STAT OPER Measurement Event STAT MEAS Questionable Event STAT QUES B 8 Status and Error Messages Models 2500 and 2502 User s Manual Eliminating common SCPI errors There are three SCPI errors that occur more often than any others e 113 Undefined header 410 Query INTERRUPTED 420 Query UNTERMINATED The following paragraphs discuss the causes for these errors and methods for avoiding them 113 Undefined header This error indicates that the command you sent to the instrument did not contain a recog nizable command name The most likely causes for t
149. Ii gt SVE saae EREA 15 4 RCL lt NRf gt recall woos eeeeeseceeeeneeeseeeeeeeeeneeeaes 15 4 SAV RCL programming example sses 15 5 IRS TOS ace park accitsans ei seussesesesiesnsoss sotssuiessioatavenssmiedeobecs 15 5 TRG WIS pet ornoen i oaeen ET EE aE 15 5 TRG programming example sseseeeeseeseesererrsrereereee 15 6 TST self test Query ricsina iiare 15 6 WAI wait to continue e sssseseeseseseessessrserssessereressessrsse 15 6 SCPI Signal Oriented Measurement Commands Command SUMMALY ipocsesnsisssto resit sie oerien rei krear ie 16 2 Configuring measurement function ssssessssssessessessrseseseresee 16 2 CONFigure CURRent DC ooo eee eeeeeeesneeeneeeeeeeeneeeees 16 2 Acquiring readings scssi iiaii ai 16 3 FETCH seta sated leeesetexernacdebeta puesta e E R RE 16 3 DATA ELATESU visctess cede cure seteints desta a ete 16 4 READ aeaee ea e EE E E EA AT Saa 16 4 MEASure CURRent DC ececececesseessteeessneeessneees 16 5 SCPI Command Reference Reference tables x cccscvcss set vcesdenseensebadees dobeeagathegeaeseasietvesviceeeeetee 17 2 Calculate subsystems oo eee eeeeseeseceeecseeeseseeeeseseeeeseesneeaees 17 22 CALCulate 1 and CALCulate2 oo cece ecsecesseeseesteeeneees 17 23 Select math function 20 ceeeecessecessteecesteeeesteeessseeeseseees 17 23 FOR Mat lt name gt 0 ccccccscceessseeesseeeseseeeesseeessseeeess 17 23 FORMat lt name gt cccscsscccccsss
150. L Control Fail Pattern a fests End i Yes Store Limit 4 6 Fail Pattern in Memory nd Any No i i n Display Failures gt PASS No 4 e iait Immediate Binning Control Any Failures Yes Yy Y Output First Output Pass Fail Pattern Pattern lt Press LIMIT 11 6 Limit Testing Models 2500 and 2502 User s Manual Binning control The binning control selection determines when the testing process stops and the appropri ate binning operation occurs The results are communicated through the Digital I O port based on limit test data See Binning systems page 11 10 There are two types of bin ning control for the grading mode immediate and end Immediate binning Use immediate binning when you want to stop all testing after the first failure occurs Any pending tests will be cancelled and the DUT will be placed in the bin assigned to that test failure If no failures occur all enabled tests will be performed and the DUT will be placed in the assigned pass bin This process is demonstrated in Figure 11 3 Using a sweep with immediate binning lets you test different devices at different source levels For example assume a 3 point linear sweep at 1V 2V and 3V step levels The first DUT is tested at 1V the second DUT is tested at 2V and the third DUT is tested at 3V End binning End binning allows a sweep to finish before performing the b
151. L H 5 L H H L 6 L H H H 7 H L L L 8 H L L H 9 H L H L 10 H L H H 11 H H L L 12 H H L H 13 H H H L 14 H H H H 15 L Low Gnd H High gt 3V OUT 4 not used in 3 bit mode values 0 to 7 The Model 2500 can be configured to place the defined fail bit pattern on the digital output immediately when a fail condition occurs or it can wait until all testing on a device package is completed operation leaves trigger layer See Composite testing BCONtrol lt name gt page 17 37 for details Models 2500 and 2502 User s Manual SCPI Command Reference 17 35 PASS SOURce3 lt NRf gt NDN CALCulate7 LIMitx PASS SOURce3 lt NRf gt lt NDN gt Set sorting mode pass pattern x 3 6 Parameters lt NRf gt 0 to 7 3 bit Decimal value 0 to 15 4 bit Decimal value lt NDN gt Oto b111 3 bit Binary value Oto b1111 4 bit Binary value 0 to q7 3 bit Octal value 0 to q17 4 bit Octal value 0 to h7 3 bit Hexadecimal value 0 to hF 4 bit Hexadecimal value Query SOURce3 Query programmed source value Description This command is used to define the 3 bit or 4 bit output pattern for the digital I O port when a test Limit 3 6 for the sorting mode passes Note that the output value can be specified in binary octal decimal or hexa decimal format Use the table provided in SOURce3 lt NRf gt lt NDN gt Description page 17 34 to determine the parameter value for the desired dec
152. LAA 50 60Hz C RATINGS MAX 8 60 VA MAX 100V 20mA Tage E 630 mAT 100 VAC A SB 120 VAC 315 mAT 220 VAC VOLTAGE SO SURCE Bu ae SCE VOLTAGE OUTPUT CHANNEL OUTPUT CHANNEL 2 CAUTION F N CONTINUED PROTECTION AGAINST FIRE HAZARD REPLACE FUSE WITH SAME TYPE AND RATING m Model 2500 OUTPUT Connectors Model 2500 and 2502 User s Manual Connections 2 3 Connector terminals Triax INPUT connectors The electrical configuration of each triax INPUT connector is shown in Figure 2 2 Con nector terminals are designated as follows Center conductor of the connector and triax cable input HI This terminal connects to one terminal of the photodiode being tested e Inner ring of the connector and inner cable shield input LO analog common Outer ring of connector shell and outer cable shield chassis ground Figure 2 2 INPUT connector terminals INPUT HI INPUT LO Analog Common Chassis Ground INPUT Triax Connector OUTPUT connectors Each channel has a single OUTPUT banana jack for the voltage bias source Each connec tor is the HI terminal for the corresponding voltage source channel and connects to one terminal of the photodiode being tested NOTE There are no separate external connections for voltage source LO The LO node of each voltage bias source is internally connected to floating analog common See Photodiode connections later in this section for connection deta
153. MOVing or REPeat REPeat TCONtrol Query filter control mode ADVanced Configure the advanced filter v NTOLerance lt NRf gt Set filter noise window in 0 to 105 5 v NTOLerance Query filter noise window setting v STATe lt b gt Enable or disable advanced filter OFF y STATe Query state of advanced filter v MEDian Configure and control the median filter RANK lt NRf gt Specify median filter rank 1 to 5 1 RANK Query median filter rank STATe lt b gt Enable or disable median filter OFF STATe Query state of median filter Models 2500 and 2502 User s Manual SCPI Command Reference 17 13 Table 17 6 SOURce command summary Default Command Description parameter SCPI SOURce 1 Path to control channel 1 source A CLEar Path to clear source IMMediate Turn selected source off AUTO Automatically turn source on off OFF MODE lt name gt Specify auto on off mode ALWays or TCOunt ALWays MODE Query auto on off mode DELay lt n gt Specify settling time in sec 0 to 9999 999 0 001 AUTO lt b gt Enable or disable auto settling time AUTO Query state of auto settling time DELay Query source settling time GCONnect lt b gt Enable or disable ground connect mode OFF GCONnect Query ground connect state VOLTage Path to configure V Source v MODE lt n gt Select V Source mode FIXed SWEep or LIST FIXed v MODE Query V Source mode v RANGe lt
154. Models 2500 and 2502 Photodiode Meter User s Manual ent NET An Interworld Highway LLC Company TEquipm A GREATER MEASURE OF CONFIDENCE WARRANTY Keithley Instruments Inc warrants this product to be free from defects in material and workmanship for a period of year from date of shipment Keithley Instruments Inc warrants the following items for 90 days from the date of shipment probes cables rechargeable batteries diskettes and documentation During the warranty period we will at our option either repair or replace any product that proves to be defective To exercise this warranty write or call your local Keithley representative or contact Keithley headquarters in Cleveland Ohio You will be given prompt assistance and return instructions Send the product transportation prepaid to the indicated service facility Repairs will be made and the product returned transportation prepaid Repaired or replaced products are warranted for the balance of the original warranty period or at least 90 days LIMITATION OF WARRANTY This warranty does not apply to defects resulting from product modification without Keithley s express written consent or misuse of any product or part This warranty also does not apply to fuses software non rechargeable batteries damage from battery leakage or problems arising from normal wear or failure to follow instructions THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES EXPRESSED
155. Models 2500 and 2502 User s Manual Triggering 10 21 Trigger delay A programmable delay is available before the Source Action The Trigger Delay can be manually set from 0 00000 to 999 99990 seconds Note that this delay is separate from the Delay Action of the SDM cycle The Delay Action is discussed next Source delay and measure actions The SDM cycle of the Model 2500 consists of three actions Source Delay and Measure SOURCE action Any programmed output voltage level changes are performed DELAY action This programmable delay is used to allow the source to settle before a measurement is performed It can be manually set from 0 00000 to 9999 99800 seconds or Auto Delay can be enabled With Auto Delay enabled the Model 2500 automatically selects a nominal delay period based on the selected current range MEASURE action During this phase of the SDM cycle the measurement process takes place If the repeat filter is enabled as shown in Figure 10 10 the instrument sam ples the specified number of reading conversions to yield a single filtered reading mea surement If using the moving filter or if the filter is disabled only a single reading conversion will yield a reading Figure 10 10 Measure action MEASURE Action Filter Process Autorange CALC Repeat CONV Reading Conversion 10 22 Triggering Models 2500 and 2502 User s Manual Counters Programmable counters are used to repeat operations wi
156. N OUTPutl ON or OUTPut2 ON the Model 2500 will perform one SDM cycle when the INITiate command is sent After the measurement the Model 2500 returns to the idle state Operation summary The trigger model is designed to offer versatility for the various source measure applica tions Typically it allows you to perform a specified number of measurements at various source levels For example assume you want to perform three measurements each at two different chan nel voltage bias source levels 1V and 2V To do this set the arm count to two arm count 2 the trigger count to three trigger count 3 and use the list sourcing mode with the following defined list sourl list volt 1 1 1 2 2 2 On the first pass through the trigger model three measurements will be performed at the 1V source level On the second pass three measurements will be performed at the 2V source level After the last measurement the Model 2500 returns to the idle state Note that the product of the arm count finite value and trigger count determines the number of measurements that are performed In this example six measurements are performed 2 x 3 For details on the list source mode see Section 17 SOURce 1 and SOURce 2 10 24 Triggering Models 2500 and 2502 User s Manual Remote trigger commands Table 10 1 summarizes remote trigger commands These commands are covered in more detail in Section 17 Trigger subsystem except for T
157. ND RATING Model 2500 For this example the Model 2500 and Switching Mainframe are configured as follows Models 2500 and 2502 User s Manual Triggering 10 11 Model 2500 setup Step 1 Restore bench defaults Press the MENU key select SAVESETUP then press the ENTER key From the SAVESETUP menu select RESET then press ENTER Select BENCH then press ENTER Step 2 Configure channel Press MSR1 or MSR2 key to select the channel to measure then select the desired range Press SRC1 or SRC2 to select the voltage source then set the source to the desired value using the EDIT or numeric keys Step 3 Set up trigger parameters Press the CONFIG key and then the TRIG key to access the CONFIGURE TRIGGER menu Select TRIG LAYER and then press ENTER to access the CONFIGURE TRIG LAYER menu Step 4 Set trigger in event to TRIGGER LINK Select TRIGGER IN then press ENTER Select TRIGGER LINK then press ENTER Step 5 Set trigger input line to 2 Select 2 then press ENTER three times to return to CONFIGURE TRIG LAYER menu Step 6 Set trigger output line to 1 Select TRIGGER OUT then press ENTER Select LINE then press ENTER Select 1 then press ENTER Step 7 Set trigger out events to MEAS ON all others to OFF Select EVENTS then press ENTER Select MEAS OFF and toggle the value to ON using the EDIT A and W keys Press ENTER and then press EXIT to return to the CON FIGURE TRIG LAYER menu Step 8 Set trig
158. NEL SELECT Key sissspscseveaserestoisstensiteiveereeeeiiaianes 1 14 DISPLAY TOGGLE Key ssieiieiiiiovavisiienrrie 1 14 Status and error MESSAGES oo ee cece eseeeseeseeeeeeeeeaeeeeens 1 14 Disabling front panel display 0 eee eee eeeeeseeeeeereeeeeenees 1 14 Front panel control s cc s0cc cccesseiseccseesetaasespadeapeseanaevesaays 1 14 Remote display programming 1 0 00 cece eeeeeseeseeeeeeeeeeeeees 1 15 Front panel TeSts cccccsseisecesiesetsecessasisaigeecnpsboauedpesdaveduazaess 1 15 Default Sct gs 1 18 cccisiesciep eke ani stivsse tds eels ia 1 16 Saving and restoring User Setups 0 eee eeeeeeeseeeeeeeeeeeeee 1 16 SAVING SCIPS ssion eriari aai 1 16 Restoring SCLUPS lt ccciisscsiiasccsescsnesseesscesseneeeieeseaeesoesenya 1 16 Power on configuration 0 0 ce eeeeseeeeeseeeeeereeeeeteeneeeeeaes 1 16 Factory default settings ccsccstcissecascasenssesaetssasecnasseneseeuesearenss 1 16 Remote set ps ci civ cscessececisscesselseeses isai 1 19 Men s eisena ian ctheeeiins en eee est 1 20 Main MENU a iosas cesensecas reoni R weeds tens tenasess 1 20 Rules to navigate Menus ele eee eseeeeeseeeeseeeeeeaeeseeeaees 1 23 Editing voltage bias values 0 tei eeeeeeeeeeeeseeeeeeseeeeeeaees 1 24 Configuration Menus 00 ee eeeeseceeeeeceeeeeeeeeeteeeeeseeenees 1 24 Connections Connection precautions 0 eee eeeeseeseeeeeeseceeeeaeseeeeseeseeeeeeeees 2 2 INPUT and OUTPUT connectors oo eee ee eseeseseeeeenseeees 2 2
159. NOND GNVWWOD QANYWWOD WSYIAINN AISSIAAAYV Or NMTH Ree eee ocoo0o0orrr KY OC0O0OCr Kr re OF NMTONON CO coooocoocooocoOr rer rrr A moy lt uuwnyjop A gt a gt a L ee Ea level D 12 IEEE 488 Bus Overview Models 2500 and 2502 User s Manual Typical command sequences For the various multiline commands a specific bus sequence must take place to properly send the command In particular the correct listen address must be sent to the instrument before it will respond to addressed commands Table D 3 lists a typical bus sequence for sending the addressed multiline commands In this instance the SDC command is being sent to the instrument UNL is generally sent as part of the sequence to ensure that no other active listeners are present Note that ATN is true for both the listen command and the SDC command byte itself Table D 3 Typical addressed multiline command sequence Data bus Step Command ATN state Decimal 1 UNL Set low 63 2 LAG Stays low 57 3 SDC Stays low 4 4 Returns high Assumes primary address 25 Table D 4 gives a typical common command sequence In this instance ATN is true while the instrument is being addressed but it is set high while sending the common command string Table D 4 Typical addressed common command sequence Data bus Step Command ATN state Decimal 1 UNL Set low 63 2 LAG Stays low 57 3 Data Set high 4 Data Stays high 5 Data
160. NRf gt Recall command Returns the Model 2500 to the user saved setup RST Reset command Returns the Model 2500 to the RST default conditions SAV lt NRf gt Save command Saves the present setup as the user saved setup SRE lt NRf gt Service request enable command _ Programs the service request enable register SRE Service request enable query Reads the service request enable register STB Status byte query Reads the status byte register TRG Trigger command Sends a bus trigger to the Model 2500 TST Self test query Performs a checksum test on ROM and returns the result WAI Wait to continue command Wait until all previous commands are executed 1 Status commands are covered in Section 14 Models 2500 and 2502 User s Manual Common Commands 15 3 Command reference IDN identification query Reads identification code The identification code includes the manufacturer model number serial number and firm ware revision levels and is sent in the following format KEITHLEY INSTRUMENTS INC MODEL 2500 xxxxxxx yyyyy zzzzz a d Where xxxxxxx is the serial number yyyyy zzzzz is the firmware revision levels of the digital board ROM and display board ROM including date and time of build a is the analog board revision level d is the digital board revision level OPC operation complete Sets OPC bit OPC operation complete query Places a 1 in output queue When OPC is sent
161. OM2 port Place the Model 2500 into the RS 232 mode from the front panel main menu press MENU select COMMUNICATION select RS 232 When the com munication setting is changed the Model 2500 will reset into that mode RDS SPACES 1500 Set string space CLS Clear screen PRINT Set COM2 baud rate to 9600 PRINT Set no flow control and CR as terminator Configure serial port parameters The following values are the default settings for the Model 2500 ComOpen COM2 9600 N 8 1 ASC CD0 CS0 DS0 LF OP0 RS TB8192 RB8192 OPEN ComOpen FOR RANDOM AS 1 Model 2500 setup commands PRINT 7 RST Reset instrument to default parameters PRINT SENS2 CURR NPLC 1 Set Ch 2 measurement speed to 1 PLC PRINT SOUR2 VOLT 10 Set Ch 2 source to output 10V PRINT SOUR2 CLE AUTO ON Enable Ch 2 source auto output off PRINT TRIG COUN 1 Set to perform one measurement PRINT FORM ELEM CURR2 Set to output Ch 2 readings to PC Initiate a reading and print results PRINT READ Trigger and acquire one reading LINE INPUT 1 RDS RD Current RD PRINT RDS Clean up and quit finish CLOSE 1 Close file CLEAR Interface clear END 14 Status Structure Overview Provides an operational overview of the status structure for the Model 2500 Clearing registers and queues Covers the actions that clear reset registers and queues Progra
162. OURCE output jack for either channel can be left floating or connected to chassis ground by selecting the appropriate ground connect mode When ground con nect is enabled the VOLTAGE SOURCE terminal will be connected to chassis ground as shown in Figure 3 3 This configuration allows you to bias and measure the DUT using a single triax cable as shown When ground connect is disabled Figure 3 4 you must make separate SOURCE OUTPUT connections to the DUT See Section 2 for connection details NOTE The ground connect mode can be individually controlled for each channel Front panel ground connect Enable or disable the ground connect mode as follows 1 Press CONFIG then SRC1 or SRC2 2 Select GND CONNECT then press ENTER 3 Choose ENABLE or DISABLE as required then press ENTER Remote command ground connect Use the appropriate command shown in Table 3 5 to program the ground connect mode via remote See Section 17 for details For example the following command enables ground connect on channel 1 SOUR1 GCON ON Table 3 5 Ground connect commands Command Description SOURce 1 GCONnect lt State gt Enable disable channel 1 ground connect ON or OFF SOURce2 GCONnect lt State gt Enable disable channel 2 ground connect ON or OFF Models 2500 and 2502 User s Manual Basic Operation 3 9 Figure 3 3 Ground connect enabled Triax INPUT HI To Ammeter LO Chassis DUT Ground SOURCE OUTPUT y 9 oO
163. Query center point Configure SWEep source mode Select sweep spacing type LINear or LOGarithmic Query sweep spacing Specify number of sweep points 2 to 3000 Query number of points in sweep Sweep from start to stop UP or from stop to start DOWN Query sweep direction Select source ranging mode BEST AUTO or FIXed Query source ranging mode Configure LIST source mode Create list of V Source values 100 to 100 Add up to 100 V Source values to end of list Query number of source values in list Query V Source list Default parameter LINear 3000 UP BEST No effect SCPI SSSS SSS SSSS Models 2500 and 2502 User s Manual SCPI Command Reference 17 15 Table 17 6 continued SOURce command summary Default Command Description parameter SCPI SOURce2 Path to control channel 2 source v CLEar Path to clear source IMMediate Turn selected source off AUTO Select source auto on off mode source MODE lt name gt Specify auto on off mode ALWays or TCOunt ALWays MODE Query auto on off mode DELay lt n gt Specify settling time in sec 0 to 9999 999 0 001 AUTO lt b gt Enable or disable auto settling time ON AUTO Query state of auto settling time DELay Query source settling time GCONnect lt b gt Enable disable ground connect mode OFF GCONnect Query ground connect state VOLTage Path to configure V Source v MODE lt n gt Select V Source mode
164. RESP lt n gt Set responsivity value in amps watt 1 RESP Query responsivity STATe lt b gt Enable or disable CALC1 math OFF v STATe Query state of math v DATA Path to CALC1 data LATest Return only most recent math result DATA Read result of math v CALCulate2 Subsystem to control CALC2 channel 2 math y FORMat lt name gt Select math format MXB2 COND2 POWER2 MXB2 Jv RES2 or OP2 KMATh Configure MX B parameters MBFactor lt n gt Set B parameter 9 99999e20 to 9 99999e20 0 MBFactor Query B parameter MMFactor lt n gt Set M parameter 9 99999e20 to 9 99999e20 1 MMFactor Query M parameter MUNits lt string gt Set MX B units 1 to 3 character ASCII string MXB MUNits Query M parameter DC lt n gt Set dark current value in amps 0 DC Query dark current RESP lt n gt Set responsivity value in amps watt 1 RESP Query responsivity STATe lt b gt Enable or disable CALC2 math OFF v STATe Query state of math v DATA Path to CALC2 data LATest Return only most recent math result DATA Read result of math v 17 4 SCPI Command Reference Table 17 1 continued CALCulate command summary Models 2500 and 2502 User s Manual Default Command Description parameter SCPI CALCulate3 Subsystem to control CALC3 channel 1 REL y FEED lt name gt Select input path SENSe 1 or CALCulate 1 SENS1 v FEED Query CALC3 feed v NULL Path to confi
165. RG a common command covered in Section 15 Table 10 1 Remote trigger command Command INITiate ABORt ARM COUNt lt n gt ARM SOURce lt name gt ARM TIMer lt n gt ARM DIRection lt name gt ARM ILINe lt NRf gt ARM OLINe lt NRf gt ARM OUTPut lt event list gt TRIGger CLEar TRIGger COUNt lt n gt TRIGger DELay lt n gt TRIGger SOURce lt name gt TRIGger DIRection lt name gt TRIGger ILINe lt NRf gt TRIGger OLINe lt NRf gt TRIGger INPut lt event list gt TRIGger OUTPut lt event list gt TRG Description Take Model 2500 out of idle state Abort operation return to idle Set arm count n count Specify arm control source Name IMMediate TLINk TIMer MANual BUS NSTest PSTest or BSTest Set arm layer timer interval n interval Control arm bypass Name SOURce or ACCeptor Select arm layer input line NRf input line Select arm layer output line NRf output line Select arm layer output events Event list TRIGger or NONE Clear any pending input triggers immediately Set trigger count n count Set trigger delay n delay Specify trigger control source Name IMMediate or TLINkK Control trigger bypass Name SOURce or ACCeptor Select trigger layer input line NRf input line Select trigger layer output line NRf output line Select trigger input layer events Event list SOURce DELay SENSe or NONE
166. RM TIMer DEFault Sets timer to 0 1 sec ARM TIMer MINimum Sets timer to 1 msec ARM TIMer MAXimum Sets timer to 99999 99 sec Numlist Specify one or more numbers for a list Example STATus QUEue ENABle 110 222 Enable errors 110 through 222 13 12 Remote Operations Models 2500 and 2502 User s Manual lt NDN gt Non decimal numeric This parameter is used to send values in the binary octal or hexadecimal format The prefix designates the format type BXxX X B specifies the binary format xx X is the binary number using Os and 1s QXX X Q specifies the octal format Xx X is the octal number values 0 through 7 HXxx x H specifies the hexadecimal format XX X is the hexadecimal number values 0 through 9 and A through F Examples to send the decimal value 36 in the non decimal formats ESE b100100 Binary format ESE q44 Octal format ESE h24 Hexadecimal format Angle brackets lt gt Angle brackets lt gt are used to denote a parameter type Do not include the brackets in the program message For example OUTPut2 lt b gt The lt b gt indicates a Boolean type parameter is required Therefore to enable the selected source you must send the command with the ON or 1 parameter as follows OUTPut2 ON OUTPut2 1 Query commands This type of command requests queries the presently programmed status It is identified by the question mark at the end of the fundamenta
167. Refer to the SYSTem ERRor command Models 2500 and 2502 User s Manual Status and Error Messages B 3 Table B 1 Status and error messages Number Error message Event Status register Bit 440 Query UNTERMINATED after EE Standard Event 2 indefinite response 430 Query DEADLOCKED EE Standard Event 2 420 Query UNTERMINATED EE Standard Event 2 410 Query INTERRUPTED EE Standard Event 2 363 Input buffer overrun EE Standard Event 3 362 Framing error in program message EE Standard Event 3 361 Parity error in program message EE Standard Event 3 360 Communications error EE Standard Event 3 350 Queue overflow SYS Standard Event 3 330 Self test failed EE Standard Event 3 314 Save recall memory lost EE Standard Event 3 315 Configuration memory lost EE Standard Event 3 285 Program syntax error EE Standard Event 4 284 Program currently running EE Standard Event 4 282 Ilegal program name EE Standard Event 4 281 Cannot create program EE Standard Event 4 260 Expression error EE Standard Event 4 241 Hardware missing EE Standard Event 4 230 Data corrupt or stale EE Standard Event 4 225 Out of memory EE Standard Event 4 224 Ilegal parameter value EE Standard Event 4 223 Too much data EE Standard Event 4 222 Parameter data out of range EE Standard Event 4 221 Settings conflict EE Standard Event 4 220 Parameter error EE Standard Event 4 215 Arm deadlock EE Standard Event 4 214 Trigger deadlock EE Standard Event 4 213 Init i
168. SOUR BUS _ Select BUS control source ARM COUN INF Set arm layer count to infinite OUTP1 ON Turn on output INIT Take Model 2500 out of idle TRG Trigger one measurement TST self test query Run self test and read result Use this query command to perform a checksum test on ROM The command places the coded result 0 or 1 in the output queue When the Model 2500 is addressed to talk the coded result is sent from the output queue to the computer A returned value of zero 0 indicates that the test passed and a value of one 1 indicates that the test failed WAI wait to continue Wait until previous commands are completed Effectively the WAI command is a No Op no operation for the Model 2500 and thus does not need to be used Two types of device commands exist Sequential commands A command whose operations are allowed to finish before the next command is executed Overlapped commands A command that allows the execution of subsequent com mands while device operations of the overlapped command are still in progress The WAI command is used to suspend the execution of subsequent commands until the device operations of all previous overlapped commands are finished The WAI command is not needed for sequential commands 16 SCPI Signal Oriented Measurement Commands Command summary Summarizes those commands used to configure and acquire readings Configuring me
169. Select this option if you want the display to disable while performing a sweep The display will disable as soon as sweep is started The display will automatically re enable after the sweep is completed STORE Select this option if you want the display to disable when storing source measure readings in the buffer The display will disable as soon as the buffer is enabled The display will automatically re enable after the storage process is completed Note that with this option the display will disable while performing a sweep Sweep readings are automatically stored in the buffer Remote display programming The display can be controlled by various SCPI DISPlay subsystem commands Table 1 2 summarizes basic commands See Section 17 DISPlay subsystem for more information on using these commands Table 1 2 Basic display commands Command Description DISPplay ENABle lt state gt Enable disable display state ON or OFF DISPlay DIGits lt n gt Set display resolution n 3 to 6 DISPlay MODE lt name gt Select display mode name CALC3 CALC4 CALC5 CALC6 or DUAL Front panel tests Use the TEST DISPLAY TESTS selection of the main MENU to test various aspects of the front panel Test selections include e KEYS Front panel keys are tested Pressing a key displays a message that identifies that key Pressing EXIT twice cancels this test e DISPLAY PATTERNS Use this selection to turn o
170. Stays high 6 Data Stays high Assumes primary address 25 Models 2500 and 2502 User s Manual IEEE 488 Bus Overview D 13 IEEE command groups Command groups supported by the Model 2500 are listed in Table D 5 Common com mands and SCPI commands are not included in this list Table D 5 IEEE command groups HANDSHAKE COMMAND GROUP NDAC NOT DATA ACCEPTED NRFD NOT READY FOR DATA DAV DATA VALID UNIVERSAL COMMAND GROUP ATN ATTENTION DCL DEVICE CLEAR IFC INTERFACE CLEAR REN REMOTE ENABLE SPD SERIAL POLL DISABLE SPE SERIAL POLL ENABLE ADDRESS COMMAND GROUP LISTEN LAG LISTEN ADDRESS GROUP MLA MY LISTEN ADDRESS UNL UNLISTEN TALK TAG TALK ADDRESS GROUP MTA MY TALK ADDRESS UNT UNTALK OTA OTHER TALK ADDRESS ADDRESSED COMMAND GROUP ACG ADDRESSED COMMAND GROUP GTL GO TO LOCAL SDC SELECTIVE DEVICE CLEAR STATUS COMMAND GROUP RQS REQUEST SERVICE SRQ SERIAL POLL REQUEST STB STATUS BYTE EOI END D 14 IEEE 488 Bus Overview Models 2500 and 2502 User s Manual Interface function codes The interface function codes which are part of the IEEE 488 standards define an instru ment s ability to support various interface functions and should not be confused with pro gramming commands found elsewhere in this manual The interface function codes for the Model 2500 are listed in Table D 6 The codes define Model 2500 capabilities as follows Ta
171. T AS 1 Open IEEE 488 output path OPEN IEEE FOR INPUT AS 2 Open IEEE 488 input path PRINT INTERM CRLF Set input terminator PRINT OUTTERM LF Set output terminator PRINT REMOTE 25 CLS PRINT OUTPUT 25 RST Restore GPIB defaults PRINT ao 25 SENS1 CURR RANG AUTO ON Channel 1 auto range PRINT go 25 SOUR1 VOLT TRIG 10 Source 1V when triggered P T E 25 SOUR1 DEL 0 1 0 1s source delay P T p Yoy 25 CALC7 FEED CALC3 Use Ch 1 data for limit tests P T O 25 CALC7 LIM3 UPP 10e 3 Limit 3 upper limit 10mA PRINT 7 S 25 CALC7 LIM3 LOW 4e 3 Limit 3 lower limit 4mA PRINT gO 25 CALC7 LIM4 UPP 8e 3 Limit 4 upper limit 8mA PRINT 7 O 25 CALC7 LIM4 LOW 6e 3 Limit 4 lower limit 6mA T OUTPUT 257 CALC7 CLIM PASS SOUR3 1 Dig I O pass 1 al jA OUTP 25 CALC7 LIM3 UPP SOUR3 2 Dig I O Lim 3 upper fail 2 OUTPUT 25 CALC7 LIM3 LOW SOUR3 2 Dig I O Lim 3 low fail 2 NT OUTP 25 CALC7 LIM4 UPP SOUR3 3 Dig I O Lim 4 upper fail 3 NT OUTPUT 25 CALC7 LIM4 LOW SOUR3 3 Dig I O Lim 4 low fail 3 NT OUTPUT 25 CALC7 CLIM BCON IMM Update Dig I O immediately a cater J G J U D V VVDD 5 J P T OUTPUT 25 CALC7 LIM1 STAT 0 Turn off Limit 1 PRINT OU 25 CALC7 LIM3 STAT 1 Turn on Limit 3 P T mA rO 25 CALC7 LIM4 STAT 1 Turn on Limit 4 PRINT j O
172. TER is pressed Entering an invalid parameter generates an error and the entry is ignored However entering an out of range value too small or too large selects the lower or upper limit respectively The EXIT key is used to back out of the menu structure Any change that is not entered is cancelled when EXIT is pressed 1 24 Getting Started Model 2500 and 2502 User s Manual Editing voltage bias values Use the following keys to edit voltage bias values SRC1 or SRC2 selects the channel 1 Src1 or channel 2 Src2 source display field on the lower line for editing A blinking cursor will appear in the field to be edited If no key is pressed within a few seconds the edit mode will be cancelled automatically EDIT lt q and p places the display cursor on the display digit to be changed EDIT A or w increments or decrements the source value Note that pressing either of these keys will automatically enable the source edit mode RANGE A or y Selects the voltage bias source range 10V or 100V Numeric keys 0 9 allow you to directly enter source values EXIT exits the edit mode without waiting for the time out period The basic procedure for editing source values is outlined below See Section 3 Basic measurement procedure for more details 1 Press the SRC1 or SRC2 key so the blinking cursor is in either the channel 1 Src1 or channel 2 Src2 source display field to be edited If desired use the RANGE A and y ke
173. Tage STARt SOURce2 VOLTage STOP SOURce2 VOLTage STEP SOURce2 VOLTage POINts SOURce2 VOLTage CENTer SOURce2 VOLTage SPAN REN GTL SOURce 1 VOLTage STEP SOURce 1 VOLTage CENTer SOURce 1 VOLTage SPAN SOURce 1 VOLTage STEP SOURce 1 VOLTage CENTer SOURce 1 VOLTage SPAN SOURce 1 VOLTage POINts SOURce 1 VOLTage STEP SOURce 1 VOLTage STARt SOURce 1 VOLTage STOP SOURce 1 VOLTage STEP SOURce 1 VOLTage STARt SOURce 1 VOLTage STOP SOURce 1 VOLTage STEP SENSe2 CURRent RANGe AUTO NPLC for other channel SOURce2 VOLTage RANGe AUTO SOURce2 VOLTage STEP SOURce2 VOLTage CENTer SOURce2 VOLTage SPAN SOURce2 VOLTage STEP SOURce2 VOLTage CENTer SOURce2 VOLTage SPAN SOURce2 VOLTage POINts SOURce2 VOLTage STEP SOURce2 VOLTage STARt SOURce2 VOLTage STOP SOURce2 VOLTage STEP SOURce2 VOLTage STARt SOURce2 VOLTage STOP SOURce2 VOLTage STEP See local and remote transition in Section 13 Differences remote vs local operation Measurement Considerations F 2 Measurement Considerations Models 2500 and 2502 User s Manual NOTE This appendix summarizes considerations to make accurate measurements using the Model 2500 For comprehensive information on these and additional mea surement considerations refer to the Low Level Measurements handbook which is available from Keithley Low current measurements Low current measurements are subj
174. The above command structure has three levels The first level is made up of the root com mand STATus and serves as a path The second level is made up of another path OPERation and a command PRESet The third path is made up of one command for the OPERation path The three commands in this structure can be executed by sending three separate program messages as follows stat oper enab lt NRf gt stat oper enab stat pres In each of the above program messages the path pointer starts at the root command stat and moves down the command levels until the command is executed Multiple command messages You can send multiple command messages in the same program message as long as they are separated by semicolons The following is an example showing two commands in one program message stat oper stat oper enab lt NRf gt When the above is sent the first command word is recognized as the root command stat When the next colon is detected the path pointer moves down to the next command level and executes the command When the path pointer sees the colon after the semicolon it resets back to the root level and starts over Commands that are on the same command level can be executed without having to retype the entire command path Example stat oper enab lt NRf gt enab After the first command enab is executed the path pointer is at the third command level in the structure Since enab is also on the th
175. UT Photodiode Outer Shield Chassis Ground Laser wy B rr rr rr rrr rrr j Diode Chassis Ground Channel 2 Forward INPUT Photodiode Outer Shield Analog Common INPUT HI i I I I I I I I I I Channel 2 I I I I I I I I I I Model 2500 Model 2500 and 2502 User s Manual Connections 2 9 Alternate connecting methods Although the Model 2500 is designed primarily to bias and measure photodiodes in a laser diode test system it can also be used for stand alone current measurements or as a stand alone voltage source with any suitable device Current measurement connections Figure 2 7 shows typical connections using channel to measure the DUT current Note that the INPUT HI terminal center conductor is connected to DUT HI while the INPUT LO terminal analog common is connected to DUT LO Figure 2 7 Stand alone current measurement connections INPUT HI Center Conductor Channel 1 INPUT WARNING NO INTERNAL OPERATOR SERVICABLE PARTS SERVICE BY QUALIFIED PERSONNEL ONLY N RATINGS MAX 100V 20m O KEITHLEY a MADE IN CHANGE ee Be ness mone usa OLN HBSS Pane NESE l l I Triax Cable INPUT DIGITAL 0 C CHANNEL 1 CHANNEL 2 m l 7 ewe i aL TRIGGER LINK RS 232 l T CATI LINE RATING M INPUT LO recs gue I Inner Shield Co ath NE Sa VOLTAGE SOURCE VOLTAGE SOURCE A Tag ave Optional Noise Shield OUTPUT CHANNEL 1 OUTPUT CHANNEL 2 Ht lees
176. WARNING Maximum common mode voltage voltage between INPUT analog common and chassis ground is 200V Exceeding this value may result in a shock hazard When making connections do not leave any exposed connections Be sure that all external circuits are properly insulated CAUTION Maximum INPUT and OUTPUT connector rating is 100V 20mA Exceeding these values may result in instrument damage INPUT and OUTPUT connectors Figure 2 1 shows the location of the INPUT and OUTPUT connectors on the rear panel Each of these connectors has the following function INPUT CHANNEL 1 A 3 lug triax connector for direct current input from the photo diode or other DUT to channel 1 INPUT CHANNEL 2 A 3 lug triax connector for direct current input from the photo diode or other DUT to channel 2 e VOLTAGE SOURCE CHANNEL 1 OUTPUT A safety banana jack used to apply the channel HI voltage bias source signal to the photodiode or other DUT e VOLTAGE SOURCE CHANNEL 2 OUTPUT A safety banana jack used to apply the channel 2 HI voltage bias source signal to the photodiode or other DUT Figure 2 1 Model 2500 rear panel showing INPUT and OUTPUT connectors INPUT Connectors VARNING No NTERNAL OPERATOR SERVICABLE PARTS SERVICE BY QUALIFIED PERSONNEL ONLY KEITHLEY eed MADE IN gt CHANGE IEEE ADDRESS USA wa FRONT PANEL MENU INPUT DIGITAL 1 0 A sume INPUT CHANNEL 1 TRIGGER LINK RS 232 CATI LINE RATING
177. a elements TRACe lt item list gt FORMat ELEMents TRAce lt item list gt Specify data elements for buffer Parameters lt item list gt CURRent 1 Includes channel 1 current reading TIME Query CURRent2 Includes channel 2 current reading CALCulatel Includes CALC1 element CALCulate2 Includes CALC2 element CALCulate3 Includes CALC3 element CALCulate4 Includes CALC4 element CALCulate5 Includes CALCS5 element CALCulate6 Includes CALC6 element CALCulate7 Includes CALC7 element TIME Includes timestamp STATus Includes status information ALL Includes all data elements DEFault Includes only CURR1 and CURR2 NOTE Each item in the list must be separated by a comma i e CURRI CALC2 TRACe Query elements in data string This command is used to specify the elements to be recalled from the Description data store buffer see TRACe subsystem page 17 87 You can specify from one to all 11 elements or use ALL to specify all elements Each element in the list must be separated by a comma These elements are explained as follows NOTE An overflow reading reads as 9 9E37 CURRent 1 This element provides the channel current reading If no reading is available the NAN not a number value of 9 91e37 is used CURRent2 This element provides the channel 2 current reading If no current reading is available the NAN not a number value of 9 91e37 is used CALCulate1 CALCulate7 These elements include the
178. a trigger pulse Since the instrument is programmed to scan 10 channels operation loops back to point B where it waits for an input trigger E and F With the Model 2500 operation at point A the output trigger pulse from the Model 7001 2 triggers a measurement of DUT 1 point E After the measurement is complete the Model 2500 outputs a trigger pulse and then loops back to point A where it waits for another input trigger 10 14 Triggering Models 2500 and 2502 User s Manual The trigger applied to the Model 7001 2 from the Model 2500 closes the next channel in the scan which then triggers the Model 2500 to measure that DUT This process continues until all 10 channels are scanned and measured Configuring triggering Triggering is configured from the CONFIGURE TRIGGER menu and is structured as follows NOTE See Trigger model front panel operation page 10 2 for details on the fol lowing programmable aspects of triggering CONFIGURE TRIGGER menu Press CONFIG and then TRIG to display the menu shown below and in Figure 10 8 Note that bullets indicate the primary items of the menu while dashes and slashes indi cate options See Section 1 Rules to navigate menus to check and or change trigger options e ARM LAYER Use this menu item to configure the arm layer of the trigger model ARM IN Use to select the detection event for the arm layer o IMMEDIATE Ev
179. able delay Description This command is used to manually set a delay settling time for the source After the programmed source is turned on this delay occurs to allow the source level to settle before a measurement is taken Note that this delay is the same for both channels Do not confuse this source delay with the trigger delay The source delay is part of the device action SDM cycle while the trigger delay occurs before the device action See Section 10 Trigger model front panel operation for more information Auto delay can instead be used to automatically set the source delay See the next command AUTO lt b gt SOURce 1 DELay AUTO lt b gt Enable disable auto source delay SOURce2 DELay AUTO lt b gt Enable disable auto source delay Parameters lt b gt 0 or OFF Disable auto delay 1 or ON Enable auto delay Query AUTO Query state of auto delay Description These commands are used to enable or disable auto delay When enabled the instrument will automatically select a delay period RST and SYST PRES default is OFF Note that this delay is the same for both channels 17 66 SCPI Command Reference Models 2500 and 2502 User s Manual Select ground connect mode GCONnect lt b gt SOURce 1 GCONnect lt b gt Enable disable source 1 ground connect SOURce2 GCONnect lt b gt Enable disable source 2 ground connect Query GCONnect Query state of ground connect Description These commands are used to enable or
180. abled Amplitude 0 0 Model 2500 and 2502 User s Manual Table 1 3 continued Factory default settings Getting Started 1 19 Setting BENCH default GPIB default Triggering Arm layer Event Immediate Immediate Count 1 1 Timer 0 1 0 1 Input line 1 1 Output trigger Line 2 Off Line 2 Off Trigger layer Event Immediate Immediate Count 1 1 Timer 0 1 0 1 Input line 1 1 Output triggers Line 2 All off Line 2 All off Delay 0 0 sec 0 0 sec Voltage bias sources Amplitude OV OV Range 10V 10V Mode Fixed Fixed Remote setups You can also save and recall setups via remote using the following SCPI commands e Save and recall user setups using SAV and RCL Section 15 Restore GPIB defaults using RST Section 15 Restore bench defaults using SYSTem PRESet Section 17 e Save the power on configuration using SYSTem POSetup Section 17 1 20 Getting Started Menus Model 2500 and 2502 User s Manual The following paragraphs discuss the main menu configuration menus and rules to navi gate menus Main menu Use the MENU key to access the Main Menu to select configure and or perform various instrument operations These include default setup conditions communications GPIB or RS 232 calibration front panel tests digital output states auto zero timestamp and numeric display format The Main Menu structure is summarized in Table 1 4 Use the Rules to navigate
181. abled auto ranging could be very slow See Median filter page 6 8 for details Auto range limits Upper and lower auto range limits are included to support the auto range change mode The upper limit must be greater than or equal to the lower limit and the lower limit must be less than or equal to the upper limit If the lower limit is equal to the upper limit auto ranging is effectively disabled When auto ranging is disabled you can manually change to any range below the lower limit or any range above the upper limit Setting auto range limits To set the upper or lower auto range limit press CONFIG A or CONFIG Y respectively then use the manual RANGE keys to set the limit at the ULIMIT or LLIMIT prompt Auto range speed limitations With auto range enabled a minimum of two extra readings are required to move up range and one additional reading is needed to move down range No additional readings are required if no range change is required Auto range operation with range limits The auto range limits are only evaluated when an auto range condition exists and forces the limits to be re evaluated Only the upper limit is evaluated if the unit needs to up range likewise only the lower limit is evaluated if the unit needs to down range Both limits are not checked simultaneously for any given auto range evaluation For example if the unit is on a higher manual range that is above the programmed upper range limit and auto ra
182. actor Query M slope value for MX B Description These commands program the M slope value for the MX B math function see FORMat lt name gt above Use CALC1 for channel 1 or CALC2 for channel 2 MUNits lt name gt CALCulate 1 KMATh MUNits lt name gt Specify units for channel 1 MX B CALCulate2 KMATh MUNits lt name gt Specify units for channel 2 MX B Parameters lt name gt Up to three ASCII characters enclosed in single or double Query Description quotes MUNits Query units for MX B These commands are used to specify the units suffix name for the MX B math function for channel 1 CALC1 and channel 2 CALC2 Use up to three ASCII characters for the units suffix name consisting of upper or lower case characters no numbers spaces dashes etc Models 2500 and 2502 User s Manual Set optical power parameters DC lt n gt CALCulate 1 KMATh DC lt n gt CALCulate2 KMATh DC lt n gt Parameters lt n gt 9 999999e20 to SCPI Command Reference 17 25 Set channel 1 dark current value Set channel 2 dark current value 9 999999e20 Specify dark current in amps DEFault 0 0 MINimum 9 999999e20 MAXimum 9 999999e20 Query DC Query dark current value DC DEFault Query RST default dark current DC MINimum Query minimum allowable dark current DC MAXimum Query maximum allowable dark current Description These commands set the dark current parameter for optical power mea surements as p
183. adings with RATIO Pass Fail DELTA pa Let Store with Pass Fail C Limit tests and data store enabled 5 10 Measurement Concepts Models 2500 and 2502 User s Manual Figure 5 7 CALC block data flow READ FETC DATA CALC1 DATA CALC3 DATA l l l l l Bypass if CALCI disabled Sample Buffer ids CAL CALC7 CALC6 Data Store m CHANNEL 2 _____ RAT LIMITS DELTA Buffer l l Poy C5 10 el SENS2 Sample Buffer y y 4 Bypass if CALC5 DATA CALC7 DATA CALC6 DATA CALC8 DATA l CALC2 l l disabled TRAC DATA READ CALC2 DATA CALC4 DATA FETC DATA 6 Range Digits Speed and Filters Range and digits Discusses available ranges maximum readings ranging limita tions manual and autoranging and display resolution e Speed Discusses speed settings which are used to control the integration period of the A D converter Filters Provides information on the filtering process that can be used to reduce reading noise 6 2 Range Digits Speed and Filters Models 2500 and 2502 User s Manual Range and digits Measurement range The selected measurement range affects the accuracy of the measurements as well as the maximum signal that can be measured Available ranges Table 6 1 lists the available current measurement ranges resolution values and maximum readings for each Model 2500 channel NOTE The
184. ages 17 84 SCPI Command Reference Models 2500 and 2502 User s Manual Simulate key presses KEY SYSTem KEY lt NRf gt Simulate key press Parameters lt NRf gt 1 RANGE A key 2 EDIT w key 3 EDIT lt key 4 MENU key 5 DELTA key 6 FILTER key 7 SPEED key 8 CHANNEL SELECT key 9 AUTO key 10 EDIT key 11 EXIT key 12 SRC1 key 13 LIMITS key 14 STORE key 15 MSR key 16 DISPLAY TOGGLE key 17 RANGE y key 18 ENTER key 19 SRC2 key 20 TRIG key 21 RECALL key 22 MSR2 key 23 LOCAL key 24 ON OFF key 2500 26 EDIT A key 27 SWEEP key 28 CONFIG key 29 RATIO 30 REL key 31 DIGITS key Query KEY Query last pressed key Description This command is used to simulate front panel key presses For example to select the channel 1 measurement function MSR1 you can send the following command to simulate pressing the MSR1 key isyst key 15 The parameter listing above provides the key press code in numeric order Models 2500 and 2502 User s Manual SCPI Command Reference 17 85 The queue for the KEY query command can only hold one key press When KEY is sent over the bus and the Model 2500 is addressed to talk the key press code number for the last key pressed either physi cally or with KEY is sent to the computer The key press code number for the last key pressed either physically or with key is sent to the computer Read version of SCPI standard VERSion SYSTem VERSion Desc
185. aiting in trigger layer SE Operation Event 5 306 Waiting in arm layer SE Operation Event 6 310 Entering idle layer SE Operation Event 10 Questionable events 408 Questionable Calibration SE Questionable Event 8 414 Command Warning SE Questionable Event 14 B 6 Status and Error Messages Models 2500 and 2502 User s Manual Table B 1 continued Status and error messages Number Error message Event Status register Bit Calibration errors 500 Date of calibration not set EE Standard Event 3 501 Next date of calibration not set EE Standard Event 3 502 Calibration data invalid EE Standard Event 3 503 DAC calibration overflow EE Standard Event 3 504 DAC calibration underflow EE Standard Event 3 505 Source offset data invalid EE Standard Event 3 506 Source gain data invalid EE Standard Event 3 507 Measurement offset data invalid EE Standard Event 3 508 Measurement gain data invalid EE Standard Event 3 509 Not permitted with cal locked EE Standard Event 3 510 Not permitted with cal unlocked EE Standard Event 3 Lost data errors 601 Reading buffer data lost EE Standard Event 3 602 GPIB address lost EE Standard Event 3 603 Power on state lost EE Standard Event 3 604 DC calibration data lost EE Standard Event 3 605 Calibration dates lost EE Standard Event 3 606 GPIB communication language lost EE Standard Event 3 Communication errors 700 Invalid system communication EE Standard Event 3 701 ASC
186. allow sufficient light penetration to affect the test results Areas to check for light leaks include doors and door hinges tubing entry points and connectors or connector panels Models 2500 and 2502 User s Manual Measurement Considerations F 9 Electrostatic interference Electrostatic interference occurs when an electrically charged object is brought near an uncharged object thus inducing a charge on the previously uncharged object Usually effects of such electrostatic action are not noticeable because low impedance levels allow the induced charge to dissipate quickly However the high impedance levels of many mea surements do not allow these charges to decay rapidly and erroneous or unstable readings may result These erroneous or unstable readings may be caused in the following ways DC electrostatic field can cause undetected errors or noise in the reading e AC electrostatic fields can cause errors by driving the input preamplifier into satura tion or through rectification that produces DC errors Electrostatic interference is first recognizable when hand or body movements near the experiment cause fluctuations in the reading Means of minimizing electrostatic interfer ence include 1 Shielding Possibilities include a shielded room a shielded booth shielding the sensi tive circuit and using shielded cable The shield should always be connected to a solid connector that is connected to signal low If circuit low is f
187. ame gt ALWays Output on before reading off after reading TCOunt Output on trigger layer entry off on trigger layer exit Query MODE Query state of auto on off Description These commands are used to control the source auto on off output mode for the two sources With ALWays selected the source output will turn on before each reading and then off after each reading With TCOunt selected the source will turn on when entering the trigger layer and off when exiting the trigger layer See Section 10 for details on the trigger model Models 2500 and 2502 User s Manual Select sourcing mode MODE lt name gt SOURce 1 VOLTage MODE lt name gt SOURce2 VOLTage MODE lt name gt SCPI Command Reference 17 61 Select sourcing mode for source 1 Select sourcing mode for source 2 Parameters lt name gt FIXed Select fixed sourcing mode LIST Select list sourcing mode SWEep Select sweep sourcing mode Query MODE Query DC sourcing mode Description These commands are used to select the sourcing mode for the specified source The three modes are explained as follows FIXed In this sourcing mode the specified source will output a fixed level Use the RANGe and AMPLitude commands to specify the fixed source level See Select range page 17 61 and Set amplitude for fixed source page 17 63 LIST In this mode the source will output levels that are specified in a list See Configure list page 17 71 for
