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Model 2701 Ethernet-Based DMM / Data Acquisition

1. 8 6 E ir e mt e ERE Ee 8 6 External mogor eiea a 8 7 a Dd aa aaa 8 8 External trigget t Ea seca aiit en dee dens 8 8 Voltmeter iiti nennen nenne 8 10 External triggering example eee 8 11 External triggering with BNC 8 14 Remote programming triggering e 8 16 Trigger model remote 8 16 Trigger model operation 8 18 Triggering commands essesssseeeeneeeneenen nme 8 19 Programming example nennen 8 20 9 Limits and Digital l O sss 9 1 LIMIS EM 9 2 Seann er 9 4 Basic limits Operation iarsin iesiri dereit erii ad 9 4 Digital VO E 9 5 Digital input trigger link mH 9 5 Digital OUTPUTS ae e ee e e etat MA 9 6 Setting digital OutpUti ieiuniis aana aa tnn 9 10 Senis 9 11 Remote programing limits and digital 9 12 Limits and digital output commands 9 12 Limits and digital outputs programming exam
2. 1 21 Remote programming default and user setups 1 26 Remote programming information 1 27 Quick start exercises en a oe QS3 1 28 Basic DMM measurements front panel inputs 1 29 Closing and opening channels system channel operation 1 31 Simple scarnning ssec ete e pa sede pda 1 35 Trigger and return readings remote programming 1 38 2 Closing and Opening Switching Module Channels 2 1 Close open overview ssssssssssssssssee eene ennemis 2 2 Switching module installation and connections 2 4 Module installation eeeseeeeeennn nnne 2 4 Table of Contents Model 2701 Ethernet Based DMM Data Acquisition System oeil 2E 2 5 PSEUGOCAIOS M DES 2 6 Channel assignments sssssssssssssss eene nnne enne 2 6 System channel operation ssssssssssseseeeee eren 2 7 2 Wire TUNCUONS enne nnn nene 2 8 4 wire functions paired channels see 2 9 Controlling the system channel sssssseeeee 2 10 Non amp and non measure switching modules 2 14 Multiple channel operation
3. A 2 Model 7700 20 Channel Differential A 6 Accuracy calculations eres A 7 Calculating DC characteristics A 7 Calculating AC characteristics accuracy A 7 Calculating dBm characteristics A 8 Calculating dB characteristics A 9 Additional derating A 9 Optimizing measurement A 10 DC voltage DC current and A 10 AC voltage and AC current ssssssssssssseeeeeeen ne A 10 Temperature niit B sS UI HRS IC A FSI CERE TX HS A 10 Optimizing measurement speed A 10 DC voltage DC current and A 10 AC voltage and AC A 10 Temperature eee eere d serit ege D Er ame ud e d s A 10 B Model 7700 Connection Guide B 1 Card configuration schematic B 2 Document Num
4. deve pee HARD Te dad 11 18 Event enable 11 18 UI cc rts 11 22 Output queue n aia a ie ERREUR EE 11 22 Eor QqUOlle i aide certet beo qi hte mte runs 11 22 12 Common Commands 5 52 b adt wales 12 1 13 SCPI Signal Oriented Measurement Commands 13 1 CONFigure lt function gt lt rang gt lt res gt clist 13 4 zer LEES 13 6 READ xg ie devia odisti dente dae M E eec sim Aura 13 7 MEASure lt function gt lt rang gt lt res gt lt 13 8 14 FORMat and Miscellaneous SYSTem Commands 14 1 FORMat commands ssssssssssssseeeeeeee rennen nnne 14 2 FORMat ELEMents item list sess 14 2 Miscellaneous SYSTem 14 4 SYSTem PRESOEL ated ar te coa edo eine ases tutae 14 4 SYSTemiVERSIOn icu dba oreet 14 4 SYSTem KEY 14 4 SYSTem BEEPer STATe lt gt 14 5 15 SCPI Reference Tables 15 1 Reference 15 2 Model 2701 Ethernet Data Acquisition
5. P 7 21 8 m 7 21 thee eda ede euge esu p desee due As 7 21 8 iie ete ente ier EE bei zar 7 22 Manual external trigger scan 7 23 Monitor scan analog trigger 7 24 Remote programming scanning esee 7 26 Trigger tmodel itio e Eos eo RBS ERROR RAE 7 26 Channel Setup n recom e ee me teste eoe Proc ex de es 7 27 iv Document Number 2701 900 01 Rev F August 2011 Model 2701 Ethernet Based DMM Data Acquisition System Table of Contents Butlers s tine taedet bendi an ete he 7 27 Scanning commands sse eee eene 7 27 Scanning programming example sese 7 32 Scanning examples ries aet ex cede oe ee eet ne gun drag 7 32 External trigger scan EARN eene 7 32 Monitor SCan ecce eo iesus eed ere ba ea dee Da ede xe Le d dex Po Das du x ez 7 35 8 TFIGUering oct uh ule tse Tete Ad Tm Edtu S eEEUE 8 1 Trigger model decreti ie Dad Leere dre Pe e Pe EO de 8 2 ee r 8 2 Control source and event detection ssssesssssssee 8 3 Delay auto or manual sese ene 8 3 DeVICG ACHON Rt M ict hei Atel ae a 8 5 Output THQ OCR tit te ei reb e ei ai ene 8 5 Reading hold
6. Display ALL option and press OPEN again Display MULTI option and press EN TER OPEN ALL OPEN MULTI OPEN MULT XXX Specify channel number XXX and press EN TER 2 20 Close Open Switching Module Channels Model 2701 User s Manual Remote programming Multiple channel control commands The commands to close and open the system channel are listed in Table 2 2 Table 2 2 Multiple channel control commands Commands Description Ref ROUTe MULTiple CLOSe lt clist gt Specify one or more channels to close a ROUTe MULTiple OPEN lt clist gt Open channels specified in list Unlisted b channels not affected ROUTe OPEN ALL Open all channels ROUTe MULTiple CLOSe Returns a lt clist gt of all closed channels d ROUTe MULTiple CLOSe S TATe Query closed channels in specified list e lt clist gt 1 closed Channel list parameter lt clist gt SCH where S Mainframe slot number 1 or 2 CH Switching module channel number must be 2 digits Examples 101 Slot 1 Channel 1 101 203 Slot 1 Channel 1 and Slot 2 Channel 3 101 110 Slot 1 Channels 1 through 10 Reference a ROUTe MULTiple CLOSe lt clist gt This command functions like the front panel CLOSE key MULTI menu option to close channels When you send this command to close the channels specified in the lt clist gt only those listed channels will close Channels not specified are not affected and channel p
7. Model 2701 User s Manual 0 C to 500 C Ou V to 20 644u V 500 C to 1 372 C 20 644u V to 54 8861 V F 4 Temperature Equations Table F 4 Type K inverse function polynomial 200 C to 0 C 5 891pu V to On V Cy 0 0 2 5173462x 10 c7 1 166287 8x 106 cz 1 083 363 8 x 10 c4 8 977 3540 10712 cs 3 734 2377 10716 8 663 2643 x 10720 c 2 1 045 059 8 x 10723 cg 5 192 0577 102 Co Error 0 04 C to 0 02 C 0 0 2 508 355 2 x 10 7 860 106 2x 10 2 503 1312 x 10 19 8 315 270 2 x 10714 1 228 034 2 x 107 9 804 036 2 10722 4 413 030 2 x 10726 1 057 734 2 x 1079 1 052 755 2 x 1077 0 04 C to 0 05 C 1 318 058 x 10 4 830 222 x 102 1 646 031 x 10 5 464 731 x 1071 9 650 715 x 10 16 8 802 193 x 1072 3 110 810 x 1026 0 06 C to 0 05 C too Co c4E c4E was c E where tog is the calculated temperature in C E is the measured voltage in microvolts Table F 5 Type N inverse function polynomial 200 C to 0 C 3 990u V to Ou V 0 C to 600 C OuV to 20 613uV 600 C to 1 300 C 20 613u V to 47 513u V C5 C6 c7 Cg Co Error 0 0 3 843 684 7 x 10 1 101 048 5 x 10 5 222 9312 x 10 7 206 052 5 x 10 5 848 858 6 x 1015 2 775 491 6 x 10718 7 707 5166 x 1022 1 158 266 5 x 10725 7 313 886 8 x 10730 0 03 C to 0 02 C 0 0 3 868 96 x 10 1 082 67 x 10 4
8. ce mH 1710 ms Hm tk AMEN ote ee M PNE po ROF BO ML Master Limit BHF Buffer Half Full HL1 High Limit 1 Event Buffer Three quarter Full Buffer Available LL1 Low Limit 1 Event BOF Buffer Quarter Full BN Buffer Notify ROF Reading Overflow HL Hardware Limit Event RAV Reading Available BOF Buffer Overflow HL2 High Limit 2 Event amp Logical AND BF Buffer Full LL2 Low Limt 2 Event OR Logical OR 11 16 Status Structure Model 2701 User s Manual Questionable event register The used bits of the Questionable Event Register Figure 11 7 are described as follows Bits BO through B3 Not used Bit B4 Temperature Summary Temp Set bit indicates that an invalid reference junction measurement has occurred for thermocouple temperature measurements Bits B5 B6 and B7 Not used Bit B8 Calibration Summary Cal Set bit indicates that an invalid calibration constant was detected during the power up sequence The instrument will instead use a default calibration constant This error will clear after successful calibration of the instrument Bits B9 through B13 Not used Bit B14 Command Warning Warn Set bit indicates that a Signal Oriented Measurement Command parameter has been ignored Bit B15 Not used NOTE Whenever a questionable event occurs the ERR annunciator will turn on The annunciator will turn off when
9. 1 32 Getting Started Model 2701 User s Manual Figure 1 5 Connection to DMM for 4 wire function system channel 106 closed 7700 7700 Switching Module Switching Module o o r0 i o0 HI Ch 6 Input OL o o0 3 Ot Oo LO DMM HI Ch 16 Sense 1 1 To Oo LO NOTE Switching module channels can also be controlled using multiple channel oper ation This allows individual control of all module channels switches Multiple channel operation should only be used by experienced service personnel who recognize the dangers associated with multiple channel closures See Section 2 for details Close open operation The following points on operation pertain to system channel operation only Only one input channel or channel pair is closed at one time When you close an input channel the previously closed input channel s will open When a system channel is closed the channel number will be displayed on the Model 2701 The slot number for the module is also displayed For example 103 indicates that system input channel 3 for a module in slot 1 is closed The paired channel for a 4 wire function is not displayed Only the system channel number is displayed For example in Figure 1 5 channel number 106 will be dis played with the Model 7707 installed in slot 1 of the mainframe Switching modules that have current measurement capability have separate chan nels reserved ex
10. lt clist gt Select ACV range n 0 to 757 5 V 750 VOLTage AC RANGe AUTO lt b gt Control ACV auto range b ON or OFF ON lt clist gt CURRent DC RANGe n lt clist gt Select DCI range n 0 to 3 A 3 CURRent DC RANGe AUTO lt b gt Control DCI auto range lt b gt ON or OFF ON lt clist gt CURRent AC RANGe lt n gt lt clist gt Select ACI range n 0 to 3 A 3 CURRent AC RANGe AUTO lt b gt Control ACI auto range lt b gt ON or OFF ON lt clist gt RESistance RANGe lt n gt lt clist gt Select range n 0 to 120e6 120e6 RESistance RANGe AUTO lt b gt lt clist gt Control 2 auto range b ON or OFF ON FRESistance RANGe lt n gt lt clist gt Select range n 0 to 120e6 120e6 FRESistance RANGe AUTO lt b gt lt clist gt Control auto range b ON or OFF ON Channel list parameter lt clist gt SCH where S Mainframe slot number 1 or 2 CH Switching module channel number must be 2 digits Examples 101 Slot 1 Channel 1 101 203 Slot 1 Channel 1 and Slot 2 Channel 3 101 110 Slot 1 Channels 1 through 10 1 The lt clist gt parameter is used to configure one or more channels for a scan Each channel in the lt clist gt must be set to the function specified by the range command If not a conflict error 221 will occur For example VOLTage AC RANGe
11. The CONFiguration and MEASure commands for the TEMPerature and CONTinuity functions do not use the rang and res parameters The command is ignored and causes error 108 parameter not allowed The CONFigure and MEASure commands cannot be used while scanning The command is ignored and causes error 221 settings conflict 13 4 SCPI Signal Oriented Commands Model 2701 User s Manual CONFigure function lt rang gt lt res gt lt clist gt CONFigure VOLTage DC lt rang gt lt res gt lt clist gt Configure DCV CONFigure VOLTage AC lt rang gt lt res gt lt clist gt Configure ACV CONFigure CURRent DC lt rang gt lt res gt lt clist gt Configure DCI CONFigure CURRent AC lt rang gt lt res gt lt clist gt Configure ACI CONFigure RESistance lt rang gt lt res gt lt clist gt Configure Q2 CONFigure FRESistance lt rang gt lt res gt lt clist gt Configure 4 CONFigure FREQuency lt rang gt lt res gt lt clist gt Configure FREQ CONFigure PERiod lt rang gt lt res gt lt clist gt Configure PERIOD CONFigure TEMPerature lt clist gt Configure TEMP CONFigure CONTinuity lt clist gt Configure CONT Parameters lt rang gt lt res gt lt clist gt Range parameter for the specified function For example for DCV range parameter value 10 selects the 10V range See the NOTES that follow Table 13 1 for addi
12. lt clist gt FETCh READ MEASure lt function gt lt rang gt lt res gt lt clist gt Places the Model 2701 in a one shot measurement mode for the specified function Requests the latest reading Performs an ABORt INITiate and FETCh Performs an ABORt CONFigure lt function gt and READ See Note Channel list parameter lt clist gt SCH where S Mainframe slot number 1 or 2 Examples 101 Slot 1 Channel 1 CH Switching module channel number must be 2 digits 101 203 Slot 1 Channel 1 and Slot 2 Channel 3 101 110 Slot 1 Channels 1 through 10 Note Only one channel can be specified in the lt clist gt for the MEASure command Model 2701 User s Manual NOTE SCPI Signal Oriented Commands 13 3 The CONFigure function and MEASure function commands can be sent without any of the optional parameters rang res lt clist gt For details see the Description for the CONFigure and MEASure commands When using the clist parameter it is interpreted as the last parameter Any parameter after clist will generate error 102 syntax error If only one parameter is used and it is not a clist it is interpreted as the range parameter rang If two parameters are used and the second one is not a clist the first parameter is the range parameter rang and the second is the resolution parameter lt res gt