188. and Description OUTPut 1 ENABle lt state gt Enable disable output enable state ON or OFF OUTPut 1 ENABle TRIPped Query output enable tripped state 1 tripped SOURce 1 CLEar Turn output source off when in idle state SOURce 1 CLEar AUTO lt state gt Enable disable auto output off State ON output off after measurement or OFF output stays on SOURce 1 CLEar AUTO MODE lt name gt Auto clear mode Name ALWays every reading default or TCOunt ON when trigger layer entered OFF when leaving trigger layer SOURce2 CLEar Turn output source off when in idle state SOURce2 CLEar AUTO lt state gt Enable disable auto output off State ON output off after measurement or OFF output stays on SOURce2 CLEar AUTO MODE lt name gt Auto clear mode Name ALWays every reading default or TCOunt ON when trigger layer entered OFF when leaving trigger layer 12 10 Digital I O Port Output Enable and Output Configuration Models 2500 and 2502 User s Manual Output configuration programming example Table 12 3 lists the command sequence for output configuration These commands set up the Model 2500 as follows Output enable on e Auto off mode on NOTE Connect pins 8 and 9 of the digital I O port together to simulate a closed output enable switch Otherwise the unit will not turn on its output when the measure ment is made Table 12 3 Output configuration programming example
189. arameters Source and measure channel channel 2 Source mode sweep Start voltage 1V Stop voltage 10V Step voltage 1V Source delay 100ms Table 9 3 lists the command sequence for the photodiode programming example See Section 2 Connections for details on how to connect the photodiode to the channel 2 INPUT and OUTPUT connectors NOTE See Appendix H for a complete program listing Table 9 3 Staircase sweep programming example photodiode test Command Description RST Restore GPIB default conditions FORM ELEM CURR2 Select channel 2 measurement data SENS2 CURR RANG AUTO ON Enable channel 2 measure auto range SOUR2 VOLT START 1 1V channel 2 start voltage SOUR2 VOLT STOP 10 10V channel 2 stop voltage SOUR2 VOLT STEP 1 1V channel 2 step voltage SOUR2 VOLT MODE SWE Select channel 2 sweep mode SOUR2 SWE RANG AUTO Channel 2 auto source ranging SOUR2 SWE SPAC LIN Select channel 2 linear staircase sweep TRIG COUN 10 Trigger count sweep points SOUR2 DEL 0 1 100ms source delay OUTP2 ON Turn on channel 2 source output READ Trigger sweep request data OUTP2 OFF Turn off channel 2 source output 1 This command should normally be sent after START STOP and STEP to avoid delays caused by rebuilding sweep when each command is sent 2 For single sweep trigger count should equal number of points in sweep Points Stop Start Step 1 You can use SOUR SWE POIN query to read
190. art Step 1 Points Span Step 1 An alternate way to set the source and measure points in a linear sweep is to simply specify the number of source and measure points in the sweep using the POINts command Note that the STEP and POINts commands are coupled Changing the step size also changes the number of source and measure points Con versely changing the number of source and measure points changes the step size 17 70 SCPI Command Reference Models 2500 and 2502 User s Manual POINts lt n gt SOURce 1 SWEep POINts lt n gt Set number of points for source 1 SOURce2 SWEep POINts lt n gt Set number of points for source 2 Parameters lt n gt 1 to 3000 Specify number of source measure points MINimum 1 MAXimum 3000 DEFault 3000 Query POINts Query number of sweep points POINts DEFault Query RST default number of sweep points POINts MINimum Query lowest allowable number of sweep points POINts MAXimum Query highest allowable number of sweep points Description The POINts command specifies the total number of source and measure points in a sweep For a linear sweep the source and measure points are equally spaced stepped between the start level and the stop level For a log sweep the source and measure points are equally spaced on a loga rithmic scale Note that the start and stop levels are source and measure points Step size for a linear sweep can be calculated as follows Step Size Stop Star
191. art of the formula Optical power Imeasured ldark current Responsivity RESP lt n gt CALCulate 1 KMATh RESP lt n gt CALCulate2 KMATh RESP lt n gt Parameters lt n gt 9 999999e20 9 999999e20 DEFault MINimum MAXimum Query RESP RESP DEFault RESP MINimum RESP MAXimum Set channel 1 responsivity value Set channel 2 responsivity value Specify responsivity in amps watt zero excluded 1 0 9 999999e20 9 999999e20 Query responsivity value Query RST default responsivity Query minimum allowable responsivity Query maximum allowable responsivity Description These commands set the responsivity value as part of the formula Optical power Imeasured ldark current Responsivity NOTE Zero is not an acceptable value for responsivity as this value would cause an infinite result 17 26 SCPI Command Reference Models 2500 and 2502 User s Manual Enable and read math function result STATe lt b gt CALCulate 1 STATe lt b gt Control channel 1 math function CALCulate2 STATe lt b gt Control channel 2 math function Parameters lt b gt 0 or OFF Disable CALC1 or CALC2 math function 1 or ON Enable CALC1 or CALC2 math function Query STATe Query state on or off of CALC1 or CALC2 Description These commands are used to enable or disable the CALC1 and CALC2 math function for channels and 2 respectively When enabled the selected math function calculation will be performed when th
192. asurement function Provides detailed information on commands to configure the measurement function Acquiring readings Describes commands to acquire post processed readings both trigger and acquire readings and to perform a single measurement 16 2 SCPI Signal Oriented Measurement Commands Models 2500 and 2502 User s Manual Command summary The signal oriented measurement commands are used to acquire readings You can use these high level instructions to control the measurement process These commands are summarized in Table 16 1 Table 16 1 Signal oriented measurement command summary Command Description CONFigure FETCh READ CONFigure CURRent DC Configures Model 2500 for current measurements Out MEASure CURRent DC One shot measurement mode Performs a CONFigure put turns on Returns active function amps Requests latest readings Performs an INITiate and a FETCh and a READ Configuring measurement function CONFigure CURRent DC Query CONFigure Returns active function current Description This command configures the instrument to measure DC current The READ command is then typically used to trigger a specified number of measurements See READ page 16 4 When this command is sent the Model 2500 will be configured as follows Select current function All controls related to the current function are defaulted to the RST val
193. ata The READ buffer is a separate 3000 reading buffer that can only be accessed over the bus using the READ command or INIT FETCh You can store and access data from these two buffers separately as outlined below Using TRACe commands to store data Use TRAC POIN lt n gt and TRIG COUN lt n gt followed by TRAC FEED CONT NEXT to store data n number of readings 3000 maximum Use FORM ELEM TRAC CURRI1 CURR2 to select the channel Turn on the output with OUTP1 ON or OUTP2 ON and then send INIT to take the unit out of idle and store readings After data is stored send TRAC DATA to access it See Table 8 1 in this section for a summary of these commands and Section 17 TRACe subsystem for more details 8 6 Data Store Models 2500 and 2502 User s Manual Using READ to store data Use TRIG COUN lt n gt to set the number of readings to be stored n number of read ings 3000 maximum Use the FORM ELEM CURR CURR to select the channel Turn on the output with OUTP1 ON or OUTP2 ON and then send the READ command to trigger and access readings Once you access these readings you will still be able to access previously stored TRACe buffer readings using TRAC DATA See Section 10 and Section 17 Trigger subsystem for triggering details and Section 16 for information on the READ command Remote command data store Data store commands Table 8 1 summarizes commands associated with data store
194. ata format for the returned value Table 14 2 For non decimal formats one of the following headers will accompany the returned value to indicate which format is selected B Header for binary values H Header for hexadecimal values Q Header for octal values Table 14 2 Data format commands for reading status registers Command Description Default FOR Mat SREGister lt name gt Select data format for reading status registers ASCii lt name gt ASCii Decimal format HEXadecimal Hexadecimal format OCTal BINary Octal format Binary format Models 2500 and 2502 User s Manual Status Structure 14 7 Status byte and service request SRQ Service request is controlled by two 8 bit registers the status byte register and the service request enable register Figure 14 3 shows the structure of these registers Figure 14 3 Status byte and service request SRQ Status Summary Message lt Read by Serial Poll ESB MAVIQSB EAV MSBI Status Byte B5 B4 B3 B2 B1 B0 Register lt Read by STB Service Request Generation STB Serial Poll Service OSB ESB MAV QSB EAV MSB Request B7 B6 B5 B4 B3 B2 B1 B0 Enable Register OSB Operation Summary Bit MSS Master Summary Status RQS Request for Service ESB Event Summary Bit MAV Message Available QSB Questionable Summary Bit EAV Er
195. attern will be output When SORTING is selected the Digital T O bit pattern can also be set 0 to 7 3 bit 0 to 15 4 bit AUTO CLEAR Use this menu item to ENABLE or DISABLE auto clear for the digital output After enabling auto clear you will be prompted to set the pass fail pattern pulse width delay 0 to 60 00000sec You will then be prompted to set the digital output clear pattern 0 to 7 3 bit 0 to 15 4 bit 0 to 65535 16 bit NOTE 16 bit digital output patterns are available only with the 2499 DIGIO option Models 2500 and 2502 User s Manual Limit Testing 11 17 H W LIMITS Use this menu item to control and set the fail mode for the Limit 1 channel 1 and Limit 2 channel 2 compliance tests CONTROL Use to ENABLE or DISABLE the test FAIL MODE Use to select the fail mode for Limit 1 and Limit 2 tests With IN selected the test will fail when the Model 2500 is in compliance With OUT selected the test will fail when not in compliance Also use to specify the digital output bit pattern for Limit 1 and Limit 2 IN or OUT test failure 0 to 7 3 bit 0 to 15 4 bit 0 to 65535 16 bit e S W LIMITS Use this menu item to control set limits for and define output bit patterns for Limit 3 to Limit 6 tests CONTROL Use to ENABLE or DISABLE the test LOLIM Use to set the low limit and for the grading mode specify the fail bit pattern 0 to 7 3 bit 0 to 15 4 bit 0 to 65535
196. bit indicates that the Model 2500 has been turned off and turned back on since the last time this register has been read Models 2500 and 2502 User s Manual Status Structure 14 13 Operation event register The used bits of the operation event register Figure 14 5 are described as follows Figure 14 5 Bit BO Calibrating Cal Set bit indicates that the Model 2500 is calibrating Bits B1 through B4 Not used Bit B5 Waiting for Trigger Event Trig Set bit indicates that the Model 2500 is in the trigger layer waiting for a TLINK trigger event to occur Bit B6 Waiting for Arm Event Arm Set bit indicates that the Model 2500 is in the arm layer waiting for an arm event to occur Bits B7 through B9 Not used Bit B10 Idle State Idle Set bit indicates the Model 2500 is in the idle state Bits B11 through B15 Not used Operation event status Stat oper cond Stat oper 2 To Operation Summary Bit OSB of Status Byte Register Figure 14 3 stat oper enab lt NRf gt stat oper enab e _ am tig swe cal l e eton B15 B11 B10 B9 B7 B6 B5 B4 B3 B2 B1 BO Register Idle Arm Trig Swp Cal gi B15 B11 B10 B9 B7 B6 B5 B4 B3 B2 B1 BO Register boo Operation Idle Arm Trig Swp Cal Event B15 B11 B10 B9 B7
197. ble D 6 Model 2500 interface function codes Code Interface function SH1 Source Handshake capability AHI Acceptor Handshake capability T5 Talker basic talker serial poll unaddressed to talk on LAG L4 Listener basic listener unaddressed to listen on TAG SR1 Service Request capability RL1 Remote Local capability PPO No Parallel Poll capability DC1 Device Clear capability DT1 Device Trigger capability CO No Controller capability El Open collector bus drivers TEO No Extended Talker capability LEO No Extended Listener capability SH Source Handshake Function SH1 defines the ability of the instrument to initiate the transfer of message data over the data bus AH Acceptor Handshake Function AH1 defines the ability of the instrument to guarantee proper reception of message data transmitted over the data bus T Talker Function The ability of the instrument to send data over the bus to other devices is provided by the T function Instrument talker capabilities T5 exist only after the instrument has been addressed to talk L Listener Function The ability for the instrument to receive device dependent data over the bus from other devices is provided by the L function Listener capabilities L4 of the instrument exist only after it has been addressed to listen SR Service Request Function SR1 defines the ability of the instrument to request service from the contro
198. ble disable auto off mode Keep output on Turn output off after each measurement After each measurement When trigger count expires Enable disable output enable Disable output enable Enable output enable Enable disable display Disable display immediately Never disable display Turn display off during sweep Turn display off during buffer store 2 Connections Connection precautions Summarizes precautions that should be observed when making test connections to the Model 2500 INPUT and OUTPUT connectors Shows the locations of the triax INPUT jacks used for photodiode measurements and the OUTPUT jacks used to apply the voltage bias to the photodiodes Connector terminals Details the terminal configuration of the triax INPUT con nectors and the OUTPUT jacks Output enable Briefly covers the output enable circuit which can be used to inhibit the voltage sources with external switching Photodiode connections Provides detailed diagrams for connecting the Model 2500 INPUT and OUTPUT connectors to the photodiodes in a laser diode test system Alternate connecting methods Provides connecting diagrams for using the Model 2500 as a stand alone ammeter or stand alone voltage source Analog output connections Model 2502 only Summarizes connections to the analog outputs and gives equivalent circuits 2 2 Connections Model 2500 and 2502 User s Manual Connection precautions
199. c Operation Current measurement ranges eee eeeeseeeeereeeeeeeeeeeeseeees 3 2 Voltage source Tanges oes ee eeeeeeeeeeeseeeeeceeeeeesseeeseeseeeaeeneees 3 2 Auto so rce delay cece cescccsccass siessssseedteseaeseedescuadeuiveesbabecneesens 3 5 Source delay commands 0 0 ceeeeeseeseeeeceeceseseeeeseeeeeeaeeeees 3 7 Ground connect Commands ee eeseeeeseeeceereeeeeeseteeeeseeeees 3 8 Basic measurement and voltage source commands 3 13 Basic measurement command sequence n se 3 14 Analog output voltage examples 00 0 0 eee eseeeeeseeeeeeneeeeeees 3 14 Photodiode Measurements MSR1 and MSR2 configuration menus 0 0 eee eeeeeeeeeees 4 2 Photodiode measurement commands eeeeeseeseereeeeeees 4 6 Basic measurement command sequence s s s 4 8 Range Digits Speed and Filters Current measurement ranges ee eeeeeseceseeeeeeeeeeeeeeeeeeeeteeees 6 2 Range and digits commands occ eeeeseeeereeeeeeeeeeeeeeaes 6 4 Range and digits programming example 0 0 0 ce eeeeeeeeeees 6 5 Speed commands sisis sceveec sisceveccesecavescescateavesssensecdeaseceeueeseveess 6 7 Filter configuration mMenu 200 0 eee eee eseeeseeseeeseeseeeeeeeeeaeees 6 12 Filter commands sissies iiir ea E 6 13 7 Relative Math Ratio and Delta Table 7 1 Rel commands 0se cetasccesescsecoseuecsedeesnssesscesscosontevavencassveoseess 7 3 Table 7 2 Rel programming example ccc eeeeseeeeeeseeeceeseeeeeeseeeeeeaes 7 4 Table 7
200. ce clear and DCL device clear commands can be executed under any circumstance while operat ing within the trigger model They will abort any other command or query e ABORt e SYSTem PRESet TRG or GET RST e RCL NOTE SDC DCL or ABORt place the Model 2500 in the idle state For fastest response use SDC or DCL to return to idle Event detection Once the instrument is taken out of idle operation proceeds through the trigger model to perform the Source Delay and Measure actions In general operation is held up at an event detector until the programmed event occurs Note however that if an event detector has a bypass DIRection operation can be pro grammed to loop around the event detector Arm layer Event Detector Bypass As shown in Figure 10 9 there is a bypass ARM DIRection for the Arm Event Detector This bypass can only be used if TLINk PSTest NSTest or BSTest is the selected Arm In Event The bypass serves to jump start operation With the bypass set to SOURCce operation will loop around the Arm Event Detector when an INITiate command is sent assuming the output is turned ON The programmable arm in events for the Arm Layer are described as follows IMMediate Event detection occurs immediately allowing operation to continue BUS Event detection occurs when a bus trigger GET or TRG is received TIMer Event detection occurs immediately on the initial pass through the trigger mod
201. ce measure cycle INITiate INITiate IMMediate Take Model 2500 out of idle state Description This command is used to initiate source and measure operation by tak ing the Model 2500 out of idle The READ and MEASure com mands also perform an initiation Command processing will halt until the trigger model returns to the idle state with the following exceptions ABORt SDC DCL e IFC e SYSTem PRESet RST or RCL e TRG or GET with TRIG SOUR BUS If any other command is sent after an INIT only SDC IFC and DCL will work Abort source measure cycle ABORt Abort operation Description When this action command is sent the Model 2500 aborts operation and returns to the idle state A faster way to return to idle is to use the DCL or SDC command Models 2500 and 2502 User s Manual SCPI Command Reference 17 91 Program trigger model COUNt lt n gt ARM SEQuence 1 LAYer 1 COUNt lt n gt Set arm count TRIGger SEQuence 1 COUNt lt n gt Set trigger count Parameters lt n gt 1 to 3000 Specify count see NOTE DEFault Sets count to 1 MINimum Sets count to 1 MAXimum See NOTE INFinite ARM COUNt only NOTE The product of arm count and trigger count cannot exceed 3000 Query Description COUNt Queries programmed count COUNt DEFault Queries RST default count COUNt MINimum Queries lowest allowable count COUNt MAXimum Queries largest allowable count This command is used to spe
202. ceeeeseceeeeseseaeeeeeeees 2 14 Analog output equivalent circuit with ground COMMECE enabled oss ss seccces ct sevadsssegieseceegaessaes copes R tees 2 15 Basic Operation Basic circuit configuration 0 0 ee eee eeeeseeeeeeaeeeeeeaeeeeeeaeenees 3 3 Output slew time 2 6 cise ceseeesee iiaii i iia 3 6 Ground connect enabled 0 ee eeeeseeseeseeeceeeeeeeeaeeeeeeaeeeaes 3 9 Ground connect disabled oo eee eeeseeseeeceeeeeeeeseeeeeeeenees 3 9 Circuit configuration for basic measurements 3 10 Photodiode Measurements Measurement configuration menu tree eee eee eeeeeeee 4 2 Circuit configuration for photodiode measurements 4 4 Measurement Concepts Source delay measure SDM cycle oo eee eeeeeseeeeeeeeeeeees 5 2 Simplified trigger model ooo eee ee eeeeeeeceeeeeeseeeeseteeeeaeeeees 5 3 Basic sweep waveform types 0 0 ce eeseeceseesceeneeeeeeseeeeeeeeeeaes 5 4 Bias source limit lines eee eeeeseeseeeeeeeeeaeeeeeeaeeeeeeaeenaes 5 6 Figure 5 5 Figure 5 6 Figure 5 7 6 Figure 6 1 Figure 6 2 Figure 6 3 Figure 6 4 Figure 6 5 Figure 6 6 9 Figure 9 1 Figure 9 2 Figure 9 3 Figure 9 4 Figure 9 5 10 Figure 10 1 Figure 10 2 Figure 10 3 Figure 10 4 Figure 10 5 Figure 10 6 Figure 10 7 Figure 10 8 Figure 10 9 Figure 10 10 11 Figure 11 1 Figure 11 2 Figure 11 3 Figure 11 4 Figure 11 5 Figure 11 6 Figure 11 7 Figure 11 8 Figure 11 9 Figure 11 10 Loading CHECKS 2 ics
203. cify how many times an operation is per formed in the specified layer of the trigger model For example assume the arm count is set to 2 and the trigger counter is set to 10 the Model 2500 is configured to perform 10 source measure operations twice for a total of 20 source measure operations The product of the arm count and trigger count cannot exceed 3000 If for example the arm count is 2 then the maximum trigger count is 1250 NOTE _ INFinite can be used only with ARM COUMNt and FETCh READ MEAS CALC1 DATA through CALC7 DATA cannot be used with infinite arm count Only INIT will start measurements and only interlock over temperature SDC DCL or ABORt should be used to stop the sweep ARM COUNt INFinite can be used for repetitive source waveforms or for long tests where only the last reading is important For example the limits could be used to drive the interlock to abort a test when some con dition is met DATA would then give the answer to the test 17 92 SCPI Command Reference Models 2500 and 2502 User s Manual DELay lt n gt TRIGger SEQuence 1 DELay lt n gt Set trigger layer delay Parameters lt n gt 0 to 999 9999 Specify delay in seconds DEFault 0 second delay MINimum 0 second delay MAXimum 999 9999 second delay Query DELay Query the programmed delay DELay DEFault Query the RST default delay DELay MINimum Query the lowest allowable delay DELay MAXimum Query the largest allowable d
204. commands Addressed commands are multiline commands that must be preceded by the device listen address before that instrument will respond to the command in question Note that only the addressed device will respond to these commands Both the commands and the address preceding it are sent with ATN true SDC Selective Device Clear The SDC command performs essentially the same function as the DCL command except that only the addressed device responds Generally instruments return to their power up default conditions when responding to the SDC command GTL Go To Local The GTL command is used to remove instruments from the remote mode With some instruments GTL also unlocks front panel controls if they were previously locked out with the LLO command GET Group Execute Trigger The GET command is used to trigger devices to perform a specific action that depends on device configuration for example take a reading Although GET is an addressed command many devices respond to GET without addressing Address commands Addressed commands include two primary command groups and a secondary address group ATN is true when these commands are asserted The commands include LAG Listen Address Group These listen commands are derived from an instru ment s primary address and are used to address devices to listen The actual command byte is obtained by ORing the primary address with H20 TAG Talk Address Group The talk
205. commands are derived from the primary address by ORing the address with H40 Talk commands are used to address devices to talk SCG Secondary Command Group Commands in this group provide additional addressing capabilities Many devices including the Model 2500 do not use these commands Unaddress commands The two unaddress commands are used by the controller to remove any talkers or listeners from the bus ATN is true when these commands are asserted UNL Unlisten Listeners are placed in the listener idle state by the UNL command UNT Untalk Any previously commanded talkers will be placed in the talker idle state by the UNT command D 10 IEEE 488 Bus Overview Models 2500 and 2502 User s Manual Common commands Common commands are commands that are common to all devices on the bus These com mands are designated and defined by the IEEE 488 2 standard Generally these commands are sent as one or more ASCII characters that tell the device to perform a common operation such as reset The IEEE 488 bus treats these commands as data in that ATN is false when the commands are transmitted SCPI commands SCPI commands are commands that are particular to each device on the bus These com mands are designated by the instrument manufacturer and are based on the instrument model defined by the Standard Commands for Programmable Instruments SCPI Consor tium s SCPI standard Generally these commands are sent
206. current measurement range can be individually set for each channel Table 6 1 Current measurement ranges Model 2500 Maximum Maximum I range resolution reading 2nA 1fA 2 1nA 20nA 10fA 21nA 200nA 100fA 210nA 2nA IpA 2 luA 20u A 10pA 21uA 200p A 100pA 210UA 2mA InA 2 1mA 20mA 10nA 21mA Maximum readings As shown in Table 6 1 the full scale input for each current measurement range is 105 of the selected range For example 21mA is the full scale reading for the 20mA range Input levels that exceed the maximum levels cause the Oflo message to be displayed Manual ranging Press the MSR1 or MSR2 key then use the RANGE A and 9 keys to select a fixed chan nel or channel 2 manual range NOTE Use the lowest range possible without causing an overflow to ensure best accu racy and resolution Models 2500 and 2502 User s Manual Range Digits Speed and Filters 6 3 Auto ranging Press the MSR1 or MSR2 key then press AUTO RANGE to enable auto ranging on chan nel 1 or channel 2 respectively The AUTO annunciator turns on when auto ranging is selected With auto ranging selected the instrument automatically chooses the best range to measure the applied signal In 2 channel RATIO or DELTA display modes the AUTO annunciator appears if either channel is in auto range Pressing the AUTO key in the 2 channel display mode toggles auto range on both channels ON or OFF NOTE With the median filter en
207. currents Table 3 8 Analog output voltage examples Range Input Current Analog Output 20nA 10nA 5V 2nA 2nA 10V 20pA 7pA 3 5V 2mA 0 5mA 2 5V 20mA 15mA 7 5V Photodiode Measurements Configuring measurements Outlines the configuration menu that allows you to set up various channel and channel 2 measurement aspects and covers a configuration procedure Front panel photodiode measurements Provides a detailed procedure for making photodiode measurements from the front panel e Remote photodiode measurements Summarizes remote commands for making photodiode measurements via remote and also gives a programming example 4 2 Photodiode Measurements Models 2500 and 2502 User s Manual Configuring measurements Measurement configuration menu Press CONFIG then MSR1 or MSR2 to access channel or channel 2 configuration menu shown in Table 4 1 In Section use the Rules to navigate menus to select the various items in the menu tree which is shown in Figure 4 1 Table 4 1 MSR1 and MSR2 configuration menus Configuration menu item Description CONFIG MSR1 Configure channel 1 measurement CONFIG MSR1 BUTTON I Current measurement I V I V measurement conductance V I V I measurement resistance MX B_UNIT MX B measurement PY Electrical power measurement V X I P Optical power lneasured ldark current Responsivity CONFIG MSR2 Configure channel 2 measurement
208. curs programming example 14 10 Speed programming examples 6 7 Staircase sweep programming example 9 13 Sweep and list programming examples 17 72 Factory defaults 1 16 Filter 6 7 Average 17 57 Commands 6 13 Configuration 6 11 Configuration menu 6 12 Configure and control 17 57 Control 6 12 Median filter 6 8 17 59 Menus 1 26 Moving filter 6 10 Programming example 6 14 Remote programming 6 13 Repeat filter 6 8 Stages 6 7 Flow control 13 18 FORMat subsystem 17 43 Front panel 1 6 Front panel operation Auto zero 3 4 Data store 8 2 Digital output control 12 5 Filter 6 7 GPIB 13 9 Ground connect 3 8 Line frequency 1 12 Math functions 7 6 Measurement procedure 3 11 Menus 1 20 Output configuration 12 8 Photodiode measurements 4 4 Range and digits 6 2 RATIO and DELTA 7 10 Relative 7 2 Source delay 3 7 Speed 6 5 Sweep operation 9 6 Trigger model 10 2 Fuse replacement 1 12 General information 1 2 GET group execute trigger 13 8 GPIB 13 3 Connections 13 4 Defaults 10 23 Description D 3 Front panel operation 13 9 Primary address 13 6 Standards 13 3 Status indicators 13 9 GPIB 488 1 protocol G 1 Differences G 3 Selecting G 2 Grading mode limits operation 11 4 Fail condition 11 7 Pass condition 11 7 Ground connect mode 3 8 Commands 3 8 Connections 2 7 Selecting 17 66 Ground loops F 7 GTL go to local 13 7 Handler Category pulse component 11 11 Category register component 1 12 Interface 11 10
209. d the instrument automatically goes to the most sensitive range to perform the measurement When this command is used to disable auto range the instrument remains at the automatically selected range When a range is manually selected auto range is disabled See the previous command LLIMit lt n gt SENSe 1 CURRent DC RANGe AUTO LLIMit lt n gt Set auto ranging lower limit for channel 1 SENSe2 CURRent DC RANGe AUTO LLIMit lt n gt Set auto ranging lower limit for channel 2 Parameters lt n gt 21e 3 to 2le 3 Lower limit DEFault 2e 9 MINimum 0 MAXimum 20e 3 Query LLIMit Query auto range lower limit Description The lower limit programmed by these commands for both channels must be less than or equal to the upper limit If the lower limit is equal to the upper limit auto ranging is effectively disabled See below When autoranging is disabled you can manually program the unit for any range above the lower limit ULIMit lt n gt SENSe 1 CURRent DC RANGe AUTO ULIMit lt n gt Set auto ranging upper limit for channel 1 SENSe2 CURRent DC RANGe AUTO ULIMit lt n gt Set auto ranging upper limit for channel 2 Parameters lt n gt 21e 3 to 2le 3 Upper limit DEFault 20e 3 MINimum 0 MAXimum 20e 3 Query ULIMit Query auto range upper limit Description The upper limit programmed by these commands for both channels must be greater than or equal to the lower limit If the upper limit is equal to the lower limit auto
210. d 2502 User s Manual Status and Error Messages B 9 420 Query UNTERMINATED This error occurs when you address the instrument to talk and there is no response mes sage to send The most likely causes are Not sending a query You must send a valid query to the instrument before address ing it to talk e Sending an invalid query If you have sent a query and still get this error make sure that the instrument is processing the query without error For example sending an ill formed query that generates an error 113 Undefined header and then addressing the instrument to talk will generate an error 420 Query UNTERMINATED as well e Valid query following an invalid command This situation can occur when you send multiple commands or queries program message units within one command string program message When the Model 2500 detects an error in a program message unit it discards all further program message units until the end of the string for example SENS1 DATE SOURI VOLT In the above program message the program message unit SENS1 DATE will gener ate error 113 Undefined header and the Model 2500 will discard the second program message unit SOUR1 VOLT even though it is a valid query Data Flow C 2 Data Flow Models 2500 and 2502 User s Manual Introduction Data flow for remote operation is summarized by the block diagram shown in Figure C 1 Refer to this block diagram for the following discussion
211. d DEFault parameters to manually select the source range The UP parameter selects the next higher source range while DOWN selects the next lower source range Note that source range can be selected automatically by the instrument See the next command SOURce 1 VOLTage RANGe AUTO lt b gt Select auto range for source 1 SOURce2 VOLTage RANGe AUTO lt b gt Select auto range for source 2 Parameters Query Description lt b gt 0 or OFF Disable auto range 1 or ON Enable auto range AUTO Query state of auto range These commands are used to enable or disable auto range for the speci fied source When enabled the instrument will automatically select the most sensitive range for the specified source level When disabled the instrument will use the range that the instrument is currently on Auto range will be disabled if a fixed range is selected See the previous command Both RST and SYSTem PREset enables source auto range When the Model 2500 goes into the local state source auto range disables Models 2500 and 2502 User s Manual Set amplitude for fixed source IMMediate AMPLitude lt n gt SOURce 1 VOLTage LEVel AMPLitude lt n gt SOURce2 VOLTage LEVel AMPLitude lt n gt Parameters lt n gt 100 to 100 DEFault MINimum MAXimum Query VOLTage VOLTage DEFault VOLTage MINimum VOLTage MAXimum SCPI Command Reference 17 63 Set fixed source 1 amplitude Set fixed source 2 am
212. d sets display resolution to 5 digits HI ACCURACY Sets speed to 10 00 PLC and sets display resolution to 62 digits OTHER Use to set speed to any PLC value from 0 01 to 10 Display resolution is not changed when speed is set with this option NOTE The SPEED setting is global and affects both channels After setting speed dis play resolution for the single channel display mode can be changed using the DIGITS key Figure 6 1 Speed configuration menu tree 0 01PLC 0 10PLC 3 Digits 442 Digits Fast Med Normal HI Accuracy Other 1 00PLC 10PLC Set Speed 5 Digits 6 Digits 0 01 to 10PLC Models 2500 and 2502 User s Manual Range Digits Speed and Filters 6 7 Remote speed programming Filters Speed commands Table 6 4 summarizes commands to control speed Although commands for both channel 1 and channel 2 are included the NPLC setting is global and affects both channels See Section 17 for more information Table 6 4 Speed commands Command Description SENSe 1 CURRent NPLCycles lt n gt Set speed n PLC 0 01 to 10 SENSe2 CURRent NPLCycles lt n gt Set speed n PLC 0 01 to 10 Speed programming example Send the following command to set the speed for both channel 1 and channel 2 to 10 PLC SENS1 CURR NPLC 10 Filtering stabilizes noisy measurements caused by noisy input signals However the more filtering that is used the slower the measurement proce
213. d the internal feedback capacitance Cp for the ammeter Taking into account the capacitive reactance of these two elements our previous noise gain formula must be modified as follows Output Vyorse Input Vyorse 1 Zp Zpur where e Output Vyorseg is the noise seen at the output of the ammeter Input Vyorsg is the noise seen at the input of the ammeter e Zr is the internal feedback impedance for the ammeter that is formed by Cp and Rp e Zpurt is the internal impedance of the DUT that is formed by Cpyr and Rpyt Furthermore Rp 2nfR_C 1 and Zp 5e 2mfRgCy 1 Note that as Cg increases in value Zpyr decreases in value thereby increasing the noise gain Again at the point where Zpyry Zp the input noise is amplified by a factor of two Zour F 4 Measurement Considerations Models 2500 and 2502 User s Manual Generated currents Any extraneous generated currents in the test system will add to the desired current caus ing errors Currents can be internally generated as in the case of instrument input offset current or they can come from external sources such as insulators and cables Offset currents Internal offset current The ideal ammeter should read zero when its input terminals are left open Practical ammeters however do have some small current that flows when the input is open This current is known as the input offset current and it is caused by bias currents of active device
214. d the most recent error message Note 4 v ENABIe lt list gt Specify error and status messages for error queue Note 5 v ENABIe Read the enabled messages v DISable lt list gt Specify messages not to be placed in error queue Note 5 DISable Read the disabled messages CLEar Clears all messages from error queue Notes Commands in this subsystem are not affected by RST and SYSTem PREset The effects of cycling power CLS and STATus PRESet are explained by the following notes Event registers Power up and CLS clears all bits STATus PRESet has no effect Enable registers Power up and STATus PRESet clears all bits CLS has no effect Accepts the SCPI 1995 0 mandated non decimal numeric format H Q or B Error queue Power up and CLS clears all bits of the registers 1 Error queue messages Power up clears list of messages CLS and STATus PRESet have no effect Register query commands The format for the response messages ASCII hexadecimal octal or binary depends on which data format is presently selected See the FORMat SREGister command Models 2500 and 2502 User s Manual SCPI Command Reference 17 19 Table 17 8 SYSTem command summary Default Command Description parameter SCPI SYSTem PRESet Return to SYSTem PRESet defaults v POSetup lt name gt Select power on setup RST PRESet or SAV 0 4 POSetup Query power on setup VERSion Query revision level
215. ddressed to talk This technique increases GPIB speed by decreasing the transmission and parser times for the command Trigger on talk is extremely useful in the single shot reading mode RST default and is the main reason for a gt 2x speed improvement over the SCPI protocol Remember that the output must be on OUTPut 1 STATe ON or OUTPut2 STATe ON before you can take readings The ARM SOUR BUS and ARM COUN INF commands are not supported by READ with the 488 1 protocol selected If you send one of these commands a DCL or IFC may be required to reset the GPIB Message available The MAV message available bit in the Serial Poll byte will be set when the query is fin ished being processed not when there is data available in the output buffer as with the SCPI protocol For the 488 1 protocol output data will not be formatted until the first request for data is received This delay may cause unexpected time outs when using SRQ on MAV for queries that take a long time to execute General operation notes The TALK LSTN and SRQ annunciators are not functional in the 488 1 protocol This speeds up data throughput greatly The REM annunciator still operates since it is critical to fundamental GPIB operation Ifthe unit is in REMote the GTL command may not put the Model 2500 into the local mode Only the front panel LOCAL key is guaranteed to operate if not in local lockout LLO GTL will still disable LLO e TEEE 488 bus c
216. de before you attempt to program it over the bus Setting REN true does not place the instrument in the remote state You must address the instrument to listen after setting REN true before it goes into remote The Model 2500 must be in remote in order to use the following commands to trigger and acquire readings e INITiate and then FETCh READ e MEASure IFC interface clear The IFC command is sent by the controller to place the Model 2500 in the local talker lis tener idle states The unit responds to the IFC command by cancelling front panel TALK or LSTN lights if the instrument was previously placed in one of these states Note that this command does not affect the status of the instrument Settings data and event registers are not changed With auto output off enabled SOURce1 CLEar AUTO ON or SOURce2 CLEar AUTO ON the output will remain on if operation is terminated before the output has a chance to automatically turn off To send the IFC command the controller need only set the IFC line true for a minimum of 100us LLO local lockout Use the LLO command to prevent local operation of the instrument After the unit receives LLO all of its front panel controls except OUTPUT OFF are inoperative In this state pressing LOCAL will not restore control to the front panel The GTL command restores control to the front panel Cycling power will also cancel local lockout GTL go to local Use the GTL com
217. digital output IMMediate Restore clear to TTL output pattern AUTO lt b gt Enable or disable auto clear OFF AUTO Query state of auto clear DELay lt n gt Specify pulse width of pass fail pattern 0 00010 0 0000 to 60 sec DELay Query delay l 16 bit size available with 2499 DIGIO option Bit range set by BSIZe Default for 3 bit is 7 Default for 4 bit is 15 Default for 16 bit is 65535 17 18 SCPI Command Reference Models 2500 and 2502 User s Manual Table 17 7 STATus command summary Default Command Description parameter SCPI STATus Note 1 v MEASurement Control measurement event registers EVENt Read the event register Note 2 v ENABle lt NDN gt Program the enable register Note 3 v or lt NRf gt ENABle Read the enable register v CONDition Read the condition register v OPERation Control operation status registers v EVENt Read the event register Note 2 v ENABle lt NDN gt Program the enable register Note 3 v or lt NRf gt ENABle Read the enable register v CONDition Read the condition register Jv QUEStionable Control questionable status registers v EVENt Read the event register Note 2 v ENABle lt NDN gt Program the enable register Note 3 v or lt NRf gt ENABle Read the enable register v CONDition Read the condition register v PRESet Return status registers to default states v QUEue Path to access error queue NEXT Rea
218. disable the ground connect mode of the channel 1 and channel to 2 sources When ground connect is enabled the SOURCE OUTPUT terminal is connected to chassis ground When ground connect is disabled SOURCE is left floating Configure sweeps There are two methods to configure the start and stop levels of a sweep You can use either the STARt and STOP commands or you can use the CENTer and SPAN commands See Sweep and list program examples later in this section NOTE Inorder to run a sweep the selected source must be in the sweep sourcing mode and the trigger count should be the same as the number of source and measure points in the sweep Use the VOLTage MODE command to select the SWEep sourcing mode See Select sourcing mode page 17 61 The trigger count is set using the TRIGger COUNt com mand See Trigger subsystem page 17 90 RANGing lt name gt SOURCe 1 SWEep RANGing lt name gt Select source 1 ranging mode SOURce2 SWEep RANGing lt name gt Select source 2 ranging mode Parameters lt name gt BEST Use the best fixed mode AUTO Use the most sensitive source range for each sweep level FIXed Use the present source range for the entire sweep Query RANGing Query source ranging mode Description These commands are used to select the source ranging mode for sweeps using the channel 1 and channel 2 voltage sources With BEST selected the Model 2500 will select a single fixed source range that will acco
219. e lt n gt SENSe 1 CURRent RANGe AUTO lt state gt SENSe2 CURRent RANGe lt n gt SENSe2 CURRent RANGe AUTO lt state gt SOURce 1 VOLTage MODE FIXed SOURce 1 VOLTage RANGe lt n gt SOURce 1 VOLTage lt n gt SOURce2 VOLTage MODE FIXed SOURce2 VOLTage RANGe lt n gt SOURce2 VOLTage lt n gt OUTPut 1 lt state gt OUTPut2 lt state gt FORMat ELEMents lt name gt READ Set channel 1 current measure range n range Enable disable channel auto range state ON or OFF Set channel 2 measure range n range Enable disable channel 2 auto range state ON or OFF Select fixed sourcing mode for channel source Select channel source range n range 10 or 100 Set channel 1 source amplitude n volts Select fixed sourcing mode for channel 2 source Select channel 2 source range n range 10 or 100 Set channel 2 source amplitude n volts Turn channel output on or off state ON or OFF Turn channel 2 output on or off state ON or OFF Select reading channel lt name gt CURRent 1 channel 1 CURRent2 channel 2 Trigger and acquire reading Measurement programming example Table 3 7 summarizes the command sequence for a basic measurement procedure using channel 2 Note that the steps correspond to those listed previously in Front panel mea surement procedure These commands set up the Model 2500 as follows e Channel 2 measuremen
220. e the identification message will include the primary address For example if the primary address is 25 factory default the IEEE Addr 25 message is displayed If the RS 232 interface is selected the RS 232 message is displayed After the power up sequence the instrument goes to its normal display state with the out put off red ON OFF OUTPUT indicator light off System identification To obtain the serial number and revision information use the MENU GENERAL SERIAL selection or the IDN query via remote 1 12 Getting Started Model 2500 and 2502 User s Manual Line frequency setting If the line frequency setting 50 or 60Hz does not match the power line frequency in your area noisy measurement readings will result and accuracy may be affected You can man ually set the line frequency from the front panel or via remote as covered below Front panel line frequency Set the line frequency from the front panel as follows 1 Press the MENU key to display MAIN MENU 2 Using the right arrow key select AD CTRL then press ENTER to display A D CONTROLS 3 Select LINE FREQUENCY then press ENTER to display LINE FREQUENCY 4 Place the cursor on 50Hz or 60Hz and press ENTER 5 Press EXIT to return to normal display Remote command line frequency Use the following command to set the line frequency SYSTem LFRequency lt Freq gt See Section 17 for additional information on using this command Programming example
221. e ATN line determines whether the data bus con tains data addresses or commands as described in Bus commands page D 7 Figure D 2 IEEE 488 handshake sequence om XX Some DAV Source Valid All Ready Acceptor NRFD All Accepted NDAC Acceptor Models 2500 and 2502 User s Manual IEEE 488 Bus Overview D 7 Bus commands The instrument may be given a number of special bus commands through the IEEE 488 interface This section briefly describes the purpose of the bus commands which are grouped into the following four categories 1 Uniline commands Sent by setting the associated bus lines true For example to assert REN Remote Enable the REN line would be set low true 2 Multiline commands General bus commands which are sent over the data lines with the ATN line true low 3 Common commands Commands that are common to all devices on the bus sent with ATN high false 4 SCPI commands Commands that are particular to each device on the bus sent with ATN false These bus commands and their general purpose are summarized in Table D 1 Table D 1 IEEE 488 bus command summary Command State of type Command ATN line Comments Uniline REN Remote Enable X Set up devices for remote operation EOI End Or Identify X Marks end of transmission IFC Interface Clear X Clears interface ATN Attention Low Defines data bus contents SRQ Service Request X Controlled by external de
222. e Limit 2 uses the channel 2 voltage source compliance current as the limit At or above the 20mA current limit the instrument is in compliance Below the cur rent limit the instrument is not in compliance Limit 3 to 6 tests These software S W tests are used to determine if a DUT is within specified high and low limits Typically the Limit 3 test is used to test for coarse tolerance limits and the Limit 4 through Limit 6 tests are used for progressively finer tolerance limits For example assume you want to sort diodes into three groups 10 15 and gt 20 cur rent tolerance To do this configure the Limit 3 test for 20 HI and LO limits and Limit 4 for 15 HI and LO limits If Limit 3 fails the handler places the DUT in the bin labeled gt 20 If Limit 3 passes the Limit 4 test is run If Limit 4 fails the DUT is placed in the bin labeled 15 If Limit 4 passes the handler places the DUT in the bin labeled 10 Although Limit 1 and Limit 2 discussed above are dedicated to channels and 2 respec tively the Limit 3 through Limit 6 tests can be used with channel 1 channel 2 RATIO or DELTA measurements by selecting the corresponding data feed See Configuring limit tests page 11 16 as well as Appendix C Data Flow Limit test modes There are two modes of operation for limit tests grading and sorting For Limit 1 and 2 tests compliance operation is similar for both limit test modes If Limit 1 or 2 test fa
223. e Model 2500 is triggered to perform the programmed source and measure operations After the Model 2500 returns to idle you can read the result of the selected math function using the CALC1 DATA or CALC2 DATA command See below When disabled the CALC1 DATA and CALC2 DATA command will return the NAN not a number value of 9 91e37 DATA CALCulate 1 DATA Read channel 1 math CALC1 result CALCulate2 DATA Read channel 2 math CALC2 result Description These query commands are used to read the result of the CALC1 or CALC 2 calculation The largest valid calculation result can be 9 9e37 which defined by SCPI is infinity An invalid NAN not a number result of 9 91e37 indicates that CALCI or CALC2 is disabled or that a division by zero error has occurred See STATe LATest CALCulate 1 DATA LATest2 Read latest CALC1 result CALCulate2 DATA LATest Read latest CALC2 result Description These commands work exactly like CALC1 DATA and CALC2 DATA except that they return only the latest CALC1 or CALC2 result Models 2500 and 2502 User s Manual SCPI Command Reference 17 27 CALCulate3 and CALCulate4 Configure and control relative functions The CALC3 and CALC4 commands control relative for channel 1 and channel 2 respec tively They perform the remote equivalents to the front panel REL and CONFIG REL configuration menu Select input path FEED lt name gt CALCulate3 FEED lt name gt Parameters lt nam
224. e SCPI 1996 0 Standard Commands for Programmable Instruments This standard defines a command language protocol It goes one step farther than TEEE 488 2 1992 and defines a standard set of commands to control every programmable aspect of an instrument 13 4 Remote Operations Models 2500 and 2502 User s Manual GPIB connections To connect the Model 2500 to the GPIB bus use a cable equipped with standard IEEE 488 connectors as shown in Figure 13 1 Figure 13 1 JIEEE 488 connector To allow many parallel connections to one instrument stack the connectors Two screws are located on each connector to ensure that connections remain secure Figure 13 2 shows a typical connecting scheme for a multi unit test system Figure 13 2 IEEE 488 connections Instrument Instrument Instrument Controller Models 2500 and 2502 User s Manual Remote Operations 13 5 To avoid possible mechanical damage stack no more than three connectors on any one unit NOTE To minimize interference caused by electromagnetic radiation use only shielded IEEE 488 cables Available shielded cables from Keithley are Models 7007 1 and 7007 2 To connect the Model 2500 to the IEEE 488 bus follow these steps 1 Line up the cable connector with the connector located on the rear panel The connec tor is designed so it will fit only one way Figure 13 3 shows the location of the IEEE 488 connector 2 Tighten the screws securely making sure not to overti
225. e and perform the appropriate action TRIGGER OUT Use to configure the trigger layer output trigger LINE Select the Trigger Link line for the output trigger line 1 2 3 4 5 or 6 EVENTS Enable ON or disable OFF output triggers that occur after the SOURCE DELAY and MEAS actions DELAY Specify the time delay in seconds for the trigger delay COUNT Specify the trigger count 10 16 Triggering Models 2500 and 2502 User s Manual e HALT Use to return the Model 2500 to the idle state HALT does not turn off the output The programmed source level will still be available at the OUTPUT terminals The following actions will take the Model 2500 out of idle Turn the output off and then on again Reselect the arm or trigger event Exit from the menu structure and then reenter it by pressing CONFIG and then TRIG Figure 10 8 Configure trigger menu tree Config Trig Layer i Models 2500 and 2502 User s Manual Triggering 10 17 Remote triggering Trigger model remote operation The trigger model flowchart in Figure 10 9 summarizes remote trigger operation Opera tion is controlled by SCPI commands from the Trigger Subsystem Key remote commands are included in the trigger model Also note that the GPIB defaults are denoted by the symbol The primary actions of the trigger model are Source Delay and Measure The source action outputs the programmed
226. e circuit includes two ammeters to make current measurements and two voltage sources to bias the DUTs Note that channel 1 and channel 2 analog common terminals are floating and independent of one another INPUT HI Figure 2 4 Equivalent circuit of photodiode test connections ar ert ana ee a a ee ates gt INPUT HI i Channel 1 i I i I I I Channel1 Analog l Common i I Back Photodiode OUTPUT I Laser e eee eae eer Diode i Channel 2 Forward orwar i Photodiode OLA PUT I I I I I Channel 2 l Analog I Common l I I I I I I Model 2500 Connection considerations To avoid noise and offset currents that could degrade measurement accuracy be sure to use only quality low noise triax cables for INPUT connections Also keep cables and test fixtures away from vibration and varying temperatures to minimize generated cable cur rents See Appendix F Measurement Considerations for information on these and other possible measurement problems and how to avoid them Model 2500 and 2502 User s Manual Connections 2 7 Ground connect mode connections The VOLTAGE SOURCE output jack for either channel can either be connected to chassis ground or left floating depending on the selected ground connect mode See Section 3 Ground connect mode for details With ground connect disabled you must make sepa rate connections to the VOLTAGE SOURCE OUTPUT jack as shown in Figure 2 3 However with ground c
227. e com mand along with the null list parameter as follows STATus QUEue ENABle Models 2500 and 2502 User s Manual Status Structure 14 21 Table 14 9 Error queue commands Command Description Default STATus STATus Subsystem QUEue Read error queue Note 1 NEXT Read and clear oldest error status code and message ENABIe lt list gt Specify error and status messages for error queue Note 2 ENABle Read the enabled messages DISable lt list gt Specify messages not to be placed in queue Note 2 DISable Read the disabled messages CLEar Clear messages from error queue SYSTem SYSTem Subsystem ERRor Read error queue Note 1 NEXT Read and clear oldest error status code and message ALL Read and clear all errors status code and message COUNt Read the number of messages in queue CODE Code numbers only NEXT Read and clear oldest error status code only ALL Read and clear all errors status codes only CLEar Clear messages from error queue Notes 1 Power up and CLS empties the error queue STATus PRESet has no effect 2 Power up enables error messages and disables status messages CLS and STATus PRESet have no effect Programming example read error queue The following command reads the error queue STAT QUE 15 Common Commands Command summary Lists the IEEE 488 2 common commands used by the Model 2500 e Command reference Provides a detailed refer