13. 1 To avoid problems with remote programming it is good practice to routinely clear the buffer TRAC CLE at the begin ning of a program that performs multiple measurements SAMP COUN gt 1 Restoring RST or FACTory defaults does not clear the buffer 2 FACTory defaults place the instrument in a continuous measurement mode RST places the instrument in a non continu ous measurement mode 3 READ triggers and returns 15 readings These 15 readings are automatically stored in the buffer See Exercise 4 and 5 for more information on the READ command 4 Statistics for buffer readings are also stored in the buffer For remote programming CALC1 DATA only returns the read ings that were stored It does not return buffer statistics CALC2 commands are used to calculate and return buffer statistics see Section 6 for details Model 2701 User s Manual Getting Started 1 31 Closing and opening channels system channel operation NOTE See Section 2 for details on closing and opening switching module channels NOTE The following discussion assumes a multiplexing switching module i e Model 7700 is installed in slot 1 of the mainframe Switching module installa tion is covered in Section 2 see Switching module installation and connec tions page 2 4 An alternative to installing a switching module is to assign slot 1 asa pseudocard using remote programming The instrument will operate as if a switching module is
14. NOTE The following commands take a long time to process and may benefit from using OPC or OPC e RST and SYST PRES RCL and SAV e ROUT MULT CLOS and ROUT MULT OPEN Only if the lt clist gt is long e CALC2 IMM and CALC2 IMM Only when performing the standard deviation calculation on a large buffer A 450 000 point buffer takes around 5 to 6 seconds NOTE A programming example in Section 11 Example 3 located after Table 11 6 shows how to use OPC to determine when a measure store process is finished OPC Operation Complete Query Place a 1 in the output queue after all pending operations are completed Description When this common command is sent an ASCII 1 will be placed in the Output Queue after the last pending operation is completed The 1 in the Output Queue will be sent to the computer The 1 in the Output Queue will set the MAV Message Available bit B4 of the Status Byte Register If the corresponding bit B4 in the Service Request Enable Register is set the RQS MSS Request for Service Master Summary Status bit in the Status Byte Register will set When used with the Initiate Immediately command INITiate a 1 will not be placed into the Output Queue until the Model 2701 goes back into the idle state The INIT command operation is not considered finished until the Model 2701 goes back into the idle state See the description for WAI for more information on command ex
15. SEE A Cable mae FE y m 350V INPUTS NS Resistance C Under Test ES o Note Source current flows from the l INPUT HI to INPUT LO terminals B 04 Connections 3 22 Basic DMM Operation Model 2701 User s Manual Model 7700 switching module Connections for the switching module are shown in Figure 3 9 As shown in Figure 3 9A each of the 20 channels can be used to perform measurements For 04 measurements channel pair is used for each 4 wire measurement as shown in Figure 3 9B For 44 connections channels 1 through 10 which are used as the INPUT terminals paired to channels 11 through 20 which are used as the SENSE terminals Channel 1 is paired to channel 11 channel 2 is paired to channel 12 and so on Figure 3 9 42 and 421 connections for Model 7700 switching module Shielded O ptional Shield Model 7700 Switching Resistance Module U nder Test Resistance U nder Test O ptional Shield Note Source current flows from input high H to input low L B 04 Connections Shielding To achieve a stable reading it helps to shield resistances greater than 100kQ As shown in Figure 3 8 and Figure 3 9 place the resistance in a shielded enclosure and connect the shield to the input low terminal of the instrument electrically Model 2701 User s Manual Basic DMM Operation 3 23 Cable leakage For high resistance measurem
16. specifying a channel to close Press CLO SE key Display MULTI option CLO SEM ULTI press EN TER Specify channel number CLOSE M LXXX XXX and press ENTER Model 2701 User s Manual Close Open Switching Module Channels 2 19 OPEN key The OPEN key has two options to open channels ALL and MULTI The ALL option simply opens all channels in the mainframe The MULTI option opens only the specified channel All other closed channels remain closed Figure 2 7 summarizes OPEN key operation OPEN ALL Perform the following steps to open all channels in the mainframe 1 Press the OPEN key to display OPEN ALL 2 Press OPEN again or press ENTER to open all channels OPEN MULTI Perform the following steps to open only the specified channel 1 Press the OPEN key The OPEN ALL message will be displayed Press the or key to display the OPEN MULTI message Press ENTER to display the prompt to open a channel OPEN MLT XXX Using lt gt a and key in the three digit channel you want to select Press ENTER to open the channel Ch oq es NOTE Ifthe channel you open using OPEN MULTI is the system channel channel number displayed on the Model 2701 the channel will open but the system channel number will still be displayed see Multiple channel operation anomalies page 2 22 Figure 2 7 Multiple channel operation opening one or all channels CLO SE Press O PEN key
17. Accuracy 0 06 of reading 0 03 of range 0 0006 x 120V 0 0003 x 750V 0 072V 0 225V 0 297V In this case the actual reading range is 120V 0 297V or from 119 703V to 120 297V AC current calculations are performed in exactly the same manner using the pertinent specifications ranges and input signal values A 6 Specifications Model 2701 User s Manual Calculating dBm characteristics accuracy As an example of how to calculate the actual reading limits for a 13dBm measurement with a reference impedance of 50 assume an applied signal of 0 998815V The relationship between voltage and dBm is as follows 2 Vin Rrer iBm 10log 1mW From the previous example on calculating DC characteristics accuracy it can be shown that a measurement of 0 998815V on the 1 V range has an uncertainty of 36 9644mV or 0 998778V to 0 998852V using one year specifications Expressing 0 998778V as dBm 0 998778V 500 dBm 10log TH m 12 99968dBm and expressing 0 998852V as dBm 0998852V 500 1mW Thus the actual reading range is 13dBm 0 00032dBm 1B 13 00032dBm dBm and dB for other voltage inputs can be calculated in exactly the same manner using pertinent specifications ranges and reference impedances Model 2701 User s Manual Specifications A 9 Calculating dB characteristics accuracy The relationship between voltage and dB is as follows dB 20log Vin VREF As an example of
18. Anomaly 2 For a 4 wire function you can use multiple channel operation to open the paired channel If you then use system channel operation to again select the already closed system channel it will not re close the paired channel For details see Anomaly 2 example opening the paired channel NOTE The following anomaly examples assume a Model 7700 installed in slot 1 Anomaly 1 example wrong channel displayed The following example closes channel 102 and connects it to the DMM Input However the Model 2701 will not display the measurement channel that is closed It will display channel 101 instead of channel 102 1 Use the ALL option for the OPEN key to open all channels in the mainframe Remote programming ROUT OPEN ALL Press the key to close and display channel 101 This closes channel 101 which is the system channel and channel 125 to connect it to the DMM Input Figure 2 1 Remote programming ROUT CLOS 101 Use the MULTI option for the CLOSE key to close channel 102 The system chan nel is not affected Channels 101 102 and 125 are now closed Remote programming ROUT MULT CLOS 102 Use the MULTI option for the OPEN key open channel 101 Even though channel 101 is still being displayed on the Model 2701 it is channel 102 that is actually connected to the DMM Input channels 102 and 125 closed Remote programming ROUT MULT OPEN 101 To correctly display the channel that is closed
19. Bus control source G 18 KE2700 Instrument Driver Examples Model 2701 User s Manual Table G 2 continued LabVIEW examples Name Manual Reference Brief Description Simple5 None Use Case 5 32 channel scan using 7701 module Common side 4 wire ohms measurements CSIDe mode Dry circuit ohms option for Model 2750 Install jumpers to connect Input Hi and Sense Hi directly to DUT common side bus Install jumpers to connect channel 35 to Sense Lo and Input Lo Buffer Store 32 reading strings Buffer elements include reading only Triggering Immediate control source Simple6 None Use Case 6 Scan 160 channels using 7703 module see NOTE Type K thermocouple TC temperature measurements Reference junction Simulated Measurement speed rate 0 01 plc Filter Disabled no filtering Buffer Store 160 reading strings Buffer elements include reading only Triggering Bus control source NOTE When using a module that has a built in cold junction use the Internal reference junction Keep in mind that the buffer will have to be modified to accommodate the number of scanned channels Modules that have cold junction include 7700 and 7706 modules 20 available TC channels 7708 module 40 available TC channels Model 2701 User s Manual KE2700 Instrument Driver Examples G 19 Table G 2 continued LabVIEW ex
20. Close open overview NOTE For remote operations can use the internal web page of the Model 2701 to send commands queries and take readings See Internal web page in Section 10 for details Also supplied TestPoint Runtime start up software can be used to control the Model 2701 See Section 4 in the Model 2701 Instrument Networking Instruction Manual for details NOTE This section covers basic close open operations for switching module channels It also covers the operating characteristics that are unique to the Model 7700 switching module There are two modes of close open operation System channel operation This is the mode of operation that should be used exclusively by most if not all users When you close an input channel or chan nel pair other channels on the switching module close automatically to internally connect it the DMM of the Model 2701 Multiple channel operation This mode of operation provides additional flexibility by providing individual control of each switching module channel However careless operation could create a safety hazard and or damage the switching module and other equipment Multiple channel operation should only be used by experienced test engineers CAUTION WARNING To prevent damage to a switching module do not exceed the maximum signal level input for that module Most switching modules are rated for 303V The following command queries maximum module voltage SYS
21. Measurement event register The used bits of the Measurement Event Register Figure 11 6 are described as follows Bit BO Reading Overflow ROF Set bit indicates that the reading exceeds the measurement range of the instrument Bit B1 Low Limit 1 Event LL1 Set bit indicates that a reading has reached or exceeded Low Limit 1 Bit B2 High Limit 1 Event HL1 Set bit indicates that a reading has reached or exceeded High Limit 1 Bit B3 Low Limit 2 Event LL2 Set bit indicates that a reading has reached or exceeded Low Limit 2 Bit B4 High Limit 2 Event HL2 Set bit indicates that a reading has reached or exceeded High Limit 2 Bit B5 Reading Available RAV Set bit indicates that a reading was taken and processed NOTE A programming example to read the RAV bit is provided in Example 2 Read RAV bit of measurement event register on page 11 20 Bit B6 Buffer Notify BN Set bit is a notification that the user specified number of readings have been stored in the buffer The TRACe NOTify command specifies the number of stored readings that will set this bit see Section 6 for details Bit B7 Buffer Available BAV Set bit indicates that there are at least two readings in the buffer Bit B8 Buffer Half Full BHF Set bit indicates that the trace buffer is half full NOTE A programming example to read the BHF bit is provided in Example 3 Read BHF bit of measurement event regis
22. TTL Low lt 0 8V 285 gt Minimum 8 9 8 10 Triggering Model 2701 User s Manual Voltmeter complete The VMC output provides a TTL compatible output pulse that can be used to trigger other instruments The specifications for this trigger pulse are shown in Figure 8 5 Typically you would want the Model 2701 to output a trigger after the settling time of each measurement Figure 8 5 Trigger link output pulse specifications VMC M eter Complete TTL High 3 4V Typical TTL Low 0 25V Typical 10us Minimum Model 2701 User s Manual Triggering 8 11 External triggering example Figure 8 6 DUT test system For a test system that requires a large number of switching channels the Model 2701 can be used with external scanners such as the Keithley Models 7001 and 7002 For example 10 Model 7011s installed in the Model 7002 can provide up to 400 2 pole channels as shown in Figure 8 6 OUTPUT Model 2701 10 7011 MU X Cards The Trigger Link connections for this test system are shown in Figure 8 7 Trigger Link of the Model 2701 is connected to Trigger Link either IN or OUT of the Model 7002 Note that with the default trigger settings on the Model 7002 line 1 is an input and line 2 is an output This complements the trigger lines on the Model 2701 For this example the Models 2701 and 7002 are configured as follows Model 2701 Factory defaults restored accessed from S