228. e gt CALCulate 1 Use result of channel math function Select input path for channel 1 REL SENSe 1 Use channel current reading Query FEED Query input path for channel 1 REL Description This command is used to select the input path for channel 1 REL With CALCulate 1 selected the REL feed will be the result of the channel 1 math function CALC1 With SENSe 1 selected the REL feed will be the raw channel 1 current reading FEED lt name gt CALCulate4 FEED lt name gt Select input path for channel 2 REL Parameters lt name gt CALCulate2 Use result of channel 2 math function SENSe2 Use channel 2 current reading Query FEED Query input path for REL This command is used to select the input path for channel 2 REL With CALCulate2 selected the REL feed will be the result of the channel 2 math function CALC2 With SENSe2 selected the REL feed will be the raw channel 2 current reading Description 17 28 SCPI Command Reference Models 2500 and 2502 User s Manual Set or acquire relative value OFFSet lt n gt CALCulate3 NULL OFFSet lt NRf gt Specify null offset REL for channel 1 CALCulate4 NULL OFFSet lt NRf gt Specify null offset REL for channel 2 Parameters lt NRf gt 9 999999e20 to Specify null offset value 9 999999e20 Query OFFSet Query null offset value Description This command lets you establish a null offset REL value for channel 1 CALC3 or channel 2 CALC4 When Null Off
229. e repeat filter Query STATe Query state of repeat filter Description This command is used to enable or disable the median filter When enabled current readings are filtered according to the specified rank When disabled the median filter stage is bypassed 17 60 SCPI Command Reference Models 2500 and 2502 User s Manual SOURCce subsystem This subsystem is used to configure and control the two voltage sources and to set the logic level high or low of each digital output line The commands for this subsystem are summarized in Table 17 6 SOURce 1 and SOURce2 Use the following commands to configure and control the channel 1 and channel 2 voltage sources SOURce 1 controls the channel 1 source and SOURce 2 controls the channel 2 source Control source output on off NOTE All SOURx CLEar commands are global and affect both channels simultaneously IMMediate SOURce 1 CLEar IMMediate Turn source output off Description This command is used to turn off the channel 1 and channel 2 source outputs The outputs will turn off after all programmed source and mea sure operations are completed and the instrument returns to the idle state Note that if auto output off is enabled the source outputs will automati cally turn off See the next command MODE lt name gt SOURce 1 CLEar AUTO MODE lt name gt Control source auto on off mode SOURce2 CLEar AUTO MODE lt name gt Control source auto on off mode Parameters lt n
230. e to source its programmed voltage 10V For the 400Q DUT the unit will output only 8V at the fixed 20mA limit Notice that as resistance increases the slope of the DUT load line decreases As resistance approaches infinity open output the Model 2500 will source virtually 10V at OmA Con versely as resistance decreases the slope of the DUT load line increases At zero resis tance shorted output the Model 2500 will source virtually OV at 20mA Models 2500 and 2502 User s Manual Measurement Concepts 5 7 Regardless of the load current will never exceed the fixed compliance of 20mA Figure 5 5 Loading effects Current Limit Load Line 20mA Output Current 1 Operating NOMA Point lt Voltage Source Load Line Output Voltage V 10V l V R 10V 1kQ 10MA A Normal bias source operation Current Limit Load Line Operating Point 20mA Output Current I i Voltage Source Load Line 8V 10V Output Voltage V Vs IM R 20mA 4000 8V B Bias source in compliance 5 8 Measurement Concepts Models 2500 and 2502 User s Manual Data flow Data flow for front panel operation is summarized by the block diagrams provided in Figure 5 6 while Figure 5 7 shows data flow through the various CALC blocks Note that if REL is enabled the result of the rel operation is sent to the other blocks NOTE See Appendix C for remote operation data flow information that describes the CALC blocks
231. e2 AVERage TCONtrol lt name gt Set average filter type Parameters lt name gt MOVing Moving average filter REPeat Repeat average filter Query TCONtrol Query type of average filter Description These commands are used to control the type of average filter The REPeat filter places the specified number of measurement conversions into a stack and averages them to yield a single repeat filter reading The stack is then cleared and the process starts over The MOVing average filter uses a first in first out stack When the stack filter count becomes full the readings are averaged yielding a filtered reading For each subsequent reading placed into the stack the oldest reading is discarded The stack is reaveraged yielding a new reading ADVanced NTOLerance lt n gt SENSe 1 AVERage ADVanced NTOLerance lt n gt Set filter noise window SENSe2 AVERage ADVanced NTOLerance lt n gt Set filter noise window Parameters lt n gt 0 to 105 Specify filter noise tolerance in DEfault 5 MINimum 0 MAXimum 100 Query NTOLerance Query filter noise tolerance value Description When the advanced filter is enabled see STATe below a noise win dow is used with the average filter This command is used to specify the noise window If readings are within the noise window the average filter operates normally If however a reading falls outside the window the buffer is flushed of old readings and filled with the new reading ADVanced
232. e3 lt name gt Set SOUR3 and TTL response formats Parameters lt name gt ASCii ASCII format HEXadecimal Hexadecimal format OCTal Octal format BINary Binary format Query SOURce3 Query response format Description This command controls the response format for all CALC7 XXXX SOUR3 and SOUR3 TTL queries in a manner similar to formats set by the FORM SREG command See Calculate sub systems and SOURce subsystem page 17 60 topics for details CALC data elements CALCulate lt item list gt FORMat ELEMents CALCulate lt item list gt Set CALC data elements Parameters lt item list gt CALCulate Include CALC1 to CALC7 data TIME Include timestamp STATus Include status information NOTE Each item in the list must be separated by a comma for example CALCulate CALC TIME STAT Query CALCulate Query CALC data element list Description This command allows you specify the data elements returned with the CALC1 DATA through CALC7 DATA queries With CALC speci fied the corresponding CALC1 through CALC7 element will be included in the response With TIMe or STATus specified timestamp and status information will be returned with the queries See Calculate subsystems page 17 22 for a complete description of the various CALCI through CALC7 elements See also Data elements page 17 46 for a description of TIME and STATus information 17 50 SCPI Command Reference Models 2500 and 2502 User s Manual TRACe dat
233. ecautions may be required in the measurement setup Sources of EMI include e Radio and TV broadcast transmitters e Communications transmitters including cellular phones and handheld radios e Devices incorporating microprocessors and high speed digital circuits e Impulse sources as in the case of arcing in high voltage environments The effect on instrument performance can be considerable if enough of the unwanted sig nal is present The effects of EMI can be seen as an unusually large offset or in the case of impulse sources erratic variations in the displayed reading The instrument and experiment should be kept as far away as possible from any EMI sources Additional shielding of the instrument experiment and test leads will often reduce EMI to an acceptable level In extreme cases a specially constructed screen room may be required to sufficiently attenuate the troublesome signal External filtering of the input signal path may be required In some cases a simple one pole filter may be sufficient In more difficult situations multiple notch or band stop filters tuned to the offending frequency range may be required Connecting multiple capacitors of widely different values in parallel will maintain a low impedance across a wide frequency range Keep in mind however that such filtering may have detrimental effects such as increased response time on the measurement G GPIB 488 1 Protocol G 2 GPIB 488 1 Protocol Models
234. ecimal format 3 bit x 0 to 7 4 bit x 0 to F Octal format 3 bit x 0 to 7 4 bit x 0 to 17 Query digital output value This command is used to set the logic levels of the output lines of the digital I O port When set high the specified output line will be at approximately 5V When set low the output line will be at OV NOTE The maximum digital output value is 65 535 with the 2499 DIGIO option Models 2500 and 2502 User s Manual SCPI Command Reference 17 75 Use the following table to determine the parameter value for the desired decimal digital output pattern Decimal OUT4 OUT3 OUT2 OUT1 value L L L L 0 L L L H 1 L L H L 2 L L H H 3 L H L L 4 L H L H 5 L H H L 6 L H H H 7 H L L L 8 H L L H 9 H L H L 10 H L H H 11 H H L L 12 H H L H 13 H H H L 14 H H H H 15 L Low Gnd H High gt 3V 0 7 in 3 bit mode ACTual SOURce3 TTL LEVel ACTual Query bit pattern on digital output port Description This query command is used to read the bit pattern that is actually on the digital output port MODE lt name gt SOURce3 TTL4 MODE lt name gt Control digital I O port line 4 mode Parameters lt name gt EOTest Use line 4 as EOT signal BUSY Use line 4 as BUSY signal Query MODE Query digital I O line 4 mode Description This command controls the operation of digital I O line 4 to act as either an End of Test or Busy signal in the 3 bit output mode EOT is n
235. ect to a number of error sources that can have a serious impact on measurement accuracy These aspects are covered in the following paragraphs Leakage currents Leakage currents are generated by high resistance paths between the measurement circuit and nearby voltage sources These currents can considerably degrade the accuracy of low current measurements One way to reduce leakage currents is to use good quality insulators when building the test circuit Some good quality insulators include Teflon polyethylene and sapphire Avoid materials such as phenolics and nylon Humidity may also degrade low current measurements The amount of water an insulator absorbs will vary depending on the insulator It is best to choose an insulator on which water vapor does not readily form a continuous film Sometimes this is unavoidable if the material being measured absorbs water easily so it is best to make the measurements in an environmentally controlled room In some cases an insulator may have ionic contami nants and especially in high humidity a spurious current may be generated Noise and source impedance Noise can seriously affect sensitive current measurements This section discusses how DUT device under test resistance and capacitance affect noise performance DUT resistance The resistance of the DUT will affect the noise performance of the ammeters As the DUT resistance is reduced the noise gain of the ammeter will increase Noise ga
236. ed off Table 6 5 Filter configuration menu Menu item Description CONFIGURE FILTERING Configure filter AVERAGE MODE Select average mode filter MOVING Moving average REPEAT Repeat average AVERAGE COUNT Set average filter count 1 100 ADVANCED Enable disable advanced filter DISABLE Disable advanced filter ENABLE Enable advance filter MEDIAN RANK Select median rank 0 5 Figure 6 6 Configure filtering menu tree ount Average Mode Models 2500 and 2502 User s Manual Remote filter programming Filter commands Table 6 6 summarizes filter commands Table 6 6 Filter commands Commands Range Digits Speed and Filters See Section 17 for more details Description for Average Filter SENSe 1 AVERage COUNt lt n gt SENSe 1 AVERage TCONtrol lt name gt SENSe 1 AVERage STATe lt state gt SENSe 1 AVERage ADVanced NTOLerance lt NRf gt SENSe 1 AVERage ADVanced STATe lt state gt SENSe2 AVERage COUNt lt n gt SENSe2 AVERage TCONtrol lt name gt SENSe2 AVERage STATe lt state gt SENSe2 AVERage A DVanced NTOLerance lt NRf gt SENSe2 AVERage ADVanced STATe lt state gt for Median Filter SENSe 1 MEDian RANK lt NRf gt SENSe 1 MEDian STATe lt state gt SENSe2 MEDian RANK lt NRf gt SENSe2 MEDian STATe lt state gt Set Ch average filter count n count 1 to 100 Select Ch 1 filter type
237. ed to immediately restore the digital output lines to the output pattern defined by the TTL LEVel command AUTO lt b gt SOURce3 CLEar AUTO lt b gt Control auto clear for digital output Parameters lt b gt 0 or OFF Disable auto clear 1 or ON Enable auto clear Query AUTO Query auto clear Models 2500 and 2502 User s Manual SCPI Command Reference 17 77 Description This command is used to enable or disable auto clear for the digital out put lines When enabled the output pattern will clear automatically after the pass or fail output bit pattern of a limit test is sent to a handler via the digital output lines The DELay command specifies the pulse width of the limit test bit pat tern See the next command After the delay period times out the digital output clears back to the output pattern programmed by the TTL LEVel command When auto clear is disabled the digital output pattern can only be cleared by the MMediate command On power up auto clear is enabled See CALCulate lt item list gt page 17 49 and Section 11 for details on limit tests DELay lt n gt SOURce3 CLEar AUTO DELay lt n gt Set delay for auto clear Parameters lt n gt 0 to 60 Specify delay in seconds DEFault 100psec delay MINimum 0 sec MAXimum 60 sec Query DELay Query delay DELay DEFault Query RST default delay DELay MINimum Query lowest allowable delay DELay MAXimum Query maximum allowable delay Description This command
238. ee Section 17 FORMat subsystem for details After all source and measure operations are completed the Model 2500 returns to the idle state The data stored in the sample buffer will remain there until data from another source measure cycle overwrites the buffer Data in the sample buffer is lost if the Model goes to the local state REM annunciator off NOTE With no data in the Sample Buffer the FETCh and CALCulateX DATA com mands to read data will display the message Data corrupt or stale FETCh This command is used to read data stored in the sample buffer If for example there are 20 data sets stored in the sample buffer then all 20 data sets will be sent to the computer when FETCh is executed Note that FETCh does not affect data in the sample buffer Thus subsequent executions of FETCh acquire the same data READ The READ command performs an INITiate and then a FETCh The INITiate triggers a new source and measure cycle which puts new data in the sample buffer FETCh reads that new data The MEASure command places the Model 2500 in a one shot source and measure mode and then performs a READ See Section 16 for more information on READ and MEASure C 4 Data Flow Models 2500 and 2502 User s Manual CALCulate 1 DATA and CALCulate2 DATA2 If CALCulatel or CALCulate2 is enabled SENS1 or SENS2 data is fed to the CALC1 channel 1 or CALC2 channel 2 block where the results for the selected math functio
239. eeeeeseeeenees 17 63 TRIGgered AMPLitude lt n gt oo eeeeeeeeeeeeeeeeees 17 64 Set delay ei sccsse city eplhsci ent teense aed al eee 17 65 DELAY SUP cogi e R E 17 65 AUTO SDS ona iania 17 65 Select ground connect mode sseeseseessrereerrerrrrsrreresere 17 66 GCONNECt LDS uires riisiin as 17 66 Configure SWEEPS secsscstscsizseseascsensastasesesgsses sai onacdducedenseeonss 17 66 RANGing lt name gt oo ee eee eeeeeeeeeeeeeeeeeeeeeeeeaeenees 17 66 SPACING lt MAME gt crcsccessieasteseiachesdisedsseessaieaageecnstncage 17 67 STARt i gt ccna nee eee 17 67 STOP KIS coaer rrea tive eater a 17 67 CEN Tet KOP ioeie KE A 17 68 SPAN KAS aranana a araa a TEE ERA 17 68 STEP lt M nng a a E E N iE 17 69 POING lt 0 aasi n 17 70 DIRection lt name gt sisisi 17 71 Config re LSE ceesre rri reer aa Er ar AERES 17 71 VOLTage lt NRf list sssieriiirsiiiriiri 17 71 APPend lt NREVSt gt csciccicfiasieteaaschisaseasttriserpegeetageeras 17 72 POINTS svccc cess sceccsusseenestessiesserivaseusvecietecieciestienne 17 72 Sweep and list program examples cece eeeeseeeeeeeees 17 72 Linear voltage sweep 0 eee eeeeeeseteeeeeeeeeeseeeeeeaees 17 72 DASE SWEEP sciscsechssecsesdciesenansrepanensedeabseaveteas cbaseaseneenas 17 72 Logarithmic SWEEP 0 eee eeceeeceeeeseeeeeeseeeeeeseeneeeaees 17 73 SOURCES E E E N A 17 74 Setting digital output oo eee ceeeseeeeeeeeeeeteeneeeaees 17 74 LEVel lt NRf gt 1 lt NDN gt oo eeeee
240. eeeeteeteeeeeeeeeeees 17 74 ACTUal aiseee iaia ie teen 17 75 MODE lt name gt oceissecssiiestessedersiseagessupecaanncauptioenvena s 17 75 BS Pate lt b gt a aai 17 76 BSE 00 gt enrio a saaenesdeidaneayveoaseesaavdectenes 17 76 Clearing digital output sesessseeeeeesessesresesrertrrrerrsreresresese 17 76 IMMediate c ccccsseccssseccesseeessseeeesseeeeesneeeesseees 17 76 AUTO lt p gt escran NEk 17 76 DELay lt i gt epn ia a a a i aS 17 77 STAT s s bsy stem viiesviistissist isise aececi rieien esis 17 78 Read event Pegisters c csssccscsssesesessccesssesnserseeranescenenseuss 17 78 EVENT cicocissiceccieeleils sen sous stecsptetiecoctneedeveieeers 17 78 Program event enable registers 1 0 0 eee eeseeseereeeeeeeee 17 78 ENABle lt NDN gt or lt NRf gt oo eeeeeseeseereeeeeeeeeeeeeee 17 78 Read condition registers 0 0 ee eeeseeeeeseeeseeeeeeeeeeeeeseeaes 17 79 CONDIUON senise niinn 17 79 Select default conditions ssseseseeeeeeereeesesererssrerrsreresreee 17 79 PRES E nsien iiA 17 79 Err rq e T erisera aer peorien ne e eean e EEEE 17 79 ECNEXT esiin guns siutevestetssnelistecisterdsvoiieesd 17 79 CLEAT asaris a 17 79 ENABIe lt list gt sponsuni iira iioii 17 80 DiSable lt list gt E E 17 80 SYS Tem Subsystem srei cess sees eevese iaieiiea eise 17 81 Default c nditlons svcsccscsesdasssescoscagesoscesdesstenutdpnseeseavapavonses 17 81 PRESET socrii anaiai ea 17 81 POSOtUp osiers pinire eean a
241. el Each subsequent detection is satisfied when the programmed timer interval elapses The timer resets to its initial state when the instrument goes into idle MANual Event detection occurs when the TRIG key is pressed The Model 2500 must be in LOCAL mode for it to respond to the TRIG key Press the LOCAL key or send GTL over the bus to take the Model 2500 out of remote TLINk Event detection occurs when an input trigger via the Trigger Link input line is received see Trigger link for more information With TLINk selected you can loop around the Arm Event Detector by setting the event detector bypass ARM DIRection to SOURce 10 20 Triggering Models 2500 and 2502 User s Manual NSTest Event detection occurs when the SOT start of test line of the Digital I O port is pulsed low This pulse is received from the handler to start limit testing See Section 11 PSTest Event detection occurs when the SOT start of test line of the Digital I O port is pulsed high This pulse is received from the handler to start limit testing See Section 11 BSTest Event detection occurs when the SOT start of test line of the Digital I O port is pulsed either high or low This pulse is received from the handler to start limit testing See Section 11 NOTE NSTest PSTest and BSTest can be used only at the beginning of a sweep and should not be used to trigger each point in a sweep Trigger layer The Trigger Layer uses three
242. el or via remote 5 6 Measurement Concepts Models 2500 and 2502 User s Manual Bias source operating boundaries Limit lines Figure 5 4 shows the operating boundaries or limit lines for the voltage bias sources in the first quadrant both voltage and current positive Operation in the third quadrant both voltage and current negative is similar Note that each voltage bias source can output a maximum of 100V 20mA Although the voltage value can be set over a range of 100V the current compliance is fixed at 20mA Figure 5 4 Bias source limit lines Current Compliance Limit Line 20mA ie Max Output Current Voltage Source Limit Line Output Voltage Max Loading effects Where within the boundaries each Model 2500 bias source operates depends on the resis tance of the load DUT that is connected to the output Figure 5 5 shows operation exam ples for resistive loads that are 1kQ and 400Q respectively For these examples the Model 2500 bias source is programmed to source 10V with a fixed current limit of 20mA In Figure 5 5A the Model 2500 is sourcing 10V into the 1kQ load and subsequently sources 10mA As shown the load line for 1kQ intersects the 10V voltage source line at 10mA Figure 5 5B shows what happens if the resistance of the load is decreased to 400Q The DUT load line for 400Q intersects the 20mA current compliance limit line placing the Model 2500 in compliance In compliance the Model 2500 will not be abl
243. elay Description The delay is used to delay operation in the trigger layer After the pro grammed trigger event occurs the instrument waits until the delay period expires before performing the device action SOURce lt name gt ARM SEQuence 1 LAYer 1 SOURce lt name gt TRIGger SEQuence 1 SOURce lt name gt Parameters lt name gt IMMediate TLINk TIMer MANual BUS NSTest PSTest BSTest Specify arm event control source Specify trigger event control source Pass operation through immediately Select Trigger Link trigger as event Select timer as event Select manual event Select bus trigger as event Select low SOT pulse as event Select high SOT pulse as event Select high or low SOT pulse as event NOTE Only IMMediate and TLINK are available as trigger layer control sources Query SOURce Query programmed control source Description These commands are used to select the event control source With IMMediate selected operation immediately continues A specific event can be used to control operation With TLINK selected operation continues when a trigger pulse is received via the Trigger Link NOTE The following control sources are not available for the trigger layer With TIMer selected the event occurs at the beginning of the timer interval and every time it times out For example if the timer is pro grammed for a 30 second interval the first pass through the control Models 2500 and 2502 User
244. en the SOT line of the Digital I O port is pulsed either high or low After selecting this arm event you will be prompted to select the state of the event detection bypass ARM OUT Use to configure the arm layer output trigger LINE Select the Trigger Link line for the output trigger line 1 2 3 4 5 or 6 EVENTS Enable ON or disable OFF the arm layer output triggers TRIG LAYER DONE ON enables an output trigger on exiting the trigger layer COUNT Specify the arm count FINITE programmable count or INFINITE never ending count e TRIG LAYER Use this menu item to configure the trigger layer of the trigger model TRIGGER IN Use to select the detection event for the trigger layer IMMEDIATE Event detection occurs immediately TRIGGER LINK After selecting this trigger in source you will be prompted in sequence as follows gt TRIG IN TLINK LINE Select the input line 1 2 3 4 5 or 6 for the Trigger Link gt EVENT DETECT BYPASS Set the bypass for the Source Event Detec tor With ONCE operation will loop around the Source Event Detector With NEVER selected operation will wait for an input trigger gt TRIGGER IN EVENTS Enable ON or disable OFF trigger in events SOURCE DELAY and MEAS With a trigger in event ON operation will wait at that event for an input trigger With the trigger in event OFF operation will not wait It will simply continu
245. ence for all common commands except for those associated with the status structure which are discussed in Section 14 15 2 Common Commands Models 2500 and 2502 User s Manual Command summary Common commands summarized in Table 15 1 are device commands that are common to all devices on the bus These commands are designated and defined by the IEEE 488 2 standard Most of these commands are described in detail in this section NOTE The following common commands associated with the status structure are cov ered in Section 14 CLS ESE ESE ESR SRE SRE and STB Table 15 1 IEEE 488 2 common commands and queries Mnemonic Name Description CLS Clear status Clears all event registers and error queue ESE lt NRf gt Event enable command Program the standard event enable register ESE Event enable query Read the standard event enable register ESR Event status register query Read and clear the standard event enable register IDN Identification query Returns the manufacturer model number serial number and firmware revision levels of the unit OPC Operation complete command Set the operation complete bit in the standard event register after all pending commands have been executed OPC Operation complete query Places an ASCII 1 into the output queue when all pending selected device operations have been completed OPT Option query Query Model 2500 for list of installed options RCL lt
246. ent detection occurs immediately MANUAL Event detection occurs when the TRG key is pressed GPIB Event detection occurs when a bus trigger GET or TRG is received TIMER Initially event detection is satisfied immediately Subsequent event detection occurs after the timer interval elapses After selecting this arm event you will be prompted to specify the timer interval in seconds MANUAL Event detection occurs when the TRIG key is pressed TLINK After selecting this arm event you will be prompted to select the input line for the Trigger Link and the state of the event detection bypass With ONCE selected operation will loop around the arm event detector on each new pass through the trigger model With NEVER selected operation always waits for the input trigger I STEST Event detection occurs when the SOT line of the Digital I O port is pulsed low After selecting this arm event you will be prompted to select the state of the event detection bypass With ONCE selected operation will loop around the arm event detector on each new pass through the trigger model With NEVER selected operation always waits for the input trigger TSTEST Event detection occurs when the SOT line of the Digital I O port is pulsed high After selecting this arm event you will be prompted to select the state of the event detection bypass Models 2500 and 2502 User s Manual Triggering 10 15 TLSTEST Event detection occurs wh
247. eps 2 and 3 5 When finished editing source value s press ENTER or wait six seconds to exit from the edit mode Step 3 Turn source outputs on Turn the voltage source outputs on by pressing the ON OFF OUTPUT key The red OUT PUT indicator will turn on to indicate that both channel outputs are on Step 4 Observe readings on the display Observe the current readings in the channel 1 top left or channel 2 top right display field as appropriate If in the MSR1 or MSR2 display mode use the DISPLAY TOGGLE key to toggle between channels if desired or use the CHANNEL SELECT key to select the displayed channel Step 5 Turn source output off When finished turn both voltage source outputs off by pressing the ON OFF OUTPUT key The red OUTPUT indicator light will turn off Remote command measurement procedure Basic measurement procedures can also be performed via remote by sending appropriate commands in the right sequence The following paragraphs summarize the basic com mands and give a simple programming example Basic measurement and voltage source commands Table 3 6 summarizes basic measurement and voltage source commands See Section 17 for more information on using these commands as well as many other commands that con trol these functions Models 2500 and 2502 User s Manual Table 3 6 Basic Operation Basic measurement and voltage source commands 3 13 Command Description SENSe 1 CURRent RANG
248. equire a header B H or Q to identify the data format being sent The letter in the header can be upper or lower case The lt NRf gt numeric representation Status Structure Models 2500 and 2502 User s Manual format parameter type is used to send decimal values and does not use a header The following examples show the proper parameter syntax for setting Bits B5 B3 and B2 b101100 Binary format lt NDN gt parameter type h2C Hexadecimal format lt NDN gt parameter type q54 Octal format lt NDN gt parameter type 44 Decimal format lt NRf gt parameter type Valid characters for the non decimal parameter values are shown as follows lt NDN gt format Valid characters Binary 1s and Os Hexadecimal 0 through 9 and A through F Octal O through 7 Reading registers Any register in the status structure can be read by using the appropriate query com mand The following explains how to interpret the returned value response message The actual query commands are covered later in this section Table 14 3 through Table 14 7 The response message will be a value that indicates which bits in the register are set That value if not already binary will have to be converted to its binary equivalent For exam ple for a binary value of 100101 bits B5 B2 and BO are set The returned value can be in the binary decimal hexadecimal or octal format The FORMat SREGister command is used to select the d
249. er are set Program event enable registers ENABle lt NDN gt or lt NRf gt STATus MEASurement ENABle lt NDN gt or lt NRf gt STATus QUEStionable ENABle lt NDN gt or lt NRf gt STATus OPERation ENABle lt NDN gt or lt NRf gt Program Measurement Event Enable Register Program Questionable Event Enable Register Program Operation Event Enable Register Parameters lt NDN gt Bxx x Binary format each x 1 or 0 Hx Hexadecimal format x 0 to FFFF Qx Octal format x 0 to 177777 lt NRf gt 0 to 65535 Decimal format Query ENABle Read an enable register Description These commands are used to program the enable registers of the status structure The binary equivalent of the parameter value that is sent deter mines which bits in the register gets set See Section 14 for details Models 2500 and 2502 User s Manual SCPI Command Reference 17 79 Read condition registers CONDition STATus MEASurement CONDition Read Measurement Condition STATus QUEStionable CONDition Read Questionable Register STATus OPERation CONDition Read Operation Condition Description These query commands are used to read the contents of the condition registers Select default conditions PRESet STATus PRESet Return registers to default conditions Description When this command is sent the following SCPI event registers are cleared to zero 0 1 Operation Event Enable Register 2 Event Enable Register 3 Measureme
250. er rreet 13 10 LOCAL Key ais liens e E 13 10 Programming syntax oe eeeeceeescescesteceteeeeeeceneeesaeeeaeeesaeeeeees 13 10 Command Words 0 see eseeeeseeseeeseeeseeseceseeaeenseeseeeneaes 13 10 Commands and command parameters eee 13 10 Query COMMANAS secvescssscseseveiesvasesocasostsecessectsavdatesseeecc gt 13 12 Case SCMSIIVIEY oo eee eeceeeeceeceeeseeceeeeeeeceaeeeeeceaeeesaeeeaeens 13 13 Long form and short form versions 00 0 0 eeeeseeeeereee 13 13 Short form rules oo eee ee eeeeseceeceseceeeeseeeeeeseseeeeseeseeeaees 13 13 Programi MESSAGES uusine niies 13 14 Single command messages csssceseeeseeeeseeeeeeeees 13 14 Multiple command messages c ccescceeseeeeneeeneees 13 14 Command path rules oie eee eeeeeeeeeseseeeeseeeeeeaees 13 15 Using common and SCPI commands in the SAME MESSAGE 00 eee eeeeeeeseeeeeeseeeseteeceseeeeeeseeseeesees 13 15 Program message terminator PMT eee 13 15 Command execution rules eee eeeeeeeeeeseeereeeees 13 15 Response messages oo eee eeeeseeseeeeeseeeeeeaeeeseeaneeaeeseeeneeaes 13 16 Sending a response message ee eeeeeeeeeeseeeeeeeeee 13 16 Multiple response Messages 00 0 ce eeeesseeeeeseeereeees 13 16 Response message terminator RMT ee 13 16 Message exchange protocol 0 0 eeeeseeeeseeseeeneeeeeeaeeees 13 16 RS 232 interface Operation eee eeeeseeeseeseeeeeeseeeeeeeeeeaeeees 13 17 Sending and receiving data wo eee eseeeee
251. ers Select input trigger line 1 2 3 4 5 or 6 Query input trigger line Select output trigger line 1 2 3 4 5 or 6 Query output trigger line Output trigger TRIGger or NONE Query arm output trigger status Path to program Trigger Layer Specify trigger count 1 to 3000 Query trigger count Specify trigger delay 0 to 999 9999 sec Query source delay Specify control source IMMediate or TLINk Query control source Default parameter SCPI v v v v v 1 v v IMMediate v v 0 1 v v v ACCeptor v v v 1 2 NONE v v 1 v v 0 v v IMMediate v v 17 22 SCPI Command Reference Models 2500 and 2502 User s Manual Table 17 10 continued TRIGger command summary Default Command Description parameter SCPI TRIGger Path to program Trigger Layer continued SEQuence 1 TCONfigure y DIRection lt name gt Enable SOURce or disable ACCeptor bypass v DIRection Query state of bypass y ASYNchronous Configure output triggers v ILINe lt n gt Select input trigger line 1 2 3 4 5 or 6 1 ILINe Query input trigger line INPut lt event list gt Enable input event detectors SOURce DELay NONE SENSe or NONB INPut Query enabled input event detectors OLINe lt n gt Select output trigger line 1 2 3 4 5 or 6 2 OLINe Query output trigger line OUTPut lt event list gt Output trigger after SOURce DELay SENSe NONE or not
252. essis setevcosdussedeesedecosedesstedeonstesescese 14 10 Status register SETS sisii isinisisi sisie ss 14 11 Register bit descriptions esesseseeseeeeseerseeerrsresrsresreresreee 14 11 Standard event register sseseseeeeeeeessesesesreresesrsssee 14 11 Operation event register oo eee eee eseeeeeeseeeeeeeees 14 13 Measurement event register eceeeeceeseeeseeeneeeneees 14 14 Questionable event register eee eeeeeseeeseeeeteeeneees 14 16 Condition registers ciinii inio a o 14 17 Event registers iensor ie ei eenkeer eisi 14 17 15 16 17 Event enable registers 00 ee eeeeceesecereeseeeseeseseeeeeeeneeaes 14 18 Programming example program and read TESISLEL SOL voisin sitiseni iirin Eiaa 14 19 QVEUES n a S 14 19 Output QUCUC snnseiii eet edi seehieieavteenees 14 19 Etror QUCUE anera oe irn e e a ARENE 14 20 Programming example read error queue 14 21 Common Commands Command SUMMALY 2 0 0 eeseeeceeeeeceseeeeaeceseeceseeeeeceaeeeeneeeaeeseas 15 2 Command reference oo ee eeeeseesceseeseeesececeeaeeeeeesessaeeseeneeeaes 15 3 IDN identification query ceeecceeseeeeeeeteeeeeeeeeeens 15 3 OPC operation complete eee eeeeseeeeeeeeeeeeees 15 3 OPC operation complete query eeeceeeseeeeeeeeeees 15 3 OPC programming example 0 eee eeeeeeeeeeeeeee 15 4 OPT Option query seeeceeseeeeeeeeneeeeeeeeeeeetaeeeaeeeeeees 15 4 SAV lt INR
253. essseeeeeeeseeee 17 29 STATE SDP sess esses oeiiesgetdsntedesisvgcoivaied stesagecssidevereestesste 17 29 DATA 5 sore gscttsad vores shes e A E ARE 17 29 CAL Culate esse cisccsbescssevedes a dai Get eee ssdiavats cave ste eetes 17 30 Select DELTA calculation mode cccceessceeesteeeeseees 17 30 FORMat lt name gt ccccccccssseceeseeeesseeessseeeessaeeessnees 17 30 Enable and read DELTA result cceessceessteeeeeteeeeees 17 30 STATE lt b gt e3sh cscs ccsdevsscesasduvanss n TA 17 30 DATA meae r eats aetna 17 30 CAL Culate serene e a EE a AA EES 17 31 Select inp t path ceecsecsssesccvas cocerasesdaigaerendeesdceedesaicsdensetegss 17 31 FEED lt name gt sieisen ari errer iea a iir 17 31 Read limits data ccccccssccesssccsesecesseeessneeessneeeesseeesens 17 32 DATA r E AO ATN 17 32 LATES annsa a a E E E i RS 17 32 Configure and control limit tests ee eeeeeeeeeeeeeee 17 32 COMPliance FAIL lt name gt ccccccesesseeessseeeesnees 17 32 DATA lt K gt ood c5 sevesisss s2tecad on cacntesiedvedtesectesstisseceeseess 17 32 SOURce3 lt NRf gt lt NDN gt cecceseesseeeteeeseeeeeeeees 17 33 PASS SOURce3 lt NR gt I NDN uu ccecccsceeeseeeseeeees 17 35 STATE LD aasre rins ENE A EE E E S 17 35 Composite testing cee eeesseeseeneeeeeeeseeeeseeneesseeeneeaes 17 36 PASS SOURce3 lt NRf gt I NDN uu ceeeseesteeeteeereees 17 36 FAIL SOURce3 lt NRf gt 1 lt NDN gt cceee
254. est programming example 00 0 ce eeeeeeeeeeeee 11 21 12 Digital I O Port Output Enable and Output Configuration Digital 1 O port s sccccsceediveccicacsccuvetean dette cesidawediaceerescevtesvecees 12 2 Port configuration 20 eee eeeeeeeceneeeseeeeaeeeteeceaeeeeeeeaeeeteeeeas 12 2 Digital output lines oo eee eeeeeeceeeeeceeeeaeeeaeeees 12 3 SOLINE y tees cose axsvesvetsb peiseasvabeivgtecdiesteseesd tbe adtestovs 12 3 BOT BUSY line sessssissivtaces cried taateesisssgdeenteonsteteceds 12 3 EDV OUCPUE oreiro aaee eiar iieri 12 3 Digital output configuration sssseseeseeeeseesesesssssssssssssssrss 12 4 Sink operation oe eeeeeccescecsseceeeeceneeeseeceeeeseeeneeeeees 12 4 SOUPCE Operation esisiini irori 12 5 Controlling digital output lines oes eeeeeees 12 5 Front panel digital output control eee 12 5 Remote digital output control oo eee eeeeeeeeee 12 6 13 Output enable 0 scsieiensie ede a n a 12 6 Front panel output configuration 00 cece eeeseeeeeeeeeeeeeeeeees 12 8 Configure OUTPUT menu eee eee eeeeeseeeeeeeeeeeees 12 8 Remote output Configuration ee ceeeseeseeseeseeeeeeeeeeaeeeeeens 12 9 Output configuration commands see eeseeeeeeeeeeeeeees 12 9 Output configuration programming example 12 10 Remote Operations Differences remote vs local Operation cceeseeeceeeneeeseeeees 13 2 Local to remote transition ceeeeesceeseeeeeeeeneeeeeeeeeeeeees 13 2 Remote to l
255. evel Specify source 2 stop voltage level Parameters lt n gt 100 to 100 Set source level volts DEFault OV MINimum 100V MAXimum 100V Query STARt Query start level for sweep STARt DEFault Query RST default level STARt MINimum Query lowest allowable level STARt MAXimum Query highest allowable level STOP Query start level for sweep STOP DEFault Query RST default level STOP MINimum Query lowest allowable level STOP MAXimum Query highest allowable level Description These commands are used to specify the start and stop levels for a sweep If using a fixed manual source range the sweep will be per formed using a source range that will accommodate all source values 17 68 SCPI Command Reference Models 2500 and 2502 User s Manual best fixed range You can use source auto range if sweeping through one or more source ranges When the sweep is started the source will output the specified start level and after the delay period of the SDM cycle a measurement is per formed The sweep continues until the source outputs the specified stop level At this level the instrument again performs another measurement after the SDM delay and then stops the sweep The source and measure points in a sweep can be set by specifying a step size or by specifying the number of source and measure points in the sweep Refer to STEP lt n gt page 17 69 and POINts lt n gt page 17 70 STARt and STOP are coupled
256. eware of hazardous voltage that may be present on the output terminals 17 SCPI Command Reference e Reference tables Summarizes each SCPI command subsystem e SCPI subsystems Provides detailed information on all commands in each SCPI subsystem 17 2 SCPI Command Reference Models 2500 and 2502 User s Manual Reference tables Table 17 1 through Table 17 10 summarize the commands for each SCPI subsystem The following list includes the SCPI subsystem commands and the table number where each command is summarized Summary table Subsystem Function s 17 1 CALCulate Math REL ratio delta limits buffer statistics 17 2 DISPlay Display format and messages 17 3 FORMat Remote data format 17 4 OUTPut Source 1 and source 2 output on off output enable 17 5 SENSe Channel and channel 2 current measurements 17 6 SOURce Channel 1 and channel 2 source configuration 17 7 STATus Instrument status 17 8 SYSTem System presets error formats auto zero line freq 17 9 TRACe Channel and channel 2 buffer control and formats 17 10 TRIGger Unit triggering control General notes Brackets are used to denote optional character sets These optional characters do not have to be included in the program message Do not use brackets in the program message Angle brackets lt gt are used to indicate parameter type Do not use angle brackets in the program message The Boolean parameter lt b g
257. ff lt b gt 0 or OFF Turn source off standby 1 or ON Turn source on operate OUTPut 1 Query state of source 1 OUTPut2 Query state of source 2 These commands are used to turn the channel 1 and channel 1 source outputs on or off Turning a source off places the Model 2500 in the idle state The only exception to this is when source auto clear is enabled In this mode the source turns on during each source phase of the SDM cycle and then turns off after each measurement See SOURce 1 CLEar AUTO and SOURce2 CLEar AUTO in SOURce subsystem page 17 60 The SOURce 1 CLEar or SOURce2 CLEar command will also turn the respective source off Models 2500 and 2502 User s Manual SCPI Command Reference 17 53 Output enable control ENABle STATe lt b gt OUTPut 1 ENABle STATe lt b gt Control output enable for both sources Parameters lt b gt 0 or OFF Disable output enable 1 or ON Enable output enable Query ENABIle STATe Query state of output enable Description This command is used to enable or disable the output enable line When enabled the sources cannot be turned on unless the output enable line pin 8 of the rear panel digital I O connector is pulled to a logic low state When the output enable line goes to a logic high state both sources turn off See Section 12 Digital I O port and Output enable for details using output enable with a test fixture When disabled the logic level on t
258. flows for a gt 2 1mA input NOTE In single channel display mode the REL annunciator turns on for the displayed channel In dual channel display mode the REL annunciator turns on if rel is enabled for either channel Front panel rel Enabling and disabling rel Rel can be used to null out zero offsets or to establish a zero baseline on the selected mea surement channel by pressing the REL key The reading which becomes the rel value is subtracted from itself As a result a zero reading is displayed Pressing REL a second time disables rel Defining a rel value A unique rel value can be established for the selected channel from the front panel as follows 1 Press MSR1 or MSR2 to select either channel 1 or channel 2 measurement 2 Press CONFIG and then REL The present rel value will be displayed 3 Set the desired rel value See Section 1 Rules to navigate menus for details 4 With the desired rel value displayed press ENTER The Model 2500 will return to the normal display with rel enabled The reading will reflect the defined rel value Models 2500 and 2502 User s Manual Relative Math Ratio and Delta Using REL in the dual channel mode The REL key does not function while the display is in the dual channel RATIO or DELTA display modes To view two rel readings simultaneously Press MSR1 Press REL Press MSR2 Press REL Se eee Remote rel programming Rel commands Press TOGGLE to display
259. fter the Model 2500 sends the end of test EOT strobe pulse to the fourth handler line the handler places the DUT into the bin assigned to that bit pattern Category pulse component handler When using this type of handler the Model 2500 pulses one of the four handler lines when a pass or fail condition occurs The handler then places the DUT in the bin assigned to that pulsed line When interfacing to this type of handler a maximum of four component han dler bins are supported If the handler requires low going pulses then the four digital output lines of the Model 2500 must initially be set to high This initial HI HI HI HI clear pattern on the output lines represents a no action condition for the handler since it is waiting for one of the lines to go low A line goes low when the defined fail or pass pattern sets it low For example if you want a particular test failure to pulse line 4 of the handler the defined fail pattern has to be HI HI HI LO When the failure occurs line 4 will be pulled low and the DUT will be placed in the bin assigned to that pulsed line 11 12 Limit Testing Models 2500 and 2502 User s Manual If the handler requires a high going pulse the four digital output lines of the Model 2500 must initially be set low The LO LO LO LO clear pattern represents the no action condi tion for the handler When one of those lines are pulled high by a defined pass or fail bit pattern i e LO LO LO HI the DUT
260. function readings and the bottom line shows voltage bias values Channel 1 measurement function readings MSR1 are dis played on the left while channel 2 measurement function values MSR2 appear on the right You can select channel 1 channel 2 or dual channel display with the CHANNEL SELECT and DISPLAY TOGGLE keys see CHANNEL SELECT key and DISPLAY TOGGLE key below Measurement reading information can be displayed using either engineering units or sci entific notation in either fixed or floating point format Use the GENERAL NUMBERS selection of the main MENU to select the display format as discussed under Menus later in this section Engineering units example 1 234567pA Scientific notation example 1 234567e 6A Annunciators which are located along the top of the reading message display indicate various states of operation as covered previously in Front panel summary 1 14 Getting Started Model 2500 and 2502 User s Manual CHANNEL SELECT key The CHANNEL SELECT key toggles between the channel 1 and channel 2 measurements on the left hand display when the single channel display mode is selected see below DISPLAY TOGGLE key The DISPLAY TOGGLE key turns the dual channel display mode on or off When the dual channel mode is active the channel 1 measurement function reading MSR1 appears on the left I V I I V I x V or MX B while the channel 2 measurement function MSR2 appears on the r
261. ger count to 10 Use EDIT gt key to scroll to the far right of the menu selections and select COUNT then press ENTER Set the count to 10 then press the ENTER key Press the EXIT key twice to leave CONFIGURE TRIGGER menus 10 12 Triggering Models 2500 and 2502 User s Manual Switching mainframe setup Step 1 Restore bench defaults Press the MENU key select SAVESETUP and then press ENTER From the SAVESETUP menu select RESET then press ENTER Press ENTER to confirm the action Press ENTER to return to the SETUP MENU Press EXIT to leave the SETUP MENU Press EXIT to leave the MAIN MENU Step 2 Set up scan list 1 1 1 10 Press the SCAN LIST key Press 1 1 1 1 0 then press the ENTER key Step 3 Set the number of scans to 1 Press the SCAN key select SCAN CONTROL and then press ENTER From the SCAN CONTROL menu select NUMBER OF SCANS then press ENTER Select ENTER SCAN COUNT then press ENTER Set the count to 1 then press ENTER Press the EXIT key to return to the CONFIGURE SCAN menu Step 4 Set channel spacing to trigger link Select CHAN CONTROL from the CONFIGURE SCAN menu then press ENTER Select CHANNEL SPACING from the CHANNEL CONTROL menu then press ENTER Select TRIGLINK then press ENTER Select ASYNCHRONOUS then press ENTER Press ENTER ENTER then EXIT EXIT EXIT to leave the CONFIGURE SCAN menu Operation 1 To store the readings in the Model 2500 buffer press STORE and set the buffer
262. ger model front panel operation 0 0 eee eeeeeeeeeeeeeeeee 10 2 MAG rs cece 55 cases eneas area aae eae E aE OERE ia 10 2 Eyentdet ctlon ssiiisisrisreniriotissi niia 10 4 AfM LAV OR sieniin neie err rees ae eE ai 10 4 Trigger layer cennoisnecononrnncenoii a 10 5 Trigger delay vscseccsnsisdieue cacesdessoaiees sieve E oaeteassetsasers 10 5 Source delay and measure actions ceeeeeseeeseeeeeeeeeeee 10 5 CCOUWINIETS seision air eee decvebenseuilesagetetatanayeds 10 6 O tp t MIE BCLS icnn eio sie gee 10 6 Bench defaults ossessioni 10 7 Png ger WOK wisest avis hl alee 10 8 Input trigger requirements eee eeeeeeseeeeeeeseeeaeeeeeeaees 10 8 Output trigger specifications 0 eee eee eeeeeseeeeeeteeeeeeaees 10 9 External triggering example 0 eee eeeeeseeseeereeeeeenees 10 9 Model 2500 setup sociso 10 11 Switching mainframe Setup 0 0 eee eseeeseeeeeeee 10 12 Oper tion seecsesetessnadeerdecstiedscswesteevesdaesasvenesusaesedevertasy 10 12 Configuring triggering ec eeeeeeeceeeeeeeeneeceeeeeeeceeeeseeeeneees 10 14 CONFIGURE TRIGGER menu eerren 10 14 Remote tegere ssiri inaa E E 10 17 Trigger model remote operation eseeeeseeeeeeereersreereee 10 17 Tdle and initiate niensis er teenrina anieri r raea 10 17 Eventdetectlon sirere ioiii oein s EiS 10 19 Arm layer rinceoir eea EEEE 10 19 Trigger LAYER ririri tiikan oesi ei EES e 10 20 Tigger delay ceasseecsecsastesassauesadne ar r E TEATA SENA EERE
263. ghten them Figure 13 3 IEEE 488 and RS 232 connector location RS 232 IEEE 488 Connector Connector WARNING no INTERNAL OPERATOR SERVICABLH PARTS SERVICE BY QUALIFIED PERSONNE ONLY a RATINGS MAX Q 100V 20mA KEITHLEY PE e MADE IN CHANGE I EE ADDRESS MODA U S A ee WET PRON PANEL MENU INPUT INPUT CHANNEL 1 CHANNEL 2 TRIGGER LINK CATI LINE RATING 50 60Hz C RATINGS MAX SONA MAX 100V 20mA Fuse une 630 mAT 100 VAC A SB 120 VAG 315 mAT 220 VAC VOLTAGE SOURCE VOLTAGE SOURCE SB 240 VAC OUTPUT CHANNEL 1 OUTPUT CHANNEL 2 CAUTION FOR CONTINUED PROTECTION AGAINST FIRE HAZARD REPLACE FUSE WITH SAME TYPE AND RATING Model 2500 3 Connect any additional connectors from other instruments as required for your application 4 Make sure the other end of the cable is properly connected to the controller Most con trollers are equipped with an IEEE 488 style connector but a few may require a differ ent type of connecting cable See your controller s instruction manual for information about properly connecting to the IEEE 488 bus 13 6 Remote Operations Models 2500 and 2502 User s Manual NOTE You can only have 15 devices connected to an IEEE 488 bus including the con troller The maximum cable length is either 20 meters or two meters multiplied by the number of devices whichever is less Not observing these limits may cause erratic bus operatio
264. gnored EE Standard Event 4 212 Arm ignored EE Standard Event 4 211 Trigger ignored EE Standard Event 4 210 Trigger error EE Standard Event 4 202 Settings lost due to rtl EE Standard Event 4 201 Invalid while in local EE Standard Event 4 200 Execution error EE Standard Event 4 B 4 Status and Error Messages Models 2500 and 2502 User s Manual Table B 1 continued Status and error messages Number Error message Event Status register Bit 178 Expression data not allowed EE Standard Event 5 171 Invalid expression EE Standard Event 5 170 Expression error EE Standard Event 5 168 Block data not allowed EE Standard Event 5 161 Invalid block data EE Standard Event 5 160 Block data error EE Standard Event 5 158 String data not allowed EE Standard Event 5 154 String too long EE Standard Event 5 151 Invalid string data EE Standard Event 5 150 String data error EE Standard Event 5 148 Character data not allowed EE Standard Event 5 144 Character data too long EE Standard Event 5 141 Invalid character data EE Standard Event 5 140 Character data error EE Standard Event 5 128 Numeric data not allowed EE Standard Event 5 124 Too many digits EE Standard Event 5 123 Exponent too large EE Standard Event 5 121 Invalid character in number EE Standard Event 5 120 Numeric data error EE Standard Event 5 114 Header suffix out of range EE Standard Event 5 113 Undefined header EE Standard Event 5 112 Program
265. grammed separately see below FORMat lt name gt CALCulate2 FORMat lt name gt Select channel 2 math function Parameters lt name gt MXB2 MX B COND2 I2 V2 POWER2 V2 I2 RES2 V2 12 OP2 measured Taark current Responsivity Query FORMat Query selected math function Description This command selects the channel 2 math function The channel 2 cur rent reading 12 and source voltage V2 are used to calculate COND2 conductance POWER2 and RES2 resistance while MX B and OP2 parameters are programmed separately see below 17 24 SCPI Command Reference Models 2500 and 2502 User s Manual Set MX B parameters MBFactor lt n gt CALCulate 1 KMATh MBFactor lt n gt Select channel 1 B offset value CALCulate2 KMATh MBFactor lt n gt Select channel 2 B offset value Parameters lt n gt 9 99999e20 to Specify B offset value for MX B 9 99999e20 MINimum 9 99999e20 MAXimum 9 99999e20 DEFault 0 Query MBFactor Query B offset value for MX B Description These commands program the B offset value for the MX B math function see FORMat lt name gt above Use CALC1 for channel 1 or CALC2 for channel 2 MMFactor lt n gt CALCulate 1 KMATh MMFactor lt n gt Select channel 1 M slope value CALCulate2 KMATh MMFactor lt n gt Select channel 2 M slope value Parameters lt n gt 9 99999e20 to Specify M slope value for MX B 9 99999e20 MINimum 9 99999e20 MAXimum 9 99999e20 DEFault 1 Query MMF
266. gt Define message bottom display Parameters lt a gt ASCII characters for message Types String aa a or aa a Indefinite Block 0aa a Definite Block XYaa a where Y number of characters in message Up to 20 for top display Up to 32 for bottom display X number of digits that make up Y 1 or 2 Query DATA Query the defined text message Description These commands define text messages for the display A message can be as long as 20 characters for the top display and up to 32 characters for the bottom display A space is counted as a character Excess message characters result in an error An indefinite block message must be the only command in the program message or the last command in the program message If you include a command after an indefinite block message on the same line it will be treated as part of the message and is displayed instead of executed Models 2500 and 2502 User s Manual SCPI Command Reference 17 43 STATe lt b gt DISPlay WINDowI 1 TEXT STATe lt b gt Control message top display DISPlay WINDow 2 TEXT STATe lt b gt Control message bottom display Parameters lt b gt 0 or OFF Disable message for specified display 1 or ON Enable message for specified display Query STATe Query state of message mode for specified display Description These commands enable and disable the text message modes When enabled a defined message is displayed When disabled the message is removed f