23. The digital outputs of the Model 2701 can be used to further automate the test system by controlling a compatible component handler to perform the binning operations Limits Limit testing is used to test resistor tolerances Figure 9 6 shows a basic setup using 4 wire offset compensated ohms to test 100Q resistors Model 2701 User s Manual Limits and Digital I O 9 15 Figure 9 6 Setup to test 100 Qresistors A Front panel inputs Model 2701 eal ee Switching Module Limit 1 will be used to test for the 1 tolerance and Limit 2 will be used to test for the 5 tolerance The resistance values for the 1 and 5 tolerances are calculated as follows Rig 1000 1 Rsq 100Qx 5 1009x 0 01 1009x 0 05 The high and low limits are then calculated as follows HI Limit1 10004 Ri HI Limit2 1000 Rss 10004 10 10004 50 1010 1050 LO Limit 1000 Rs LO Limit2 1000 Rss 1000 10 1000 50 99Q 95Q 9 16 Limits and Digital I O Model 2701 User s Manual The limits are illustrated in Figure 9 7 Figure 9 7 Limits to sort 100 Qresistors 1 5 and gt 5 Beep Beep Beep No Beep low pitch normal pitch low pitch No Beep lt LOW k iN k HIGH gt HM M mee col 959 99 1002 101Q 1050 102 LO1 HI2 L Limit 1 1 Limit 2 596 Front Panel Operation For front panel operation the INSIDE beeper mode must be used A no
24. relative timestamp RANGE RANGE Ca gt gt RDG NO 10 Reading Value Absolute Timestamp Delta Timestamp RDG NO 9 Reading Value Absolute Timestamp Delta Timestamp RDG NO 8 Reading Value Absolute Timestamp Delta Timestamp RDG NO 7 Reading Value Absolute Timestamp Delta Timestamp RDG NO 6 Reading Value Absolute Timestamp Delta Timestamp RDG NO 5 Reading Value Absolute Timestamp Delta Timestamp RDG NO 4 Reading Value Absolute Timestamp Delta Timestamp RDG NO 3 Reading Value Absolute Timestamp Delta Timestamp RDG NO 2 Reading Value Absolute Timestamp Delta Timestamp RDG NO 1 Reading Value Absolute Timestamp Delta Timestamp STD DEV Standard Deviation Value No Timestamp Average Average Value No Timestamp Peak to Peak Peak to Peak Value No Timestamp Min At XX Minimum Value Absolute Timestamp Delta Timestamp Max At XX Maximum Value Absolute Timestamp Delta Timestamp Model 2701 User s Manual Figure 6 2 Buffer 6 7 Recalling buffer data real time clock timestamp RDG NO 10 Reading Value Time Date RDG NO 9 Reading Value Time Date RDG NO 8 Reading Value Time Date RDG NO 7 Reading Value Time Date RDG NO 6 Reading Value Time Date RDG NO 5 Reading Value Time Date RDG NO 4 Reading Value Time Date A RDG NO 3 Reading Value Time Date RANGE RDG NO 2 Reading Value Time Date RDG NO 1 Reading Value Time Date RANGE STD DEV Standard Deviation Value No Time No Date Average Average Value No Time No Date wy Peak to
25. Model 2701 User s Manual Query Description SCPI Signal Oriented Commands 13 5 CONFigure Query the selected function lt clist gt included When the lt clist gt parameter is included with CONFigure command the specified channel s for the scanlist assumes the RST default settings for the specified function Range can also be set for the channel s by including the rang parameter If the resolution parameter res is included it will be ignored The present measurement function and the trigger model settings are not affected when the CONFigure command is sent with the lt clist gt parameter lt clist gt not included When the lt clist gt parameter is not included the CONFigure command configures the instrument for subsequent measurements on the specified function Range and resolution can also be set for the specified function This command places the instrument in a one shot measurement mode You can then use the READ command to trigger a measurement and acquire a reading see READ When this command is sent without the lt clist gt parameter the Model 2701 will be configured as follows The function specified by this command is selected If specified range and or resolution are also set e controls related to the selected function are defaulted to the RST values Continuous initiation is disabled INITiate CONTinuous OFF e The control source of the Trigger Model is set to
26. lt clist gt VOLTage AC CURRent DC CURRent AC RESistance FRESistance TEMPerature FREQuency PERiod CONTinuity FUNCtion lt clist gt Query function DATA LATest Return the last reading Sec 3 DATA FRESh Return the last fresh reading Sec 3 HOLD Path to control Hold feature Sec 8 WINDow lt NRf gt Set Hold window in 0 01 to 20 1 WINDow Query Hold window COUNt lt NRf gt Set Hold count 2 to 100 5 COUNt Query Hold count STATe lt NRf gt Enable or disable Hold OFF STATe Query state of Hold CAVerage Channel average calculation Sec 5 DELay lt NRf gt lt clist gt Set delay between the two measurements 0 5 in seconds 0 to 99999 999 DELay lt clist gt Query delay STATe lt b gt lt clist gt Enable or disable channel average OFF STATe lt clist gt Query state of channel average RATio Channel ratio calculation OFF Sec 5 DELay lt NRf gt lt clist gt Set delay between the two measurements 0 5 in seconds 0 to 99999 999 DELay lt clist gt Query delay STATe b lt clist gt Enable or disable channel ratio OFF STATe lt clist gt Query state of channel ratio Model 2701 User s Manual SCPI Reference Tables 15 9 Table 15 5 continued SENSe command summary Default Command Description parameter Ref SCPI SENSe 1 VOLTage DC Path to configure DC volt
27. 20 channel scan e Models 2700 2701 100Qrange e Model 2750 10Q range dry circuit ohms enabled Measurement speed rate 0 1 plc e DCV input divider Enabled LOMQ input impedance Filter Disabled no filtering Buffer Store 40 reading strings 20 reading strings Buffer elements include reading only Limits DCV scan Limit 1 all channels 20mV Master Latch enabled Triggering Bus control source Model 2701 User s Manual Table G 1 continued Visual Basic and CVI C examples KE2700 Instrument Driver Examples G 9 Name Manual Reference Brief Description Simple4 None Use Case 4 Two scans using 7708 module 40 channel DCV scan 1V range Configuration saved in User Setup 1 20 channel 4 scan Configuration saved in User Setup 2 e Models 2700 and 2701 1000 range e Model 2750 10Q range dry circuit ohms enabled Setup 1 or Setup 2 recalled to perform scan Measurement speed rate 0 1 plc DCV input divider Enabled LOMQ input impedance Filter Disabled no filtering e Buffer Store 40 reading strings 20 reading strings Buffer elements include reading only Limits DCV scan Limit 1 all channels 20mV Master Latch enabled Triggering Bus control source Simple5 None Use Case 5 32 channel scan using 7701 module Common side 4 wire oh
28. 3 1A 00 1000 1kO 10kO 100kQ IMQ 10M 100MQ 120MQ Q4 1000 1kO 10kO 100kQ 1M 2 10M 100MQ 120MQ Offset compensated ohms OCOMP can be performed on 1000 1kQ and 10kQ ranges FREQ and PERIOD Frequency measurements from 3Hz to 500kHz and period measurements from 2us to 333us be made on the ACV ranges TEMP There is no range selection for temperature measurements Temperature measurements are performed on a single fixed range Depending on which type of sensor is being used the maximum temperature readings range from 200 C to 1820 C Appendix A Specifications lists the reading range for each sensor type Model 2701 User s Manual Range Digits Rate Bandwidth and Filter 4 3 Manual ranging To change range press the RANGE or key The instrument changes one range per key press The selected range is displayed for one second Note that the manual range keys have no effect on temperature TEMP If the instrument displays the OVERFLOW message on a particular range select a higher range until an on range reading is displayed Use the lowest range possible without causing an overflow to assure best accuracy and resolution Auto ranging To enable auto range press the AUTO key The AUTO annunciator turns on when auto ranging is selected While auto ranging is enabled the instrument automatically selects the best range to measure the applied signal Auto ranging should not be used w
29. ACQuire command is typically used to zero the display For example if the instrument is displaying a 1u V offset sending ACQuire and enabling rel STATe ON zeroes the display The ACQuire command is only functional if the instrument is on the specified function For example If the instrument is on the DCV function the only valid acquire command is VOLT DC REF ACQ Also if the instrument is overflowed OVERFLOW or a read ing has not been triggered an execution error 200 occurs when ACQuire is sent The REFerence n command is coupled to the ACQuire command When a rel value is set using REFerence n the REFerence query command returns the programmed value When rel is set using ACQuire the REFerence query command returns the acquired rel value Rel programming examples Example 1 The following command sequence zeroes the display for DCV NOTE The following example can be run from the KE2700 Instrument Driver using the example named Relativel in Table G 1 of Appendix G FUNC VOLT Select DCV VOLT REF ACQ Use input level as rel value for DCV VOLT REF STAT ON Enable rel Example 2 The following command sequence configures channel 101 of the Model 7700 to enable rel and use a 1V rel value when it is scanned NOTE The following example be run from the KE2700 Instrument Driver using the example named Relative2 in Table G 1 of Appendix G FUNC VOLT 80101
30. Advanced scan For an advanced scan each enabled channel can have its own unique setup Channels that are disabled are excluded from the scan list When you enter the channel setup menu the displayed information indicates the present setup for the selected channel The position of the decimal point in the SETUP message indicates present range Examples S ETUP V 101 1V range for channel 101 If the AC annunciator is off the function is DCV If it is on ACV is selected SE TUP 102 10kQrange for channel 102 If the 4 wire annunciator is off the function is 92 If it is on 04 is selected SETUP mA 121 100mA range for channel 121 If the AC annunciator is off the function is DCI If it is on ACI is selected SETUP C 103 TEMP function selected for channel 103 SETUP HZ 104 FREQ function selected for channel 104 SETUP 8 105 PERIOD function selected for channel 105 SETUP PR 111 For the Model 7700 channel 111 is paired to channel 101 and cannot be changed Channel pairing occurs when Ratio or Channel Average is enabled or when 4 wire function 4 or 4 wire RTD TEMP is selected The annunciators indicate which of the other instrument settings are enabled for the selected channel When you edit settings for the selected channel auto range rel rate etc the related annunciators will turn on off Model 2701 User s Manual Scanning 7 15 Advanced scan setup notes 1l The CHAN annunciator is on while
31. Also covered is offset compensated ohms OCOMP Temperature measurements Provides detailed information for making thermocouple thermistor and 4 wire RTD temperature measurements Frequency and period measurements Provides detailed information for making frequency and period measurements Continuity testing Explains how to use the CONT feature to test continuity Remote programming for basic measurements Covers the commands used to perform basic measurements Includes some simple programming examples Measurement queries Summarizes commands typically used to trigger and or return measured readings 3 2 Basic DMM Operation Model 2701 User s Manual DMM measurement capabilities NOTE Accuracy specifications for all measurement functions and the Model 7700 switching module are provided in Appendix A NOTE For remote operations can use the internal web page of the Model 2701 to send commands queries and take readings See Internal web page in Section 10 for details Also supplied TestPoint Runtime start up software can be used to control the 2701 See Section 4 in the Model 2701 Instrument Networking Instruction Manual for details WARNING The Model 2701 measurement inputs are rated measurement Category I The equipment cannot be connected to circuits with transients greater than 4kV peak Do not connect measurement inputs to measurement Category II III or IV circuits The DMM of the Model 2701 c
32. CH20 AMPS 21 AMPS 22 GCAO r a aaa 11 B 12 Model 7700 Connection Guide Model 2701 User s Manual Status and Error Messages C 2 Status and Error Messages Table C 1 Status and error messages Model 2701 User s Manual Number Description Event 440 430 420 410 363 350 330 314 315 285 284 282 281 260 241 230 225 224 223 222 221 220 215 214 213 212 211 210 203 202 201 200 178 171 170 168 161 160 Query unterminated after indefinite response Query deadlocked Query unterminated Query interrupted Input buffer overrun Queue overflow Self test failed Save recall memory lost Configuration memory lost Program syntax error Program currently running Ilegal program name Cannot create program Expression error Hardware missing Data corrupt or stale Out of memory Illegal parameter value Too much data Parameter data out of range Settings conflict Parameter error Arm deadlock Trigger deadlock Init ignored Arm ignored Trigger ignored Trigger error Command protected Settings lost due to rtl Invalid while in local Execution error Expression data not allowed Invalid expression Expression error Block data not allowed Invalid block data Block data error EE EE EE EE SYS SYS EE EE EE