267. gure 2 4 Figure 2 5 Figure 2 6 Figure 2 7 Figure 2 8 Figure 2 9 Figure 2 10 Figure 2 11 Figure 2 12 Figure 2 13 3 Figure 3 1 Figure 3 2 Figure 3 3 Figure 3 4 Figure 3 5 4 Figure 4 1 Figure 4 2 5 Figure 5 1 Figure 5 2 Figure 5 3 Figure 5 4 Getting Started Front panel ccesscecsiveee alin i E EEE 1 6 Model 2500 rear panel ceeceesccesceceeceneeeeneceeeeeeeeeseeeeeeees 1 8 Model 2502 rear panel ceeceeecceseececceseeeeeeeeeeeeseeesseeeeneees 1 9 Mainmenu tre i isessseiesssescossesesesesncderessendscosessincedtereosedenstte 1 22 Connections Model 2500 rear panel showing INPUT and OUTPUT COnmectoLs cece see ceseseeeeeeeseeeeeeceseneeeeeenes 2 2 INPUT connector terminals 000 0 ee eeeeseeseeseceeeeeeeeeeeeees 2 3 Typical photodiode connections 0 0 ce eeseeseesseeeeereeeseeeeeees 2 5 Equivalent circuit of photodiode test connections 2 6 Test connections using ground connect mode ee 2 7 Ground connect mode equivalent circuit eee eeseeseeeeeee 2 8 Stand alone current measurement connections eee 2 9 Stand alone voltage source CONNECTIONS eeeeeeeteeeseeeeees 2 10 Analog output connector terminals cceeseeseeeneeeneeeees 2 11 Non isolated analog output Connections 0 0 0 0 eee 2 12 Isolated analog output connections 0 eee eee eeeereeeeeeee 2 13 Analog output equivalent circuit with ground connect disabled oo eseeseeeceese
268. gure and control REL OFFSet lt NRf gt Specify REL value 9 999999e20 to 9 999999e20 0 OFFSet Query REL value STATe lt b gt Enable or disable REL OFF STATe Query state of REL ACQuire Automatically acquire REL value DATA Read CALC3 data v CALCulate4 Subsystem to control CALC4 channel 2 REL y FEED lt name gt Select input path SENSe2 or CALCulate2 SENS2 v FEED Query CALC4 feed v NULL Path to configure and control REL OFFSet lt NRf gt Specify REL value 9 999999e20 to 9 999999e20 0 OFFSet Query REL value STATe lt b gt Enable or disable REL OFF STATe Query state of REL ACQuire Automatically acquire REL value DATA Read CALC4 data v CALCulate5 Subsystem to control CALCS RATIO y FORMat lt name gt Select ratio math C3C4 CALC3 CALC4 C3C4 Jv C4C3 CALC4 CALC3 STATe lt b gt Enable or disable CALCS5 math OFF STATe Query state of ratio DATA Request CALCS data v CALCulate6 Subsystem to control CALC6 DELTA y FORMat lt name gt Select delta math C3C4 CALC3 CALC4 C3C4 Jv C4C3 CALC4 CALC3 STATe lt b gt Enable or disable CALCS5 math OFF STATe Query state of delta DATA Request to CALCS data v Default based on present digital output size SOURce3 BSIZe lt n gt 3 bit default is 7 4 bit default is 15 16 bit default is 65535 16 bit available only with 2499 DIGIO option 2 The format ASCII hexadecimal octal or binary for the returned value
269. han 1 10V source range Set channel 1 source amplitude SOUR1 VOLT 10 Chan 1 output 10V Set channel 2 source range SOUR2 VOLT RANG 100 Chan 2 100V source range Set channel 2 source amplitude SOUR2 VOLT 20 Chan 2 output 20V 3 Turn on channel outputs OUTP1 ON Output 1 on OUTP2 ON Output 2 on 4 Set ranges read data SENS1 CURR RANG AUTO ON Chan 1 autorange SENS2 CURR RANG AUTO ON Chan 2 autorange READ Trigger acquire C1 reading CALC2 STAT ON Enable C2 math INIT Trigger C2 math reading 5 Turn off outputs gt CALC2 DATA Acquire C2 math reading OUTP1 OFF Outputs off after OUTP2 OFF measuring Steps correspond to front panel steps previously in Front panel photodiode measurement procedure 2Commands must be sent in order given 3Instrument must be addressed to talk after INIT or READ to acquire data 3 Measurement Concepts Source delay measure cycle Describes the various phases of the source delay measure cycle Sweep waveforms Covers the various types of sweeps that can be performed Bias source operating boundaries Covers voltage output and current limit operat ing boundaries for the voltage bias sources Data flow Describes measurement readings ratio delta rel and limits operation and how data is stored in the buffer 5 2 Measurement Concepts Models 2500 and 2502 User s Manual Source delay measure cycle Overview Model
270. hange protocol MEP disables Therefore if you use the following query to request the state of MEP you will know which protocol is enabled SYSTem MEP STATe If a 1 is returned MEP is enabled and the SCPI protocol is selected A 0 indicates that MEP is disabled and the 488 1 protocol is enabled To summarize 1 SCPI protocol 0 488 1 protocol Models 2500 and 2502 User s Manual GPIB 488 1 Protocol G 3 Protocol differences The following information covers the differences between the 488 1 protocol and the SCPI protocol Message exchange protocol MEP When the 488 1 protocol is selected the MEP is disabled to speed up GPIB operation The following guidelines limitations must be followed when using the 488 1 protocol If a query is sent it must be the only command on the line this limitation also means no multiple queries can be sent Otherwise full SCPI command syntax is still sup ported including long form and short form commands multiple commands and MIN MAX DEF parameter definitions For example the following command strings are invalid SOUR2 VOLT RANG 10 OPC SENS2 CURR RANG READ READ READ The following command strings are valid SOURI VOLTage STARt 1 STOP 10 step 1 curr nple 1 0 curr rang min SENS2 CURR RANG MAX READ When a query is sent either the data must be read back or a Device Clear DCL or Interface Clear IFC must be performed to reset the query When sending
271. he ASCII format NOTE Regardless of which data format for output strings is selected the Model 2500 will only respond to input commands using the ASCII format Figure 17 1 ASCII format The ASCII data format is in a direct readable form for the operator Most BASIC languages easily convert ASCII mantissa and exponent to other formats However some speed is compromised to accommodate the conversion Figure 17 1 shows an example ASCII string that includes current and voltage for one channel as well as time and status data elements See ELEMents lt item list gt Figure 17 1 also shows the byte order of the data string Data elements not specified by the ELEMents command are simply not included in the string Keep in mind that the byte order can only be reversed for the binary for mat See BORDer lt name gt ASCII data format 1 000206E 03 1 000000E 02 7 282600E 01 4 813200E 04 es eee ees eee Channel 1 Reading Channel 2 Time Status Reading IEEE 754 single precision format REAL 32 or SREal will select the binary IEEE 754 single precision data format Figure 17 2 shows the normal byte order format for each data element For example if three valid elements are specified the data string for each reading conversion is made up of three 4 byte data blocks Note that the data string for each reading conversion is preceded by a 2 byte header that is the binary equivalent of an ASCII sign and 0 Figure 17 2 d
272. he EDIT A and W keys increment and decrement the selected digit of the loca tion number Cursor position is controlled by the EDIT lt and keys When scrolling for ward past the last stored reading the buffer wraps to the first stored reading Conversely when scrolling in reverse past the first stored reading the buffer wraps to the last stored reading The memory location number can also be keyed in using the 0 through 9 number keys Position the cursor on the appropriate digit and press the desired number key The cursor then moves right to the next least significant digit For example to display reading 0236 position the cursor all the way to the left MSD and press 0 2 3 6 Note that if keying in a number that exceeds the buffer size the reading at the highest memory location is dis played To exit from the data store recall mode press EXIT 8 4 Data Store Models 2500 and 2502 User s Manual Buffer statistics With the data store in the recall mode buffer statistics are displayed by using the DIS PLAY TOGGLE key Use the DISPLAY TOGGLE key to sequence through the statistics and return the Model 2500 to the normal data store recall state Pressing EXIT at any time returns the instrument to the normal display state NOTE Statistics calculations will be performed on the presently selected function MSR1 MSR2 RATIO or DELTA You can display these different functions while the statistics mode is active by pressing the ap
273. he SWAPped byte order must be used when transmitting binary data to any IBM PC compatible computer Status register format SREGister lt name gt FORMat SREGister lt name gt Set data format for reading status registers Parameters lt name gt ASCii Decimal format Hexadecimal Hexadecimal format OCTal Octal format BINary Binary format Query SREGister Query format for reading status registers 17 52 SCPI Command Reference Description Models 2500 and 2502 User s Manual Query commands are used to read the contents of the status event regis ters This command is used to set the response message format for those query commands When a status register is queried the response message is a value that indicates which bits in the register are set For example if bits B5 B4 B2 B1 and BO of a register are set 110111 the following values will be returned for the selected data format ASCii 55 decimal value Hexadecimal H37 hexadecimal value OCTal Q67 octal value BINary B110111 binary value See Section 14 and Status Structure in this section for more information OUTPut subsystem This subsystem is used to control the voltage source outputs and the output enable line These commands are summarized in Table 17 4 Turn source on or off STATe lt b gt OUTPut 1 STATe lt b gt OUTPut2 STATe lt b gt Parameters Query Description NOTE Turn source 1 on or off Turn source 2 on or o
274. he error queue Query DISable Query list of disabled messages Description On power up all error messages are enabled and will go into the error queue as they occur Status messages are not enabled and will not go into the queue This command is used to specify which messages you want disabled Disabled messages are prevented from going into the error queue Models 2500 and 2502 User s Manual SCPI Command Reference 17 81 SYSTem subsystem The SYSTem subsystem contains miscellaneous commands that are summarized in Table 17 8 Default conditions PRESet SYSTem PRESet Return to SYSTem PRESet defaults Description This command returns the instrument to states optimized for front panel operation SYSTem PRESet defaults are listed in the SCPI tables Table 17 1 through Table 17 10 POSetup SYSTem POSetup lt name gt Program power on defaults Parameters lt name gt RST Power up to RST defaults PRESet Power up to SYSTem PRESet defaults SAVO Power up to setup stored at memory location 0 SAV1 Power up to setup stored at memory location 1 SAV2 Power up to setup stored at memory location 2 SAV3 Power up to setup stored at memory location 3 SAV4 Power up to setup stored at memory location 4 Query POSetup Query power on setup Description This command is used to select the power on defaults With RST selected the instrument powers up to the RST default conditions With PRES selected the instrument powers up to the S YStem PRESet
275. he limit tests fail the FAIL message will be displayed Binning For the sorting mode only immediate binning can be performed After the testing process is finished FAIL or PASS displayed the appropriate output bit pattern will be sent to the component handler which will place the DUT in the assigned bin The pass fail condition can also be queried via remote with CALC7 LIM lt n gt FAIL Using a sweep with immediate binning lets you test different devices at different source levels For example assume a 3 point linear sweep at 1V 2V and 3V step levels The first DUT is tested at 1V the second DUT is tested at 2V and the third DUT is tested at 3V Models 2500 and 2502 User s Manual Limit Testing 11 9 Figure 11 5 Sorting mode limit testing Turn Output ON and press LIMIT key Wait for SOT Pulse from Handler Perform Source Measure Action Yes No Display Output Limit 1 2 FAIL Fail Pattern Yes Perform Limit 1 2 Test Limits y Dispi ama Disabled Perform Limit 3 Test Display Output Limit 3 PASS Pass Pattern Perform Limit 4 6 Tests 2 Display FAIL Output Fail Pattern Test Another Device Output Limit 4 6 Pass Pattern No Yes No Press LIMIT 11 10 Limit Testing Models 2500 and 2502 User s Manual Binning systems The Model 2500 can be used with a component handler to perform binning operations on DUT package
276. he other photodiode terminal e Channel 2 is used to bias and measure the forward detector photodiode The center conductor of INPUT CHANNEL 2 HI is connected to one photodiode terminal while the VOLTAGE SOURCE CHANNEL 2 terminal is connected to the other photodiode terminal See Section 4 Photodiode Measurements for additional information on setting up Model 2500 operating modes including making power measurements NOTE Ifan optional noise shield is used connect the shield to INPUT LO inner shield of triax cable Model 2500 and 2502 User s Manual Figure 2 3 Typical photodiode connections INPUT HI Forward Photodiode Laser i I l j INPUT LO Diode i I I I I I Triax Cables Back Photodiode Optional Noise Shield Connect to INPUT LO INPUTS INPUT INPUT DIGITAL 1 0 CHANNEL 1 CHANNEL 2 TRIGGER LINK Linees LINE RATING 50 60Hz 60 VAMAX FUSE LNE 630 mAT 100 VAC SB 120 VAG A 315 mAT 220 VAG SB 240 VAC Model 2500 OUTPUTS T owne owe Connections 2 5 INPUT HI center conductor INPUT LO inner shield ji NO INTERNAL OPERATOR SERVICABLE PARTS SERVICE BY QUALIFIED PERSONNEL ONLY IEEE 488 CHANGE IEEE ADDRESS WITH FRONT PANEL MENU o o 2 6 Connections Model 2500 and 2502 User s Manual Equivalent circuit Figure 2 4 shows an equivalent circuit for the connection scheme shown in Figure 2 3 Th
277. he output enable line has no effect on the output state of the source TRIPped OUTPut 1 ENABle TRIPped Description This query command is used to determine if output enable has been tripped The tripped condition 1 means that the sources can be turned on output enable line at logic low level A 0 will be returned if the sources cannot be turned on output enable line at logic high level 17 54 SCPI Command Reference Models 2500 and 2502 User s Manual SENSe subsystem The SENSe subsystem is used to configure and control the measurement functions of the Model 2500 SENSe 1 controls channel 1 measurement functions and SENSe2 controls channel 2 functions Some of the commands are global where a single command affects both channels Other commands are unique to a specific channel For example you can program a unique range setting for each channel A channel does not have to be selected before you can program its various configurations Whenever a programmed channel is selected it assumes the programmed states The commands for this subsystem are summarized in Table 17 5 Select measurement range UPPer lt n gt SENSe 1 CURRent DC RANGe UPPer lt n gt IUPIDOWN Select range for channel 1 SENSe2 CURRent DC RANGe UPPer lt n gt IUPIDOWN Select range for channel 2 Parameters lt n gt 21e 3 to 2le 3 Expected reading in amps DEFault 2e 4 MINimum 21e 3 MAXimum 21e 3 UP Select next higher
278. hen J STEST is the selected arm event of the trigger model the testing process will start when the SOT line is pulsed low When TSTEST is the selected arm event the testing pro cess will start when the SOT line is pulsed high When TLSTEST is the selected arm event the testing process will start when the SOT line is pulsed either high or low With the IMMEDIATE arm event selected the testing process will start as soon as the LIMIT key is pressed assuming the output is ON See Section 10 for details on trigger model configuration When using the SOT line the handler will not pulse the line while it is in a not ready con dition When the handler is ready DUT properly positioned in the handler it pulses the SOT line low or high to start the test OE line The OE output enable line of the Digital I O can be used if the component handler is equipped with an interlock switch With proper use of output enable power is removed from the DUT when the lid of the handler is opened See Section 12 Digital I O port and Output enable for operation details on the interlock Handler types The Model 2500 can be used with either of the two basic types of handlers When used with a Category Pulse Handler the Model 2500 pulses one of the four handler lines The handler then places the DUT into the bin assigned to the pulsed line When used with a Category Register Handler the Model 2500 outputs a bit pattern to three handler lines A
279. his error are e Missing space between the command and its parameter There must be one or more spaces blanks between the command and its parameter For example SENS 1 CURR RANG2e3 Incorrect no space between command and parameter SSENS1 CURR RANG 2e3 Correct Improper short or long form Check the command list in Section 17 for the correct command name e Blanks spaces within the command name For example SYST ERR Incorrect space between SYST and ERR SYST ERR Correct 410 Query INTERRUPTED This error occurs when you have sent a valid query to the instrument and then send it to another command or query or a Group Execute Trigger GET before it has had a chance to send the entire response message including the line feed EOI terminator The most likely causes are Sending a query to the instrument and then sending another command or query before reading the response to the first query For example the following sequence of com mands will cause an error 410 SYST ERR OPC This sequence generates an error because you must read the response to SYST ERR before sending the OPC query Incorrectly configured IEEE 488 driver The driver must be configured so that when talking on the bus it sends line feed with EOI as the terminator and when listening on the bus it expects line feed with EOI as the terminator See the reference manual for your particular IEEE 488 interface Models 2500 an
280. i 17 81 Control duto ZETO seninim 17 82 STATe lt MAMe gt seceeicscsivasesesseeazea s Ee aE E E RE 17 82 Select power line frequency setting eseeeeeerereeeereeeeee 17 82 LFRequency lt freq gt nesnesrrenrrarisi 17 82 Erto Quelle sees seinen deine aatleis ijn 17 82 ENEXTI seseuccciis iepesdecevecsascate tdsuehetanenesatevsMensbberestnnss 17 82 ALUT oerinoar ea a E 17 83 COUNT aga escesdentsst ototeoeptans ae a a Eea A i 17 83 CODE ENEXT onines 17 83 CODE ALL rosiers n e ae eis 17 83 CLE ar e E hi E E EE E 17 83 Simulate key presses sersicsisriseriirsscsssesessivesssrsistsrusessess 17 84 KEY shy anicalenildi nade Sa eee iy etal 17 84 Read version of SCPI standard o eee eeeeeeneeeeeeeeeee 17 85 VERSION i cs25 5006 fast soho paraad ia K a a 17 85 RS 232 interface seier ienien arei 17 85 LOC al reroncen ienaa a a a 17 85 REMOTE igi sen0ctsesesttneedvees eneeier oae ao ar Tn ais 17 85 RWLOCK sosai oa niin steed ad iae 17 86 Reset timestamp ca isesesescasicegssdnssbecestabeedesedeteedbnaisanceccesteeses 17 86 RES pozonio ac ela eds 17 86 TRAGESUDSY SUED resecie 17 87 Read and clear buffer eee eeeseeeeseeseeeeeeeeeseeseeeaeees 17 87 DATA ooa sen aE aa a iucsdeeceha tetas eesbeatas 17 87 CLEAT pcnre a eee 17 87 Configure and control buffer eseeeeeeeeeeeseereeereerrereerses 17 88 FREE soniodd oia 17 88 POINIS SOS seitin earainn E aeea E a ea eaae iR 17 88 ACTUal sinin i eee eth 17 88 CONTO lt M aime gt
281. ient over voltages often associated with local AC mains connections Assume all measurement control and data I O connections are for connection to Category I sourc es unless otherwise marked or described in the Manual Exercise extreme caution when a shock hazard is present Lethal voltage may be present on cable connector jacks or test fixtures The American National Standards Institute ANSI states that a shock hazard exists when voltage levels greater than 30V RMS 42 4V peak or 60VDC are present A good safety practice is to expect that hazardous voltage is present in any unknown circuit before measuring Operators of this product must be protected from electric shock at all times The responsible body must ensure that operators are prevented access and or insulated from every connection point In some cases connections must be exposed to potential human contact Product operators in these circumstances must be trained to protect themselves from the risk of electric shock If the circuit is capable of operating at or above 1000 volts no conductive part of the circuit may be exposed Do not connect switching cards directly to unlimited power circuits They are intended to be used with impedance limited sourc es NEVER connect switching cards directly to AC mains When connecting sources to switching cards install protective de vices to limit fault current and voltage to the card Before operating an instrument make sure the line cord is con
282. ies number of readings stored in the buffer POINts Query buffer size v CONTrol lt name gt Specify buffer control mode NEVER or NEXT v CONTrol Query buffer control mode v TSTamp Path to set timestamp format FORMat lt name gt Select format ABSolute or DELTa FORMat Query timestamp format Note SYSTem PRESet and RST have no effect on the commands in this subsystem Models 2500 and 2502 User s Manual Table 17 10 TRIGger command summary SCPI Command Reference 17 21 Command Description INITiate IMMediate ABORt ARM SEQuence 1 LAYer 1 COUNt lt n gt COUNt SOURce lt name gt SOURce TIMer lt n gt TIMer TCONfigure DIRection lt name gt DIRection AS YNchronous ILINe lt n gt ILINe OLINe lt n gt OLINe OUTPut lt name gt OUTPut TRIGger SEQuence 1 COUNt lt n gt COUNt DELay lt n gt DELay SOURce lt name gt SOURCce Initiate source and measure cycle s Reset trigger system Goes to idle state Path to program Arm Layer Specify arm count 1 to 3000 or INFinite Query arm count INFinite 9 9e37 Specify control source IMMediate TIMer MANual BUS TLINk NSTest PSTest BSTest Query control source Set timer interval in seconds 0 001 to 99999 99 Query timer interval Enable SOURce or disable ACCeptor bypass Query state of bypass Configure output trigg
283. ifying the number of mea sure points and the source level at each point See Section 9 for more details on sweep operation Figure 5 3 Basic sweep waveform types Stop Start Bias Linear Staircase Sweep Stop lt 100 10 Start 1 0 1 f Logarithmic scale Bias shown for staircase steps Logarithmic Staircase Sweep First Point Last Point ei Bias Custom Sweep Models 2500 and 2502 User s Manual Measurement Concepts 5 5 SDM cycle during sweeps An SDM cycle is performed on each step or point of the sweep Thus one measurement will be performed at each step level The time spent at each step level depends on how the SDM cycle is configured i e source delay measure speed and the trigger delay if used Typical sweep applications Typical applications for staircase sweeps include photodiode I V curves The custom sweep can be used to configure a pulse sweep with a 50 duty cycle For example a 10V pulse sweep can be configured by programming the odd numbered points for 10V and the even numbered points for OV When the sweep is run the output will alternate between 10V and OV Sweep data storage For a sweep that has a finite sweep count the data will automatically be stored in the buffer This data can be accessed from the front panel or sent to a computer remote oper ation for evaluation plotting Statistical information on readings stored in the buffer are also available from the front pan
284. igger bypass Parameters lt name gt SOURce Enable control source bypass ACCeptor Disable control source bypass Query DIRection Query state of bypass Description This command is used to enable SOURce or disable ACCeptor con trol source bypass When enabled operation will loop around the con trol source on the first pass in the layer After that repeat passes in the layer are held up and will wait for the programmed control source event 17 94 SCPI Command Reference Models 2500 and 2502 User s Manual INPut lt event list gt Parameters TRIGger SEQuence 1 TCONfigure ASYNchronous INPut lt event list gt Enable event detectors lt event list gt SOURce Enable Source Event Detector DELay Enable Delay Event Detector SENSe Enable Measure Event Detector NONE Disable all event detectors in Trigger Layer NOTE Each event in the list must be separated by a comma i e trigger input source delay sense Query Description INPut Query enabled event detectors in Trigger Layer When TLINk is the selected Trigger Layer control source and an event detector in the Trigger Layer is enabled operation will hold up at that detector until an input trigger is received via the Trigger Link When the event detector is disabled operation will not hold up It continues and performs the appropriate action A Trigger Layer event detector is enabled by including the parameter name in the event list for the INPut command
285. ight of the top line The DISPLAY TOGGLE key is also used to select the channel and display statistical data on readings stored in the data store buffer These functions are performed from the data store RECALL mode See Section 8 for data store information Status and error messages Status and error messages are displayed momentarily During Model 2500 operation and programming you will encounter a number of front panel messages Typical messages are either status or error in nature and are listed in Appendix B Disabling front panel display Front panel display circuitry can be disabled to allow the instrument to operate at a higher speed While disabled the display is frozen with the following message FRONT PANEL DISABLED Press LOCAL to resume As reported by the message all front panel controls except LOCAL TRIG and OUT PUT ON OFF are disabled Front panel control Front panel display circuitry is controlled from the DISABLE DISPLAY configuration menu which is accessed by pressing CONFIG and then CHANNEL SELECT or DIS PLAY TOGGLE To select an option NOW NEVER SWEEP or STORE use the lt and p gt keys to place the cursor on the desired option then press ENTER The options for DISABLE DISPLAY are explained as follows NOW Select this option to disable the display now NEVER Select this option if you do not want the display to disable Model 2500 and 2502 User s Manual Getting Started 1 15 SWEEP
286. ils 2 4 Connections Model 2500 and 2502 User s Manual Output enable An interlock switch can be used with the Model 2500 output enable line on the Digital I O Port to inhibit the voltage bias source outputs When output enable is activated the Model 2500 outputs will turn off when the lid of the test fixture is opened However you must ALWAYS assume that power is present until you verify that the Model 2500 output is off WARNING To prevent electric shock test connections must be configured such that the user cannot come in contact with conductors or any DUT that is in contact with the conductors Safe installation requires proper shields barriers and grounding to prevent contact with conductors Operator protection and safety are the responsibility of the person installing the product See Section 12 for complete details on using the output enable circuit Photodiode connections Typical connections Figure 2 3 shows typical connections to the back detector and forward detector photo diodes in a laser diode test setup NOTE The DUT can be biased and measured using only a triax cable with the ground connect mode See Ground connect mode connections page 2 7 The two channels are being used as follows e Channel 1 biases and measures the current for the back detector photodiode The cen ter conductor of INPUT CHANNEL 1 HI is connected to photodiode terminal while the VOLTAGE SOURCE CHANNEL 1 terminal is connected to t
287. ils the FAIL message is displayed and the testing process for that DUT or DUT element is terminated A pass condition allows the testing process to proceed to the next enabled limit test 11 4 Limit Testing Models 2500 and 2502 User s Manual With the grading mode selected each enable software test Limits 3 to 6 is performed until a failure occurs When a test fails the FAIL message is displayed and the testing pro cess for that DUT is terminated With the sorting mode selected each enabled software test Limits 3 to 6 is performed until a test passes When a test passes the PASS message is displayed and the testing pro cess for that DUT is terminated Binning Even though no additional equipment is required to perform limit tests on the DUT the Model 2500 is typically used with a component handler to perform binning operations After the testing process the DUT will be placed in an assigned bin For the grading mode the binning system can be further automated by adding a scanner With the use of a scanner the tests can be repeated cycled to test individual elements of a single package See Binning systems page 11 10 for more information on using com ponent handlers and scanners to perform binning operations Operation overview Grading mode Grading mode limits operation is detailed by the flowchart in Figure 11 2 A test is only performed if it is enabled If disabled operation proceeds to the next test The fo
288. imal digital output pattern NOTE 16 bit I O is available with the 2499 DIGIO option The maximum 16 bit output value is 65535 STATe lt b gt CALCulate7 LIMit 1 STATe lt b gt Control Limit 1 channel 1 test CALCulate7 LIMit2 STATe lt b gt Control Limit 2 channel 2 test CALCulate7 LIMitx STATe lt b gt Control Limit x test x 3 6 Parameters lt b gt 1 or ON Enable specified limit test 0 or OFF Disable specified limit test Query STATe Query state of specified limit test Description These commands are used to enable or disable Limit 1 through Limit 6 tests Limit 1 and Limit 2 are the compliance limit tests for channel 1 and channel 2 respectively while Limit 3 through Limit 6 are the soft ware limit tests Any limit test not enabled is simply not performed When a limit test is enabled the Digital I O port comes under control of limit tests That is the result of the testing process updates the output pattern on the I O port 17 36 SCPI Command Reference Models 2500 and 2502 User s Manual FAIL CALCulate7 LIMit 1 FAIL2 Read Limit 1 channel 1 test result CALCulate7 LIMit2 FAIL2 Read Limit 2 channel 2 test result CALCulate7 LIMitx FAIL 2 Read Limit x test result x 3 6 Description These commands are used to read the pass fail results of Limit 1 through Limit 6 tests 0 Limit test passed 1 Limit test failed The response message 0 or 1 only tells you if a limit test has passed or failed
289. in can be given by the following equation Output Vyorse Input Vyorse 1 Re Rpur where Output VxNojsg is the noise seen at the output of the ammeter Input Vyorsg is the noise seen at the input of the ammeter e Rp is the internal feedback resistance for the ammeter e Rpurt is the resistance of the DUT Models 2500 and 2502 User s Manual Measurement Considerations F 3 Note that as Rpyry decreases in value the output noise increases For example when Rp Rpyt the input noise is multiplied by a factor of two Since decreasing the source resistance can have a detrimental effect on noise performance there are usually minimum recommended source resistance values based on measurement range Table F 1 summa rizes minimum recommended source resistance values for various measurement ranges for the Model 2500 ammeters Note that the recommended source resistance varies by mea surement range because the Rx value also depends on the measurement range Table F 1 Minimum recommended source resistance values Minimum recommended I measure range source resistance InA 200nA IMQ to 10OMQ 2uA 200pA 1kQ to 100kQ 2mA and 20mA 1Q to 100Q Source capacitance DUT source capacitance will also affect the noise performance of the Model 2500 amme ters In general as source capacitance increases the noise gain also increases The elements of interest for this discussion are the capacitance Cpyr of the DUT an
290. indicate that an SRQ has occurred Status register sets A typical status register set is made up of a condition register an event register and an event enable register A condition register is a read only register that constantly updates to reflect the present operating conditions of the instrument When an event occurs the appropriate event register bit sets to 1 The bit remains latched to 1 until the register is reset When an event register bit is set and its corresponding enable bit is set as programmed by the user the output summary of the register will set to 1 which in turn sets the summary bit of the status byte register Queues The Model 2500 uses an output queue and an error queue The response messages to query commands are placed in the output queue As various programming errors and status mes sages occur they are placed in the error queue When a queue contains data it sets the appropriate summary bit of the status byte register Models 2500 and 2502 User s Manual Status Structure Figure 14 1 Model 2500 status register structure Questionable Questionable Questionable Event Condition Event Enable Register Register Register Logical Calibration Summary OR Error Queue Service Status Request Byte Enable Register Register Standard Standard Event Event Status Status Enable Register Register Logical OR Operation Complete Query Error Device Specific Er
291. ing Binning control Immediate Immediate Auto clear Disabled Disabled Delay 0 00001 sec 0 00001 sec Clear pattern 15 or 7 15 or 7 H W limits 1 and 2 Control Disabled Disabled Fail mode In compliance In compliance Digital I O pattern 15 or 7 15 or 7 S W limits 3 to 6 Control Disabled Disabled Low limit 1 0 1 0 Low pattern 15 or 7 15 or 7 High limit 1 0 1 0 High pattern 15 or 7 15 or 7 Feed Channel 1 measure Channel 1 measure Pass pattern 15 or 7 15 or 7 EOT Mode EOT EOT Math function and units MX B MXB MX B MXB M factor gain 1 1 B factor slope 0 0 State Disabled Disabled Settings are for both channel 1 and channel 2 15 if digout size is 4 bit 7 if digout size is 3 bit 1 17 1 18 Getting Started Model 2500 and 2502 User s Manual Table 1 3 continued Factory default settings Setting BENCH default GPIB default Numbers No effect No effect Optical power R 1 1 D 0 0 Output Off Off Output enable Disabled Disabled Power on default No effect No effect Ranging measure Auto range Enabled Enabled Upper limit 20mA 20mA Lower limit 2nA 2nA Rel Off Off Value 0 0 0 0 RS 232 No effect No effect Source delay lms lms Auto delay Enabled Enabled Speed 1 PLC 1 PLC Sweep None None Start OV OV Stop OV OV Step OV OV Direction Up Up Sweep count 1 1 Sweep points 3000 3000 Source ranging Best fixed Best fixed Triggered source Control Disabled Dis
292. inning oper ation In the event of a failure the first test failure determines the bin assignment See Figure 11 4 Using a sweep with end binning lets you test a device at different source levels For exam ple assume a 3 point list sweep at 1 1 V 2 2V and 3 3V source levels Limit testing will be performed at each source level After the completion of the three test cycles the DUT is placed in the appropriate bin Figure 11 3 Immediate binning Digital 1 0 Notification Pass Fail Pass Figure 11 4 End binning Test1 Test2 Test3 Digital I O Pass Fail Pass Notification Fail Models 2500 and 2502 User s Manual Limit Testing 11 7 Pass condition For this discussion assume that all grading mode limit tests pass After the three limit tests pass the PASS message is displayed and operation drops down to the Binning Control decision block Note that the pass condition can also be determined with the CALC7 LIM lt n gt FAIL query via remote Immediate binning For immediate binning the testing process stops The Model 2500 outputs the pass pattern to the component handler to perform the binning operation End binning For end binning operation drops down to Another Test Cycle decision block If programmed to perform additional tests i e sweep on the DUT package oper ation loops back up to perform the next source measure action After all programmed test cycles are successfully completed the Model 2500 ou
293. interface Programmable aspects of this interface include the following factory default settings are shown in parentheses e Baud rate 9600 e Data bits 8 e Parity none Terminator CR e Flow control none RS 232 settings for baud rate parity and data bits are accessible only from the front panel while RS 232 is enabled An interface is selected and configured from the COMMUNICATIONS option of the Main Menu See Section 1 Main menu For details on the programmable aspects of the interfaces see Primary address page 13 6 and RS 232 interface operation page 13 17 NOTE When changing interface selections the Model 2500 performs a power on reset To check and or change options of the selected interface you must re enter the menu structure GPIB operation This section contains information about GPIB standards bus connections and primary address selection GPIB standards The GPIB is the IEEE 488 instrumentation data bus with hardware and programming standards originally adopted by the IEEE Institute of Electrical and Electronic Engineers in 1975 The Model 2500 conforms to these standards TEEE 488 1 1987 TEEE 488 2 1992 The above standards define a syntax for sending data to and from instruments how an instrument interprets this data what registers should exist to record the state of the instru ment and a group of common commands The Model 2500 also conforms to this standard
294. ird level it can be typed in without repeating the entire path name Notice that the leading colon for enab is not included in the pro gram message If a colon were included the path pointer would reset to the root level and expect a root command Since enab is not a root command an error would occur Models 2500 and 2502 User s Manual Remote Operations 13 15 Command path rules Each new program message must begin with the root command unless it is optional e g SENSe 1 If the root is optional simply treat a command word on the next level as the root For fastest operation do not send optional data The colon at the beginning of a program message is optional and need not be used Note that eliminating the first colon will result in fastest operation Example stat pres stat pres When the path pointer detects a colon it moves down to the next command level An exception is when the path pointer detects a semicolon which is used to separate commands within the program message see next rule When the path pointer detects a colon that immediately follows a semicolon it resets to the root level The path pointer can only move down It cannot be moved up a level Executing a com mand at a higher level requires that you start over at the root command Using common and SCPI commands in the same message Both common commands and SCPI commands can be used in the same message as long as they
295. is configured to perform 10 source and measure operations and send the 10 current measurements to the computer using the binary format Bytes 2 10x4 1 43 17 46 SCPI Command Reference Models 2500 and 2502 User s Manual Data elements ELEMents lt item list gt FORMat ELEMents SENSe lt item list gt Specify data elements for data string Parameters lt item list gt CURRent 1 Includes channel 1 current reading CURRent2 Includes channel 2 current reading TIME Includes timestamp STATus Includes status information NOTE Each item in the list must be separated by a comma i e CURRI CURR2 TIME Query ELEMents Query elements in data string Description This command is used to specify the elements to be included in the data string in response to the following queries FETCh READ MEASure TRACe DATA You can specify from one to all four elements Each element in the list must be separated by a comma These elements shown in Figure 17 1 are explained as follows NOTE An overflow reading reads as 9 9E37 CURRent 1 This element provides the channel current reading If no reading is available the NAN not a number value of 9 91e37 is used CURRent2 This element provides the channel 2 current reading If no current reading is available the NAN not a number value of 9 91e37 is used TIME A timestamp is available to reference each group of readings to a point in time The relative time
296. is set by FORMat SOURce3 lt name gt Models 2500 and 2502 User s Manual SCPI Command Reference 17 5 Table 17 1 continued CALCulate command summary Default Command Description parameter SCPI CALCulate7 Path to CALC7 limit tests DATA Return all CALC7 results LATest Return most recent CALC7 result FEED lt name gt Specify Limit 3 to 6 input path CALCulate3 CALCulate4 CALCulate5 or CALCulate6 FEED Query input path LIMit 1 Path to channel hardware compliance limits IN y COMPliance Specify fail mode IN or OUT of compliance 15 or7 v FAIL lt name gt Specify output fail pattern 0 to 7 15 v FAIL Query fail bit pattern SOURce3 lt NRf gt I lt NDN gt Specify IN or OUT pattern 0 to 71 15 SOURce3 Query IN or OUT pattern OFF STATe lt b gt Enable or disable Limit 1 test STATe Query state of Limit 1 test FAIL Returns result of Limit 1 test 0 pass or 1 fail LIMit2 Path to channel 2 hardware compliance limit COMPliance Specify fail mode IN or OUT of compliance IN FAIL lt name gt Specify output fail pattern 0 to 7 15 15 or 7 FAIL Query fail bit pattern SOURce3 lt NRf gt I lt NDN gt Specify IN or OUT pattern 0 to 71 15 SOURce3 Query IN or OUT pattern STATe lt b gt Enable or disable Limit 2 test OFF v STATe Query state of Limit 2 test v FAIL Returns result of Limit 2 test 0 pass or 1 fail y Default based
297. is used to set the delay for digital output auto clear This delay determines the pulse width of the limit test output pattern as required by the handler After the delay the output returns clears to the pattern programmed by the TTL LEVel command The delay actually defines the pulse width for line 4 which is used by category register component handlers as the EOT end of test strobe The pulse width of the other three lines are 20usec longer 10psec before line 4 is toggled and 10usec after line 4 is cleared Skewing the timing on line 4 provides setup and hold time for category register com ponent handlers See Section 11 for details on timing 17 78 SCPI Command Reference Models 2500 and 2502 User s Manual STATus subsystem The STATus subsystem is used to control the status registers of the Model 2500 The com mands in this subsystem are summarized in Table 17 7 NOTE These registers and the overall status structure are fully explained in Section 14 Read event registers EVENt STATus MEASurement EVENt 2 STATus QUEStionable EVENt STATus OPERation EVENt Read Measurement Event Register Read Questionable Event Register Read Operation Event Register Description These query commands are used to read the contents of the status event registers After sending one of these commands and addressing the Model 2500 to talk a value is sent to the computer This value indicates which bits in the appropriate regist
298. ith the INIT option you can set a consecutive range of measurement points in the sweep to a specific level For example assume that for a 20 point cus tom voltage sweep POINTS 20 you want points 10 through 15 to be set for 1V After selecting the INIT option set the VALUE to 1 000000V set the START PT to 10 and set the STOP PT to 15 SWEEP COUNT Use this menu item to specify how many sweeps to perform FINITE Use this option to enter a discrete number of sweeps to perform with the results stored in the data store buffer The maximum number of finite sweeps that can be performed is determined as follows maximum finite sweep count 3000 Points in sweep INFINITE Select this option to continuously repeat the configured sweep Use the EXIT key to stop the sweep Data is not stored in the buffer Models 2500 and 2502 User s Manual Sweep Operation 9 7 e SOURCE RANGING Use this menu item to control voltage bias source ranging BEST FIXED With this option the Model 2500 will select a single fixed source range that will accommodate all of the source levels in the sweep For example if the minimum and maximum source levels in the sweep are 1V and 30V the 100V source range will be used AUTO RANGE With this option the Model 2500 will select the most sensitive source range for each source level in the sweep For example for a 1V source level the 2V source range will be used and for a 3V source level
299. l lt name gt Specify when to send binning info to handler A IMM limit test is performed IMMediate or after a sweep list or memory sequence END BCONtrol Query binning control MODE lt name gt Set how limit results control Digital I O lines GRAD GRADing or SORTing MODE Query limit results control of Digital I O lines Default based on present digital output size SOURce3 BSIZe lt n gt 3 bit default is 7 4 bit default is 15 16 bit default is 65535 16 bit available only with 2499 DIGIO option 2 The format ASCII hexadecimal octal or binary for the returned value is set by FORMat SOURce3 lt name gt 3 LIMitX LIMit3 LIMit4 LIMit5 or LIMit6 Models 2500 and 2502 User s Manual SCPI Command Reference 17 7 Table 17 1 continued CALCulate command summary Default Command Description parameter SCPI lt CALCulate7 CALC7 limit tests continues CLEar Clear test results IMMediate Clear latest limit test result and reset Digital T O port back to SOURce3 TTL settings AUTO lt b gt Enable or disable clearing of test results when ON INITiate command is sent AUTO Query state of auto clear PASS Define Digital I O output pattern when all limits pass SOURce3 lt NRf gt I lt NDN gt Specify output pass pattern 0 to 7 15 15 or 7 v SOURce3 Query pass bit pattern FAIL Define Digital I O output pattern when all limits fail SOURce3 lt NRf gt I lt NDN gt Specify ou
300. l 1 math reading Enable disable channel 1 math state ON or OFF Set channel 1 MX B B offset parameter n B Set channel 1 MX B M slope parameter n M Define Channel 1 MX B units string 0 to 3 character string Set channel 1 dark current n amps Set channel 1 responsivity n amps watt Define channel 2 math name MXB2 COND2 POWER2 RES2 or OP2 Request channel 2 math reading Enable disable channel 2 math state ON or OFF Set channel 2 MX B B offset parameter n B Set channel 2 MX B M slope parameter n M Define Channel 2 MX B units string 0 to 3 character string Set channel 2 dark current n amps Set channel 2 responsivity n amps watt Select READ reading channel name CURRent 1 CURRent2 STATus or TIME Select CALCn DATA elements name CALCulate STATus or TIME Trigger reading Turn channel output on or off state ON or OFF Turn channel 2 output on or off state ON or OFF Trigger and acquire reading Set channel 1 current measure range n range Enable disable channel 1 auto range state ON or OFF Set channel 2 measure range n range Enable disable channel 2 auto range state ON or OFF Select fixed sourcing mode for channel source Select channel source range n range 10 or 100 Set channel source amplitude n volts Select fixed sourcing mode for channel 2 source Select channel 2 sou
301. l form of the command Most com mands have a query form ARM TIMer Queries the timer interval Most commands that require a numeric parameter lt n gt can also use the DEFault MINi mum and MAXimum parameters for the query form These query forms are used to deter mine the RST default value and the upper and lower limits for the fundamental command Examples are ARM TIMer DEFault Queries the RST default value ARM TIMer MINimum Queries the lowest allowable value ARM TIMer MAXimum Queries the largest allowable value Models 2500 and 2502 User s Manual Remote Operations 13 13 Case sensitivity Common commands and SCPI commands are not case sensitive You can use upper or lower case and any case combination Examples RST rst DATA data SYSTem PRESet system preset NOTE Using all upper case will result in slightly faster command response times Long form and short form versions A SCPI command word can be sent in its long form or short form version The command subsystem tables in Section 17 provide the long form version However the short form version is indicated by upper case characters Examples SYSTem PRESet long form SYST PRES short form SYSTem PRES long form and short form combination Note that each command word must be in long form or short form and not something in between For example SYSTe PRESe is illegal and will generate an error The command will not be executed Short form
302. layer that is config ured for the TRIGGER LINK event See Trigger model front panel operation The input requires a falling edge TTL compatible pulse with the specifications shown in Figure 10 3 Figure 10 3 Trigger link input pulse specifications Triggers on Leading Edge TTL High 2V 5V Models 2500 and 2502 User s Manual Triggering 10 9 Figure 10 5 DUT test system DUT 1 Output trigger specifications The Model 2500 can be programmed to output a trigger after various trigger model actions See Trigger model front panel operation The output trigger provides a TTL compatible output pulse that can be used to trigger other instruments The specifications for this trigger pulse are shown in Figure 10 4 A trigger link line can source 1mA and sink up to 50mA Figure 10 4 Trigger link output pulse specifications Meter Complete TTL High 3 4V Typical TTL Low 0 25V Typical 10us TTH External triggering example In a simple test system you may want to close a switching channel and then measure the current of the DUT connected to that channel This test system is shown in Figure 10 5 which uses a Model 2500 to measure 10 DUTs switched by a Model 7011 multiplexer card in a Model 7001 7002 Switch System Triax WARNING NO INTERNAL OPERATOR SERVICABLE PARTS SERVICE BY QUALIFIED PERSONNEL ONLY RATINGS MAX hirt Eel KEITHLEY EEA MODS wm cunt Bones INPUT INPUT
303. le 14 6 A command to program an event enable register is sent with a parameter value that deter mines the desired state 0 or 1 of each bit in the appropriate register An enable register can be programmed using any of the following data formats for the parameter value binary decimal hexadecimal or octal The bit positions of the register Figure 14 2 indicate the binary parameter value For example if you wish to set bits B4 B3 and B1 the binary value would be 11010 where B4 1 B3 1 B1 1 and all other bits are 0 When you use one of the other formats con vert the binary number to its decimal hexadecimal or octal equivalent Binary 11010 Decimal 26 Hexadecimal 1A Octal 32 Note that Figure 14 2 includes the decimal weight for each register bit To set bits B4 B3 and B1 the decimal parameter value would be the sum of the decimal weights for those bits 16 8 2 26 Figure 14 2 16 bit status register Bit Position B7 Be Bs B4 B3 B2 B1 Bo Binary Value Decimal 128 64 32 16 8 4 2 1 Weights 27 26 25 24 23 22 21 20 A Bits 0 through 7 Bit Position B15 B14 B13 B12 B11 B10 Bo es Binary Value _0 1 Decimal 32768 16384 8192 4096 2048 1024 512 256 Weights 215 214 213 212 211 210 29 28 B Bits 8 through 15 The lt NDN gt non decimal numeric parameter type is used to send non decimal values These values r
304. le for bus connections 2 Turn on the computer and the Model 2500 3 Make sure the Model 2500 is set for its default primary address of 25 Use the front panel MENU COMMUNICATIONS GPIB selection to check or change the address 4 Make sure that the computer IEEE 488 bus driver software CECHP EXE is properly initialized 5 Enter the Basic editor and type in the desired program 6 Check thoroughly for errors then save it using a convenient filename 7 Run the program and note any display messages and data on the screen Models 2500 and 2502 User s Manual Basic measurement program Example Programs H 3 The program listing below performs basic single channel DUT measurement as covered in Section 3 This program sets up the following operating modes e Channel 2 measurement range 2UA e Channel 2 source range 10V e Channel 2 source output level 10V OPEN OPEN PRINT NE IN ti iw Basic Measurement Program EEE FOR OUTPUT AS 1 EEE FOR INPUT AS 2 INTERM CRLF z OUTTERM LF REMOTE 25 OUTPUT 25F4RST OUTPUT 25 SENS2 CURR RANG 2E 6 OUTPUT 25 FORM ELEM CURR2 OUTPUT 25 SOUR2 VOLT RANG 10 po OUTPUT 2574SOUR2 VOLT 10 OUTPUT 25 20UTP2 ON OUTPUT 25 READ r ENTER 25 PUT 2 RS Channel 2 current reading R OUTPUT 25 OUTP2 OFF Open IEEE 488 output path Open IEEE 488 input path Set input
305. ller RL Remote Local Function RL1 defines the ability of the instrument to be placed in the remote or local modes Models 2500 and 2502 User s Manual IEEE 488 Bus Overview D 15 PP Parallel Poll Function The instrument does not have parallel polling capabilities PPO DC Device Clear Function DC1 defines the ability of the instrument to be cleared initialized DT Device Trigger Function DT1 defines the ability of the Model 2500 to have readings triggered C Controller Function The instrument does not have controller capabilities CO TE Extended Talker Function The instrument does not have extended talker capa bilities TEO LE Extended Listener Function The instrument does not have extended listener capabilities LEO E Bus Driver Type The instrument has open collector bus drivers E1 E IEEE 488 and SCPI Conformance Information E 2 IEEE 488 and SCPI Conformance Information Models 2500 and 2502 User s Manual Introduction The IEEE 488 2 standard requires specific information about how the Model 2500 imple ments the standard Paragraph 4 9 of the IEEE 488 2 standard Std 488 2 1987 lists the documentation requirements Table E 1 provides a summary of the requirements and pro vides the information or references the manual for that information Table E 2 lists the coupled commands used by the Model 2500 The Model 2500 complies with SCPI version 1996 0 Table 17