33. DCI or ACI channels 21 and 22 are the only available channels The Model 7700 can accommodate 4 wire measurements by using channel pairs Primary channels 1 through 10 become paired to channels 11 through 20 For example with the Q4 function selected channel 1 becomes paired to channel 11 For example when you close channel 1 channel 11 will also close Model 2701 User s Manual Close Open Switching Module Channels 2 37 The 2 wire functions include DCV ACV DCI ACI 2 CONT FREQ PERIOD and TEMP thermocouple and thermistor The 4 wire functions operations include TEMP 4 wire RTD RATIO and CH AVG ratio and channel average are covered in Section 5 With a 4 wire function operation selected channels are paired as follows and CH11 CH6 and CH16 CH2 and CH12 CH7 and CH17 CH3 and CH13 CH8 and CH18 CH4 and CH14 CH9 and CH19 CH5 and CH15 CH10 and CH20 Schematic diagram The simplified schematic diagram of the Model 7700 is shown in Figure 2 12 Channels 1 through 20 are used for all measurements except amps Channels 21 and 22 are used for amps only There are two backplane relays channels 24 and 25 to connect the input channel s to the backplane of the Model 2701 With a 2 wire function except amps selected channel 25 will close and with a 4 wire function selected both channels 24 and 25 will close There is a 2 pole 4 pole relay channel 23 between channels 1 through 10 and channels 11 through 2
34. DUT 2 2 12 23 and 25 DUT 7 7 17 23 and 25 DUT 3 3 13 23 and 25 DUT 8 8 18 23 and 25 DUT 4 4 14 23 and 25 DUT 9 9 19 23 and 25 DUT 5 5 15 23 and 25 DUT 10 10 20 23 and 25 NOTE Do not use this application to measure the temperature of DUT using a thermocouple with the INTernal or EXTernal reference junction selected The SIMulated reference junction will instead be used resulting in invalid readings The ERR annunciator will turn on to indicate that the integrity of the temperature reading is questionable Model 2701 User s Manual Close Open Switching Module Channels 2 27 Figure 2 9 Dual multiplexer application connections External Source 2 28 Close Open Switching Module Channels Model 2701 User s Manual Figure 2 10 Testing DUT 1 External Source Ch 23 Closed Mutliple channel operation Open channels Close channel 123 Close channel 125 Close channel 101 Close channel 111 Test procedure NOTES The following test procedure assumes a Model 7700 switching module installed in slot 1 of the mainframe The procedure assumes that the instrument is operating in the continuous measurement triggering mode see Defaults and user setups page 1 21 Do not use the following procedure to perform thermocouple temperature measurements with the INTernal or EXTernal reference junction selected The SIMulated reference junction will instead be used resulting in invalid readings The
35. ERR annunciator will turn on to indicate that the integrity of the temperature reading is questionable Model 2701 User s Manual Close Open Switching Module Channels 2 29 1 Open all channels For most switching modules channels remain closed after the Model 2701 is turned off Therefore it is good safe practice to open all channels at the start and end of the test Front panel operation Press OPEN Display ALL Press OPEN Remote programming ROUT OPEN ALL 2 Close channels 23 and 25 Front panel operation Press CLOSE Select MULTI Key in 123 Press ENTER Press CLOSE Select MULTI Key in 125 Press ENTER Remote programming ROUT MULT CLOS 123 125 3 Close channels 1 and 11 to connect DUT 1 to the DMM and bias supply Front panel operation Press CLOSE gt Select MULTI gt Key in 101 gt Press ENTER Press CLOSE gt Select MULTI gt Key in 111 gt Press ENTER Remote programming ROUT MULT CLOS 101 111 4 Measure DUT 1 Front panel operation Take reading from display Remote programming DATA 5 Open channels 1 and 11 Front panel operation Press OPEN gt Select MULTI gt Key in 101 gt Press ENTER Press OPEN gt Select MULTI gt Key in 111 gt Press ENTER Remote programming ROUT MULT OPEN 101 111 6 Modify steps 3 4 and 5 to test DUT 2 That is close channels 2 and 12 measure DUT 2 and then open channels 2 and 12 7 Test the remaining eight DUT in a similar manner That is
36. General information 1 2 Getting started 1 1 Ground loops E 7 High energy circuit safety precautions 3 3 Hold Reading 8 6 Idle 7 7 8 2 8 16 IEEE 488 Connector 1 14 10 10 IEEE 488 2 common commands see Common commands Inputs Front panel 1 13 1 29 INPUTS switch 1 12 Inspection 1 2 Interface Configuration commands 10 3 Isolated LAN system using two NICs 10 9 Johnson noise equation E 5 KE2700 Instrument Driver G 1 Keyclick 1 19 Remote programming 1 19 Key press codes 14 5 Keys CLOSE 2 10 2 18 FILTER 4 18 Function 1 10 LOCAL 10 20 OPEN 2 12 2 19 Operation 1 10 Range 1 12 RATE 4 8 Special 1 10 LabVIEW examples G 12 Limits 9 2 Basic operation 9 4 Beeper settings 9 4 Commands 9 12 Default 9 2 Enabling disabling 9 4 Programming example 9 14 Remote programming 9 12 Scanning 9 4 Setting 9 4 Line cycle synchronization see LSYNC Line frequency 1 16 Line power connection 1 15 Line voltage Setting 1 16 LOCAL key 10 20 Low level considerations 3 15 AC voltage offset 3 16 Shielding 3 15 Thermal EMFs 3 15 LSYNC 3 5 Magnetic fields E 6 Manual ranging 4 3 4 5 Math 5 7 Basic operation 5 11 Commands 5 12 mX b 5 8 Percent 5 9 Percent reference 5 13 Programming examples 5 14 Reciprocal 1 X 5 10 Remote programming 5 12 Scanning 5 11 Setting mX b units 5 13 Math commands Reading math result 5 13 Measurement event status 11 15 Measurement queries 3 58 FETCh 3 58 MEASure function 3 60 READ 3 59
37. NONE MAXimum MINimum NONE FORMat Query math format v STATe lt b gt Enable or disable calculation Note 4 v STATe Query state of math function v IMMediate Recalculate raw input data in buffer v IMMediate Perform calculation and read result DATA Read math result of CALC 2 v 15 4 Table 15 1 continued SCPI Reference Tables CALCulate command summary Model 2701 User s Manual Default Command Description parameter Ref SCPI CALCulate3 Subsystem to control CALC 3 limit test Sec 9 MLIMit Path for master limit command LATChed lt b gt Enable or disable master limit latch OFF OUTPut Path for limit output commands STATe lt b gt Enable or disable limit outputs OFF STATe Query state of limit outputs PULSe Path to control limit output pulsing STATe lt b gt Enable or disable limit output pulsing OFF STATe Query state of limit output pulsing TIME lt NRf gt Set output pulse time in sec 0 001 to 0 002 99999 999 Query output pulse time LSENse lt name gt Set logic sense of all limit lines AHIGh or AHIGh ALOW LSENse Query logic sense of limit lines LIMit1 Path to control LIMIT 1 test UPPer Path to configure upper limit DATA n Set upper limit 4294967295 to 1 lt clist gt 4294967295 DATA lt clist gt Query upper limit LOWer Path to configure lower limit v DATA