306. llowing assumes the first three limit tests are enabled and the digital output of the Model 2500 is connected to a component handler for DUT binning See Binning systems page 11 10 If a handler is not used ignore digital input output handler interface actions With the limit tests properly configured turn the Model 2500 output on and press the LIMIT key The testing process will start when the component handler sends the SOT start of test strobe pulse to the Model 2500 Note that if a handler is not used testing will start when LIMIT is pressed Pressing LIMIT a second time terminates the testing process As shown in the flowchart limit tests are performed after a measurement conversion Models 2500 and 2502 User s Manual Limit Testing 11 5 Figure 11 2 Grading mode limit testing Turn Output ON and Press LIMIT key Y Wait for SOT Pulse from Handler Y Perform Source Measure Action Immediate Perform Limit 1 2 Test Output Limit 1 2 Display Fail Pattern FAIL Store Limit 1 2 Fail Pattern in Memory Yy No Display Immediate Out a put Limit 3 FAIL gt Fail Pattern af Store Limit 3 Fail Pattern in Memory No Perform No i ini Immediate pae An Display Binning Output Limit 4 6 rimit 4 6 FAI
307. loated above ground observe safety precautions and avoid touching the shield Meshed screen or loosely braided cable could be inadequate for high impedances or in strong fields Note how ever that shielding can increase capacitance in the measuring circuit possibly slowing down response time 2 Reduction of electrostatic fields Moving power lines or other sources away from the experiment reduces the amount of electrostatic interference seen in the measurement F 10 Measurement Considerations Models 2500 and 2502 User s Manual Magnetic fields A magnetic field passing through a loop in a test circuit will generate a magnetic EMF voltage that is proportional to the strength of the field the loop area and the rate at which these factors are changing Magnetic fields can be minimized by following these guidelines e Locate the test circuit as far away as possible from such magnetic field sources as motors transformers and magnets e Avoid moving any part of the test circuit within the magnetic field e Minimize the loop area by keeping leads as short as possible and twisting them together Electromagnetic Interference EMI The electromagnetic interference characteristics of the Model 2500 comply with the elec tromagnetic compatibility EMC requirements of the European Union as denoted by the CE mark However it is still possible for sensitive measurements to be affected by exter nal sources In these instances special pr
308. log staircase sweep Step 1 Configure channel Configure the Model 2500 for the desired operations as follows 1 Select the desired source channel by pressing SRC1 or SCR2 2 Set the source level to the desired value 3 Press MSR1 or MSR2 to select the desired measurement channel then choose the desired measurement range 9 10 Sweep Operation Models 2500 and 2502 User s Manual Step 2 Configure sweep Configure the sweep as follows Press SRC1 or SRC2 to select the channel Press CONFIG then SWEEP Select TYPE then press ENTER Select LOG then press ENTER At the prompts enter the desired START STOP and NO OF POINTS values From the CONFIGURE SWEEPS menu select SWEEP COUNT press ENTER then choose FINITE or INFINITE as desired 7 Again from the CONFIGURE SWEEPS menu choose SOURCE RANGING press ENTER then select BEST FIXED AUTO RANGE or FIXED as appropriate 8 Press EXIT to return to normal display he ae a e Step 3 Set delay Set the source delay as follows 1 Press CONFIG then SRC1 or SRC2 depending on the selected source channel 2 Select DELAY then press ENTER 3 Set the delay to the desired value then press ENTER 4 Press EXIT to return to normal display Step 4 Turn output on Press the ON OFF OUTPUT key to turn the output on red OUTPUT indicator turns on The Model 2500 will output the programmed bias level Step 5 Run sweep To run the sweep press the SWEEP key After the
309. ls 2500 and 2502 User s Manual Digital I O Port Output Enable and Output Configuration 12 5 Source operation Figure 12 3 shows the basic output configuration for source operation In this case the external relay coil is connected between the digital output line pins 1 to 4 and ground pin 9 With this configuration the digital output line must be set HI to energize the relay and the maximum source current is 2mA Figure 12 3 Source operation Model 2500 45V o Maximum Source Current 2mA Pin 9 External ee Fe nd Relay Digital I O Port Controlling digital output lines Although the digital output lines are primarily intended for use with a device handler for limit testing they can also be used for other purposes such as controlling external relays or indicator lights You can control these lines either from the front panel or via remote as covered below Front panel digital output control Set digital output line logic levels from the front panel as follows Press the MENU key Select GENERAL then press ENTER Select DIGOUT then press ENTER Using the EDIT keys set the digital output parameter to the desired decimal value Table 12 1 For example to set the output lines to L H H H set the digital output parameter value to 7 Ne 5 Press EXIT to return to normal display 12 6 Digital I O Port Output Enable and Output Configuration Models 2500 and 2502 User s Manual Remote digital output contr
310. lt n gt SOURce2 S WEep DIRection lt name gt Select channel 1 sweep mode Specify Ch 1 sweep start voltage n voltage Specify Ch 1 sweep stop voltage n voltage Specify Ch 1 sweep step voltage n voltage Specify Ch 1 sweep center voltage n voltage Specify Ch 1 sweep span voltage n voltage Select Ch 1 source ranging name BEST AUTO or FIXed Select Ch 1 staircase sweep type name LINear or LOGearithmic Set Ch 1 number of sweep points n points Set Ch 1 sweep direction Name UP sweep start to stop or DOWN sweep stop to start Select channel 2 sweep mode Specify Ch 2 sweep start voltage n voltage Specify Ch 2 sweep stop voltage n voltage Specify Ch 2 sweep step voltage n voltage Specify Ch 2 sweep center voltage n voltage Specify Ch 2 sweep span voltage n voltage Select Ch 2 source ranging name BEST AUTO or FIXed Select Ch 2 staircase sweep type name LINear or LOGarithmic Set Ch 2 number of sweep points n points Set Ch 2 sweep direction Name UP sweep start to stop or DOWN sweep stop to start Models 2500 and 2502 User s Manual Sweep Operation 9 13 Staircase sweep programming example As an example of linear staircase sweep operation assume the Model 2500 is to be used to generate the reverse biased V I characteristics of a photodiode For the purposes of this test assume the following basic sweep p
311. lue of 4 5 instead of 5 The Model 2500 rounds the rational number to an integer ENABle lt b gt DISPlay ENABle lt b gt Control display circuitry Parameters lt b gt 0 or OFF Disable display circuitry 1 or ON Enable display circuitry Query ENABle Query state of display Description This command is used to enable and disable the front panel display cir cuitry When disabled the instrument operates at a higher speed While disabled the display is frozen with the following message FRONT PANEL DISABLED Press LOCAL to resume As reported by the message all front panel controls except LOCAL and OUTPUT OFF are disabled Normal display operation can be resumed by using the ENABle command to enable the display or by putting the Model 2500 into local Models 2500 and 2502 User s Manual SCPI Command Reference 17 41 MODE lt name gt DISPlay MODE lt name gt Select CALC block for display Parameters lt name gt CALCulate3 Display CALC3 Ch 1 REL CALCulate4 Display CALC4 Ch 2 REL CALCulate5 Display CALCS5 RATIO CALCulate6 Display CALC6 DELTA DUAL Dual channel display mode Query MODE Query selected display CALC block Description This command is used to select which CALC block to display Dis played CALC blocks include CALC3 channel 1 REL CALC4 chan nel 2 REL CALC5 RATIO and CALC6 DELTA The DUAL parameter selects the dual channel display mode ATTRibutes DISPlay WINDow 1 ATTRibutes Q
312. m modate all the source levels in the sweep For front panel operation this is the BEST FIXED option Models 2500 and 2502 User s Manual SCPI Command Reference 17 67 With AUTO selected the Model 2500 will automatically go to the most sensitive source range for each source level in the sweep For front panel operation this is the AUTO RANGE option With FIXed selected the source remains on the range that it is presently on when the sweep is started For sweep points that exceed the source range capability the source will output the maximum level for that range For front panel operation this is the FIXED option SPACing lt name gt sSOURce 1 SWEep SPACing lt name gt SOURce2 SWEep SPACing lt name gt Select scale for source 1 sweep Select scale for source 2 sweep Parameters lt name gt LINear Linear scale LOGarithmic Logarithmic scale Query SPACing Query scale for sweep Description These commands are used to select the scale for the sweep With LINear selected the source and measure points in the sweep will be performed on a linear scale With LOGarithmic selected the source and measure points will be performed on a logarithmic scale STARt lt n gt STOP lt n gt SOURce 1 VOLTage STARt lt n gt SOURce 1 VOLTage STOP lt n gt SOURce2 VOLTage STARt lt n gt SOURce2 VOLTage STOP lt n gt Specify source 1 start voltage level Specify source 1 stop voltage level Specify source 2 start voltage l
313. m voltage bias one year accuracy specifications as follows Accuracy 0 15 of setting 5mV offset 0 05 x 5V 5mV 7 5mV 5mV 12 5mV In this case the actual voltage output range is 5V 12 5mV or from 4 9875V to 5 0125V Status and Error Messages B 2 Status and Error Messages Models 2500 and 2502 User s Manual Introduction This Appendix contains a summary of status and error messages which status register bits are set when messages occur and methods to avoid or eliminate most common SCPI errors Status and error messages Table B 1 summarizes status and error messages which are stored in the Error Queue Each message is preceded by a code number Negative numbers are used for SCPI defined messages and positive numbers are used for Keithley defined messages Note that error and status conditions will also set specific bits in various status registers as sum marized in Table B 1 Section 14 has detailed information on registers and queues Briefly you can use the fol lowing queries to obtain error and status information e SYST ERR reads Error Queue e ESR reads Standard Event Status Register e STAT OPER reads Operation Event Register e STAT MEAS reads Measurement Event Register e STAT QUES reads Questionable Event Register NOTE SCPI confirmed messages are described in volume 2 Command Reference of the Standard Commands for Programmable Instruments
314. management lines help to ensure proper interface control and management These lines are used to send the uniline commands ATN Attention The ATN line is one of the more important management lines The state of this line determines how information on the data bus is to be interpreted IFC Interface Clear As the name implies the IFC line controls clearing of instru ments from the bus REN Remote Enable The REN line is used to place the instrument on the bus in the remote mode EOI End or Identify The EOI is usually used to mark the end of a multi byte data transfer sequence SRQ Service Request This line is used by devices when they require service from the controller Handshake lines The bus handshake lines operate in an interlocked sequence This method ensures reliable data transmission regardless of the transfer rate Generally data transfer will occur at a rate determined by the slowest active device on the bus One of the three handshake lines is controlled by the source the talker sending informa tion while the remaining two lines are controlled by accepting devices the listener or lis teners receiving the information The three handshake lines are DAV DATA VALID The source controls the state of the DAV line to indicate to any listening devices whether or not data bus information is valid D 6 IEEE 488 Bus Overview Models 2500 and 2502 User s Manual NRED Not Ready For Data
315. mand sequence is used to serial poll the Model 2500 Serial polling obtains the serial poll byte status byte Typically serial polling is used by the controller to determine which of several instruments has requested service with the SRQ line 14 10 Status Structure Models 2500 and 2502 User s Manual Status byte and service request commands The commands to program and read the status byte register and service request enable reg ister are listed in Table 14 3 For details on programming and reading registers see Pro gramming enable registers page 14 5 and Reading registers page 14 6 NOTE To reset the bits of the service request enable register to 0 use 0 as the parame ter value for the SRE command i e SRE 0 Table 14 3 Status byte and service request enable register commands Command Description Default STB Read Status Byte Register SRE lt NDN gt or lt NRf gt Program the Service Request Enable Register Note lt NDN gt Bxx x Binary format each x 1 or 0 Hx Hexadecimal format x 0 to FF Qx Octal format x 0 to 377 lt NRf gt 0to 255 Decimal format SRE Read the Service Request Enable Register Note CLS and STATus PRESet have no effect on the service request enable register Programming example set MSS B6 when error occurs The first command of sequence in Table 14 4 enables EAV error available When an invalid command is sent line 4 bits B2
316. mand to put a remote mode instrument into local mode The GTL com mand also restores front panel key operation 13 8 Remote Operations Models 2500 and 2502 User s Manual DCL device clear Use the DCL command to clear the GPIB interface and return it to a known state Note that the DCL command is not an addressed command so all instruments equipped to implement DCL will do so simultaneously When the Model 2500 receives a DCL command it clears the Input Buffer and Output Queue cancels deferred commands and clears any command that prevents the processing of any other device command A DCL does not affect instrument settings and stored data SDC selective device clear The SDC command is an addressed command that performs essentially the same function as the DCL command However since each device must be individually addressed the SDC command provides a method to clear only selected instruments instead of clearing all instruments simultaneously as is the case with DCL GET group execute trigger GET is a GPIB trigger that is used as an arm event to control operation The Model 2500 reacts to this trigger if it is the programmed arm control source The following command selects the GPIB arm control source ARM SOURce BUS NOTE With ARM SOURce BUS selected and an INITiate command sent do not send any commands except GET DCL SDC IFC TRG and ABORt while per forming source and measure operations ARM annunciator o
317. mbalance that causes the current flow For example bending a triaxial cable causes friction between the center conductor HI and its surrounding insulator resulting in triboelectric currents Triboelectric currents can be minimized as follows e Use low noise cables These cables are specially designed to minimize charge genera tion and use graphite to reduce friction e Use the shortest cables possible and secure them i e taping or tying to a non vibrating surface to keep them from moving Piezoelectric and stored charge effects Piezoelectric currents are generated when mechanical stress is applied to certain insulating materials i e crystalline In some plastics pockets of stored charge cause the material to behave in a similar manner When building test fixtures choose good insulating materials and make connecting struc tures as rigid as possible Make sure there are no mechanical stresses on the insulators F 6 Measurement Considerations Models 2500 and 2502 User s Manual Dielectric absorption Dielectric absorption in an insulator can occur when a voltage across that insulator causes positive and negative charges within the insulator to polarize because various polar mole cules relax at different rates When the voltage is removed the separated charges generate a decaying current through circuits connected to the insulator as they recombine To minimize the effects of dielectric absorption on current measurements
318. measurement point in the sweep Otherwise use auto ranging Step 2 Configure sweep Configure the sweep as follows 1 Press SRC1 or SRC2 to select the channel 2 Press CONFIG then SWEEP Models 2500 and 2502 User s Manual Sweep Operation 9 9 Select TYPE then press ENTER Select STAIR then press ENTER At the prompts enter the desired START STOP and STEP values From the CONFIGURE SWEEPS menu select SWEEP COUNT press ENTER then choose FINITE or INFINITE as desired 7 Again from the CONFIGURE SWEEPS menu choose SOURCE RANGING press ENTER then select BEST FIXED AUTO RANGE or FIXED as appropriate 8 Press EXIT to return to normal display Oy E Step 3 Set delay Set the source delay as follows Press CONFIG then SRC1 or SRC2 depending on the selected source channel Select DELAY then press ENTER Set the delay to the desired value then press ENTER Press EXIT to return to normal display fee ee DO Step 4 Turn output on Press the ON OFF OUTPUT key to turn the output on red OUTPUT indicator turns on The Model 2500 will output the programmed bias level Step 5 Run sweep To run the sweep press the SWEEP key After the sweep is completed turn the output off by pressing the ON OFF OUTPUT key Step 6 Read buffer Use the RECALL key to access the readings stored in the buffer Use the DISPLAY TOG GLE key to display statistical information See Section 8 Data Store Performing a
319. measurement range DOWN Select next lower measurement range Query RANGe Query measurement range RANGe DEFault Query RST default range RANGe MINimum Query lowest range returns 0 RANGe MAXimum Query highest range Description These commands are used to manually select the measurement range for channel and channel 2 The range is selected by specifying the expected reading The instrument will then go to the most sensitive reading that will accommodate that reading For example if you expect a reading of approximately 5mA then simply let lt n gt 0 005 or 5e 3 in order to select the 20mA range You can also use the UP and DOWN parameters to select range Each time UP or DOWN is sent the next higher or lower measurement range is selected When on the maximum range sending UP is a NO Op no operation When on the lowest range sending DOWN is a NO Op Measurement ranges can instead be automatically selected by the instru ment See AUTO lt b gt page 17 55 Models 2500 and 2502 User s Manual SCPI Command Reference 17 55 Select auto range AUTO lt b gt SENSe 1 CURRent DC RANGe AUTO lt b gt Control auto ranging for channel 1 SENSe2 CURRent DC RANGe AUTO lt b gt Control auto ranging for channel 2 Parameters lt b gt 0 or OFF Disable auto range 1 or ON Enable auto range Query AUTO Query state of auto range Description This command is used to control auto ranging With auto ranging enable
320. ming example Command Description RST Restore GPIB default conditions SENS1 CURR RANG AUTO ON Turn on channel 1 measure auto range SOURI VOLT TRIG 1 Output 1V on channel 1 when triggered SOURI DEL 0 1 100ms source delay CALC7 FEED CALC3 Use CALC3 Ch 1 data for limits comparison CALC7 LIM3 UPP 10e 3 Limit 3 upper value 10mA gt CALC7 LIM3 LOW 4e 3 Limit 3 lower value 4mA CALC7 LIM4 UPP 8e 3 Limit 4 upper value 8mA gt CALC7 LIM4 LOW 6e 3 Limit 4 lower value 6mA gt CALC7 CLIM PASS SOUR3 1 Digital I O port 0001 1 when test passes gt CALC7 LIM3 UPP SOUR3 2 Digital I O port 0010 2 when upper Limit 3 fails gt CALC7 LIM3 LOW SOUR3 2 Digital I O port 0010 2 when lower Limit 3 fails gt CALC7 LIM4 UPP SOUR3 3 Digital I O port 0011 3 when upper Limit 4 fails gt CALC7 LIM4 LOW SOUR3 3 Digital I O port 0011 3 when lower Limit 4 fails gt CALC7 CLIM BCON IMM Update Digital I O port immediately after test gt CALC7 LIM1 STAT 0 Turn off Limit 1 test gt CALC7 LIM3 STAT 1 Turn on Limit 3 test CALC7 LIM4 STAT 1 Turn on Limit 4 test OUTP1 ON Turn on channel source output INIT Trigger reading and limits test OUTP1 OFF Turn off output gt CALC7 LIM3 FAIL Query Limit 3 test results 1 discard diode gt CALC7 LIM4 FAIL Query Limit 4 test results 1 send diode to QA 12 Digital I O Port Output Enable and Output Configuration Digital I O port Discusse
321. mming and reading registers Explains how to program enable registers and read any register in the status structure Status byte and service request SRQ Explains how to program the status byte to generate service requests SRQs Shows how to use the serial poll sequence to detect SRQs Status register sets Provides bit identification and command information for the four status register sets standard event status operation event status measurement event status and questionable event status Queues Provides details and command information on the output queue and error queue 14 2 Status Structure Models 2500 and 2502 User s Manual Overview The Model 2500 provides a series of status registers and queues allowing the operator to monitor and manipulate the various instrument events The status structure is shown in Figure 14 1 The heart of the status structure is the status byte register This register can be read by the user s test program to determine if a service request SRQ has occurred and what event caused it Status byte and SRQ The status byte register receives the summary bits of four status register sets and two queues The register sets and queues monitor the various instrument events When an enabled event occurs it sets a summary bit in the status byte register When a summary bit of the status byte is set and its corresponding enable bit is set as programmed by the user the RQS MSS bit will set to
322. n Primary address The Model 2500 ships from the factory with a GPIB primary address of 25 When the unit powers up it momentarily displays the primary address You can set the address to a value from 0 to 30 but do not assign the same address to another device or to a controller that is on the same GPIB bus controller addresses are usually 0 or 21 The primary address can be checked and or changed from the COMMUNICATIONS GPIB option of the Main Menu See Section 1 Main menu This menu option also allows you to select the 488 1 or SCPI protocol Appendix G General bus commands General commands are those commands such as DCL that have the same general mean ing regardless of the instrument Table 13 1 lists the general bus commands Table 13 1 General bus commands Command REN IFC LLO GTL DCL SDC GET SPE SPD Effect on Model 2500 Goes into remote when next addressed to listen Goes into talker and listener idle states LOCAL key locked out Cancel remote restore Model 2500 front panel operation Returns all devices to known conditions Returns Model 2500 to known conditions Initiates a trigger Serial polls the Model 2500 Models 2500 and 2502 User s Manual Remote Operations 13 7 REN remote enable The remote enable command is sent to the Model 2500 by the controller to set up the instrument for remote operation Generally the instrument should be placed in the remote mo
323. n 0 0 0 0 7 10 Remote RATIO and DELTA woo eeeeeecseeereeseeeaees 7 11 RATIO and DELTA function programming example 7 12 Data Store Data StOre OVEIVIEW ce ccestecsssecictateacese eats scecsevseasubesscusuediaeetieseess 8 2 Front panel data Store 0 0 eee eeeeseeeeceeeseesseeseeeaeeeeseaesseeeaeenaes 8 2 Stofing teadis csc ccsecees cade esoeeecuseeseesees cose iiie sacha 8 2 Recalling readings s 05 cciesevenscageiencesecssconaeteasearenedeasessencans 8 2 Buffer location number eee eee eeeeeeeeeeeseteeeeaeeeeees 8 3 Timestamp careca arents dectes sede siesagetsbedansedeapsiee tease ease 8 3 Displaying other buffer readings seese 8 3 B ffer Statistics censccecceeuscsdealssbcndensseeniedunsabran deessanesvaiacdesazeves 8 4 Minimum and maximum eeeeeeeeeeeeeeereeeeeeeeseees 8 4 Peak tO peak o cc cstesesscisaiaecespesascdecaieeousiteasedeasseyandezatdae 8 4 oN e VeA ESENE EE A N E E epee 8 4 Standard deviation ccccccccscccccccccsceceseeceseesseseeeseeeneeees 8 4 Timestamp format 2 cictessciiecieeccastesceecsestecnesssesanevecnenestes 8 5 Timestamp ACCULACY ssvecseseeseaicsseanscoaarsscedai sisri aa iet 8 5 Buffer considerations eseeesseeseeeseeeeesresreresrerrerrerrereresresese 8 5 Using TRACe commands to store data eee 8 5 Using READ to store data oo eee eeeeeeeeeeeseeeeeaees 8 6 Remote command data Store oo ee eeseseeseeeeeeseceeeeeeeseeeseeeeeeaes 8 6 Data store comma
324. n If you do erratic operation will occur SPE SPD serial polling Use the serial polling sequence to obtain the Model 2500 serial poll byte The serial poll byte contains important information about internal functions See Section 14 Generally the serial polling sequence is used by the controller to determine which of several instru ments has requested service with the SRQ line However the serial polling sequence may be performed at any time to obtain the status byte from the Model 2500 Models 2500 and 2502 User s Manual Remote Operations 13 9 Front panel GPIB operation This section describes aspects of the front panel that are part of GPIB operation including messages status indicators and the LOCAL key Error and status messages See Appendix B for a list of status and error messages associated with IEEE 488 program ming The instrument can be programmed to generate an SRQ and command queries can be performed to check for specific error conditions GPIB status indicators The REM remote TALK talk LSTN listen and SRQ service request annunciators show the GPIB bus status Each of these indicators is described below REM This indicator shows when the instrument is in the remote state REM does not necessarily indicate the state of the bus REN line as the instrument must be addressed to listen with REN true before the REM indicator turns on When the instrument is in remote all front panel keys except fo
325. n are calculated The CALC1 DATA or CALC2 DATA command will read the results of the math function If CALC1 or CALC2 is enabled that block is bypassed and SENS1 or SENS data is fed directly to CALC3 or CALC4 CALCulate3 DATA and CALCulate4 DATA 2 If CALCulate3 or CALCulate4 channel 1 or channel 2 REL is enabled data is fed to the CALC3 channel 1 or CALC4 channel 2 block where the programmed or acquired REL value is subtracted from the data CALC3 data comes from either CALC1 or SENS1 depending on the selected feed Similarly CALC4 data comes from CALC2 or SENS2 depending on the selected feed The CALC3 DATA or CALC4 DATA command will read the results of the REL operation Note that CALC3 and CALC4 can also be fed to the CALC7 block for limit testing and to the data store buffer for TRACe DATA CALC8 DATA buffer statistics CALCulate5 DATA and CALCulate6 DATA If CALCulate5 RATIO or CALCulate6 DELTA is enabled data is fed to the CALCS5 or CALC6 block where the ratio or difference between measurement data for the two chan nels is calculated The CALC5 DATA returns the calculated ratio result and CALC6 DATA reads the results of the delta computation Note that CALCS and CALC6 can also be fed to the CALC7 block for limit testing and to the data store buffer for TRACe DATA CALC8 DATA buffer statistics CALCulate7 DATA 2 If CALCulate7 is enabled data becomes available to the CALC7 block for limit testing Dependi
326. n Directive 73 23 EEC WARM UP 1 hour to rated accuracy DIMENSIONS 89mm high x 213mm wide x 370mm deep 3 in x 8 in x 14 in Bench configuration with handle and feet 104mm high x 238mm wide x 370mm deep 4 in x 9 in x 14 e in WEIGHT 23 1kg 10 5 Ibs ENVIRONMENT Operating 0 50 C 70 R H up to 35 C non condensing Derate 3 R H C 35 50 C Storage 25 to 65 C non condensing Specifications are subject to change without notice HW 4 22 02 Models 2500 and 2502 User s Manual Specifications A 3 Accuracy calculations The following information discusses how to calculate accuracy for both current measure ment and voltage bias functions Current measurement accuracy Current measurement accuracy is calculated as follows Accuracy of reading offset As an example of how to calculate the actual reading limits assume that you are measur ing 1mA on the 2mA range You can compute the reading limit range from one year mea surement specifications as follows Accuracy of reading offset 0 1 x ImA 2uA luA 2A 3uA Thus the actual reading range is ImA 3uA or from 0 997mA to 1 003mA Voltage bias accuracy Voltage bias accuracy is calculated similarly except that voltage bias specifications are used As an example of how to calculate the actual source output limits assume that you are sourcing 5V on the 10V range You can compute the output limits fro
327. n all display pixels and annun ciators Subsequent key presses cycle through tests that turn off annunciators and cor ner pixels of each digit turn on the rows of the top left display digit and turn on all annunciators and pixels of each digit in a sequential manner Press EXIT to cancel this test e CHAR SET This test displays special characters Press EXIT to cancel the test See Menus page 1 20 for more menu information 1 16 Getting Started Model 2500 and 2502 User s Manual Default settings By using appropriate menu selections you can save and recall various instrument setups define the power on configuration or restore factory defaults as outlined below Saving and restoring user setups You can save and restore up to five of your own user setups using the following procedures Saving setups l 2 3 4 Select the various instrument operating modes you wish to save Press the MENU key select SAVESETUP then press ENTER From the SAVESETUP MENU select SAVE then press ENTER Select the setup position 0 4 to save then press ENTER to complete the process Restoring setups 1 2 3 Press the MENU key select SAVESETUP then press ENTER From the SAVESETUP MENU select RESTORE then press ENTER Select the setup position 0 4 to restore then press ENTER to complete the process Power on configuration You can also define which of the stored setups factory default or user the instrument
328. n two ways Large ground currents flowing in one of the wires will encounter small resistances either in the wires or at the connecting points This small resistance results in voltage drops that can affect the measurement Even if the ground loop currents are small magnetic flux cutting across the large loops formed by the ground leads can induce sufficient voltages to disturb sensitive measurements To prevent ground loops instruments should be connected to ground at only a single point as shown in Figure F 3 Note that only a single instrument is connected directly to power line ground Experimentation is the best way to determine an acceptable arrangement For this purpose measuring instruments should be placed on their lowest ranges The configu ration that results in the lowest noise signal is the one that should be used Figure F 2 Power line ground loops Signal Leads Instrument 1 Instrument 2 Instrument 3 eS oe Ground 4 Loop X Current Power Line Ground F 8 Measurement Considerations Models 2500 and 2502 User s Manual Light Figure F 3 Eliminating ground loops Instrument 1 Instrument 2 Instrument 3 Power Line Ground Some components such as semiconductor junctions and MOS capacitors on semiconduc tor wafers are excellent light detectors Consequently these components must be tested in a light free environment While many test fixtures provide adequate light protection oth ers may
329. nd The service request enable register clears when power is cycled or a parameter value of 0 is sent with the SRE command i e SRE 0 The commands to pro gram and read the SRQ enable register are listed in Table 14 3 Serial polling and SRQ Any enabled event summary bit that goes from 0 to 1 will set bit B6 and generate an SRQ service request In your test program you can periodically read the status byte to check if an SRQ has occurred and what caused it If an SRQ occurs the program can for exam ple branch to an appropriate subroutine that will service the request Typically SRQs are managed by the serial poll sequence of the Model 2500 If an SRQ does not occur bit B6 RQS of the status byte register will remain cleared and the pro gram will simply proceed normally after the serial poll is performed If an SRQ does occur bit B6 of the status byte register will set and the program can branch to a service subroutine when the SRQ is detected by the serial poll The serial poll automatically resets RQS of the status byte register This allows subsequent serial polls to monitor bit B6 for an SRQ occurrence generated by other event types After a serial poll the same event can cause another SRQ even if the event register that caused the first SRQ has not been cleared The serial poll does not clear MSS The MSS bit stays set until all status byte summary bits are reset SPE SPD serial polling The SPE SPD general bus com
330. nd or Identify EOI is used to positively identify the last byte in a multi byte transfer sequence thus allowing data words of various lengths to be transmitted easily IFC Interface Clear IFC is used to clear the interface and return all devices to the talker and listener idle states ATN Attention The controller sends ATN while transmitting addresses or multiline commands SRQ Service Request SRQ is asserted by a device when it requires service from a controller Universal multiline commands Universal commands are those multiline commands that require no addressing All devices equipped to implement such commands will do so simultaneously when the commands are transmitted As with all multiline commands these commands are transmitted with ATN true LLO Local Lockout LLO is sent to the instrument to lock out the LOCAL key and thus all the front panel controls DCL Device Clear DCL is used to return instruments to some default state Usually instruments return to the power up conditions SPE Serial Poll Enable SPE is the first step in the serial polling sequences which is used to determine which device has requested service SPD Serial Poll Disable SPD is used by the controller to remove all devices on the bus from the serial poll mode and is generally the last command in the serial polling sequence Models 2500 and 2502 User s Manual IEEE 488 Bus Overview D 9 Addressed multiline
331. nd then STORE to display the timestamp choices 2 Place the cursor on ABSOLUTE or DELTA and press ENTER Timestamp accuracy Because of internal timing methods the timestamp value is only approximate The method in which the timestamp is implemented limits its use in time critical applications If accu rate test timing is crucial it is recommended that an external timer be used in conjunction with the Model 2500 The timestamp is based on an oscillator with a frequency of approximately 8kHz This oscillator is used as the system clock and is divided by eight to generate system ticks every millisecond Therefore the timestamp should provide Ims resolution for test timing However since the actual oscillator frequency is 8 192kHz a system tick occurs every 8 192kHz 8 or 1 024 times a second which results in a system tick every 0 9765625ms As a result the reported timestamp value is off by 24ms every second Thus to obtain more accurate timestamp values simply multiply the timestamp displayed on the front panel or returned via remote by a factor of 0 9765625 Buffer considerations From the front panel 3000 source and measure readings can be stored and accessed using the method described earlier in this section Over the bus however there are actually two separate 3000 reading buffers for a total of 6000 readings The TRACe buffer is a 3000 reading buffer used by front panel data store bus TRACe commands and to store sweep d
332. nds 0 0 lee eeeteeseceeeeeeeeeeeeeaeeeeeeeeeaeenaes 8 6 Data store programming example cece eeeeeeeeeeseeeeeeees 8 7 9 Sweep Operation Sweep LY POS non annon r enn O E E EE AE E 9 2 Linear staircase sweep sssssssessssssssessrssrseressessrssreseersresreseet 9 2 Logarithmic staircase sweep seseseesseesseeresesrreresrerrsreresrese 9 3 Custom SWEEP ssssssssssssssssssrssessressessersresstssesseesseesesrensessesens 9 4 Custom sweep examples sssseseseeseseseesrreessreresesrrereses 9 5 Configuring and running a SWEEP 2 0 0 eee ese eeeeeseceeeeseeeeeeeeeeees 9 6 Front panel sweep Operation oo ee ee eeeeseeeeeseeeeeeeeeeeeaee 9 6 Configuring a SWEEP eceesceeceeeneeeseeeeaeeeteeceaeeeseeeeaees 9 6 Setting delay eiiie ir nner E ae n ROES 9 7 Trigger count and sweep points eseeseesseeseseeresreerseese 9 8 Performing sweeps sssisesisesrssesissesesiuseriusersessusosossiesensessuss 9 8 Performing a linear staircase sweep sssseesseeeeeseereseeee 9 8 Performing a log staircase sweep sssssseessseereerererreee 9 9 Performing a custom sweep sssseeessssessesresrrsrerrsreresreee 9 11 Remote sweep operation ssesseeessereseerestsreseseesresresesrrerese 9 12 Staircase sweep commands ssssesessesesseseeresereessesreees 9 12 Staircase sweep programming example 9 13 Custom sweep Commands eee eseeeeseceseeseeeseeees 9 14 Custom sweep programming example ee 9 15 10 Triggering Trig
333. nds used to make basic photodiode measurements See Section 17 for more information on using these commands as well as many other com mands that can be used for photodiode measurements 4 6 Photodiode Measurements Table 4 2 Photodiode measurement commands Models 2500 and 2502 User s Manual Command Description CALCulate 1 FORMat lt name gt CALCulate 1 DATA CALCulate 1 STATe lt state gt CALCulate 1 KMATh MBFactor lt n gt CALCulate 1 KMATh MMFactor lt n gt CALCulate 1 KMATh MUNits lt string gt CALCulate 1 KMATh DC lt n gt CALCulate 1 KMATh RESP lt n gt CALCulate2 FOR Mat lt name gt CALCulate2 DATA CALCulate2 STATe lt state gt CALCulate2 KMATh MBFactor lt n gt CALCulate2 KMATh MM Factor lt n gt CALCulate2 K MATh MUNits lt string gt CALCulate2 KMATh DC lt n gt CALCulate2 KMATh RESP lt n gt FORMat ELEMents lt name gt FORMat ELEMents CALCulate lt name gt INIT OUTPut 1 lt state gt OUTPut2 lt state gt READ SENSe 1 CURRent RANGe lt n gt SENSe 1 CURRent RANGe AUTO lt state gt SENSe2 CURRent RANGe lt n gt SENSe2 CURRent RANGe AUTO lt state gt SOURce 1 VOLTage MODE FIXed SOURce 1 VOLTage RANGe lt n gt SOURce 1 VOLTage lt n gt SOURce2 VOLTage MODE FIXed SOURce2 VOLTage RANGe lt n gt SOURce2 VOLTage lt n gt Define channel 1 math name MXB 1 COND 1 POWER 1 RES 1 or OP 1 Request channe
334. ne frequency and NPLC caching AUTO ZERO Control auto zero DISABLE Disable auto zero ENABLE Enable auto zero LINE FREQUENCY Set the line frequency 50 or 60Hz GENERAL Select general operations DIGOUT Set Digital I O port bit pattern 0 15 SERIAL Display serial number firmware revision SCPI version YES or NO TIMESTAMP Reset timestamp ENGR NUMBERS Select engineering units or scientific notation display SCIENTIFIC format Notes 1 Top level menu choices indicated in bold Indentation identifies each lower submenu level 2 When the remote operation interface selection GPIB or RS 232 is changed the Model 2500 performs a power on reset To check or change options of the selected interface you must re enter the menu structure 3 Password is required to unlock calibration See Service Manual 4 Press EXIT key to cancel test J Disabling auto zero will reduce measurement accuracy 1 22 Getting Started Model 2500 and 2502 User s Manual Figure 1 4 Main menu tree Press MENU key Use lt and gt to select item then press ENTER SAVESETUP SAVE RESTORE POWERON BENCH GPIB USER SETUP NUMBER RESET COMMUNICATION GPIB RS 232 BAUD BITS PARITY TERMINATOR FLOW CTRL CAL UNLOCK EXECUTE VIEW DATES SAVE LOCK CHANGE PASSWORD TEST t DISPLAY TESTS KEYS DISPLAY PATTERNS CHAR SET A D CTRL AUTO ZERO LINE FREQUENCY GENERAL DIGOUT SERIAL TIMESTAMP NUMBERS Model 2500 and 2502 User s Ma
335. nected to a properly grounded power receptacle Inspect the con necting cables test leads and jumpers for possible wear cracks or breaks before each use When installing equipment where access to the main power cord is restricted such as rack mounting a separate main input pow er disconnect device must be provided in close proximity to the equipment and within easy reach of the operator For maximum safety do not touch the product test cables or any other instruments while power is applied to the circuit under test ALWAYS remove power from the entire test system and discharge any capacitors before connecting or disconnecting ca 5 02 bles or jumpers installing or removing switching cards or making internal changes such as installing or removing jumpers Do not touch any object that could provide a current path to the common side of the circuit under test or power line earth ground Al ways make measurements with dry hands while standing on a dry insulated surface capable of withstanding the voltage being measured The instrument and accessories must be used in accordance with its specifications and operating instructions or the safety of the equipment may be impaired Do not exceed the maximum signal levels of the instruments and accessories as defined in the specifications and operating in formation and as shown on the instrument or test fixture panels or switching card When fuses are used in a product replace with same
336. neeeeeeeeeeeeees 13 17 AUG Talee 25525225 s cveescesyecesuessasstuatounasesassuvensenghevasseessentyssess 13 17 Data bits and parity eee eseeseeseceeecneeeeeeseeeaeeseeeneeaes 13 17 TEMINAT secari ein ii aiea 13 18 Flow control signal handshaking eee eeeeseeeeereee 13 18 RS 232 COMMECUOUS sissioni s a 13 18 FTO MESSAGES onyte iniae secneecvens 13 19 Programming example 0 eee eeeeseeseeeseeeeeeseeeeeeaeees 13 20 14 Status Structure VEL VIEW ierra aurera Ees A eE desde EEE EE Ee rE EEE EE E STi 14 2 Status byte and SRQ sssssessessssesessssrssrssrrssessrsssessesesssreseesess 14 2 Status rerIst r Sets sereias cnici a ae 14 2 OET E E E E E E E E E A 14 2 Clearing registers and queues sseseeeseeeeesresessesrrsrrsrerrsrsresrese 14 4 Programming and reading registers eeeseseeeeeeeeeeseseeresrererreeee 14 5 Programming enable registers lee eeeeseeeeeeseeeeeeeees 14 5 Reading registers esississisissisisossiesessssessoseseisonsostasoessesessi 14 6 Status byte and service request SRQ oo eeeseeseeeseeeteeeteeeeees 14 7 Status byte register oo eee eeeeeseeeseeseeeseeeeeaeeeeeeaeees 14 8 Service request enable register 0 eee eee eseeseereeeeeeneees 14 9 Serial polling and SRQ eee eseeeeeeseeeseeseeeseeneeeaeees 14 9 SPE SPD serial polling 0 0 ee eeeeeeseeeseeesteeeeeeeeees 14 9 Status byte and service request commands 14 10 Programming example set MSS B6 when ETTOT OCCUTS wiassisscs
337. nel mode eee 7 3 Remote rel programming o eee eeeeseeseeeseeneeeeeeeeeseeeeeaes 7 3 ReliComm and ciccccssessssessesseesssssssvostsasecvzssiveseversseoseons 7 3 Rel programming example eee eeeeseeeeeereeeeees 7 4 Measurement math functions 00 lee ee eee ceeceeeeeeeseeeeeeaeesnees 7 4 Math functions 03 ssesecesessccecsccescscvscssevunsssdetvocandvesotneresteoonse 7 4 I V saesssscessstesvssesscssceteusssaissoassscesnsuessaess soasvesseavncsavetsunesssts 7 4 W L E AA A E E O 7 5 MIXED scisse ests seta cevosvasbbessadesvsadeassatesvesenivecssuniveshinssoapeees 7 5 Electrical pOwer sesh dccevissesesseseticescessttastiveecies aatieees dis 7 5 Optical power eceecesscceeeeeeseeceeeeeeeeseeeeseeeeeeeeeeeeeees 7 5 Front panel math functions oo ee eee eeeeeeceeeereeeseeseeaes 7 6 Remote math functions 0 ee eseeeeseceeeeseceeeeeeeseeeenees 7 7 Math function programming example oe ee eeeeeeeeeees 7 8 RATIO and DELTA ssssessesessossesesssossssessecesecessesessonsssesrsessssessesee 7 8 RATIO functions 55 2 c 0cdeededbecescencs cease devahensdes cataressscetevesatovess 7 8 MSR1 MSR2 ssrin sain 7 8 MSRIMSR l sssescsredssscivasstisists atten okinawa tisseweseress 7 9 DELTA functions oo eee eeceeseeseeeseeeeeesececeeaecneeeaeeeseeaeenaes 7 9 MSR1I MSR2 5 cscccesetssievnesetsasetsstenisivstanenthsssdavsnies loeesess 7 9 MSR2 MSRLU oon eeeneeeeeeeaeeeaceesaeeetseeerseeeeneeees 7 9 Front panel RATIO and DELTA configuratio
338. nformation LOCAL key The LOCAL key cancels the remote state and restores local operation of the instrument Pressing the LOCAL key also turns off the REM indicator and returns the display to nor mal if a user defined message was displayed If the LLO Local Lockout command is in effect the LOCAL key is also inoperative For safety reasons the OUTPUT key can be used to turn the output off while in LLO Programming syntax The information in this section covers syntax for both common commands and SCPI com mands For information not covered here see the IEEE 488 2 and SCPI standards See Section 15 and Section 17 for more details on common and SCPI commands respectively Command words Program messages are made up of one or more command words Commands and command parameters Common commands and SCPI commands may or may not use a parameter The following are some examples SAV lt NRf gt Parameter NRf required RST No parameter used CALCulatel STATe lt b gt Parameter lt b gt required SYSTem PRESet No parameter used NOTE Atleast one space between the command word and the parameter is required Brackets Some command words are enclosed in brackets These brackets are used to denote an optional command word that does not need to be included in the pro gram message For example INITiate MMediate Models 2500 and 2502 User s Manual Remote Operations 13 11 These brackets indicate that MMediate
339. ng 7 3 Set or acquire value 17 28 Relative see Rel Remote operation 13 1 Auto zero 3 4 Digital output control 12 6 Ground connect 3 8 Limit testing 11 20 Line frequency 1 12 Measurement procedure 3 12 Output configuration 12 9 Photodiode measurements 4 5 Source delay 3 7 Triggering 10 17 Remote programming Data store 8 6 Display 1 15 Filter 6 13 Math functions 7 7 Range and digits 6 4 RATIO and DELTA 7 11 Relative 7 3 Speed 6 7 Sweeps 9 12 REN remote enable 13 7 Response messages 13 16 RS 232 13 17 17 85 Connections 13 18 Programming example 13 20 Safety Symbols and terms 1 2 SCPI Command reference 17 1 Eliminating common errors B 8 Reference tables 17 2 Standard read version 17 85 SCPI signal oriented measurement commands 16 1 CONFigure CURRent DC 16 2 CONFigure 16 2 DATA LATest 16 4 FETCh 16 3 MEASure CURRent DC 16 5 READ 16 4 SDC selective device clear 13 8 Select input path 17 27 17 31 SENSe subsystem 17 54 Serial number identification 1 11 1 12 Serial polling and SRQ 14 9 Service request enable register 14 9 Settings 1 16 Digital output line 12 6 Factory default 1 16 Line frequency 1 12 Power line frequency 17 82 Remote setups 1 19 Restoring setups 1 16 Saving setups 1 16 Sink operation 12 4 Sorting mode 11 8 SOT line 11 11 12 3 Source Menus 1 26 Turn on or off 17 52 Source delay 3 5 Auto delay period 3 5 Commands 3 7 Manual 3 6 Output slew time 3 6 Source operation 12 5 S
340. ng Models 2500 and 2502 User s Manual Sorting mode Sorting mode limits operation is detailed by the flowchart in Figure 11 5 A test is only performed if it is enabled If disabled operation proceeds to the next test The following assumes the digital output of the Model 2500 is connected to a component handler for DUT binning See Binning systems page 11 10 If a handler is not used ignore digital input output handler interface actions With the limit tests properly configured turn the Model 2500 output on and press the LIMIT key The testing process will start when the component handler sends the start of test SOT strobe pulse to the Model 2500 Note that if a handler is not used testing will start when LIMIT is pressed Pressing LIMIT a second time terminates the testing process As shown in the flowchart limit tests are performed after a measurement conversion For Limit 1 and 2 tests compliance a failure will display the FAIL message and termi nate the testing process for that DUT For the pass condition operation will proceed to the next enabled limit test If however there are no software limit tests Limits 3 to 6 enabled the testing process will terminate and the PASS message will be displayed Assuming Limit 1 or 2 passes each enabled software limit test will be performed until one of them passes When a test passes the PASS message is displayed and any pending limit tests for that DUT are cancelled If all t
341. ng on the selected feed limit testing can be performed on the channel 1 measure ment function channel 2 measurement RATIO or DELTA If null rel is enabled the readings used for limit testing will be the results of the null operation The CALCulate7 DATA command acquires the readings used for limit testing TRACe DATA If the data store is enabled data becomes available to the TRACE block for storage The selected FORM ELEM TRAC data elements determines which group of readings are stored CALC3 through CALC6 The TRACe DATA command reads the entire contents of the data store CALCulate8 DATA 2 Statistical information minimum maximum mean standard deviation and peak to peak is available for measure readings stored in the buffer The CALCulate8 DATA command acquires the results of the selected statistical calculation The data source for CALC 8 is determined by the DISPlay MODE command D IEEE 488 Bus Overview D 2 IEEE 488 Bus Overview Models 2500 and 2502 User s Manual Introduction Basically the IEEE 488 bus is a communication system between two or more electronic devices A device can be either an instrument or a computer When a computer is used on the bus it serves to supervise the communication exchange between all the devices and is known as the controller Supervision by the controller consists of determining which device will talk and which device will listen As a talker a device will output informati
342. nge is then enabled the unit will not re evaluate the range limits until a change in the input signal level forces a range change In this example the unit would stay on a range above the programmed upper limit with auto range enabled until the input signal level changes accordingly 6 4 Range Digits Speed and Filters Models 2500 and 2502 User s Manual Digits The display resolution of the measured reading depends on the DIGITS setting This set ting is global which means the digits setting selects display resolution for both channels The DIGITS setting has no effect on the remote reading format The number of displayed digits does not affect accuracy or speed Those parameters are controlled by the SPEED setting Setting display resolution There are two ways to set display resolution e DIGITS Press the DIGITS key until the desired number of digits is displayed e CONFIG DIGITS Press CONFIG and then DIGITS to display the digits menu Place the cursor on the desired number of digits 3 5 4 5 5 5 or 6 5 and press ENTER NOTE The DIGITS setting affects only the single channel display mode it does not affect dual channel display Changing SPEED changes DIGITS but changing DIGITS does not change SPEED Remote range and digits programming Table 6 2 summarizes the commands necessary to control range and digits See Section 17 for more details on these commands Table 6 2 Range and digits commands Commands Desc
343. nnel 1 or channel 2 measure ment was made with the filter enabled Cleared to 0 otherwise Bit 3 COMPLIANCE1 Set to 1 if the channel voltage source is in compliance Cleared to 0 otherwise Bit 4 COMPLIANCE2 Set to 1 if the channel 2 voltage source is in compliance Cleared to 0 otherwise Bit 5 NULL1_ACTIVE Set to 1 if channel 1 REL CALC3 is enabled Cleared to 0 otherwise Bit 6 NULL2_ACTIVE Set to 1 if channel 2 REL CALC4 is enabled Cleared to 0 otherwise Bit 7 LIMITS_ACTIVE Set to 1 if a limit test CALC7 is enabled Cleared to 0 otherwise Bit 8 LIMIT_A Encoded limit test summary bit See grading and sorting modes in Limit test bits below Bit 9 LIMIT_B Encoded limit test summary bit See below Bit 10 LIMIT_C Encoded limit test summary bit See below Bit 11 LIMIT_D Encoded limit test summary bit See below Bit 12 LIMIT_HIGH Limit test 3 6 failed high See below Bit 13 CH1_OUTPUT Set to 1 if the channel 1 source output is on Cleared to 0 otherwise Bit 14 CH2_OUTPUT Set to 1 if the channel 2 source output is on Cleared to 0 otherwise Bit 15 Not used Bits 8 through 12 flag pass fail conditions for the various limit tests The bit values for the grading and sorting modes are covered below See CALC7 CLIM MODE and associated commands in Calculate sub systems page 17 22 17 48 SCPI Command Reference Models 2500 and 2502 Use
344. nt Event Enable Register NOTE The Standard Event Register is not affected by this command Error queue NEXT STATus QUEue NEXT Read error queue Description As error and status messages occur they are placed into the error queue This query command is used to read those messages See Appendix B for a list of messages NOTE The STATus QUEue NEXT query command performs the same function as the SYSTem ERRor query command See SYSTem subsystem page 17 81 CLEar STATus QUEue CLEar Clear error queue Description This action command is used to clear the error queue of messages 17 80 SCPI Command Reference ENABle lt list gt Models 2500 and 2502 User s Manual STATus QUEue ENABle lt list gt Enable messages for error queue Parameters lt list gt numlist where numilist is a specified list of messages that you wish to enable for the Error Query ENABle Query list of enabled messages Description On power up all error messages are enabled and will go into the error queue as they occur Status messages are not enabled and will not go into the queue This command is used to specify which messages you want enabled Messages not specified will be disabled and prevented from entering the queue DlSable lt list gt STATus QUEue DISable lt list gt Disable messages for error queue Parameters lt list gt numlist where numilist is a specified list of messages that you wish to disable for t
345. nt Event Enable Register ENABle lt NDN gt or lt NRf gt Program enable register See Parameters ENABle Read enable register QUEStionable Questionable Event Enable Register ENABle lt NDN gt or lt NRf gt Program enable register See Parameters ENABle Read Measurement Event Enable Register Parameters lt NDN gt Bxx x Binary format each x 1 or 0 Hx Hexadecimal format x 0 to FFFF Qx Octal format x 0 to 177777 lt NRf gt 0 to 65535 Decimal format Note Power up and STATus PRESet resets all bits of all enable registers to 0 CLS has no effect Models 2500 and 2502 User s Manual Status Structure 14 19 Programming example program and read register set The command sequence in Table 14 8 programs and reads the measurement register set Registers are read using the binary format which directly indicates which bits are set The command to select format FORMat SREGister is documented in Table 14 2 Table 14 8 Program and read register programming example Command Description FORM SREG BIN Select binary format to read registers STAT MEAS ENAB 512 Enable BFL buffer full STAT MEAS COND Read Measurement Condition Register STAT MEAS Read Measurement Event Register Queues The Model 2500 uses two queues which are first in first out FIFO registers Output Queue Used to hold reading and response messages Error Queue Used to hold erro
346. nterface ssnin ae 11 10 Digital I O connector eee eeeceeeseeeseeeseeeseeeeeeeenees 11 10 Digital output lines oo ee eeeeeeceeceeeeeeeseeeneeaees 11 10 SOT Mine 24 soa eed Ae 11 11 JOB TIME cirese senean a a TE a eai 11 11 Handler typessr oriire e A ii nS 11 11 Category pulse component handler eee 11 11 Category register component handler ee 11 12 Basic binning SYSteMs 00 eee eeeeeeeeeeeceseeeeeeaeeeeeneeaes 11 12 Single element device binning 0 0 ee eee eeeeeeeeeeeeeeeee 11 12 Multiple element device binning 0 0 0 eee eeeeeeeeeeee 11 14 Digital output clear pattern eee eeeeeeeeeeeeeeeeesseeeeeeeees 11 14 Enabling auto cleaf sssrinin 11 14 Auto clear timing sssmsissiseirieii esisiini 11 15 Configuring and performing limit tests oer 11 16 Configuring limit tests 0 eee ee eeeeeseeeseeeeeeaeeeeeeeetaes 11 16 Performing limit tests 2 0 eee eeeeeseeseeeeeseeeneeeeeeaeees 11 18 Step 1 Configure test system 2 0 ceeeeseeseeeeeeeeee 11 18 Step 2 Configure bias source and measure TUNCHONS cies cvccsau deesetinenecstiaseciGetsuecise a 11 18 Step 3 Configure limit tests 0 0 ee eeeeseeeeereeee 11 19 Step 4 Turn output On oo ee eeeeseeeeeereeeeeeaeees 11 19 Step 5 Start testing Process oe eee eseeeeeseeeeereees 11 19 Step 6 Stop testing Process oo ee eeseeeeseeeeereees 11 19 Remote limit testing oo eeeeseeseeseesseeseeeeeeaeeeaeeeeeeaeeaes 11 20 Limit Commands sisses 11 20 Limit t
347. nual Getting Started 1 23 Rules to navigate menus Many functions and operations are configured from the front panel menus Use the follow ing rules to navigate through these configuration menus e A menu item is selected by placing the cursor on it and pressing ENTER Cursor posi tion is denoted by the blinking menu item or option The edit left and right arrow keys control cursor position A displayed arrow on the bottom line indicates there are one or more additional items or messages to select from Use the appropriate cursor key to display them e A measurement or voltage bias source range is changed by selecting the channel and function with the MSR1 MSR2 SRC1 or SRC2 key and using the RANGE A or W keys Note that when the next higher or lower range is selected the reading increases or decreases by a decade A parameter value is keyed in by placing the cursor on the digit to be changed and using one of the following methods NOTE You can clear a parameter value by pressing the 0000 MENU key Use the EDIT lt or p or RANGE A or y keys to increment or decrement the digit Use the number keys 0 through 9 to key in the value at the selected digit e Use the key to change source value polarity regardless of cursor position Boolean selections such as ON OFF and HIGH LOW are toggled by placing the cur sor on the selection and pressing an EDIT lt or p or RANGE A or y key e A change is only executed when EN
348. nual explains hazards that could damage the instrument Such damage may invalidate the warranty Model 2500 and 2502 User s Manual Getting Started 1 3 Inspection The Model 2500 was carefully inspected electrically and mechanically before shipment After unpacking all items from the shipping carton check for any obvious signs of physi cal damage that may have occurred during transit There may be a protective film over the display lens which can be removed Report any damage to the shipping agent immedi ately Save the original packing carton for possible future shipment The following items are included with every Model 2500 Dual Photodiode Meter order e Model 2500 with line cord e Accessories as ordered e Certificate of calibration e User s Manual e Service Manual e Manual addenda containing any improvements or changes to the instrument or manual If an additional user s manual is required order the appropriate manual package for example 2500 900 00 The manual packages include a manual and any pertinent addenda Options and accessories The following options and accessories are available from Keithley for use with the Model 2500 Manuals Model 2500 902 00 This manual package includes the service manual and any perti nent addenda Triax cables and adapters Model 7078 TRX 1 This low noise 12 inch triax cable is terminated at both ends with 3 slot male triax connectors CS 751 Barrel Adap
349. nus Configuration menu item Description CONFIG MSR1 CONFIG MSR1 BUTTON I I V V I MX B_UNIT P P gt CONFIG MSR2 CONFIG MSR2 BUTTON I I V V I MX B_UNIT P P gt CONFIG RATIO CONFIG RATIO BUTTON MSR1 MSR2 MSR2 MSR1 CONFIG DELTA CONFIG DELTA BUTTON MSR1 MSR2 MSR2 MSR1 Configure channel 1 measurement Current measurement Conductance I V measurement Resistance V I measurement MX B measurement program M and B values Electrical power V x I measurement Optical power Cmeasured Idark current Responsivity Configure channel 2 measurement Current measurement Conductance I V measurement Resistance V I measurement MX B measurement program M and B values Electrical power V x I measurement Optical power measured Idark current Responsivity Configure ratio function MSR1 MSR2 function MSR2 MSR1 function Configure delta function MSR1 MSR2 function MSR2 MSR1 function Getting Started Table 1 6 Source configuration menus Model 2500 and 2502 User s Manual Configuration menu item Description CONFIG SRC1 Configure delay and ground connect mode CONFIG SRC1 DELAY Set source delay 0 9999 998s AUTO DELAY Control source auto delay DISABLE Disable auto delay ENABLE Enable auto delay delay depends on current range GND CONNECT Control ground connect mode DISABLE Disable ground connect mode
350. ocal transition eceeeeeseeeseeeeeeeeeeeeeeeeeeeeees 13 2 Selecting an interface eee eeeeeseceneeeneeceeeeseeseaeeeseeeeeeesees 13 2 GPIB Operation sete ivisteeiidascasviinescidventietiersteinnevtstseten oes 13 3 GPIB standards oo ee eeeeceeseceeeseeeseceeeeseseeeeaeeeeeeseeenees 13 3 GPIB connections ineeie R 13 4 Primary address s senseeeseeseeeeeesesssessesessssesesrsrsseessrnsesssesse 13 6 General bus commands 0 cei eeeeseeeeeseceeeeseeeseeseeeseeseeeseeseeens 13 6 REN remote enable ccccscscccceessssecceeesssceeeceessneeeees 13 7 IFG interface cleat Junona a ss 13 7 LLO local lockout oo cece ecccesssecceesssseeeceesesseeeeeeessenees 13 7 GTL goto local iisieseocrscisa esiseina 13 7 DCL device clear cccccccccsssscceceessseceeeessssceeecesssseeeees 13 8 SDC selective device Clear ccesscccesseccesseeeesseeessseeeees 13 8 GET group execute trigger oo eee eeeeereeseeeseeseeeaees 13 8 SPE SPD serial polling eee eeecceeseeeseeeeeeeeeneeeeeeeees 13 8 Front panel GPIB operation o0 eee eee eseesseeseeeseeeeeeeeeeeeneees 13 9 Error and status messages ceseeesecesceeseceneeeeeeceneeeeeeeeas 13 9 GPIB status indicators eee eee eeeeseeeeseeceeeeseeeseeseeeaees 13 9 REM pireng isin tvsty dearth ecsechesonans sihazetirvigtdene eieseeiese 13 9 TALR soos re eE a e aves a EEE EE ANERE eee 13 9 CSTN s An iii tice dees dele EE ENS 13 9 SROS re ernest E erence E e
351. ode NRf NDN bit pattern Enable disable Limit X test state ON or OFF Query Limit X test result 0 pass 1 fail 1 LIMit 1 dedicated to channel 1 LIMit2 dedicated to channel 2 hardware limits 2 CALC3 channel 1 measurement CALC4 channel 2 measurement CALC5 RATIO CALC6 DELTA 3 LIMitX LIMit3 LIMit4 LIMit5 and LIMit6 software limits Models 2500 and 2502 User s Manual Table 11 1 continued Limit commands Limit Testing 11 21 Command Description CALCulate7 CLIMits PASS SOURce3 lt NRf gt lt NDN gt CALCulate7 CLIMits FAIL SOURce3 lt NRf gt lt NDN gt CALCulate7 CLIMits BCONtrol lt name gt CALCulate7 CLIMits CLEar CALCulate7 CLIMits CLEar AUTO lt state gt CALCulate7 CLIMits MODE lt name gt SOURce3 BSIZe lt n gt SOURce3 TTL lt NRf gt lt NDN gt SOURce3 TTL ACTual SOURce3 TTL4 MODE lt name gt SOURce3 TTL4 BSTate lt state gt SOURce3 CLEar SOURce3 CLEar AUTO lt state gt SOURce3 CLEar AUTO DELay lt n gt Specify pass bit pattern NRf NDN pattern Sorting mode only if Limits 3 6 enabled Specify fail bit pattern for sorting mode NRf NDN pattern Control I O port pass fail update Name IMMediate at failure or END end of sweep Clear test results reset I O port Enable disable auto clear state ON or OFF Select Digital I O control mode name GRAD ing or SORTing Set Digital I O port bit
352. oes not show the byte for the terminator that is attached to the end of each data string Models 2500 and 2502 User s Manual SCPI Command Reference 17 45 Figure 17 2 IEEE 754 single precision data format 32 data bits Header Byte 1 Byte 2 Byte 3 s sign bit 0 positive 1 negative e exponent bits 8 f fraction bits 23 Normal byte order shown For swapped byte order bytes sent in reverse order Header Byte 4 Byte 3 Byte 2 Byte 1 The header and terminator are sent only once for each READ During binary transfers never un talk the Model 2500 until after the data is read input to the computer Also to avoid erratic operation the readings of the data string and terminator should be acquired in one piece The header 0 can be read separately before the rest of the string NOTE The Model 2500 terminates the binary data string with LF EOI If your pro gram is set to terminate on CR and or LF data transfer may terminate prema turely because one or more data bytes has a CR or LF value To avoid the problem set your computer program to terminate on EOI only The number of bytes to be transferred can be calculated as follows Bytes 2 Rdgs x 4 1 where 2 is the number of bytes for the header 0 Rdgs is the product of the number of selected data elements arm count and trigger count 4 is the number of bytes for each reading 1 is the byte for the terminator For example assume the Model 2500
353. of the Model 2500 cannot be turned on unless the output enable line is pulled low through a switch to ground as shown in Figure 12 4A If the lid of the test fixture opens Figure 12 4B the switch opens and the output enable line goes high turning the OUTPUT of the Model 2500 OFF high impedance The output can only be turned back on by first closing the lid of the test fixture and then pressing the OUTPUT ON OFF key Figure 12 4 Using test fixture output Model 2500 Test Fixture Output Enable Pin 8 i Interlock Switch Digital I O Lid Closed GND 7 7 Pin 5 or 9 A Model 2500 OUTPUT can be turned on Model 2500 Test Fixture Output i Enable gt Pin 8 i E Interlock Switch Digital I O i Lid Open GND r t Pin 5 or 9 B Model 2500 OUTPUT turns off NOTE Output enable can be driven by digital I O Allow 100s settling and response time The digital I O lines are open collector edge sensitive and signals should be de bounced to avoid erratic operation 12 8 Digital I O Port Output Enable and Output Configuration Models 2500 and 2502 User s Manual Front panel output configuration The output is configured from the CONFIGURE OUTPUT menu and is structured as fol lows Note that bullets indicate the primary items of the sweep menu while dashes indi cate options Use Section 1 Rules to navigate menus to check and or change operate options Configure OUTPUT menu Press CON
354. og Scale 10 5 6234 Volts 3 1623 1 7783 Log Points 5 k T Ff fF T Measure Measure Measure Measure Measure 1 2 3 4 5 X Measurement Point The programmable parameters for a log sweep include the start and stop levels and the number of measurement points for the sweep The specified start stop and point parame ters determine the logarithmic step size for the sweep Step size for the sweep in Figure 9 2 is calculated as follows Log Step Size log10 stop log10 start Points 1 _ log10 10 log10 1 5 1 0 0 4 0 25 9 4 Sweep Operation Models 2500 and 2502 User s Manual Thus the five log steps for this sweep are 0 0 25 0 50 0 75 and 1 00 The actual voltage bias levels at these points are listed in Table 9 1 the voltage bias level is the anti log of the log step Table 9 1 Logarithmic sweep points Measure point Log step Bias level volts Point 1 0 1 Point 2 0 25 1 7783 Point 3 0 50 3 1623 Point 4 0 75 5 6234 Point 5 1 0 10 When this sweep is triggered to start the output will go from the bias level to the start source level 1V and sweep through the symmetrical log points With trigger delay set to zero the time duration at each step is determined by the source delay and the time it takes to perform the measurement NPLC setting Custom sweep This sweep type lets you configure a customized sweep Programmable parameters include the
355. ol Use the SOURce3 TTL lt NRf gt command to control the digital output line logic levels where lt NRf gt is the decimal value shown in Table 12 1 For example send the following command to set the output lines to L H L H SOUR3 TTL 5 Table 12 1 Digital output line settings Decimal OUT 4 OUT 3 OUT 2 OUT 1 value L L L L 0 L L L H 1 L L H L 2 L L H H 3 L H L L 4 i H L H 5 L H H L 6 L H H H 7 H L L L 8 H L L H 9 H L H L 10 H L H H 11 H H L L 12 H H L H 13 H H H L 14 H H H H 15 L Low Gnd H High gt 3V 0 7 in 3 bit mode which is controlled by CONFIG LIMIT menu See Section 11 Output enable The digital I O port provides an output enable line for use with a test fixture interlock switch When properly used the voltage source outputs of the Model 2500 will turn OFF when the lid of the test fixture is opened WARNING To prevent electric shock test connections must be configured such that the user cannot come in contact with conductors or any DUT that is in contact with the conductors Safe installation requires proper shields barriers and grounding to prevent contact with conductors Operator protection and safety are the responsibility of the person installing the product Models 2500 and 2502 User s Manual Digital I O Port Output Enable and Output Configuration 12 7 When the output enable is activated see Front panel output configuration page 12 8 the output
356. ommands and features GET IFC SDC DCL LLO Serial Poll and SRQ are still fully supported e Multiple TALKs on the same query are supported as in the SCPI protocol This feature is useful when reading back long ASCII strings Example Programs H 2 Example Programs Models 2500 and 2502 User s Manual Introduction This section provides several complete functional listings for example programs through out this manual These programs include e Basic measurement program from Section 3 e Photodiode measurement program from Section 4 e Data store program from Section 8 e Sweep program from Section 9 e Limit test program from Section 11 Hardware requirements The following computer hardware is required to run the example programs IBM PC compatible computer Keithley KPC 488 2 KPS 488 2 or KPC 488 2AT or CEC PC 488 IEEE 488 inter face for the computer Shielded IEEE 488 connecting cable Keithley Model 7007 Software requirements In order to use the example programs you will need the following computer software e Microsoft QBasic supplied with MS DOS 5 0 or later or Quick Basic e MS DOS version 5 0 or later or Windows 95 98 HP style Universal Language Driver CECHP EXE supplied with Keithley and CEC interface cards listed above General program instructions 1 With the power off connect the Model 2500 to the IEEE 488 interface of the com puter Be sure to use a shielded IEEE 488 cab
357. ommands are aborted The reading buffer is cleared i e FETCh CALC1 DATA and CALC2 DATA will not return any data until the Model 2500 takes readings while in remote All other settings remain unaffected including TRACe buffer storage Sources are placed in the FIXed mode Remote to local transition When changing from remote to local operation the following takes place The Model 2500 stops taking readings and is placed into the IDLE layer of the Trigger Model All user defined displays are disabled The display is re enabled if it was previously turned off Readings are continuously taken Sources are placed in the FIXed mode Selecting an interface The Model 2500 supports two built in remote interfaces GPIB General Purpose Interface Bus RS 232 interface You can use only one interface at a time The factory interface selection is the GPIB bus You can select the interface only from the front panel The interface selection is stored in non volatile memory it does not change when power has been off or after a remote inter face reset The GPIB bus is the IEEE 488 interface You must select a unique address for the Model 2500 The address is displayed when the instrument is turned on At the factory the address is set to 25 The IEEE 488 address can only be changed from the front panel while the IEEE 488 bus is enabled Models 2500 and 2502 User s Manual Remote Operations 13 3 The RS 232 interface is a serial
358. on and as a listener a device will receive information To simplify the task of keeping track of the devices a unique address number is assigned to each one On the bus only one device can talk at a time and is addressed to talk by the controller The device that is talking is known as the active talker The devices that need to listen to the talker are addressed to listen by the controller Each listener is then referred to as an active listener Devices that do not need to listen are instructed to unlisten The reason for the unlisten instruction is to optimize the speed of bus information transfer since the task of listening takes up bus time Through the use of control lines a handshake sequence takes place in the transfer process of information from a talker to a listener This handshake sequence helps ensure the credi bility of the information transfer The basic handshake sequence between an active con troller talker and a listener is as follows 1 The listener indicates that it is ready to listen 2 The talker places the byte of data on the bus and indicates that the data is available to the listener 3 The listener aware that the data is available accepts the data and then indicates that the data has been accepted 4 The talker aware that the data has been accepted stops sending data and indicates that data is not being sent 5 The listener aware that there is no data on the bus indicates that it is ready for the next
359. on as required by the component handler Note that the delay specifies the pulse width of line 4 The pulse width of lines 1 2 and 3 is actually 20usec longer Line 4 is skewed because it is used as the end of test EOT strobe by category register component han dlers Lines 1 2 and 3 establish the bit pattern and then 10usec later the SOT strobe tells the handler to read the bit pattern and perform the binning operation This 10psec offset is used to make sure the correct bit pattern is read by the handler After the pass fail is read by the handler the digital output returns to the clear pattern 11 16 Limit Testing Models 2500 and 2502 User s Manual Configuring and performing limit tests Configuring limit tests Press CONFIG and then LIMIT to display the CONFIG LIMITS MENU The limits con figuration menu is structured shown below and in Figure 1 10 The limits configuration menu is structured as follows Note that bullets indicate the primary items of the limit menu and dashes indicate the options of each menu item Refer to Section 1 Rules to navigate menus to configure the limit tests e DIGOUT Use this menu item to control the following Digital I O aspects SIZE Use to select 3 BIT or 4 BIT Digital I O bit size or 16 BIT with 2499 DIGIO option In the 3 BIT mode Digital I O line 4 becomes the EOT EOT BUSY or BUSY signal depending on the selected END OF TEST mode In the 4 BIT mode Digital I O line
360. on by taking the instrument out of idle NOTE READ is illegal when the ARM SOUR BUS command is in effect See Section 10 Triggering for details After all source and measure operations are completed the Model 2500 goes back into idle at which time the FETCh command is executed The readings are sent to the computer and displayed when the Model 2500 is addressed to talk NOTE The FORM ELEM command controls the reading source To access channel 1 readings send FORM ELEM CURR before sending READ To access chan nel 2 readings send FORM ELEM CURR2 before using READ See Section 17 FORMat subsystem for details READ will work with the output off If in the sweep mode with a trig ger count gt 1 the source value on the display will update however the actual output will be OV If auto output off is enabled SOURce1 CLEar AUTO ON or SOURce2 CLEar AUTO ON then the corresponding output will auto matically turn on at the beginning of each SDM source delay measure cycle and turn off after each measurement NOTE See Appendix C for a detailed explanation on how data flows through the vari ous operation blocks of the Model 2500 It clarifies the type of readings that are acquired by the various commands to read data Models 2500 and 2502 User s Manual SCPI Signal Oriented Measurement Commands 16 5 MEASure CURRent DC Parameters Description CURRent DC Amps function This command combine
361. on menu 7 6 Math functions 7 4 Menus 1 25 Photodiode 4 4 Programming example 3 13 Range 6 2 Remote command procedure 3 12 Time 5 3 Measurement range Select 17 54 Measurement speed Setting 17 56 Menus 1 20 Configuration 1 24 Configure filtering tree 6 12 Configure OUTPUT 12 8 CONFIGURE TRIGGER 10 14 Configure trigger tree 10 16 Data store 1 29 DELTA 7 10 Digits 1 29 Display 1 30 Filter 6 12 Limit 1 27 Limits configuration tree 11 18 Main 1 20 Measurement 1 25 Measurement configuration 4 2 Measurement configuration tree 4 2 Measurement function configuration 7 6 Navigating 1 23 Output 1 30 Output configuration tree 12 8 Range 1 26 RATIO 7 10 Rel 1 26 Source 1 26 Speed 1 29 Speed configuration tree 6 6 SPEED ACCURACY 6 6 Sweep 1 29 Sweep configuration tree 9 7 Tree 1 22 Trigger 1 28 Messages Exchange protocol 13 16 Program 13 14 Response 13 16 Status and error 1 14 13 9 B 2 Multiple element device binning 11 14 MX B 7 5 Setting parameters 17 24 Operating boundaries Bias source 5 6 Loading effects 5 6 Operation Front panel GPIB 13 9 GPIB 13 3 Local to remote transition 13 2 Overview 3 2 11 4 Remote to local transition 13 2 RS 232 13 17 Optical power 7 5 Optical power conversion 4 3 Options 1 3 Output Menus 1 30 Output control 3 10 Output enable 2 4 12 2 12 6 Output enable control 17 53 Output enable line 11 11 Output slew time 3 6 OUTPut subsystem 17 52 O
362. on occurs when a bus trigger GET or TRG is received TIMER With the Timer selected event detection occurs immediately when the output is turned ON On repeated passes via Another Arm Yes event detection occurs when the programmed timer interval expires If operation takes the Another Arm No route the Timer resets allowing event detection to again occur immediately MANUAL Event detection occurs when the TRIG key is pressed TLINK Event detection occurs when an input trigger via the Trigger Link input line is received see Trigger link for more information With TLink selected you can loop around the Arm Event Detector by setting the event detector bypass to ONCE JSTEST Event detection occurs when the SOT start of test line of the Digital I O port is pulsed low This pulse is received from the handler to start limit testing See Section 11 TSTEST Event detection occurs when the SOT line of the Digital I O port is pulsed high This pulse is received from the handler to start limit testing See Section 11 TLSTEST Event detection occurs when the SOT line of the Digital I O port is pulsed either high or low This pulse is received from the handler to start limit testing See Section 11 NOTE STEST can be used only at the beginning of a sweep and should not be used to trigger each point in a sweep Models 2500 and 2502 User s Manual Triggering 10 5 Trigger layer The Trigger Layer u
363. onnect enabled you can bias and measure the DUT using a single triax cable as shown in Figure 2 5 Note that one DUT terminal is connected to INPUT HI while the other DUT terminal is connected to chassis ground through the outer shield of the triax cable connection Figure 2 6 shows an equivalent circuit Figure 2 5 Test connections using ground connect mode INPUT HI i I Forward l Photodiode i Chassis Ground I Laser i INPUT LO Triax Cables Diode i l INPUT HI center conductor Back i INPUT LO inner shield Photodiode Chassis Ground outer shield I I Optional Noise Chassis Ground Shield Connect to INPUT LO INPUTS NARNIBG No INTERNAL OPERATOR SERVICABLE PARTS SERVICE BY QUALIFIED PERSONNEL ONLY MMON KEN IEEE 488 MADE IN CHANGE IEEE ADDRESS DE E COMPETI KO ESSER INPUT INPUT DIGITAL VO CHANNEL 1 CHANNEL 2 SRR l O came TRIGGER LINK RS 232 CATI LINE RATING 50 60H2 RATINGS MAX SOVA NAX 100V 20mA Fuse Une E30 mAT 100 VAG 88 120 VAC A hertan VOLTAGE SOURCE VOLTAGE SOURCE 68 _ 240 VAC OUTPUT CHANNEL 1 OUTPUT CHANNEL 2 g CAUTION FOR CONTINUED PROTECTION AGAINST FIRE HAZARD REPLACE FUSE WITH SAME TYPE AND RATING j Model 2500 as 2 8 Connections Model 2500 and 2502 User s Manual Figure 2 6 Ground connect mode equivalent circuit te ee ee a ee es a E gt INPUT HI Channel 1 Channel 1 Analog Common Back INP
364. operating modes e Number of points 10 Trigger count 10 e Data store source channel 1 readings only e Acquired data all buffer readings mean average and standard deviation Data Store Program OPEN IEEE FOR OUTPUT AS 1 Open IEEE 488 output path OPE TEEE FOR INPUT AS 2 Open IEEE 488 input path PRINT INTERM CRLF Set input terminator PRINT OUTTERM LF Set output terminator PRINT REMOTE 25 CLS PRINT OUTPUT 25 RST Restore GPIB defaults PRINT rO 25 STAT MEAS ENAB 512 SRE 1 Enable buffer full SRQ PRINT o TO 257 SOURI VOLT 10 Output 10V on channel 1 PRINT PO 25 SOUR1 DEL 0 5 0 5 sec source 1 delay PRINT Fao 25 TRAC POIN 10 Store 10 readings PRINT 1 NO 25 TRAC FEED CONT NEXT Turn on data store PRINT 1 OUTPUT 25 TRIG COUN 10 Trigger count data store points PRINT OU 25 FORM ELEM TRAC CURRI Select channel 1 current PRINT O 25 OUTP1 ON Turn on channel 1 output PRINT OUTPUT 25 INIT Trigger readings PRINT Waiting for buffer to fill DO PRINT 1 SRQ Request SRO status INPUT 2 S t Input SRO status LOOP UNTIL S Wait for buffer to fill PRINT 1 OUTPUT 25 OUTP1 OFF n Turn off channel 1 output PRINT 1 OUTPUT 25 TRAC DATA Request all data store readings PRINT 1 ENTER 25 Address 2500 to talk LINE INPUT 2 R Input
365. or 230 Data corrupt or stale will be generated 2 If there are a lot of readings stored in the buffer some statistic oper ations may take too long and cause a bus time out error To avoid this situation send the calc8 data command and then wait for the MAV message available bit in the status byte register to set before addressing the Model 2500 to talk See Section 14 3 See Appendix C for a detailed explanation on how data flows through the various operation blocks of the Model 2500 It clarifies the types of readings that are acquired by the various commands to read data 17 40 SCPI Command Reference Models 2500 and 2502 User s Manual DISPlay subsystem The display subsystem controls the display of the Model 2500 and is summarized in Table 17 2 Control display DIGits lt n gt DISPlay DIGits lt n gt Set display resolution Parameters lt n gt 4 3 5 digit resolution 5 4 5 digit resolution 6 5 5 digit resolution 7 6 5 digit resolution DEFault 5 5 digit resolution MINimum 3 5 digit resolution MAXimum 6 5 digit resolution Query DIGits Query display resolution DIGits DEFault Query RST default resolution DIGits MINimum Query lowest allowable display resolution DIGits MAXimum Query largest allowable display resolution Description This command is used to set the display resolution Note that you can instead use rational numbers For example to select 4 5 digit resolution you can send a parameter va
366. or fixed source Query Description TRIGgered DEFault Query RST default amplitude TRIGgered MINimum Query lowest allowable amplitude TRIGgered MAXimum Query highest allowable amplitude These commands perform the same as the MMediate AMPLitude commands except that the source amplitude is not updated immediately With this command the amplitude is updated when the Model 2500 is triggered to perform a source and measure operation For example if the instrument is waiting in the trigger layer for an external trigger the amplitude of the source will not update until that external trigger is received by the Model 2500 See Section 10 Triggering for details on trigger model operation The MINimum and MAXimum parameters are only valid if the 100V source range is presently selected Sending the MINimum or MAXi mum parameters on the 10V source range will generate error 221 Set ting Conflict Models 2500 and 2502 User s Manual SCPI Command Reference 17 65 Set delay NOTE All SOURx DEL commands are global and affect both simultaneously DELay lt n gt SOURce 1 DELay lt n gt Manually set source delay SOURce2 DELay lt n gt Manually set source delay Parameters lt n gt 0 to 999 998 Specify delay in seconds MINimum 0 seconds MAXimum 999 998 seconds DEFault 0 001 Query DELay Query delay DELay DEFault Query RST default delay DELay MINimum Query lowest allowable delay DELay MAXimum Query highest allow
367. ore sending CALCn DATA CALCI Ch 1 math feeds into CALC3 Ch 1 rel CALC2 Ch 2 math feeds into CALC4 Ch 2 rel See CALCulate subsystems in Section 17 for details 7 12 Relative Math Ratio and Delta Models 2500 and 2502 User s Manual RATIO and DELTA function programming example Table 7 8 summarizes commands that program the following RATIO and DELTA functions e RATIO function CALC3 CALC4 DELTA function CALC4 CALC3 Table 7 8 RATIO and DELTA programming example Command Description gt CALC5 FORM C3C4 Select CALC3 CALC4 ratio CALC5 STAT ON Enable ratio function OUTP1 ON OUTP2 ON Turn on outputs INIT Trigger ratio reading CALC5 DATA Request ratio reading CALC6 FORM C4C3 Select CALC4 CALC3 delta CALC6 STAT ON Enable delta function INIT Trigger delta reading CALC6 DATA Request delta reading OUTP1 OFF OUTP2 OFF Turn off outputs Data Store Data store overview Outlines basic data store buffer capabilities Storing readings Discusses the procedure for storing readings in the internal buffer Recalling readings Provides detailed information for recalling readings stored in the buffer Buffer statistics Discusses the various statistics available on buffer data including minimum and maximum values average mean standard deviation and peak to peak values Timestamp format Explains how to select the timestamp format absolute or delta for
368. ot auto matically controlled in 4 bit mode See BSIZe lt n gt page 17 76 Like wise with BUSY enabled in the 4 bit mode the unit behaves as if it were in 3 bit mode by ignoring all attempts to drive digital I O line 4 17 76 SCPI Command Reference Models 2500 and 2502 User s Manual BSTate lt b gt SOURce3 TTL4 BSTate lt b gt Control BUSY and EOT polarity Parameters lt b gt 1 Set EOT BUSYpolarity high 0 Set EOT BUSY polarity low Query BSTate Query EOT BUSY polarity Description This command sets the polarity of the EOT or BUSY signal in the 3 bit mode BSIZe lt n gt SOURce3 BSIZe lt n gt Set digital I O bit size Parameters lt n gt 3 Set 3 bit size Set 4 bit size 16 Set 16 bit size 2499 DIGIO option Query BSIZe Query digital I O port bit size Description This command sets the digital I O bit size to 3 or 4 In the 3 bit mode digital I O line 4 becomes EOT EOT BUSY or BUSY based on the SOUR3 TTL4 MODE and SOUR3 TTL4 BST commands above In 4 bit mode digital I O line 4 is controlled manually if SOUR3 TTL4 MODE is set to EOT If SOUR3 TTL4 MODE is set to BUSY operation is identical to the 3 bit mode The 16 bit size is avail able with the 2499 DIGIO option connected to the digital I O port NOTE This command is not affected by RST SYSTem PRESet or RCL Clearing digital output IMMediate SOURce3 CLEar IMMediate Clear digital output lines Description This action command is us
369. ou wanted to repeat the sweep three times the arm counter would be set to three Three 10 point sweeps can then be performed for a total of 30 source delay measure actions The maximum buffer size for the Model 2500 is 3000 readings The product of the two counter values cannot exceed 3000 For example if you set an arm count of two the max imum trigger count will be 1500 3000 2 1500 However you can set the arm count to INFINITE With an infinite arm count the maximum trigger count is 3000 NOTE When a sweep is configured the trigger model settings will not change until the sweep is started After the sweep is finished the trigger model will reset to the previous settings Output triggers The Model 2500 can be programmed to output a trigger via rear panel Trigger Link con nector after various trigger model operations An output trigger is used to trigger another instrument to perform an operation See Trigger link page 10 8 for more information Trigger Layer Output Triggers After each action Source Delay and Measure the Model 2500 can be programmed to send out an output trigger if Trigger Link is the selected Trigger In Source For example if the Trigger Out Event for Measure is ON an output trigger will be sent after the Measure action When used with a scanner an output trigger after each measurement can signal the scanner to select the next channel in the scan Arm Layer Output Trigger The Model 2500
370. ource output on off Controlling 17 60 SOURCce subsystem 17 60 Source measure cycle Abort 17 90 Initiate 17 90 SOURce 1 17 60 SOURce2 17 60 SOURce3 17 74 Source delay measure cycle Actions 10 5 10 21 Delay phase 5 3 During sweeps 5 5 Measurement time 5 3 Overview 5 2 Triggering 5 2 Sourcing mode Selecting 17 61 SPE SPD serial polling 13 8 14 9 Specifications A 1 Speed 6 5 Commands 6 7 Menus 1 29 Programming example 6 7 Remote programming 6 7 Setting 6 6 Statistics Aquire 17 39 Select 17 39 Status and error messages 1 14 13 9 B 2 Status byte and SRQ 14 2 14 7 Commands 14 10 Status byte register 14 8 Status register format 17 51 Status register sets 14 2 14 11 Status structure 14 1 STATus subsystem 17 78 Sweep Configuration menu tree 9 7 Configure 9 6 17 66 Custom 5 4 9 4 9 11 Custom commands 9 14 Custom programming example 9 15 Data storage 5 5 Linear staircase 5 4 9 2 9 8 Logarithmic staircase 5 4 9 3 9 9 Menus 1 29 Performing a custom 9 11 Performing a linear staircase 9 8 Performing a log staircase 9 9 Setting delay 9 7 Staircase commands 9 12 Staircase programming example 9 13 Types 5 4 9 2 Typical applications 5 5 Waveforms 5 4 Syntax 13 10 SYSTem subsystem 17 81 Terminator 13 18 Tests Front panel 1 15 Limit see Limit tests Timestamp 8 3 Accuracy 8 5 Format 8 5 Resetting 17 86 Select format 17 89 TRACe subsystem 17 87 Trigger 5 2 Commands 10 24 Configure 10 14 Delay 10 5 10
371. ous NOTE Auto zero control affects both channels simultaneously Front panel auto zero Set the auto zero state from the front panel as follows Press the MENU key Select A D CTRL from the main menu then press ENTER Select AUTO ZERO then press ENTER Select ENABLE or DISABLE as appropriate then press ENTER Press EXIT as necessary to return to normal display Bee Remote command auto zero Use the SYSTem AZERo command to enable or disable auto zero via remote For exam ple send the following command to disable auto zero iSYST AZER ON Conversely send this command to disable auto zero SYST AZER OFF Source delay Models 2500 and 2502 User s Manual Basic Operation 3 5 The source delay options are used to set the settling time for the voltage bias source This source delay is the delay phase of the source delay measure cycle See Section 5 Mea surement Concepts for more information Auto delay period The auto delay period depends both on the current range Table 3 3 and during sweeps Section 9 on the voltage step size With the source auto delay mode enabled the total source delay for both channels will be the sum of the current range based delay in Table 3 3 and the voltage slew time for the channel that has the greater total delay Worst case voltage slew time Tyg is given by the equation Table 3 3 Tys 3 07ms V Auto source delay I range 2nA 20nA 200nA 2uA 20uA
372. owe e Shield INPUT CHANNEL 1 LO ANALOG OUT Model 2500 and 2502 User s Manual Connections 2 13 Isolated connections To maintain proper isolation between the analog outputs and chassis ground it is strongly recommended that you use the isolated connections shown in Figure 2 11 In this case an Analog Devices 3B41 03 Isolated Wideband Voltage Input is used to provide isolation between the Model 2502 ANALOG OUT and the measuring instrument Analog output HI center conductor is connected to the HI input terminal of the isolator and analog output LO inner shield is connected to the LO input The two isolator Voyr terminals are con nected to the measuring instrument HI and LO INPUT terminals as shown Refer to the 3B41 03 documentation for connections power supply and configuration information for your application Figure 2 11 Isolated analog output connections Analog Devices 3B41 03 Wideband Isolated Voltage Input Center Conductor Model 2502 KEITHLEY Vo UT H l maA ry Input owe ce VOUT Common LO Shield CHANNEL 1 ANALOG OUT 2 14 Connections Model 2500 and 2502 User s Manual Equivalent circuits Figure 2 12 shows an equivalent circuit of the analog outputs with the ground connect mode disabled Only one channel is shown the other channel is identical Note that the analog output circuit consis
373. pecify span 200 to 200 Query span Specify center point 100 to 100 Query center point Configure SWEep source mode Select sweep spacing type LINear or LOGarithmic Query sweep spacing Specify number of sweep points 2 to 3000 Query number of points in sweep Sweep from start to stop UP or from stop to start DOWN Query sweep direction Select source ranging mode BEST AUTO or FIXed Query source ranging mode Configure LIST source mode Create list of V Source values 100 to 100 Add up to 100 V Source values to end of list Query number of source values in list Query V Source list Default parameter LINear 3000 UP BEST No effect SCPI NNNSNN No NN NN Models 2500 and 2502 User s Manual SCPI Command Reference 17 17 Table 17 6 continued SOURce command summary Default Command Description parameter SCPI SOURce3 Path to control digital output lines BSIZe lt n gt Set Digital I O bit size 3 or 4 No effect BSIZe Query Digital I O bit size TTL LEVel DEFault lt NRf gt Specify digital output pattern 15 or 7 lt NDN gt ACTual Query actual pattern on digital output port DEFault Query the programmed output pattern value TTL4 MODE lt name gt Set Digital I O mode EOTest or BUSY EOTest MODE Query Digital I O line 4 mode BSTate lt b gt Set BUSY and EOT polarity HI or LO LO BSTate Query BUSY and EOT polarity CLEar Clear
374. plitude Set source amplitude volts OV 100V 100V Query programmed source amplitude Query RST default amplitude Query lowest allowable amplitude Query highest allowable amplitude Description This command is used to immediately update the amplitude of a fixed source This command is not valid if the list or sweep mode is selected NOTE The sourcing MODE command is used to select a fixed source See Select sourcing mode page 17 61 If a manual source range is presently selected then the specified ampli tude cannot exceed that range For example if the source is on the 10V range auto range disabled you will not be able to set the source ampli tude to 20V In auto range the amplitude can be set to any level that is within the capabilities of the source The MINimum and MAXimum parameters are only valid if the 100V source range is presently selected Sending the MINimum or MAXi mum parameters on the 10V source range will generate error 221 Set ting Conflict 17 64 SCPI Command Reference Models 2500 and 2502 User s Manual TRIGgered AMPLitude lt n gt SOURce 1 VOLTage LEVel TRIGgered AMPLitude lt n gt Set fixed source 1 amplitude when Parameters triggered SOURce2 VOLTage LEVel TRIGgered AMPLitude lt n gt Set fixed source 2 amplitude when triggered lt n gt 100 to 100 Set source amplitude volts DEFault OV MINimum 100V MAXimum 100V TRIGgered Query triggered amplitude f
375. press ENTER Select ENABLE then press ENTER At the prompts set the auto clear pulse width Os to 60s and clear bit pattern 0 to 15 4 bit 0 to 7 3 bit size Use EXIT to return to normal display le net ote Models 2500 and 2502 User s Manual Limit Testing 11 15 Auto clear timing The following example timing diagram Figure 11 9 and discussion explain the relation ship between the digital output lines for auto clear This example uses the 3 bit digital out put mode and uses line 4 as EOT That is line 4 will pulse low to signal end of test Initially the four digital output lines are cleared in this case they are all set high Limit tests start when the start of test SOT pulse is received from the component handler When the testing process is finished the pass or fail pattern is applied to the digital output As shown in the diagram lines 2 3 and 4 go low while line remains high Figure 11 9 Digital output auto clear timing example SOT ti Line 1 H H i lt Meas gt i i Line 2 ee e O O Line 3 _ ap Line 4 L h JEOT 3 bit mode 104s gt Delay gt Ik 104s With the SOT line being pulsed low as shown STEST must be the selected arm event for the trigger model If the SOT line is instead pulsed high by the handler TSTEST must be the selected arm event The pulse width delay of the pass fail pattern can be set from 0 to 60sec 100usec resolu ti
376. propriate function key For example if V I readings are displayed on MSR all buffer statistics displayed are based on those readings Minimum and maximum This mode displays the minimum and maximum readings stored in the buffer The buffer location number and timestamp are also provided for these readings If desired you can go to those buffer locations to obtain more data about the readings Peak to peak This mode displays the peak to peak reading peak to peak Maximum Minimum Average The average mode displays the mean average of all measured readings stored in the buffer The following equation is used to calculate mean Lx She y n where y is the average X is a stored reading n is the number of stored readings Standard deviation This mode displays the standard deviation of buffered readings The following equation is used to calculate standard deviation Eee i n 1 i 1 n 1 where yis the average X is a stored reading n is the number of stored readings Models 2500 and 2502 User s Manual Data Store 8 5 Timestamp format Buffer readings can be recalled using the absolute timestamp format or the delta format For the absolute format readings are referenced to zero seconds For the delta format the timestamp indicates the time between the displayed reading and the previous reading Perform the following steps to set the timestamp format 1 While in the normal display mode press CONFIG a
377. r s Manual Grading mode status bit values Meas Event Result Bit 12 11 10 9 8 Status All limit tests passed 0 JO JO JO JO Bit 5 LP Limit test 1 failed 0 JO JO JO 1 BitO L1 Limit test 2 failed O JO JO 1 O Bit1 L2 Limit test 3 high failed 1 JO JO 1 1 Bit 4 LFH Limit test 3 low failed O JO JO 1 1 Bit 2 3 Limit test 4 high failed 1 JO 1 JO JO Bit4 LFH Limit test 4 low failed O JO 1 JO O Bit 3 L4 Limit test 5 high failed 1 JO 1 JO JI l Limit test 5 low failed O JO 1 JO JI J Limit test 6 high failed 1 JO 1 1 JO Bit4 LFH Limit test 6 low failed O JO 1 1 JO J 1 See Section 14 Measurement event register and Figure 14 6 for details Sorting mode status bit values Meas Event Result Bit 12 11 10 9 8 Status Limit 1 amp 2 passed 3 6 disabled 0 0 Bit5 LP 0 1 Bit0 L1 1 0 Bit 1 2 1 1 Bit3 3 1 lo Jo Bit4 L4 0 Limit test 1 failed Limit test 2 failed Limit test 3 passed Limit test 4 passed OSOS SooS o o o o o o o Limit test 5 passed 1 1 Limit test 6 passed 1 1 O J All Limits 3 6 failed 1 1 J1 J1 fl j Limits 1 and 2 passed 1 See Section 14 Measurement event register and Figure 14 6 for details Models 2500 and 2502 User s Manual SCPI Command Reference 17 49 SOURce3 lt name gt FORMat SOURc
378. r ratio delta and offset functions Reading and setup storage Up to 3000 5 2 digit readings for each channel and seven setups five user defaults factory default RST default can be stored and recalled Closed cover calibration The instrument can be calibrated either from the front panel or remote interface The Model 2502 adds an analog output for each channel Each analog output provides a 10V to 10V output voltage analogous to the input current 1 6 Getting Started Model 2500 and 2502 User s Manual Front and rear panel familiarization Front panel summary The front panel of the Model 2500 is shown in Figure 1 1 Figure 1 1 Front panel KEITHLEY 2500 DUAL PHOTODIODE METER DISPLAY rce LocaL REL ETER LMT TRIG SWEEP l 0000 ON OFF Dicirs SPEED SPEED STORE jRECALI ONFIG MENU OUTPUT Model 2500 Measurement function keys MSR1 Measure channel 1 MSR2 Measure channel 2 DELTA Difference function RATIO Ratio function Voltage bias source function keys SRC1 Channel 1 voltage bias source SRC2 Channel 2 voltage bias source Range keys AUTO Enable disable auto range A v Increase manual range Decrease manual range EDIT keys VAP Increase value Decrease value Move cursor left Move cursor right Model 2500 and 2502 User s Manual Operation keys CHANNEL SELECT DISPLAY TOGGLE LOCAL REL FILTER LIMIT TRIG SWEEP DIGITS SPEED STORE
379. r Full BFL Set bit indicates that the trace buffer is full Bit B10 Not used Bit B11 Output Enable Asserted OE Set bit indicates that the Digital I O port output enable line is at digital low asserted Source outputs can be turned on Bit B12 Not used Bit B13 Source 1 Compliance S1C Set bit indicates that the channel 1 voltage source is in compliance Bit B14 Source 2 Compliance S2C Set bit indicates that the channel 2 voltage source is in compliance Bit B15 Not used Models 2500 and 2502 User s Manual Status Structure 14 15 Figure 14 6 Measurement event status S2C SIC OE BFL BAV ROF RAV LP LFH L4 L3 L2 LI B15 B14 TI B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 BO S2C S1C OE BFL BAV ROF RAV LP LFH L4 L3 E2 L1 B15 B14 B13 B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 BO Measurement Condition Register stat meas cond Measurement Event Register stat meas To Measurement Summary Bit OSB of Status Byte Register Figure 14 3 stat meas enab lt NRF gt stat meas enab Measurement Event Enable Register S2C Source 2 In Compliance Limits Pass S1C Source 1 In Compliance PIE Limit Failed High OE Output Enable Asserted L4 Limit 4 Summary BFL Buffer Full L3 Limit 3 Summary BAV Buffer Available L2 Limit
380. r and status messages See Appendix B The Model 2500 status model Figure 14 1 shows how the two queues are structured with the other registers Output queue The output queue holds data that pertains to the normal operation of the instrument For example when a query command is sent the response message is placed in the output queue When data is placed in the output queue the Message Available MAV bit in the status byte register sets A data message is cleared from the output queue when it is read The output queue is considered cleared when it is empty An empty output queue clears the MAV bit in the status byte register A message is read from the output queue by addressing the Model 2500 to talk after the appropriate query is sent 14 20 Status Structure Models 2500 and 2502 User s Manual Error queue The error queue holds error and status messages When an error or status event occurs a message that defines the error status is placed in the error queue When a message is placed in the error queue the error available EAV bit in the status byte register is set An error status message is cleared from the error queue when it is read The error queue is considered cleared when it is empty An empty error queue clears the EAV bit in the status byte register The error queue holds up to 10 error status messages The commands to read the error queue are listed in Table 14 9 When you read a single message in the error que
381. r sending this command and addressing the Model 2500 to talk the oldest message is sent to the computer and is then removed from the queue NOTE The STATus Queue command performs the same function as oSYSTem ERRor NEXT See STATus subsystem page 17 78 Models 2500 and 2502 User s Manual SCPI Command Reference 17 83 ALL SYSTem ERRor ALL 2 Read all errors codes and messages Description This query command is similar to the NEXT command except that all messages in the error queue are sent to the computer when the Model 2500 is addressed to talk All messages are removed from the queue COUNT SYSTem ERRor COUNt Return the number of errors Description After sending this command and addressing the Model 2500 to talk a decimal number will be sent to the computer That is the number of mes sages in the error queue CODE NEXT SYSTem ERRor CODE NEXT Read oldest error code only Description This command is identical to the NEXT command except only the code is returned The message itself is not returned The error is cleared from the queue CODE ALL SYSTem ERRor CODE ALL Read all errors codes only Description This query command is identical to the ALL command except only the codes are returned The actual messages are not returned All errors are cleared from the queue CLEar SYSTem CLEar Clear error queue Description This action command is used to clear the error queue of mess
382. r the LOCAL key are locked out When REM is turned off the instrument is in the local state and front panel operation is restored NOTE If LLOis in effect LOCAL will be locked out OUTPUT ON OFF is still opera tional in remote If ARM SOUR is set to manual the TRIG key will be active in remote TALK This indicator is on when the instrument is in the talker active state Place the unit in the talk state by addressing it to talk with the correct MTA My Talk Address command TALK is off when the unit is in the talker idle state Place the unit in the talker idle state by sending a UNT Untalk command addressing it to listen or sending the IFC Interface Clear command LSTN This indicator is on when the Model 2500 is in the listener active state which is activated by addressing the instrument to listen with the correct MLA My Listen Address com mand LSTN is off when the unit is in the listener idle state Place the unit in the listener idle state by sending UNL Unlisten addressing it to talk or sending IFC Interface Clear command over the bus 13 10 Remote Operations Models 2500 and 2502 User s Manual SRQ You can program the instrument to generate a service request SRQ when one or more errors or conditions occur When this indicator is on a service request has been generated This indicator stays on until the serial poll byte is read or all the conditions that caused SRQ have been cleared See Section 14 for more i
383. r the RS 232 interface and Table 13 2 shows the pinout for the connector If your computer uses a DB 25 connector for the RS 232 interface you will need a cable or adapter with a DB 25 connector on one end and a DB 9 connector on the other wired straight through not null modem Figure 13 4 RS 232 interface connector RS 232 5432 1 987 6 Rear Panel Connector Models 2500 and 2502 User s Manual Table 13 2 RS 232 connector pinout Pin number Description 1 Not used 2 TXD transmit data 3 RXD receive data 4 Not used 5 GND signal ground 6 Not used 7 RTS ready to send 8 CTS clear to send 9 Not used Note CTS and RTS are tied together Pins 1 4 and 6 are tied together Remote Operations 13 19 Table 13 3 provides pinout identification for the 9 pin DB 9 or 25 pin DB 25 serial port connector on the computer PC Table 13 3 PC serial port pinout DB 9 pin DB 25 pin Signal number number DCD data carrier detect 1 8 RXD receive data 2 3 TXD transmit data 3 2 DTR data terminal ready 4 20 GND signal ground 5 T DSR data set ready 6 6 RTS request to send 7 4 CTS clear to send 8 5 RI ring indicator 9 22 Error messages See Appendix B for RS 232 error messages 13 20 Remote Operations Models 2500 and 2502 User s Manual Programming example The following QuickBasic 4 5 programming example will control the Model 2500 via the RS 232 C
384. rameters lt name gt NEXT Fills buffer and stops NEVer Disables buffer storage Query CONTrol Query buffer control Description This command is used to select the buffer control When NEXT is selected the asterisk annunciator turns on to indicate that the buffer is enabled The storage process starts when Model 2500 is taken out of idle to perform source measure operations After the buffer stores the specified number of reading arrays as set by the POINts command the asterisk annuciator turns off to indicate that storage is done With NEVer selected storage into the buffer is disabled Select timestamp format FORMat lt name gt TRACe TSTamp FORMat lt name gt Select timestamp format Parameters lt name gt ABSolute Reference to first buffer reading DELTa Time between buffer readings Query FORMat Query timestamp format Description This command is used to select the timestamp format for buffer read ings With ABSolute selected each timestamp is referenced to the first reading stored in the buffer With DELTa selected timestamps provide the time between each buffer reading 17 90 SCPI Command Reference Models 2500 and 2502 User s Manual Trigger subsystem The Trigger subsystem is made up of a series of commands and subsystems to configure the Trigger Model These commands and subsystems are summarized in Table 17 10 NOTE See Section 10 for more details on triggering and the trigger model Initiate sour
385. range is disabled When auto ranging is disabled you can manually program the unit for any range below the upper limit 17 56 SCPI Command Reference Models 2500 and 2502 User s Manual Set measurement speed NPLCycles lt n gt SENSe 1 CURRent DC NPLCycles lt n gt Set channel 1 speed PLC SENSe2 CURRent DC NPLCycles lt n gt Set channel 2 speed PLC Parameters lt n gt 0 01 to 10 Power line cycles per integration DEFault 1 MINimum 0 01 MAXimum 10 Query NPLCycles Query programmed PLC value Description NPLCycles DEFault Query RST default PLC NPLCycles MINimum Query minimum PLC NPLCycles MAXimum Query maximum PLC This command is used to set the integration period speed for measure ments NPLC Number of Power Line Cycles expresses the integration period by basing it on the power line frequency For example for a PLC of 1 the integration period would be 1 60 for 60Hz line power which is 16 67 msec Note that this is a global command Thus if you set the speed for chan nel 1 measurements to 10 PLC then channel 2 will also set to 10 PLC Models 2500 and 2502 User s Manual Configure and control filters SCPI Command Reference 17 57 NOTE Detailed information on the average and median filters are provided in Section 6 Filters All filter commands are global and commands affect both channels simultaneously Average filter commands COUNt lt n gt SENSe 1 AVERage COUNt l
386. ration complete messages See Appendix D Cannot enter an invalid address Address changes and bus resets Determine by SYSTem POSetup See Section 17 2048 bytes None All queries Common Commands and SCPI None See Table E 2 Contained in SCPI command sub systems tables see Table 17 1 through Table 17 10 Block display messages 32 characters max See Section 13 Programming syntax See Section 13 Programming syntax None See Section 17 FORMat subsystem See Section 15 Common Commands See Service Manual Not applicable Not applicable See Section 15 Common Commands Not applicable Not applicable See Section 15 Common Commands See Section 15 Common Commands See Section 14 Status Structure All are sequential except INIT OPC OPC and WAT see Section 15 Common Commands IEEE 488 and SCPI Conformance Information Models 2500 and 2502 User s Manual Table E 2 Coupled commands Command Also changes SENSe 1 CURRent RANGe UPPER SENSe 1 CURRent RANGe AUTO SENSe 1 CURRent NPLC NPLC for other channel SOURce 1 VOLTage RANGe SOURce 1 VOLTage RANGe AUTO SOURce 1 VOLTage STARt SOURce 1 VOLTage STOP SOURce 1 VOLTage STEP SOURce 1 VOLTage POINts SOURce 1 VOLTage CENTer SOURce 1 VOLTage SPAN SENSe2 CURRent RANGe UPPER SENSe2 CURRent NPLC SOURce2 VOLTage RANGe SOURce2 VOL
387. rce range n range 10 or 100 Set channel 2 source amplitude n volts Models 2500 and 2502 User s Manual Photodiode Measurements 4 7 Photodiode measurement programming example Table 4 3 summarizes the command sequence for a photodiode measurement procedure using channel 1 to measure the current of the back photodiode detector and channel 2 displaying optical power Note that the steps correspond to those listed previously in Front panel photodiode measurement procedure See Figure 4 2 earlier in this section for basic connections and Section 2 for detailed connection information These commands set up the Model 2500 as follows Channel 1 measurement current measurement auto range Channel 2 measurement optical power Channel 2 responsivity constant R of detector for wavelength of interest 1 Channel 2 dark current D 1 Channel 1 source 10V range 10V amplitude Channel 2 source 100V range 20V amplitude NOTE See Appendix H for a complete program listing 4 8 Photodiode Measurements Table 4 3 Basic measurement command sequence Models 2500 and 2502 User s Manual Step Action Commands Comments RST Restore GPIB defaults 1 Configure channel 1 FORM ELEM CURRI Select channel reading measurement Configure channel 2 gt CALC2 FORM OP2 Optical power on chan 2 measurement gt CALC2 KMAT RESP 1 R 1 gt CALC2 KMAT DC 0 D 0 2 Set channel 1 source range SOURI VOLT RANG 10 C
388. rder NORMal or SWAPped Note v BORDer Query byte order v ELEMents SENSe 1 lt item list gt Specify data elements CURRent 1 CURRent2 CURRI TIME and STATus CURR2 SENSe 1 Query data format elements CALCulate lt item list gt Specify CALCulate elements CALCulate TIME CALC or STATus CALCulate Query CALC data elements TRACe lt item list gt Specify TRACe data elements CURRent 1 DEFault CURRent2 CALCulatel CALCulate2 CALCulate3 CALCulate4 CALCulate5 CALCulate6 CALCulate7 TIME STATus ALL DEFault CURRent 1 CURRent2 TRACe Query TRACe elements SOURce3 lt name gt Specify SOURce3 data format ASCii ASCii HEXadecimal OCTal or BIN SOURce3 Query SOURce3 data format Note RST default is NORMal SYST PRES default is SWAPPed This command specifies data elements for CALC1 through CALC7 17 10 SCPI Command Reference Models 2500 and 2502 User s Manual Table 17 4 OUTPut command summary Default Command Description parameter SCPI OUTPut 1 Path to control output 1 Jv STATe lt b gt Turn source on or off OFF y STATe Query state of source 1 s ENABle Path to control output enable STATe lt b gt Enable or disable output enable for both sources OFF STATe Query state of output enable TRIPped Output enable tripped 1 no or 0 yes OUTPut2 Path to control output 2 v STATe lt b gt Turn source 2 on or off OFF y
389. refore when offset cur rent drifts significantly you will have to re zero the ammeter Models 2500 and 2502 User s Manual Measurement Considerations F 5 Electrochemical effects Error currents also arise from electrochemical effects when ionic chemicals create weak batteries on a circuit board These batteries could generate a few nanoamps of current between conductors Ionic contamination may be the result of body oils salts or solder flux The problem is further enhanced by high humidity moisture that decreases insula tion resistance When building test fixtures select insulators that resist water absorption and use the fix ture in a moderate humidity environment Also be sure that all insulators are kept clean and free of contamination Humidity Excess humidity can reduce insulation resistance on PC boards and in test connection insulators Reduction in insulation resistance can of course seriously affect high impedance measurements Also humidity moisture can combine with contaminants to produce offset currents caused by electrochemical effects see Electrochemical effects To minimize the effects of moisture keep humidity to a minimum ideally lt 50 and keep components and connectors in the test system clean Triboelectric effects Triboelectric currents are generated by charges created between a conductor and an insula tor due to friction Here free electrons rub off the conductor and create a charge i
390. rements Photodiode measurement circuit configuration The basic circuit configuration for the photodiode measurement procedures in this section is shown in Figure 4 2 This example shows channel connections to one photodiode Channel 2 connections to the other photodiode are similar See Section 2 Connections for detailed connection information Figure 4 2 Circuit configuration for photodiode measurements Model 2500 Se INPUT HI CHANNEL 1 5 Photodiode Floating Analog Common VOLTAGE SOURCE L OUTPUT CHANNEL 1 See Section 2 for detailed connections Front panel photodiode measurement procedure Step 1 Configure measurement functions For this example channel 1 will be used to measure the current of the back photodiode detector while channel 2 will measure the forward photodiode optical power Configure each channel as follows 1 To configure channel 1 press CONFIG then MSR1 2 From the CONFIG MSR1 BUTTON menu select I then press ENTER 3 To configure channel 2 press CONFIG then MSR2 4 From the CONFIG MSR2 BUTTON display select P then press ENTER Set the parameters R and D as desired Models 2500 and 2502 User s Manual Photodiode Measurements 4 5 Step 2 Set bias voltage source values Set up channel 1 and channel 2 voltage sources as follows 1 Press SRC1 to edit the channel 1 source 2 Use the RANGE A and keys to select the source range that will accommodate the
391. resrsreresrrserrrsrrrrssese 17 56 NPLCYClES lt AI gt inniinn 17 56 Configure and control filters seeseeseeeseeeeesesreeeereerrsrerrses 17 57 Average filter commands ssesssseseseseeesesrerrsreerrererrses 17 57 COUN GS actini aeaa isana i oi hentia 17 57 ESTATE lt b gt isini orione aa 17 57 TCONIroL lt name gt 3 c ccscsesecdeiees tiesiosios 17 58 ADVanced NTOLerance lt n gt sesssessssresrererrrrrerrererrsee 17 58 ADVanced STATe lt b gt eeeececcesseeseseeesseeessnees 17 58 Median filter commands 0 0 0 eee ee eeeeeeeeeeeeseeeseeeees 17 59 MEDian RANK lt NRf gt ooo eeeeeeeeeeseeteeeeeeeeaeeeeeees 17 59 MEDian STATe lt b gt oon eeeeeeeeeseeeeeneeseeeeeeeeaes 17 59 SOURCE SUBSYStEML s c cicccscsscetescseceascesetsdesasancdsbensons ieneseecnstneaas 17 60 SOURce 1 and SOURCE2 oo eeecccessteessseeessteeessnees 17 60 Control source output on off oo eee eee eeeeereeeeeeeeeeee 17 60 EIMMe diate scenerii anona as 17 60 MODE lt name gt siiret tarties eisie 17 60 Select sourcing mode sssessesesesessssessersesersereesensreresesrese 17 61 MODE lt name gt cci ssscsrescsessecoordsestennescsensenesteosssesseceets 17 61 Select range veie oie esodeeetevties edearne eset eee 17 61 RANGS lt i gt 2 je ciertsgeteceetivisheteiedecaciascoassnenalsiagecobetcetes 17 61 AUTO SDS sitesi ncigs de he ee 17 62 Set amplitude for fixed source 0 eee ee eeeeeseeeeeeeeeeeeees 17 63 IMMediate AMPLitude lt n gt ce
392. rigger model arm layer ARM IN Select arm layer detection event IMMEDIATE Immediate event detection GPIB GPIB GET or TRG TIMER After timer interval elapses enter interval MANUAL Front panel TRIG key TLINK Enter TLINK line and state ONCE Bypass event detection once NEVER Never bypass event detection TSTEST When Digital I O SOT line is pulsed high ONCE Bypass event detection once NEVER Never bypass event detection VSTEST When Digital I O SOT is pulsed low ONCE Bypass event detection once NEVER Never bypass event detection TLSTEST When Digital I O SOT line is pulsed low or high ONCE Bypass event detection once NEVER Never bypass event detection ARM OUT Configure arm layer output trigger LINE Select trigger link output line 1 4 EVENTS Enable disable events TRIG LAYER DONE Enable ON or disable OFF on exiting trigger layer COUNT Specify arm count FINITE Programmable count INFINITE Never ending count TRIG LAYER Configure trigger layer of trigger model TRIGGER IN Select trigger layer detection event IMMEDIATE Trigger even occurs immediately TRIGGER LINK TRIGGER OUT LINE EVENTS DELAY COUNT HALT Select trigger link line as event 1 4 Configure trigger layer output trigger Select trigger link line 1 4 Enable ON or disable OFF Program trigger delay time Program trigger count Return unit to idle state Model 2500 and 2502 User s Manual Getting Started 1 29 Table 1 10 Sweep
393. riggering Figure 10 9 Trigger model remote operation See Note SOURce ARM DIRection ARM SOURce IMMediate BUS TIMer MANual TLINk NSTest PSTest BSTest ACCeptor Arm Event Detector ARM OUTPut TRIGger SOURCE DIRection ACCeptor Source Event Detector Trigger Delay SOURCE Action TRIGger OUTPut F gt SOURce Delay Event Detector TRIGger INPut SOURce TRIGger SOURce IMMediate TLINk TRIGger INPut Trigger In Source SOURceX DELay DUA lt n gt lAUTO enon 0 0005 sec TRIGger OUTPut gt DELay Measure Event Detector MEASURE Action TRIGger OUTPut F gt SENSe TRIGger INPut SENSe GPIB Default Output Trigger GPIB default parameter for TRIGGER OUTPut is NONE SOURceX SOURce 1 or SOURce2 Another Trigger 2 Models 2500 and 2502 User s Manual Note The following commands place the Model 2500 into idle DCL SDC ABORt RST SYSTem PREset and RCL Idle Arm Layer ARM COUNt lt n gt lINF a E gt NONEITRIGger Trigger Layer TRIGger COUNt lt n gt 1 Models 2500 and 2502 User s Manual Triggering 10 19 While operating within the trigger model ARM indicator on most commands will not be executed until the Model 2500 completes all of its programmed source measure opera tions and returns to the idle state The IFC interface clear SDC selected devi
394. ription RS 232 interface Read SCPI version This query command is used to read the version of the SCPI standard being used by the Model 2500 Example code 1996 0 The above response message indicates the version of the SCPI standard NOTE The following commands are intended for use over the RS 232 interface but they can also be used over the GPIB LOCal SYSTem LOCal Description REMote SYSTem REMote Description Take Model 2500 out of remote Normally during RS 232 communications front panel keys are opera tional However the user may wish to lock out front panel keys during RS 232 communications See RWLock This action command is used to remove the Model 2500 from the remote state and enables the operation of front panel keys in a manner similar to the GPIB GTL command Place the Model 2500 in remote This action command is used to place the Model 2500 in the remote state in a manner similar to the GPIB REN command In remote the front panel keys will be locked out if local lockout is asserted See RWLock page 17 86 17 86 SCPI Command Reference Models 2500 and 2502 User s Manual RWLock SYSTem RWLock Disable or enable front panel keys Description This command is used to enable local lockout in a manner similar to the GPIB LLO command see Section 13 When enabled the front panel keys except OUTPUT OFF are locked out not operational when the instrument is in remote See REMote
395. ription SENSe 1 CURRent RANGe lt n gt Select channel 1 manual amps range n range SENSe 1 CURRent RANGe AUTO lt state gt Enable disable Ch 1 auto range state ON or OFF SENSe 1 CURRent RANGe AUTO ULIMit lt n gt Set upper limit for Ch 1 auto range n range SENSe 1 CURRent RANGe AUTO LLIMit lt n gt Set lower limit for Ch 1 auto range n range SENSe2 CURRent RANGe lt n gt Select channel 2 manual amps range n range SENSe2 CURRent RANGe AUTO lt state gt Enable disable Ch 2 auto range state ON or OFF SENSe2 CURRent RANGe AUTO ULIMit lt n gt Set upper limit for Ch 2 auto range n range SENSe2 CURRent RANGe AUTO LLIMit lt n gt Set lower limit for Ch 2 auto range n range DISPlay DIGits lt n gt Set display digits n 4 5 6 or 7 Models 2500 and 2502 User s Manual Range Digits Speed and Filters 6 5 Speed Range and digits programming example Table 6 3 shows a programming example for controlling range and digits The Model 2500 is set up as follows e Channel auto range ON e Channel upper range limit 2mA e Channel 1 lower range limit 200nA e Display digits 51 2 Table 6 3 Range and digits programming example Command Description RST Restore GPIB defaults SOURI VOLT 10 Source 10V on Ch 1 SENS 1 CURR RANG AUTO ON Enable Ch 1 auto range SENS 1 CURR RANG AUTO ULIM 2e 3 2mA upper range limit SENS 1 CURR RANG AUTO LLIM 200e
396. rm event selected the handler must pulse SOT either high or low in order to provide event detection and start the testing process EOT BUSY line Line 4 can be used for a normal bit pattern end of test EOT or BUSY signal depending on the selected END OF TEST mode NOTE See Section 11 for details on performing limit tests and Section 10 for informa tion on programming the Model 2500 to respond to the start of test SOT pulse from a handler 5V output The digital I O port provides a 5V output that can be used to drive external logic cir cuitry Maximum current output for this line is 300mA This line is protected by a self resetting fuse one hour recovery time 12 4 Digital I O Port Output Enable and Output Configuration Models 2500 and 2502 User s Manual Digital output configuration There are two basic methods to connect external components to the digital output lines sink operation and source operation Sink operation Figure 12 2 shows the basic output configuration for sink operation Note that the external relay coil is connected between the digital output line pins 1 to 4 and 5V pin 7 With this configuration the digital output line must be set LO to energize the relay and the maximum sink current is 500mA Figure 12 2 Sink operation Model 2500 External Poo eS a Relay 5V0 Pin 7 a I q l To Other i Circuits Li T Maximum Sink Current 500mA Pin 9 mw a a a d Digital I O Port Mode
397. rom 0000 0000 seconds to 9999 9980 seconds If using auto delay the delay is set automatically see Section 3 for details The manually set delay up to 9999 998 sec is available to compensate for longer settling required by external circuitry The more capacitance seen at the output the more settling time is required for the voltage bias source The actual delay period needed can be calcu lated or determined by trial and error The slew rate of the output circuit is constant at about 3 07ms V Therefore the minimum source delay must be 3 07ms x voltage step size NOTE The delay period is the same for both channels If you change the delay on one channel the delay period on the other channel will change to the same value Measurement time The measure time depends on the selected measurement speed For example if speed is set at 0 01 PLC power line cycles the measure time would be 167psec for 60Hz opera tion 0 01 60 5 4 Measurement Concepts Models 2500 and 2502 User s Manual Sweep waveforms There are three basic sweep types to select from linear staircase logarithmic staircase and custom as shown in Figure 5 3 Staircase sweeps The linear staircase sweep goes from the start level to the stop level in equal linear steps The logarithmic staircase sweep is similar except it is done on a log scale with a specified number of steps per decade Custom sweep The custom sweep lets you construct your own sweep by spec
398. rom the display GPIB operation A user defined text message remains displayed only as long as the instrument is in remote Taking the instrument out of remote by pressing the LOCAL key or sending LOCAL 25 cancels the message and disables the text message mode RS 232 operation A user defined test message can be cancelled by sending the SYSTem LOCal command or pressing the LOCAL key FORMat subsystem The commands for this subsystem are used to select the data format for transferring instru ment readings over the bus These commands are summarized in Table 17 3 Data format DATA lt type gt length FORMat DATA lt type gt lt length gt Select data format Parameters lt type gt lt length gt ASCii ASCII format REAL 32 IEEE754 single precision format SREal TEEE754 single precision format NOTE lt length gt is not used for the ASCii or SREal parameters It is optional for the REAL parameter If you do not use lt length gt with the REAL parameter the lt length gt defaults to 32 single precision format Query DATA Query data format 17 44 SCPI Command Reference Models 2500 and 2502 User s Manual Description This command is used to select the data format for transferring readings over the bus Only the ASCII format is allowed over the RS 232 interface This command only affects the output of READ FETCh MEASure TRACe DATA CALCx DATA over the GPIB All other queries are returned in t
399. ror Execution Error Command Error User Request Master Summary Status MSS Power On MSB Measurement Summary Bit EAV Error Available QSB Questionable Summary Bit MAV Message Available ESB Event Summary Bit RQS MSS Request for Service Master Summary Staus OSB Operation Summary Bit Always Zero Note RQS bit is in serial poll byte MSS bit is in STB response Measurement Operation Measurement Measurement Event Operation Operation Event Condition Event Enable Condition Event Enable Register Register Register Register Register Register Limit 1 Summary Limit 2 Summary Limit 3 Summary Limit 4 Summary Limit Fail High Limits Pass Reading Available Reading Overflow Buffer Available Buffer Full Sweeping Waiting for Trigger Waiting for Arm Output Enable Src 1 Compliance Src 2 Compliance Always Zero 14 3 14 4 Status Structure Models 2500 and 2502 User s Manual Clearing registers and queues When the Model 2500 is turned on the bits of all registers in the status structure are cleared reset to 0 and the two queues are empty Commands to reset the event and event enable registers and the Error Queue are listed in Table 14 1 In addition to these com mands any enable register can be reset by sending the 0 parameter value with the individ ual command to program the register NOTE SYSTem PRESet and RST have no effect on status structure registers and
400. ror Available MSB Measurement Summary Bit amp Logical AND OR Logical OR 14 8 Status Structure Models 2500 and 2502 User s Manual Status byte register The summary messages from the status registers and queues are used to set or clear the appropriate bits BO B2 B3 B4 B5 and B7 of the status byte register These summary bits do not latch and their states 0 or 1 are solely dependent on the summary messages 0 or 1 For example if the standard event register is read its register will clear As a result its summary message will reset to 0 which in turn will reset the ESB bit in the sta tus byte register The bits of the status byte register are described as follows Bit BO Measurement Summary Bit MSB Set summary bit indicates that an enabled measurement event has occurred Bit B1 Not used Bit B2 Error Available EAV Set summary bit indicates that an error or status message is present in the Error Queue Bit B3 Questionable Summary Bit QSB Set summary bit indicates that an enabled questionable event has occurred Bit B4 Message Available MAV Set summary bit indicates that a response mes sage is present in the Output Queue Bit B5 Event Summary Bit ESB Set summary bit indicates that an enabled stan dard event has occurred Bit B6 Request Service RQS Master Summary Status MSS Set bit indicates that an enabled summary bit of the Status Byte Register is set Bit B
401. round is 200V Exceeding this value may result in a shock hazard CAUTION Maximum INPUT and OUTPUT connector rating is 100V 20mA Exceeding these values may result in instrument damage Digital input output port DIGITAL I O Male DB 9 connector for digital output lines output enable line and component handler signals Model 2500 and 2502 User s Manual Getting Started 1 9 Power module Contains the AC line receptacle and the power line fuse Trigger link connector TRIGGER LINK 8 pin micro DIN connector for sending and receiving trigger pulses Use a trigger link cable or adapter such as Models 8501 1 8501 2 8502 8504 RS 232 connector RS 232 Connector for RS 232 remote operation Use a straight through not null modem DB 9 cable such as a Keithley Model 7009 5 GPIB connector IEEE 488 INTERFACE Connector for GPIB remote operation Use a shielded cable Model 7007 1 or 7007 2 ANALOG OUT connectors Model 2502 only ANALOG OUT Triax connectors for CHANNEL 1 and CHANNEL 2 analog outputs Figure 1 3 Model 2502 rear panel WARNINGi no INTERNAL OPERATOR SERVICABLE PARTS SERVICE BY QUALIFIED PERSONNEL ONLY a Kem CE Fa Bil MADE IW ent Has EEG RATINGS MAX S A WITH FRONT PANEL MENU DIGITAL 1 0 ani 1 re carats mmm J A I ANALOG LINK RS 232 LINE RATING eo VA fie VOLTAGE FUSE LINE 630 mAT 100 VAC A SB 120 VAC 315 mAT 220 VAC SB 240 V
402. rrent amps Responsivity amps watt When you select this math function you will be prompted to enter responsitivity R and dark current D values in amps per watt and amps respectively The Model 2500 will then display optical power in watts NOTE Zero is not an acceptable value for responsivity as this value would cause an infinite result 7 6 Relative Math Ratio and Delta Models 2500 and 2502 User s Manual Front panel math functions Using Table 7 3 as a guide configure measurement math functions as follows 1 Press CONFIG then MSR1 or MSR2 to select channel 1 or channel 2 respectively 2 Using the EDIT keys place the cursor on the desired function then press ENTER 3 From normal display press the MSR1 or MSR2 key to display the function reading 4 To cancel the function and return to normal current measurement display repeat steps 1 and 2 but select I in the configuration menu Table 7 3 Measurement function configuration menu Configuration menu item Description CONFIG MSR1 Configure channel 1 measurement CONFIG MSR1 BUTTON I Current measurement V V Conductance I V measurement Ch 11 Ch 1V V I Resistance V I measurement Ch 1V Ch 11 MX B_UNIT MX B measurement PY Electrical power V x I measurement Ch 1V x Ch 1D Po Optical power measured Idark current Responsivity CONFIG MSR2 Configure channel 2 measurement CONFIG MSR2 BUTTON I Current measurement V V Conductance
403. rs are con trolled with the TRIGger OUTPut command For example to output a trigger after the Measure Action the following command must be sent TRIGger OUTPut SENSe The above command disables output triggers for the Source and Delay Actions since their parameter names SOURce and DELay are not included in the parameter list When used with a scanner an output trigger after each measurement can signal the scan ner to select the next channel in the scan Arm layer output trigger As shown in Figure 10 9 the Model 2500 can be pro grammed to output a trigger when operation leaves the Arm Layer and enters the Trigger Layer This output trigger is typically sent to another instrument to signal the end of a scan or sweep The ARM OUTPut command is used to control this output trigger The TRIGger parameter enables the trigger on exiting the Trigger Layer and the NONE parameter dis ables the output trigger Models 2500 and 2502 User s Manual Triggering 10 23 GPIB defaults The GPIB defaults are listed as follows They are also denoted in Figure 10 9 by the symbol e Arm In Event Immediate Trigger In Source Immediate e Arm Count 1 Trigger Count 1 Trigger Delay 0 0 sec Delay Action 0 001 sec Enabled event detector Source Event Detector Delay and Measure detection disabled Enabled output triggers None Event detection bypasses Acceptor both layers With output turned O
404. rules Use the following rules to determine the short form version of any SCPI command Ifthe length of the command word is four letters or less no short form version exists Example auto auto These rules apply to command words that exceed four letters Ifthe fourth letter of the command word is a vowel including y delete it and all the letters after it Example immediate imm Ifthe fourth letter of the command word is a consonant retain it but drop all the letters after it Example format form Ifthe command contains a question mark query or a non optional number included in the command word you must include it in the short form version Example delay del Command words or characters that are enclosed in brackets are optional and need not be included in the program message NOTE For fastest response to commands always use short forms 13 14 Remote Operations Models 2500 and 2502 User s Manual Program messages A program message is made up of one or more command words sent by the computer to the instrument Each common command is a three letter acronym preceded by an asterisk SCPI commands are categorized in the STATus subsystem and are used to explain how command words are structured to formulate program messages STATus Path Root OPERation Path ENABle lt NRf gt Command and parameter ENABle Query command PRESet Command Single command messages
405. ry Error CME Command Error OPC Operation Complete EXE Execution Error amp Logical AND OR Logical OR 14 12 Status Structure Models 2500 and 2502 User s Manual Bit BO Operation Complete Set bit indicates that all pending selected device oper ations are completed and the Model 2500 is ready to accept new commands This bit only sets in response to the OPC query command See Section 15 for details on OPC and OPC Bit B1 Not used Bit B2 Query Error QYE Set bit indicates that you attempted to read data from an empty output queue Bit B3 Device Dependent Error DDE Set bit indicates that an instrument oper ation did not execute properly due to some internal condition Bit B4 Execution Error EXE Set bit indicates that the Model 2500 detected an error while trying to execute a command Bit B5 Command Error CME Set bit indicates that a command error has occurred e Command errors include TEEE 488 2 syntax error Model 2500 received a message that does not follow the defined syntax of the IEEE 488 2 standard e Semantic error Model 2500 received a command that was misspelled or received an optional IEEE 488 2 command that is not implemented The instrument received a Group Execute Trigger GET inside a program message Bit B6 User Request URQ Set bit indicates that the LOCAL key on the Model 2500 front panel was pressed Bit B7 Power ON PON Set
406. s Ch dark current n amps Ch 1 responsivity n amps watt Enable enable Ch 1 math State ON or OFF Request Ch 2 math reading Set Ch 2 math function Name MXB2 MX B COND2 12 V2 POWER2 I2 V2 RES2 V2 12 or OP2 Ch 2 MX B offset n B Ch 2 MX B slope n M Ch 2 MX B units String units Ch 2 dark current n amps Ch 2 responsivity n amps watt Enable enable Ch 2 math State ON or OFF Define CALC data elements Name CALCulate TIME or STATus Trigger CALC readings must use before sending CALCn DATA 7 8 Relative Math Ratio and Delta Models 2500 and 2502 User s Manual Math function programming example Table 7 5 summarizes commands that program the following math function parameters e Channel 2 math function MX B Channel 2 MX B slope M 10 e Channel 2 MX B offset B 5 Table 7 5 Math function programming example Command Description gt CALC2 FORM MXB2 Select Ch 2 MX B function gt CALC2 KMAT MBF 5 Ch 2 offset B 5 gt CALC2 KMAT MMEF 10 Ch 2 slope M 10 CALC2 STAT ON Enable Ch 2 math OUTP2 ON Turn on Ch 2 output INIT Trigger math reading gt CALC2 DATA Request Ch 2 MX B result OUTP2 OFF Output 2 off RATIO and DELTA RATIO functions The Model 2500 has built in RATIO functions to calculate the following e MSRI MSR2 e MSR2 MSR1 MSR1 MSR2 This function computes the ratio
407. s With this system you can test single element devices such as a single diode Adding a scanner to the system allows binning operations on multiple element DUT packages See Limit test programming example page 11 21 Handler interface The Model 2500 is interfaced to a handler via the Digital I O port as shown in Figure 11 6 The I O port has four lines for output signals and one line for input signals The output lines are used to send the test pass fail signal s to the handler to perform the binning operation Figure 11 6 Handler interface connections Model 2500 Handler O Line 4 EOT or BUSY O SOT Strobe Line Input SOT Digital I O connector These digital I O lines are available at the DB 9 Digital I O connector on the rear panel of the Model 2500 A custom cable using a standard female DB 9 connector is required for connection to the Model 2500 See Section 12 Digital I O port for more information Digital output lines The four output lines output a specific bit pattern based on the pass fail results of the vari ous limit tests See Types of limits page 11 2 In the 3 bit output mode Line 4 can be used either as an end of test EOT or BUSY signal depending on the END OF TEST mode See Configuring limit tests page 11 16 Models 2500 and 2502 User s Manual Limit Testing 11 11 SOT line The input line SOT of the Digital I O is used to control the start of the testing process W
408. s D 12 IEEE command groups ceccesseessecesceceseeeseeceeeeeneeeaeeees D 13 Interface function codes ou eeceeeeeeeessessscscsscescecscscesceeeseseseeeeees D 14 IEEE 488 and SCPI Conformance Information TRtPO UGH ONY snee a a AE E 2 Measurement Considerations Low current measurements esceeececeseeeseeceaceeeeeeeaeeeseeeneeesaes F 2 Leakage currents sininen ieia aaa F 2 Noise and source impedance oo eee eeeeseeeeeeseeeeeseeeeeeseees F 2 DUT resistance srep reiris erii nE EA a F 2 Source capacitance eessisisiisessssusisosesssseseesissesiaresravs F 3 G ner ted CUTTEN S sieocriorriisriosiriernsvcsini dso ipip aani Nai ioii F 4 Offset CUTEN S sisisi crireiryr aai iios onies AEn E EA EAEE F 4 Electrochemical effects s soseesseeeeeeeeeeeeseresereeeeerreee F 5 Humidity nrcnneeirenerasn per aa F 5 Triboelectric effects oo cee eeeeessceeseesneeeeeeeseeeeteeeneeeeaes F 5 Piezoelectric and stored charge effects eee F 5 Dielectric absorption eee eee eeeeeeeeeeeeeeeeeeteeeeaeeeees F 6 Voltage DUTAEN 3 s ccissesastseetvasecdetasonitaieae dvsencealecagessesstoasesie F 6 General measurement Considerations cccccsssseeesseesereeeees F 7 Ground LOOPS sregepan eui e e a aai F 7 IENA n AEE E A T EA E A E EE F 8 Electrostatic interference 0 0 ceeceeseesecenceeeeeeeeeeseeeeeeeeaes F 9 Magnetic fields innin F 10 Electromagnetic Interference EMI sssesseesseseeseessrsresese F 10 GPIB
409. s ENTER 3 From normal display press the RATIO or DELTA key to display the desired function reading 4 To cancel the function and return to normal display press the MSR1 or MSR2 key Table 7 6 RATIO and DELTA configuration menus Configuration menu item CONFIG RATIO CONFIG RATIO BUTTON MSR1 MSR2 MSR2 MSR1 CONFIG DELTA CONFIG DELTA BUTTON MSR1 MSR2 MSR2 MSR1 Description Configure RATIO function MSR1 MSR2 function MSR2 MSR1 function Configure DELTA function MSR1 MSR2 function MSR2 MSRI1 function Models 2500 and 2502 User s Manual Relative Math Ratio and Delta 7 11 Remote RATIO and DELTA Table 7 7 summarizes commands to control the RATIO and DELTA function via remote See the CALCS5 and CALC6 subsystems in Section 17 for detailed information Table 7 7 RATIO and DELTA function commands Command Description CALCulate5 DATA Request ratio reading CALCulate5 FOR Mat lt name gt Set ratio function Name C3C4 CALC3 CALC4 C4C3 CALC4 CALC3 CALCulate5 STATe lt state gt Enable enable ratio State ON or OFF CALCulate6 DATA Request delta reading CALCulate6 FOR Mat lt name gt Set delta function Name C3C4 CALC3 CALC4 C4C3 CALC4 CALC3 CALCulate6 STATe lt state gt Enable enable delta State ON or OFF FOR Mat ELEMents CALCulate lt name gt Define CALC data elements Name CALCulate TIME or STATus INIT Trigger CALC readings must use bef
410. s as well as by leakage currents through insulators within the instrument The internal input offset current adds to the source current so that the meter measures the sum of the two currents Iv Is Tio where I is the measured current I is the source current Ijo is the internal input offset current External offset current Offset currents can also be generated from external effects such as electrochemical effect discussed below The external offset current also adds to the source current and the ammeter again measures the sum of the currents Iv Is Tio Igo where Igo is the external offset current As long as the internal and external offsets remain stable for a reasonable period of time the relative feature of the Model 2500 can be used to zero out offset current With the source current Ig set to zero the ammeter will only measure and display the offset cur rent reading When REL is enabled the display will zero What happens is that the offset current reading is acquired as the rel value and is subtracted from present and future read ings When the source current is applied the displayed reading will not include the offset Iv Is lho Igo rel Iv Is where rel is the rel value Ij Igo As long as the rel value equals the sum of the offsets only the source current will be dis played See Section 7 for details on relative Offset current drift is a function of time and or temperature The
411. s back into idle NOTE The FETCh command is automatically asserted when the READ or MEASure command is sent The readings that are acquired depend on which data elements are selected Section 17 FORMat subsystem Data elements Measure readings take priority over source readings and data from channels not sourced or measured are assigned the NAN not a number value of 9 91e37 NOTE Send FORM ELEM CURRI before FETCh for channel 1 readings or FORM ELEM CURR2 for channel 2 readings See Appendix C for a detailed explanation on how data flows through the vari ous operation blocks of the Model 2500 It clarifies the types of readings that are acquired by the various commands to read data 16 4 SCPI Signal Oriented Measurement Commands Models 2500 and 2502 User s Manual DATA LATest Description This command works exactly like FETCh except that it returns only the most recent reading from the channel selected by FORM ELEM READ Description This command is used to trigger and acquire readings The number of readings depends on how the trigger model is configured For example if configured for 20 source and measure operations arm count 1 trigger count 20 then 20 sets of readings will be acquired after the Model 2500 returns to the idle state When this command is sent the following commands execute in the order that they are presented INITiate e FETCh The INITiate command starts operati
412. s command summary csceceeseeeeeseeeseeeeees D 7 Hexadecimal and decimal command codes 0 0 eee D 10 Typical addressed multiline command sequence D 12 Typical addressed common command sequence D 12 TEEE command groups oo eee eseesseseeeseeereeseeseeeaeeeeeeseesnes D 13 Model 2500 interface function codes sssr D 14 TEEE 488 documentation requirements 0 0 0 eeeeeeeeeeeeees E 3 Coupled commands cceescescesesceeseeeeeeeseeeceaeeeseeseaeeeeeeeaes E 4 Measurement Considerations Minimum recommended source resistance values F 3 Getting Started General information Covers general information that includes warranty informa tion contact information safety symbols and terms inspection and available options and accessories Product overview Summarizes the features of the Model 2500 Dual Photodiode Meter Familiarization Summarizes the controls and connectors on the unit Power up Covers line power connection line voltage settings fuse replacement and the power up sequence Display Provides information about the Model 2500 display Default settings Covers factory default setups and saving and recalling user setups Menus Covers the main and configuration menus as well as rules to navigate menus 1 2 Getting Started Model 2500 and 2502 User s Manual General information Warranty information Warranty information is loca
413. s control the RATIO function They perform the remote equivalents to the front panel RATIO and CONFIG RATIO configuration menu Select RATIO calculation mode FORMat lt name gt CALCulate5 FORMat lt name gt Select RATIO calculation mode Parameters lt name gt C3C4 CALC3 CALC4 C4C3 CALC4 CALC3 Query FORMat Query selected RATIO calculation Description This command selects the RATIO calculation mode With C3C4 selected the CALC3 result channel 1 REL is divided by the CALC4 result channel 2 REL With C4C3 selected the CALC4 result is divided by the CALC3 result Enable and read RATIO result STATe lt b gt CALCulate5 STATe lt b gt Control RATIO Parameters lt b gt 1 or ON Enable RATIO 0 or OFF Disable RATIO Query STATe Query state of RATIO Description This command is used to enable or disable the RATIO mode When enabled the CALCS reading will be RATIO value determined by FORMat above When disabled or if a divide by zero error occurs the CALCS reading will return a NAN not a number value of 9 91e37 DATA CALCulate5 DATA Read RATIO result Description This query command is used to read the result of the CALCS ratio cal culation When enabled the CALCS reading will be ratio value deter mined by FORMat above When disabled or if a divide by zero error occurs the CALC5 reading will return a NAN not a number value of 9 91e37 17 30 SCPI Command Reference Models 2500 and 2502 User s Manual
414. s other signal oriented measurement commands to perform a one shot measurement and acquire the reading When this command is sent the following commands execute in the order that they are presented e CONFigure CURRent DC e READ When CONFigure is executed the instrument goes into a one shot measurement mode See CONFigure CURRent DC for more details NOTE MEAS is illegal when the ARM SOUR BUS command is in effect See Section 10 Triggering for details When READ is executed its operations will then be performed In general another ABORt is performed then an INITiate and finally a FETCh to acquire the readings See READ page 16 4 for more details NOTE The FORM ELEM command controls the reading source To access channel 1 readings send FORM ELEM CURR before sending MEAS To access chan nel 2 readings send FORM ELEM CURR2 before using MEAS When MEASure is sent the source turns on and a single measurement is performed If auto output off is enabled SOURce1 CLEar AUTO ON or SOURce2 CLEar AUTO ON then the corresponding output will turn off after the measurement is completed If auto output off is disabled s OURce1 CLEar AUTO OFF or SOURce2 CLEar AUTO OFF then the corresponding output will remain on after the measure ment is completed WARNING With auto output off disabled the output will remain on after the one shot source measure operation is performed B
415. s the various input output lines on the digital I O port as well as the 5V line that can be used to power external logic circuits Output enable Describes how to use the digital I O port output enable line to inhibit the voltage source outputs Front panel output configuration Details configuration of the digital I O port as output enable line and output auto on off states Remote output configuration Summarizes the remote commands used to control the digital I O port output enable and main output off states A simple programming example is also provided 12 2 Digital I O Port Output Enable and Output Configuration Models 2500 and 2502 User s Manual Digital I O port The Model 2500 has a digital input output port that can be used to control external digital circuitry such as a handler that is used to perform binning operations when testing limits Port configuration The digital I O port is located on the rear panel and is shown in Figure 12 1 Note that a standard male DB 9 connector is used for the digital I O port NOTE The four digital output lines and the SOT line are primarily intended for limit testing with a device handler See Section 11 Limit Testing for details on per forming limit tests and interfacing to handlers and Section 10 Triggering for information on programming the Model 2500 to respond to the start of test SOT pulse from a handler Figure 12 1 Output Enable and digital
416. scceceeeesseceeceessseees 17 23 Set MX B parameters 0 0 eeeeseesteseteeeeeeeeeeeseeeeeeeees 17 24 MBFactor lt m gt s ccic sccciiisieeesddetssdeicesssceevestscdesievcesetees 17 24 MME actor lt n gt sicir ar 17 24 MUNits lt name gt ceccceeesseeesseeessseeeeesseeeesseeeesnees 17 24 Set optical power parameters oo eee ee eeeeseeeteeeeeeseeees 17 25 DE 1 rere nea a oe ere ep eee ne eee eee 17 25 RESPO gt rinon ani a dete pehavsecsaves etexeets 17 25 Enable and read math function result ccccsseeeeeeees 17 26 STATE lt b E A 17 26 DATA F orrea tein eap iee E E EE SS 17 26 LATEST aE A A tpes ant eneee stan 17 26 CALCulate3 and CALCulate4 oc ccccessecsesteceesteeeeseeees 17 27 Select input path sesocan a EEEn 17 27 FEED lt name gt ieee reir a a 17 27 FEED lt name gt 00 cccceccscceseseceesseeeceseeeessnseeessneeesnees 17 27 Set or acquire relative value oo eee eseeeeeseeeeeeeeeeeeees 17 28 OFFS Yi AS ooie a ee ene ERS 17 28 AGC QUITE erriei i E N 17 28 Enable and read relative result ccccscceesessseeeeeeeseeee 17 28 STATE lt b arnes EEE EA R NEA 17 28 DATA ssc siccccdeteeate sstsvatesssedeans oockSsieesedivadeorvtivasdsstceys 17 28 CAL Culates 355 35 sores eshsadinces E hee ae daeeoees 17 29 Select RATIO calculation mode ceecceeesseeessteeeseees 17 29 FORMat lt name gt cccccesssecseseeeessseessseeeessaeeessnees 17 29 Enable and read RATIO result cececceeee
417. se widths ov fe Delay xtc delay gt fe Delay gt fe Delay ote Delay gt fe Delay gt f 1 2 3 4 5 6 7 All have same delay but pulse widths differ 9 6 Sweep Operation Models 2500 and 2502 User s Manual Configuring and running a sweep Front panel sweep operation Configuring a sweep The sweep configuration menu is structured as follows and shown in Figure 9 5 Note that bullets indicate the primary items of the sweep menu and dashes indicate the options of each menu item Using Section 1 Rules to navigate menus go through the following menu to select and configure the desired sweep NOTE Before configuring a sweep press SRC1 or SRC2 to select the channel to be used for the sweep You can also switch between channel I and channel 2 by pressing SRCI or SRC2 while in the CONFIGURE SWEEPS menu CONFIGURE SWEEPS menu Press CONFIG then SWEEP to display the sweep configuration menu TYPE Use this menu item to select the type of sweep NONE Disables all sweeps STAIR When the linear staircase sweep is selected you will be prompted to enter the START STOP and STEP levels LOG When the logarithmic staircase sweep is selected you will be prompted to enter the START and STOP levels and specify the number of measurement points CUSTOM With the custom sweep selected you specify the number of measure ment points POINTS in the sweep and the source level at each point ADJUST POINTS W
418. seeseeeeees 17 37 BCONtrol lt name gt cccccccessseeesseeesssseeesseeessseeeess 17 37 MODE lt name gt cseeihe i eeneeincen ences 17 38 Clear test TeSults 25 co5ssectassescesseadsvesteasecendisventevesteeatedatieend 17 38 IMMedtate eccssscsisccteestetesAccenciesl nieestsenteees eee 17 38 PUTO DS E vaaeaiducdassanseeapaiendieeseoak 17 38 CAL Culates 3 58 cise A ened ee 17 39 Select StAtISthC lt cveseccocsatcessidesassoeedavedecsentaalseexstuesdenseecaasseess 17 39 FOR Mat lt name gt senenn 17 39 Acquire statisti o ss dccseeescnacesscdevepesenidaatsoneastenessapedicncbsdees 17 39 DATA kransen ne OA 17 39 DISPlay s bsySteni lt c ccacerasscceces riesis ernia ia 17 40 Control display ssiessicseicios iriiri 17 40 DIGIts lt gt sasira erster sre eesinsta rre tarin rnan ni 17 40 ENABIE lt b gt ia A T 17 40 MODE lt name gt ccccccceescccescscesecctsesccesssdscasseeeesesceasss 17 41 ATTRIBUTES aiene R E AE 17 41 Read display szscscescssseccsteciedicasnesdesausans reer aa arar N E 17 42 DATA 3 cident tala a 17 42 Define TEXT messages ceeceesceesteceseeeeeeseneeeeaeeeeees 17 42 DATA CaS e a OA seein ae 17 42 STATS lt B gt rnein aE AA RESE 17 43 FOR Mat subsystem cc c cc scccsccsheeceecsssseedeeeeceseeueesesseuiveecseneeees 17 43 Data fOrm at csop A RR 17 43 DATA lt type gt length eee eeeeeeeeeseeeneeeneees 17 43 Data elements ccccccessccesssceesscecesseeeessseesssaeeessnneeesees 1
419. ses three event detectors one for each action Source Delay and Measure Event Detector Bypass As shown in Figure 10 1 there is a bypass for the Source Event Detector This bypass is in effect only if Trigger Link is the selected Trigger In Source With this event detector bypass set to ONCE operation will proceed around the Source Event Detector The programmable trigger in sources for the Trigger Layer are described as follows IMMEDIATE With Immediate selected event detection for the three detectors is satis fied immediately Operation proceeds through the Trigger Layer to perform the Source Delay and Measure actions TRIGGER LINK With Trigger Link selected event detection at each enabled detector occurs when an input trigger via the Trigger Link input line is received For example if the Trigger In Event for the Source Event Detector is ON operation will hold up at that detec tor until an input trigger is received If however the Source Event Detector is disabled OFF operation will not hold up Operation will simply continue and perform the Source action With the Trigger Link Trigger In Source selected operation will go around the Source Event Detector Figure 10 1 by setting the event detector bypass to ONCE Trigger delay A programmable delay is available before the Source Action The Trigger Delay can be manually set from 0 00000 to 999 99990 seconds Note that this delay is separate from the Delay Ac
420. set is enabled the result is the algebraic difference between the feed reading see FEED lt name gt above and the offset value CALC3 or CALC4 reading feed reading null offset ACQuire CALCulate3 NULL ACQuire Acquire channel 1 REL value CALCulate4 NULL ACQuire Acquire channel 2 REL value Description These commands automatically acquire the null offset values for chan nel 1 CALC3 and channel 2 CALC4 The next available reading will become the offset value Enable and read relative result STATe lt b gt CALCulate3 NULL STATe lt b gt Control channel 1 REL CALCulate4 NULL STATe lt b gt Control channel 2 REL Parameters lt b gt 1 or ON Enable REL 0 or OFF Disable REL Query STATe Query state of REL Description These commands are used to enable or disable the null or offset value for REL When enabled the CALC3 or CALC4 reading will include the null offset value see OFFSet lt n gt When disabled the CALC3 or CALC4 reading will not include the null offset DATA CALCulate3 DATA Read channel 1 REL result CALCulate4 DATA Read channel 2 REL result Description These query commands are used to read the CALC3 or CALC4 REL result When CALC3 or CALC4 is enabled see STATe lt b gt the returned value will include the offset value see OFFSet lt n gt and ACQuire Models 2500 and 2502 User s Manual SCPI Command Reference 17 29 CALCulate5 Configure and control RATIO function The CALCS5 command
421. source values 1 Press SRC1 or SRC2 to enter the edit mode for the desired channel The flashing digit indicates which value Src1 or Src2 is presently selected for editing 2 Use the RANGE A and 9 keys to select either the 10V or 100V range that will accom modate the value you want to set For best accuracy use the lowest possible source range 3 Enter the desired source value There are two methods to edit the value value adjust and numeric entry NOTE To clear the source value to OV press the 0000 MENU key while in the edit source field Value adjust To adjust the value use the EDIT lt and keys to place the cursor at the appropriate position and use the EDIT A and W keys to increment or decre ment the value 3 12 Basic Operation Models 2500 and 2502 User s Manual Numeric entry When the edit mode is entered the cursor is located on the most significant digit of the value From this position you can key in the value using the number keys 0 through 9 After each number is keyed in the cursor moves one position to the right If desired you can use the EDIT lt q and gt keys to place the cursor on a digit to be changed and press the appropriate number key The cursor does not have to be on the polarity sign of the value to change polarity If the 0000 MENU key is pressed the source value will be clear to OV 4 To edit the source on the other channel press SRC1 or SRC2 to select it and repeat st
422. ss becomes The Model 2500 uses two stages of filtering average and median The displayed stored or transmitted reading is simply the result of the filtering processes Filter stages The Model 2500 uses a 2 stage filtering system as shown in Figure 6 2 The first stage applies the Average Filter Moving or Repeat to the measurement conversions The sec ond stage applies the Median Filter to the output of the first stage When a filter stage is disabled a reading simply passes through it Figure 6 2 2 stage filtering Final A D Average Median s Conversions Filter Filter Filtered Readings Repeat or Moving 6 8 Range Digits Speed and Filters Models 2500 and 2502 User s Manual Each filter stage uses a stack to temporarily store readings to be filtered The size of a stack which is set by the user determines how many readings will be filtered A stack size of one disables that filter NOTE A source level change due to a sweep step resets the filters That is readings are flushed from stack and the filtering process starts over at the beginning When not sweeping source level changes do not reset the filters Any range change will also reset the filters Repeat filter The Repeat Filter places the specified number of measurement conversions into a stack and averages them to yield a single Repeat Filter reading The stack is then cleared and the process starts over For example if the repeat count stack size is 10
423. ssages for all the queries are sent to the com puter when the Model 2500 is addressed to talk The responses are sent in the order the query commands were sent and are separated by semicolons Items within the same query are separated by commas The following example shows the response message for a program message that contains four single item query commands 0 1 1 0 Response message terminator RMT Each response is terminated with an LF Line Feed and EOI End Or Identify The fol lowing example shows how a multiple response message is terminated 0 1 1 0 lt RMT gt Message exchange protocol Two rules summarize the message exchange protocol Rule 1 You must always tell the Model 2500 what to send to the computer The following two steps must always be performed to send information from the instru ment to the computer 1 Send the appropriate query command s in a program message 2 Address the Model 2500 to talk Rule 2 The complete response message must be received by the computer before another program message can be sent to the Model 2500 Models 2500 and 2502 User s Manual Remote Operations 13 17 RS 232 interface operation NOTE The programmable aspects of RS 232 operation baud rate data bits parity and terminator are configured from the COMMUNICATION option of the Main Menu See Section 1 Main menu Sending and receiving data The RS 232 interface transfers data using 8 data bits
424. stamp operates as a timer that starts at zero seconds when the instrument is turned on or when the relative timestamp is reset SYSTem TIME RESet The timestamp for each reading sent over the bus is referenced in seconds to the start time After 99 999 999 seconds the timer resets to zero and starts over Timestamp is also available for buffer readings Timestamp can be refer enced to the first reading stored in the buffer absolute format which is timestamped at 0 seconds or can provide the time between each reading delta format The TRACe TSTamp FORMat command is used to select the absolute or delta format Models 2500 and 2502 User s Manual SCPI Command Reference 17 47 NOTE Timestamp values are approximate See Section for details Limit test bits STATus A status word is available to provide status information con cerning Model 2500 operation The 24 bit status word is sent in a deci mal form and must be converted by the user to the binary equivalent to determine the state of each bit in the word For example if the status value is 65 the binary equivalent is 0000000000001000001 Bits 0 and 6 are set The significance of each status bit is explained as follows Bit 0 OFLO1 Set to 1 if channel 1 measurement was made while in over range Cleared to 0 otherwise Bit 1 OFLO2 Set to 1 if channel 2 measurement was made while in over range Cleared to 0 otherwise Bit 2 FILTERED Set to 1 if either cha
425. store GPIB defaults RCL 2 Recall location 2 setup RST reset Return Model 2500 to GPIB defaults When the RST command is sent the Model 2500 performs the following operations e Returns the Model 2500 to the GPIB default conditions Refer to Default parameters column of SCPI tables in Section 17 e Cancels all pending commands e Cancels response to any previously received OPC and OPC commands TRG trigger Send bus trigger to Model 2500 Use the TRG command to issue a GPIB trigger to the Model 2500 It has the same effect as a group execute trigger GET Use the TRG command as an event to control operation The Model 2500 reacts to this trigger if BUS is the programmed arm control source The control source is programmed from the TRIGger subsystem NOTE Details on triggering are covered in Section 10 15 6 Common Commands Models 2500 and 2502 User s Manual TRG programming example The command sequence in Table 15 4 configures the Model 2500 to be controlled by bus triggers The last command which sends a bus trigger triggers one measurement Each subsequent bus trigger will also trigger a single measurement NOTE With ARM SOURce BUS selected do not send any commands except TRG GET DCL SDC IFC and ABORt t while performing source measure opera tions Otherwise erratic operation will occur Table 15 4 TRG programming example Command Description RST Restore GPIB defaults ARM
426. sweep is completed turn the output off by pressing the ON OFF OUTPUT key Step 6 Read buffer Use the RECALL key to access the readings stored in the buffer Use the DISPLAY TOG GLE key to display statistical information Models 2500 and 2502 User s Manual Sweep Operation 9 11 Performing a custom sweep Step 1 Configure channel Configure the Model 2500 for the desired source measure operations as follows l 2 3 Select the desired source channel by pressing SRC1 or SRC2 Set the source level to the desired value Press MSR1 or MSR2 to select the desired measurement channel then choose the desired measurement range Step 2 Configure sweep Configure the sweep as follows OU Se B 8 Press SRC1 or SRC2 to select the channel Press CONFIG then SWEEP Select TYPE then press ENTER Select CUSTOM then press ENTER Use the displayed menu selections to enter the desired POINTS individual point val ues ADJUST POINTS and INIT initial value From the CONFIGURE SWEEPS menu select SWEEP COUNT press ENTER then choose FINITE or INFINITE as desired Again from the CONFIGURE SWEEPS menu choose SOURCE RANGING press ENTER then select BEST FIXED AUTO RANGE or FIXED as appropriate Press EXIT to return to normal display Step 3 Set delay Set the source delay as follows Beet Press CONFIG then SRC1 or SRC2 depending on the selected source channel Select DELAY then press ENTER Set the
427. t Points 1 Step Size Span Points 1 Step size for a logarithmic sweep can be calculated as follows log 10 Stop log10 Start Log Step Size CES EE Pare Points 1 An alternate way to set the source and measure points in a sweep is to specify the step size using the STEP command Note that the POINts and STEP commands are coupled Changing the number of source and measure points also changes the step size Con versely changing the step size changes the number of source and mea sure points Models 2500 and 2502 User s Manual SCPI Command Reference 17 71 DIRection lt name gt SOURce 1 SWEep DIRection lt name gt Set direction of source 1 sweep SOURce2 SWEep DIRection lt name gt Set direction of source 2 sweep Parameters lt name gt UP Run sweep from start to stop DOWN Run sweep from stop to start Query DIRection Query direction of sweep Description Normally a sweep is run from the start level to the stop level The STARt and STOP or CENTer and SPAN commands are used to set these levels This command lets you change the execution direction of the sweep With DOWN selected the sweep will begin at the stop level and end at the start level Selecting UP restores sweep operation to the normal start to stop direction Configure list VOLTage lt NRf list gt SOURce 1 LIST VOLTage lt NRf list gt Define source 1 list SOURce2 LIST VOLTage lt NRf list gt Define source 2 list Parameters
428. t Read Questionable Event Register Note Power up and CLS resets all bits of all event registers to 0 STATus PRESet has no effect 14 18 Status Structure Models 2500 and 2502 User s Manual Event enable registers As Figure 14 1 shows each status register set has an enable register Each event register bit is logically ANDed amp to a corresponding enable bit of an enable register Therefore when an event bit is set and the corresponding enable bit is set as programmed by the user the output summary of the register will set to 1 which in turn sets the summary bit of the status byte register The commands to program and read the event enable registers are listed in Table 14 7 For details on programming and reading registers see Programming enable registers page 14 5 and Reading registers page 14 6 NOTE The bits of any enable register can be reset to 0 by sending the 0 parameter value with the appropriate enable command i e STATus OPERation ENABle 0 Table 14 7 Event enable register commands Command Description Default ESE lt NDN gt or lt NRf gt Program Standard Event Enable Register See Parameters Note ESE Read Standard Event Enable Register STATus STATus Subsystem OPERation Operation Event Enable Register ENABle lt NDN gt or lt NRf gt Program enable register See Parameters ENABle Read enable register MEASurement Measureme
429. t is used to enable or disable an instrument operation or ON enables the operation and 0 or OFF disables the operation Upper case characters indicate the short form version for each command word Default Parameter Listed parameters are both the RST and SYSTem PRESet defaults unless noted otherwise Parameter notes are located at the end of each table SCPI A checkmark V indicates that the command and its parameters are SCPI con firmed An unmarked command indicates that it is a SCPI command but does not conform to the SCPI standard set of commands It is not a recognized command by the SCPI con sortium SCPI confirmed commands that use one or more non SCPI parameters are explained by notes Models 2500 and 2502 User s Manual SCPI Command Reference 17 3 Table 17 1 CALCulate command summary Default Command Description parameter SCPI CALCulate 1 Subsystem to control CALC1 channel 1 math y FORMat lt name gt Select math format MXB 1 COND 1 MXB 1 y POWER 1 RES 1 or OP 1 KMATh Configure MX B parameters MBFactor lt n gt Set B parameter 9 99999e20 to 9 99999e20 0 MBFactor Query B parameter MMFactor lt n gt Set M parameter 9 99999e20 to 9 99999e20 1 MMFactor Query M parameter MUNits lt string gt Set MX B units 1 to 3 character ASCII string MXB MUNits Query M parameter DC lt n gt Set dark current value in amps 0 DC Query dark current
430. t n gt SENSe2 AVERage COUNt lt n gt Set average filter count Set average filter count Parameters lt n gt 1 to 100 Specify average filter count DEFault 10 MINimum 1 MAXimum 100 Query COUNt Query filter count COUNt DEFault Query the RST default filter count COUNt MINimum Query the lowest allowable filter count COUNt MAXimum Query the largest allowable filter count Description These commands are used to specify the average filter count for channel 1 and channel 2 In general the filter count is the number of readings that are acquired and stored in the filter buffer for the averaging calcula tion Each aquired group of readings yields a single filtered reading The larger the filter count the more filtering that is performed STATe lt b gt SENSe 1 AVERage STATe lt b gt SENSe2 AVERage STATe lt b gt Enable disable average filter Enable disable average filter Parameters lt b gt 0 or OFF Disable average filter 1 or ON Enable average filter Query STATe Query state of average filter Description These commands are used to enable or disable the average filter When enabled current readings are filtered according to how the average filter is configured see TCONtrol lt name gt When disabled the average filter stage is bypassed 17 58 SCPI Command Reference Models 2500 and 2502 User s Manual TCONtrol lt name gt SENSe 1 AVERage TCONtrol lt name gt Set average filter type SENS
431. t range 2UA e Channel 2 source range 10V e Channel 2 source output level 10V NOTE See Appendix H for a complete program listing 3 14 Basic Operation Models 2500 and 2502 User s Manual Table 3 7 Basic measurement command sequence Step Action Commands Comments RST Restore GPIB defaults 1 Select channel 2 measure range SENS2 CURR RANG 2e 6 Select 2UA range Select channel 2 current reading FORM ELEM CURR2 Return channel 2 reading 2 Set channel 2 source range SOUR2 VOLT RANG 10 Select 10V source range Set channel 2 source amplitude SOUR2 VOLT 10 Source 2 output 10V 3 Turn on channel 2 output OUTP2 ON Output on before measuring 4 Read data READ Trigger acquire reading 5 Turn off channel 2 output OUTP2 OFF Output off after measuring Steps correspond to front panel steps previously in Front panel measurement procedure Commands must be sent in order given 3Instrument must be addressed to talk after READ to acquire data Using the analog outputs Model 2502 only Each analog output provides a 10V to 10V DC output analogous to the input current The analog output signal will nominally source a 10V proportional but inverted signal to the input current on all measurement ranges For example with a 1mA current on the 2mA measurement range the analog output voltage would be 5V Table 3 8 list typical analog output voltages for various ranges and input
432. tage is used Ambient temperature F Relative humidity Other Any additional information If special modifications have been made by the user please describe Be sure to include your name and phone number on this service form Equipment An Interworld Highway LLC Company Specifications are subject to change without notice All Keithley trademarks and trade names are the property of Keithley Instruments Inc All other trademarks and trade names are the property of their respective companies KENT HLEY Keithley Instruments Inc 28775 Aurora Road Cleveland Ohio 44139 440 248 0400 Fax 440 248 6168 1 888 KEITHLEY 534 8453 e www keithley com Sales Offices BELGIUM Bergensesteenweg 709 B 1600 Sint Pieters Leeuw 02 363 00 40 Fax 02 363 00 64 CHINA Yuan Chen Xin Building Room 705 12 Yumin Road Dewai Madian Beijing 100029 e 8610 6202 2886 Fax 8610 6202 2892 FINLAND Tietajintie 2 e 02130 Espoo Phone 09 54 75 08 10 Fax 09 25 10 51 00 FRANCE 3 all e des Garays 91127 Palaiseau C dex 01 64 53 20 20 Fax 01 60 11 77 26 GERMANY Landsberger Strasse 65 82110 Germering 089 84 93 07 40 Fax 089 84 93 07 34 GREAT BRITAIN Unit 2 Commerce Park Brunel Road Theale Berkshire RG7 4AB 0118 929 7500 Fax 0118 929 7519 INDIA Flat 2B Willocrissa 14 Rest House Crescent Bangalore 560 001 91 80 509 1320 21 Fax 91 80 509 1322 ITALY Viale San Gimignano
433. ted at the front of this manual Should your Model 2500 require warranty service contact the Keithley representative or authorized repair facility in your area for further information When returning the instrument for repair be sure to fill out and include the service form at the back of this manual to provide the repair facility with the necessary information Contact information Worldwide phone numbers are listed at the front of this manual If you have any questions please contact your local Keithley representative or call one of our Application Engineers at 1 800 348 3735 U S and Canada only Manual addenda Any improvements or changes concerning the instrument or manual will be explained in an addendum included with the manual Be sure to note these changes and incorporate them into the manual Safety symbols and terms The following symbols and terms may be found on the instrument or used in this manual The J symbol on an instrument indicates that the user should refer to the operating instructions located in the manual The A symbol on the instrument shows that high voltage may be present on the termi nal s Use standard safety precautions to avoid personal contact with these voltages The WARNING heading used in this manual explains dangers that might result in per sonal injury or death Always read the associated information very carefully before per forming the indicated procedure The CAUTION heading used in this ma
434. ter This is a barrel adapter that allows you to connect two triax cables together Both ends of the adapter are terminated with 3 lug female triax connectors CS 1053 Barrel Adapter This barrel adapter is terminated at both ends with 3 slot male triax connectors Model 237 BNC TRX Adapter This is a male BNC to 3 lug female triax adapter guard disconnected It is used to terminate a triax cable with a BNC plug Model 237 TRX T Adapter This is a 3 slot male to dual 3 lug female triax tee adapter for use with triax cables 1 4 Getting Started Model 2500 and 2502 User s Manual Model 7078 TRX BNC Adapter This is a 3 slot male triax to female BNC adapter This adapter lets you connect a BNC cable to the triax input of the Model 2500 Model 237 TRX TBC Connector This is a 3 lug female triax bulkhead connector with cap for assembly of custom panels and interface connections Interface cables Models 7007 1 and 7007 2 shielded GPIB cables Connect the Model 2500 to the GPIB bus using shielded cables and connectors to reduce Electromagnetic Interference EMI The Model 7007 1 is 1m long the Model 7007 2 is 2m long Model 7009 5 shielded RS 232 cable Connect the Model 2500 to computer serial port using shielded cables and connectors to reduce EMI Models 8501 1 and 8501 2 trigger link cables Connect the Model 2500 to other instruments with Trigger Link connectors e g Model 7001 Switch System The Model
435. the previous Revision of the manual are incorporated into the new Revision of the manual Each new Revision includes a revised copy of this print history page Revision A Document Number 2500 900 01 csesesessesseceseeseeeceeeseeeeeeeeeeaeeeeeeaeenes August 2000 Revision B Document Number 2500 900 01 scessescsseseeeeeeseeseeeceeeseeeeeeseeaeeeeeeseenes April 2001 Revision C Document Number 2500 900 01 csessssesseeeeesseeceeceeseeeeeeeseeaeeeseeeeeeeneeas June 2002 All Keithley product names are trademarks or registered trademarks of Keithley Instruments Inc Other brand names are trademarks or registered trademarks of their respective holders KEUS Safety Precautions The following safety precautions should be observed before using this product and any associated instrumentation Although some instruments and accessories would normally be used with non hazardous voltages there are situations where hazardous conditions may be present This product is intended for use by qualified personnel who recognize shock hazards and are familiar with the safety precautions required to avoid possible injury Read and follow all installation operation and maintenance information carefully before us ing the product Refer to the manual for complete product specifications If the product is used in a manner not specified the protection provided by the product may be impaired The types of product users are Responsible body is
436. the OPC bit in the standard event register will set after all pending command operations are complete When OPC is sent an ASCII 1 is placed in the output queue after all pending command operations are complete Typically either one of these commands is sent after the INITiate command The INITiate command is used to take the instrument out of idle in order to perform measurements While operating within the trigger model layers all sent commands except DCL SDC IFC SYSTem PRESet RST RCL TRG GET and ABORt will not execute After all programmed operations are completed the instrument returns to the idle state at which time all pending commands including OPC and or OPC are executed After the last pending command is executed the OPC bit and or an ASCII 1 is placed in the output queue 15 4 Common Commands Models 2500 and 2502 User s Manual OPC programming example The command sequence in Table 15 2 will perform 10 measurements After the measure ments are completed in approximately 10 seconds an ASCII 1 will be placed in the output queue and displayed on the computer CRT Note that additional codes must be added to query the instrument for the presence of the ASCII 1 in the output queue Table 15 2 OPC programming example Command Description RST Return Model 2500 to GPIB defaults idle TRIG DEL 1 Set trigger delay for 1 second ARM COUN 10 Program for 10 measurements and stop
437. the individual or group responsible for the use and maintenance of equipment for ensuring that the equip ment is operated within its specifications and operating limits and for ensuring that operators are adequately trained Operators use the product for its intended function They must be trained in electrical safety procedures and proper use of the instrument They must be protected from electric shock and contact with hazardous live circuits Maintenance personnel perform routine procedures on the product to keep it operating properly for example setting the line voltage or replacing consumable materials Maintenance procedures are described in the manual The procedures explicitly state if the operator may perform them Otherwise they should be performed only by service personnel Service personnel are trained to work on live circuits and perform safe installations and repairs of products Only properly trained service personnel may perform installation and service procedures Keithley products are designed for use with electrical signals that are rated Installation Category I and Installation Category II as described in the International Electrotechnical Commission IEC Standard IEC 60664 Most measurement control and data T O signals are Installation Category I and must not be directly connected to mains voltage or to voltage sources with high tran sient over voltages Installation Category II connections require protection for high trans
438. then the FILTER key to access the filter configuration menu 2 Select AVERAGE MODE then choose the REPEAT or MOVING filter as required 3 Place the cursor on AVERAGE COUNT and press ENTER to display the present aver age count for the filter 4 Use the lt gt A and W keys to display the desired count 1 to 100 and press ENTER 5 Place the cursor on ADVANCED and press ENTER The blinking cursor will indicate the state of Advanced Filter 6 Use the lt or gt key to place the cursor on the desired Advanced Filter selection DIS ABLE or ENABLE and press ENTER 7 If you enabled the Advanced Filter use the lt gt A and W keys to display the desired noise window 0 to 105 and press ENTER 8 Place the cursor on MEDIAN RANK and press ENTER to display the present median rank for the Median Filter 9 Place the cursor on the desired rank value 0 to 5 and press ENTER Keep in mind that a rank of 0 disables the Median Filter 10 Use the EXIT key to back out of the menu structure 6 12 Range Digits Speed and Filters Models 2500 and 2502 User s Manual Filter control When filtering is being applied to the input signal the FILT annunciator will be on The FILTER key is used to control filtering Pressing FILTER turns on the FILT annunciator to indicate that the filter configuration is being applied to the input Pressing FILTER a sec ond time turns the FILT annunciator off to indicate that filtering is turn
439. thin the trigger model layers For example if performing a 10 point sweep the trigger counter would be set to 10 TRIGger COUNt 10 Operation will stay in the Trigger Layer until the 10 source delay measure points of the sweep are performed If you wanted to repeat the sweep three times the arm counter would be set to three ARM COUNt 3 Three 10 point sweeps can then be performed for a total of 30 source delay measure actions The maximum buffer size for the Model 2500 is 3000 readings The product of the finite values of the two counters cannot exceed 3000 For example if you set an arm count of two the maximum trigger count will be 3000 3000 2 1500 However you can set the arm count to infinite INF With an infinite arm count the maximum trigger count is 3000 NOTE With front panel operation only when a sweep is configured the trigger model settings will not change until the sweep is started After the sweep is finished the trigger model will reset to the previous settings Output triggers The Model 2500 can be programmed to output a trigger via rear panel Trigger Link con nector after various trigger model operations An output trigger is used to trigger another instrument to perform an operation See Trigger link page 10 8 for more information Trigger layer output triggers The Model 2500 can be programmed to output a trigger after each action of the SDM cycle Source Delay and Measure Output trigge
440. this you would specify the center to be 10V and the span to be 4 volts 12 8 Use the STEP or POINts command to specify the number of source and measure points in the sweep CENTer and SPAN are coupled to STARt and STOP Thus when center and span values are changed the values for start and stop are affected as follows Start Center Span 2 Stop Center Span 2 STEP lt n gt SOURce 1 VOLTage STEP lt n gt Specify step size source 1 sweep SOURce2 VOLTage STEP lt n gt Specify step size source 2 sweep Parameters lt n gt 200 to 200 Set source level volts DEFault OV MINimum 200V MAXimum 200V Query STEP Query step size for sweep STEP DEFault Query RST default level STEP MINimum Query lowest allowable level STEP MAXimum Query highest allowable level Description These commands are used to specify a step size for a linear sweep When the sweep is started the source level changes in equal steps from the start level to the stop level A measurement is performed at each source step including the start and stop levels NOTE This command cannot be used for a logarithmic sweep Use the POINts com mand to set the source and measure points for a log sweep To avoid a setting conflicts error make sure the step size is greater than the start value and less than the stop value The number of source and measure points in a linear sweep can be cal culated as follows Points Stop St
441. tings eee eseeeeeereeeeeeeeseeeaeees 12 6 Table 12 2 Output configuration commands cee eee eeeereeeeeeeeees 12 9 Table 12 3 Output configuration programming example 12 10 13 Remote Operations Table 13 1 General bus commands 00 eee eeeeeeeseeseeeseeseeeeeeeeeseeeeeaeens 13 6 Table 13 2 RS 232 connector pinout 0 eee ese eeeeeeeeeeeeeeeeeeeeaeeees 13 19 Table 13 3 PC serial port pinout 0 eee ceeeeeeseeeeeesseeeaeeseeeaeeneeeatees 13 19 14 Table 14 1 Table 14 2 Table 14 3 Table 14 4 Table 14 5 Table 14 6 Table 14 7 Table 14 8 Table 14 9 15 Table 15 1 Table 15 2 Table 15 3 Table 15 4 16 Table 16 1 17 Table 17 1 Table 17 2 Table 17 3 Table 17 4 Table 17 5 Table 17 6 Table 17 7 Table 17 8 Table 17 9 Table 17 10 Status Structure Common and SCPI commands to reset registers anid clear QUCUES cionet iosi eo eeste ee EE as 14 4 Data format commands for reading status registers 14 6 Status byte and service request enable register COMMAS cscscvccseassevacavcsssvssoteesossdsedsuconedgevsteeassceneset ecestontey 14 10 Status byte programming example 0 0 eeeeeeeeeeseeeeeeeeee 14 10 Condition register commands 00 0 eeeeeeeeeseeeteeeteeeeeeeeaeees 14 17 Event register commands eeseeseeseeeeseeeteeeeteeeeaeeeaeers 14 17 Event enable register commands eeceeeeeeseeeeseeeneeeeees 14 18 Program and read register programming example
442. tion of the SDM cycle The Delay Action is discussed next Source delay and measure actions The SDM cycle of the Model 2500 consists of three actions Source Delay and Measure SOURCE Action Any programmed output voltage level changes are performed DELAY Action This programmable delay is used to allow the source to settle before a measurement is performed It can be manually set from 0 00000 to 9999 99800 seconds or Auto Delay can be enabled With Auto Delay enabled the Model 2500 automatically selects a nominal delay period based on the selected current measurement range NOTE The Delay Action is set from the CONFIGURE SRCI or CONFIGURE SRC2 menu See Section 3 Source delay MEASURE Action During this phase of the SDM cycle the measurement process takes place If the repeat filter is enabled as shown in the blow up drawing for Measure Action the instrument samples the specified number of reading conversions to yield a sin gle filtered reading measurement If using the moving filter or if the filter is disabled only a single reading conversion will yield a reading 10 6 Triggering Models 2500 and 2502 User s Manual Counters Programmable counters are used to repeat operations within the trigger model layers For example if performing a 10 point sweep the trigger counter would be set to 10 Operation will stay in the Trigger Layer until the 10 source delay measure points of the sweep are performed If y
443. tion register is a real time read only register that constantly updates to reflect the present operating conditions of the instrument For example while the Model 2500 is in the idle state bit B10 Idle of the operation condition register will be set When the instrument is taken out of idle bit B10 clears The commands to read the condition registers are listed in Table 14 5 For details on read ing registers see Reading registers page 14 6 Table 14 5 Condition register commands Command Description STATus OPERation CONDition Read Operation Condition Register STATus MEASurement CONDition Read Measurement Condition Register STATus QUEStionable CONDition Read Questionable Condition Register Event registers As Figure 14 1 shows each status register set has an event register When an event occurs the appropriate event register bit sets to 1 The bit remains latched to 1 until the register is reset Reading an event register clears the bits of that register CLS resets all four event registers The commands to read the event registers are listed in Table 14 6 For details on reading registers see Reading registers page 14 6 Table 14 6 Event register commands Command Description Default ESR Read Standard Event Status Register Note STATus OPERation EVENt Read Operation Event Register STATus MEASurement EVENt Read Measurement Event Register STATus QUEStionable EVEN
444. to CENTer and SPAN Thus when start and stop values are changed the values for center and span are affected as follows Center Start Stop 2 Span Stop Start CENTer lt n gt SPAN lt n gt SOURce 1 VOLTage CENTer lt n gt SOURce 1 VOLTage SPAN lt n gt SOURce2 VOLTage CENTer lt n gt SOURce2 VOLTage SPAN lt n gt Specify center point of source 1 sweep Specify span of source 1 sweep Specify center point of source 2 sweep Specify span of source 2 sweep Parameters lt n gt 200 to 200 Set SPAN source level volts 100 to 100 Set CENT source level volts DEFault OV MINimum 200V SPAN 100V CENT MAXimum 200V SPAN 100 CENT Query CENTer Query center point for sweep CENTer DEFault Query RST default level CENTer MINimum Query lowest allowable level CENTER MAXimum Query highest allowable level SPAN Query span for sweep SPAN DEFault Query RST default level SPAN MINimum Query lowest allowable level SPAN MAXimum Query highest allowable level Description A sweep can be configured by specifying center and span parameters By specifying a center point you can sweep through the operating point of a device The span determines the sweep width with the operating point at the center of the sweep Models 2500 and 2502 User s Manual SCPI Command Reference 17 69 For example assume you are testing a device that operates at 10V and you want to sweep from 8 to 12 volts To do
445. tput trigger occurs after the source is set With DELay specified an output trigger occurs after the delay period With MEASure specified an out put trigger occurs after the measurement NOTE When disabling triggers the NONE parameter must be sent alone i e trig outp none If it is listed with any of the other event parameters NONE will be ignored Specifications 2500 and 2502 Dual Photodiode Meters The Models 2500 and 2502 Dual Photodiode Meters can measure and display either photodiode current or optical power for two photodiodes with appro priate user supplied optical power gain wavelength calibration factors The Model 2502 includes an analog output jack on the rear panel for each channel Measurement Specifications TEMPERATURE ACCURACY COEFFICIENT DC INPUT MAXIMUM 23 C 45 C 0 18 C amp 28 50 C IMPEDANCE RANGE RESOLUTION rdg offset rdg offset C Maximum 2 000000 nA 1 fA 1 00 2pA 0 01 200 fA 20 KQ 20 00000 nA 10 fA 0 40 2pA 0 01 200 fA 20 kQ 200 0000 nA 100 fA 0 30 200 pA 0 02 20 pA 200 Q 2 000000 pA 1 pA 0 20 200 pA 0 02 20 pA 200 Q 20 00000 pA 10 pA 0 10 20 nA 0 01 2nA 2 0 Q 200 0000 pA 100 pA 0 10 20 nA 0 01 2nA ZU 2 000000 mA 1nA 0 10 2 pA 0 02 200 nA 0 2 Q 20 00000 mA 10 nA 0 10 2 pA 0 02 200 nA 0 2 2 MAXIMUM INPUT 20 0mA Typical Speed and Noise Rejection READINGS s DIGITS GPIB SCPI GPIB 488 1 NPLC NMRR 4 700 900 0 01 5 460 475 0 1
446. tput fail pattern 0 to 7 15 SOURce3 Query fail bit pattern CALCulate8 Subsystem to control CALC8 channel 1 buffer stats y FORMat lt name gt Specify math format MEAN SDEViation MEAN v MAXimum MINimum or PKPK FORMat Query math format v DATA Read math result of CALC8 v 1 Default based on present digital output size SOURce3 BSIZe lt n gt 3 bit default is 7 4 bit default is 15 16 bit default is 65535 16 bit available only with 2499 DIGIO option 2 The format ASCII hexadecimal octal or binary for the returned value is set by FORMat SOURce3 lt name gt 17 8 SCPI Command Reference Models 2500 and 2502 User s Manual Table 17 2 DISPlay command summary Default Command Description parameter SCPI DISPlay ENABle lt b gt Turn on or turn off front panel display Note 1 s ENABIe Query state of display v MODE lt name gt Select display function Name CALC3 DUAL CALC4 CALC5 CALC6 or DUAL MODE Query selected display function WINDow 1 Path to locate message to bottom display y TEXT Control user test message Note 2 y DATA lt a gt Define ASCII message a up to 32 characters v DATA Query text message s STATe lt b gt Enable or disable message mode Note 3 v STATe Query text message state s DATA Query data on bottom portion of display ATTRibutes Query attributes of message characters blinking 1 or not blinking 0 WIN
447. tput lines of the digital I O port will reset when the INITiate command is sent to start a new test sequence When disabled you must use MMediate to perform the clear actions Models 2500 and 2502 User s Manual SCPI Command Reference 17 39 CALCulate8 Provides statistical data on buffer readings Select statistic FORMat lt name gt CALCulate8 FORMat lt name gt Parameters lt name gt MEAN Specify channel 1 buffer format Mean value of readings in buffer SDEViation Standard deviation of readings in buffer MAXimum Largest reading in buffer MINimum Lowest reading in buffer PKPK MAXimum MINimum Query FORMat Query programmed buffer math format Description This command is used to select the desired statistic on readings stored in the channel 1 buffer See Section 8 for details on these statistics NOTE Buffer statistics are performed on the presently selected display function MSR1 MSR2 RATIO or DELTA selected with the DISPlay MODE command Buffer Statistics cannot be performed in the dual channel display mode Acquire statistic DATA CALCulate8 DATA Read channel 1 buffer statistic result Description This query command is used to perform the selected statistic operation and read the result s The result s is always returned in ASCII format Statistic operations are not performed on TIME and STATus data ele ments that are stored in the buffer Notes 1 If there is no data in the buffer err
448. tputs the pass pattern to the compo nent handler to perform the binning operation If configured to test another DUT package operation loops back to the top of the flowchart and waits for the start of test SOT pulse from the component handler Fail condition When a failure occurs the FAIL message is displayed and can also be read via remote with CALC7 LIM lt n gt FAIL and operation proceeds to the Binning Control decision block Immediate binning For immediate binning the testing process is terminated and the fail pattern for that particular failure is sent to the component handler to perform the bin ning operation End binning For end binning the fail pattern for the first failure is stored in memory and operation proceeds to Another Test Cycle decision block If programmed to perform additional tests i e sweep on the DUT package operation loops back up to perform the next source and measure action Note that when a failure occurs subsequent tests in the test cycle are not performed After all programmed test cycles are completed the Model 2500 outputs the fail pattern stored in memory This reflects the first failure that occurred in the testing process for the device package The component handler places the DUT in the appropriate bin If configured to test another DUT package operation loops to the top of the flowchart and waits for the start of test SOT pulse from the component handler 11 8 Limit Testi
449. ts Fine Limits Pass fail information Pass fail information for limit tests can be obtained as follows A PASS or FAIL indication on the front panel display By programming the unit to output specific pass fail bit patterns on the Digital I O port which can be used to control other equipment such as a device handler for bin ning operations See Binning systems page 11 10 and Section 12 Digital I O port for more information With the CALCulate7 LIMit lt n gt FAIL query via remote where lt n gt is the limit test number Section 17 CALCulate7 By reading various status bits Section 14 Status Structure and Section 17 FORMat subsystem By noting a P or F preceding buffer location numbers Section 8 Buffer location number Models 2500 and 2502 User s Manual Limit Testing 11 3 Data flow All limit tests are part of the CALC7 data block See Appendix C for an overview on how limit testing fits into the overall data flow through the Model 2500 Limit test feeds You can use the following feeds data sources for the software limit tests Limit 3 to Limit 6 MSR1 MSR2 RATIO and DELTA See Configuring and performing limit tests page 11 16 Limit 1 and 2 tests compliance These hardware H W tests check the voltage source compliance states of the Model 2500 Limit 1 uses the channel voltage source current compliance current value 20mA as the limit whil
450. ts of a gain buffer amplifier and the analog output LO is con nected to floating common Figure 2 13 shows an equivalent circuit with the ground connect mode enabled In this case since one side of the voltage bias source is connected to chassis ground analog output LO can float up to 100V above chassis ground depending on the voltage bias source setting Figure 2 12 Analog output equivalent circuit with ground connect disabled Re Feedback Ammeter Triax INPUT 20mA Max To A D Converter Chassis Ground VOLTAGE SOURCE ANALOG OUT OUT Output Enable Ground Connect Disabled Bias Source Floating channel 1 Oto 10V or or channel 2 O to 100V common ZUMA Max Buffer Chassis Chassis Note One channel shown Amplifier Ground Ground Other channel is identical Model 2500 and 2502 User s Manual Figure 2 13 Analog output equivalent circuit with ground connect enabled Re Feedback Ammeter Triax INPUT 20mA Max To A D Converter Chassis Ground VOLTAGE SOURCE OUT eine Output Ground Enable Bias Source Floating channel 1 Connect 0to 10Vor or channel 2 Enabled 0 to 100V common 20mA Max Chassis Note One channel shown Amplifier Ground Other channel is identical Buffer Connections 2 15 ANALOG OUT Chassis Ground Basic Operation Operation overview Discusses current measurement and voltage
451. type and rating for continued protection against fire hazard Chassis connections must only be used as shield connections for measuring circuits NOT as safety earth ground connections If you are using a test fixture keep the lid closed while power is applied to the device under test Safe operation requires the use of a lid interlock If or Pe is present connect it to safety earth ground using the wire recommended in the user documentation The A symbol on an instrument indicates that the user should refer to the operating instructions located in the manual The A symbol on an instrument shows that it can source or measure 1000 volts or more including the combined effect of normal and common mode voltages Use standard safety precautions to avoid personal contact with these voltages The WARNING heading in a manual explains dangers that might result in personal injury or death Always read the associated information very carefully before performing the indicated procedure The CAUTION heading in a manual explains hazards that could damage the instrument Such damage may invalidate the war ranty Instrumentation and accessories shall not be connected to humans Before performing any maintenance disconnect the line cord and all test cables To maintain protection from electric shock and fire replacement components in mains circuits including the power transformer test leads and input jacks must be purchased from Keithley Instruments
452. u 12 8 RATIO and DELTA 7 10 Sweep 9 6 17 66 Triggering 10 14 Conformance Information TEEE 488 and SCPI E 1 Connections Alternate methods 2 9 Current measurement 2 9 Equivalent circuit 2 6 2 8 GPIB 13 4 Ground connect mode 2 7 Handler interface 11 10 TEEE 488 13 4 Photodiode 2 4 Precautions 2 2 RS 232 13 18 Voltage source 2 10 Connector ANALOG OUT Model 2502 only 1 9 Digital I O 1 8 11 10 GPIB 1 9 TEEE 488 13 4 13 5 INPUT 1 8 2 2 2 3 Line power 1 9 OUTPUT 2 2 2 3 RS 232 1 9 13 5 13 18 Serial port 13 19 Terminals 2 3 Trigger link 1 9 VOLTAGE SOURCE 1 8 Controls Power 1 7 Counters 10 6 10 22 Current measure 2 9 Custom sweep 5 4 9 4 9 11 Data bits and parity 13 17 Data elements 17 46 CALC 17 49 TRACe 17 50 Data flow 5 8 11 3 C 1 Block diagrams 5 9 C 2 Data storage enabled 5 8 Limit test enabled 5 8 Data format 17 43 Data store Commands 8 6 Enabled 5 8 Menus 1 29 Overview 8 2 Programming example 8 7 Recalling readings 8 2 Storing readings 8 2 Sweep 5 5 DCL device clear 13 8 Default conditions 17 81 Selecting 17 79 Define TEXT messages 17 42 Delay Auto 3 5 Manual 3 6 Phase 5 3 Setting 9 7 17 65 Trigger 10 5 10 21 DELTA function 7 9 Commands 7 11 Enable and read result 17 30 Menu 7 10 Programming example 7 12 Select calculation mode 17 30 Digital I O port 1 8 12 2 5V output 12 3 Configuration 12 2 Digital output Clearing 17 76 Setting 17 74 Digital output clear pattern 11 1
453. ue the oldest message is read and then removed from the queue If the queue becomes full the message 350 Queue Overflow will occupy the last memory location On power up the error queue is empty When empty the message 0 No Error is placed in the queue Messages in the error queue are preceded by a code number Negative numbers are used for SCPI defined messages and positive numbers are used for Keithley defined messages The messages are listed in Appendix B As shown in Table 14 9 there are com mands to read the entire message code and message or the code only On power up all error messages are enabled and will go into the error queue as they occur Status messages are not enabled and will not go into the queue As listed in Table 14 9 there are commands to enable and or disable messages For these commands the lt list gt parameter is used to specify which messages to enable or disable The messages are speci fied by their codes The following examples show various forms for using the lt list gt parameter lt list gt 110 Single message 110 222 Range of messages 110 through 222 110 222 220 Range entry and single entry separated by a comma When you enable messages messages not specified in the list are disabled When you dis able messages each listed message is removed from the enabled list NOTE To prevent all messages from entering the error queue send the enabl
454. uery attributes top display DISPlay WINDow2 ATTRibutes Query attributes bottom display Description This query command is used to determine which characters on the dis play are blinking and which are not The response message provides that status of each character position for the specified display The primary display consists of 20 characters and the secondary display consists of 32 characters 1 Character is blinking 0 Character is not blinking For example assume the following menu is displayed with the SAVESETUP option blinking MAIN MENU SAVESETUP COMMUNICATION CAL gt The response message for disp attr top display will result in 20 zeroes as follows 00000000000000000000 The response message for disp wind 2 attr bottom display will dis play ones at the character positions for SAVESETUP as follows 11111111100000000000000000000000 17 42 SCPI Command Reference Models 2500 and 2502 User s Manual Read display DATA DISPlay WINDow 1 DATA Read top display DISPlay WINDow2 DATA Read bottom display Description These query commands are used to read what is currently being dis played on the top and bottom displays After sending one of these com mands and addressing the Model 2500 to talk the displayed data message or reading will be sent to the computer Define TEXT messages DATA lt a gt DISPlay WINDow 1 TEXT DATA lt a gt Define message top display DISPlay WINDow 2 TEXT DATA lt a
455. ues The event control source of the Trigger Model is set to Immediate The count values of the Trigger Model are set to one The Delay of the Trigger Model is set to zero All math calculations are disabled Buffer operation is disabled Auto zero is enabled Both source outputs will turn on Models 2500 and 2502 User s Manual SCPI Signal Oriented Measurement Commands 16 3 WARNING When CONFigure is sent the outputs will turn on Beware of hazard ous voltage that may be present on the output terminals NOTE This command is automatically asserted when the MEASure command is sent Acquiring readings FETCh Description This query command requests the latest post processed readings stored in the sample buffer After sending this command and addressing the Model 2500 to talk the readings are sent to the computer This com mand does not affect the instrument setup This command does not trigger source and measure operations it sim ply requests the last available readings Note that this command can repeatedly return the same readings Until there are new readings this command continues to return the old readings For example assume that the Model 2500 performed 20 source and measure operations The FETCh command will request the readings for those 20 source and measure operations If FETCh is sent while performing source and measure operations ARM annunciator on it will not be executed until the Model 2500 goe
456. uto range operation with range limits oe 6 3 DUIS oss ssa aed basa E E E E E 6 4 Setting display resolution ee eeeeeeeeeeeeeeeeeeee 6 4 Remote range and digits programming eee eee 6 4 Range and digits programming example 6 5 Speed cst crecds sacs can aves A E E E AET 6 5 DEMING speed serrie ss pia e R EER E aS 6 6 SPEED ACCURACY MENU oeseri 6 6 Remote speed programming seesesseesesesresssseeresrerrsreresreserees 6 7 Speed commands eeeeeeeeeseceseeceteeeseeeeaeeesaeeeeeeteeees 6 7 Speed programming example seseeseseessseeresrresrsrerrsrese 6 7 Balter scrinia inani eiriaa a odasi iiiter 6 7 Filter Stages siema a E E ETE 6 7 Repeat filter s c 2ss sscovsecsss stvevessaestusiveciesatess sag rbesoateactonsts 6 8 Median filter raspii aiii oinei aii 6 8 Moving filter 0 eee eescesceceneeeseeeeeeesseeeeeeeeeeeeeeeeneeeeae 6 10 Filter configuration ssis ciiise ani ene 6 11 Filt r control seesi iesin tinier eiss 6 12 Remote filter programming sessesessseessesreseerreresrerrsreresreses 6 13 Filter commands s ssssessseeseeessesresesesersesresersrsresrsresresese 6 13 7 Relative Math Ratio and Delta REL AINE svcseccesincsntiedeveveseccteus aevssbonesudeteoucessetevs ieostenesussiesebevaenrseees 7 2 Front panel tel sieri isad a E 7 2 Enabling and disabling rel oo eee eeeeseeeeeereeeeees 7 2 Defining a rel value oo eset eeeeeeeeeeseeeeseeneeeseeeees 7 2 Using REL in the dual chan
457. verview 1 5 Panel Front 1 6 Rear 1 8 Photodiode connections 2 4 Equivalent circuit 2 6 2 8 Ground connect mode 2 7 Photodiode measurement Circuit configuration 4 4 Commands 4 6 Front panel procedure 4 4 Power math function Electrical 7 5 Optical 7 5 Power controls 1 7 Power line frequency setting Selecting 17 82 Power up 1 10 Sequence 1 11 Primary address 13 6 Program messages 13 14 Program trigger model 17 91 Programming syntax 13 10 Queues 14 2 14 19 Clearing 14 4 Error 14 20 17 79 17 82 Output 14 19 Rack mount kits 1 4 Range 6 2 Auto 6 3 Limits 6 3 Commands 6 4 Current measurement 3 2 Manual 6 2 Maximum readings 6 2 Menus 1 26 Programming example 6 5 Remote programming 6 4 Selecting 17 61 Voltage source 3 2 RATIO function 7 8 Commands 7 11 Enable and read result 17 29 Menu 7 10 Programming example 7 12 Select calculation mode 17 29 Read display 17 42 Read version of SCPI standard 17 85 Readings Acquiring 16 3 Displaying 8 3 Recalling 8 2 Storing 8 2 Rear panel 1 8 Registers Clearing 14 4 Condition 14 17 17 79 Event 14 17 17 78 Event enable 14 18 17 78 Measurement event 14 14 Operation event 14 13 Programming 14 5 Questionable event 14 16 Reading 14 6 Service request enable 14 9 Standard event 14 11 Status byte 14 8 Rel Commands 7 3 Defining a value 7 2 Dual channel mode 7 3 Enable and read result 17 28 Enabling and disabling 7 2 Menus 1 26 Programming example 7 4 Remote programmi
458. ves trigger layer See BCONtrol lt name gt page 17 37 for details For the sorting mode this command defines the 3 bit or 4 bit output pass pattern for the Limit 1 and Limit 2 tests compliance when Limits 3 6 are disabled NOTE 16 bit I O is available with the 2499 DIGIO option The maximum 16 bit output value is 65535 Models 2500 and 2502 User s Manual SCPI Command Reference 17 37 FAIL SOURce3 lt NRf gt lt NDN gt CALCulate7 CLIMits FAIL SOURce3 lt NRf gt lt NDN gt Specify fail pattern Parameters lt NRf gt 0 to 7 3 bit Decimal value 0 to 15 4 bit Decimal value lt NDN gt Oto b111 3 bit Binary value Oto b1111 4 bit Binary value 0 to q7 3 bit Octal value 0 to q17 4 bit Octal value 0 to h7 3 bit Hexadecimal value 0 to hF 4 bit Hexadecimal value Query SOURce3 Query programmed source value Description For the sorting mode this command is used to define the 3 bit or 4 bit output pattern for the digital I O port when there are any limit test fail ures Note that the output value can be specified using binary octal dec imal or hexadecimal format Use the table provided in SOURce3 lt NRf gt lt NDN gt Description page 17 34 to determine the decimal parameter value for the desired digital output pattern BCONtrol lt name gt CALCulate7 CLIMits BCONtrol lt name gt Control digital I O port pass fail update Parameters lt name gt IMMediate Update
459. vice Multiline LLO Local Lockout Low Locks out local operation Universal DCL Device Clear Low Returns device to default conditions SPE Serial Poll Enable Low Enables serial polling SPD Serial Poll Disable Low Disables serial polling Addressed SDC Selective Device Low Returns unit to default conditions Clear GTL Go To Local Low Returns device to local Unaddressed UNL Unlisten Low Removes all listeners from the bus UNT Untalk Low Removes any talkers from the bus Common High Programs IEEE 488 2 compatible instruments for common operations SCPI High Programs SCPI compatible instru ments for particular operations D 8 IEEE 488 Bus Overview Models 2500 and 2502 User s Manual Uniline commands ATN IFC and REN are asserted only by the controller SRQ is asserted by an external device EOI may be asserted either by the controller or other devices depending on the direction of data transfer The following is a description of each command Each command is sent by setting the corresponding bus line true REN Remote Enable REN is sent to set up instruments on the bus for remote opera tion When REN is true devices will be removed from the local mode Depending on device configuration all front panel controls except the LOCAL key if the device is so equipped may be locked out when REN is true Generally REN should be sent before attempting to program instruments over the bus EOI E
460. y With BUSY selected the unit behaves as if it is in 3 bit mode 11 18 Limit Testing Models 2500 and 2502 User s Manual Figure 11 10 Limits configuration menu tree H W S W Limits 1 2 Limits LOLIM HILIM BUSY BUSY EOT Performing limit tests Perform the following steps to run limit tests Step 1 Configure test system As previously explained in Section 2 your test system could be as simple as connecting one or two DUTs to the Model 2500 or could employ the use of a handler for binning operations Adding a scanner to the test system allows you to test multiple devices Make sure that the Digital I O is configured appropriately for the handler you are using Step 2 Configure bias source and measure functions Configure the Model 2500 for the desired operations as follows Select the desired source channel by pressing SRC1 or SRC2 2 Set the source level to the desired value 3 Press MSR1 or MSR2 to select the desired measurement channel then choose the desired measurement range Refer to Section 3 Basic Operation for more information Models 2500 and 2502 User s Manual Limit Testing 11 19 Step 3 Configure limit tests Select and configure the following limit tests parameters as explained in Configuring limit tests page 11 16 e Use DIGOUT to configure the Digital I O port for SIZE MODE and AUTO CLEAR Set your H W LIMITS and S W LIMITS parameters as desired Remember that
461. y using the trigger delay This user specified delay 0000 0000 to 9999 9990 seconds occurs before each SDM cycle device action of the sweep Thus the trigger delay is executed before each new source point in the sweep See Section 10 Trigger model front panel operation and Configuring triggering to set trigger delay Trigger count and sweep points The trigger count and number of sweep points should be the same or multiples of one another For example with five sweep points and a trigger count of 10 the sweep will run twice See Section 10 for details on trigger count Performing sweeps Procedures for the various sweep types are covered below NOTE The following procedure assumes that the Model 2500 is already connected to the DUT as explained in Section 2 Performing a linear staircase sweep Step 1 Configure channel Configure the Model 2500 for the desired channel as follows 1 Select the desired source function by pressing SRC1 or SRC2 2 Set the source level to the desired value 3 Press MSR1 or MSR2 to select the desired measurement channel then choose the desired measurement range See Section 3 Basic Operation for more information The source level you set becomes the bias level for the sweep When turned on the output will maintain this bias level until the sweep is started Typically OV is used as the bias level If using a fixed measurement range make sure it can accommodate every
462. ys to select the desired source range Use the lowest range possible for best accuracy To simply increment or decrement the displayed source value use the EDIT lt q and p keys to place the blinking cursor on the digit to be changed then increment or decre ment the value with the EDIT A and y keys Note that the source value will be updated immediately you need not press ENTER to complete the process To enter the source value directly simply key in the desired value with the numeric keys while the cursor is blinking Again the source value will be updated immediately Configuration menus There are a number of configuration menus that can be accessed by pressing the CONFIG key followed by the appropriate function or mode key For example you can configure the measurement functions by pressing CONFIG then MSR1 channel 1 or MSR2 channel 2 Configuration menus which are summarized in Table 1 5 through Table 1 11 are available for the following operating modes Measurement functions MSR1 MSR2 RATIO DELTA Table 1 5 Voltage source SRC1 and SRC2 Table 1 6 REL FILTER and RANGE Table 1 7 LIMIT Table 1 8 TRIG Table 1 9 SWEEP DIGITS SPEED and STORE Table 1 10 ON OFF OUTPUT and DISPLAY TOGGLE Table 1 11 Model 2500 and 2502 User s Manual Getting Started 1 25 These various configuration menus are covered in detail in the pertinent sections of this manual Table 1 5 Measurement configuration me

Models 2500 And 2502 Dual Photodiode Meter User`s Manual

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