38. NOTE OPC or OPC should be used with SYST PRES which is slow responding command Details on OPC and OPC are provided in Section 12 SYSTem VERSion Read the version of the SCPI standard being used by Model 2701 Example response message 1996 0 SYSTem KEY lt NRf gt Parameters 1 SHIFT key 15 Cursor right arrow key 2 DCV key 16 TEMP key 3 ACV key 17 LOCAL key 4 DCI 18 EX TRIG key 5 ACI key 19 TRIG key 6 key 20 STORE key 7 Okey 21 RECALL key 8 FREQ key 22 FILTER key 9 23 RELkey 10 24 Cursor left arrow key 11 RANGE up arrow key 25 12 AUTO key 26 OPEN key 13 RANGE down arrow key 27 CLOSE key 14 ENTER key 28 STEP key 29 SCAN key 30 DIGITS key 31 RATEkey 32 EXIT key This command is used to simulate front panel key presses For example to select the volts measurement function send the following command to simulate pressing the DCV key SYSTem KEY 2 The key press codes are also shown in Figure 14 2 Model 2701 User s Manual FORMat and Misc SYSTem Commands 14 5 The queue for the KEY query command can only hold one key press The KEY command is used to acquire the key press code number for the last key pressed This query command will only return the key pressed by the KEY command It will not return a key physically pressed by the operator SYSTem BEEPer STATe b You can disable the beeper for limits an
39. Operation event status 11 13 Options 1 3 Output trigger 7 10 8 5 Paired channels see 4 wire functions Password 10 4 Pead to peak buffer statistic 6 7 Percent math function 5 9 Configuration 5 9 Reference 5 13 Performance considerations 3 4 Plug in switching modules 1 3 1 7 Power module 1 14 1 16 Power switch 1 10 Power up 1 15 Sequence 1 17 Program message terminator PMT 10 26 Program messages 10 24 Programming syntax 10 21 Pseudocards 1 7 2 6 10 2 Query commands 10 23 Questionable event status 11 17 Queues 11 2 11 22 Clearing 11 4 Error queue 11 22 Output queue 11 22 Quick start 1 1 Exercises 1 28 Rack mount kits 1 6 Radio frequency interference E 6 Range 4 2 Auto ranging 4 3 4 5 Commands 4 4 Keys 1 12 Manualranging 4 3 4 5 Measurement 4 2 Programming examples 4 5 Remote programming 4 4 Scanning 4 3 Range Digits Rate Bandwidth and Filter 4 1 Rate 4 8 Aperture 4 12 Bandwidth 4 12 Bandwidth conflict error 4 13 Commands 4 11 Programming examples 4 13 Remote programming 4 11 Scanning 4 10 Settings 4 9 RATE key 4 8 Ratio 5 15 Basic operation 5 16 Channel pairing 5 15 Commands 5 18 DCV 5 16 Delay 5 18 Enabling disabling 5 18 Programming examples 5 19 Remote programming 5 18 Scanning 5 17 Ratio and channel average delay 5 18 Reading count 7 10 Reading hold Example 8 6 Readings Maximum 4 2 Recall while storing 6 12 Recalling 6 6 Storing 6 5 Rear panel Summary 1 13 Recip
40. Pressing the EX TRIG key places the instrument in the external trigger mode TRIG annunciator on When the STEP or SCAN key is then pressed that scan is enabled However the scan does not start until an external trigger is received or the TRIG key is pressed The external trigger or TRIG keypress satisfies event detection STEP operation Each time an external trigger is received or TRIG key is pressed one channel is scanned SCAN operation Each time an external trigger is received or TRIG key is pressed one complete scan is performed Model 2701 User s Manual Scanning 7 9 Delays As shown in the trigger models operation may be subjected to one or more delays before a channel is measured NOTE As previously explained if the timer control source is selected and its user set interval is greater than the user set Delay the Timer interval will supersede the Delay period after the first pass through the loop Delay Auto or Manual The user can select either auto delay or manual delay With auto delay selected the instrument automatically selects a delay period that will provide sufficient settling for function changes autorange changes and multi phase measurements The auto delay period cannot be adjusted by the user It is a fixed delay for the selected function and range Table 8 1 NOTE When scanning the auto delay times in Table 8 1 are valid for all control sources Immediate External Timer Manual or Bu
41. READ MEAS TRACe DATA CALC 1 DATA LAT CALC 1 D ATA FRESh D 8 Signal Processing Sequence and Data Flow Model 2701 User s Manual NOTE For the following discussion a data array is defined as the group of data elements that are included with each measured reading Each data array includes the reading as well as the channel reading number units timestamp and limits result see FORMat ELEMents item list gt page 14 2 for details For example assume the selected data elements to be returned by a read command include the reading units designator and reading number Now assume a 1VDC input and the READ command is sent to trigger two readings and return the two data arrays The two returned data arrays would look like this 1 00000000E 00VDC 00000RDNG 1 00000000E 00VDC 400001 RDNG Data Array 1 Data Array 2 SENSe and sample buffer The TRACe CLEar command clears the data store INITiate CONTinuous OFF command disables continuous initiation and TRIGger COUNt 1 configures the instrument to perform one measurement cycle The INIT command can then be used to initiate the measurement cycle When the INIT command is sent the programmed number of measurements set by the SAMPle COUNt command are performed and the respective data is temporarily stored in the sample buffer For example if 20 measurements were performed SAMP COUN 20 then 20 data arrays will be stored in the sample buffer Data from this
42. Rel ed reading Reading Rel value Y mX b Moving or Repeating Math mX b Percent or Reciprocal Reference Reciprocal 1 X Recall Display Reading D 4 Signal Processing Sequence and Data Flow Model 2701 User s Manual OComp offset compensated ohms The Model 2701 performs a normal ohms measurement by sourcing a known current I measuring the voltage V and then calculating the resistance R V I Offset compensated ohms cancels the effects of thermal EMFs which can adversely affect low resistance measurements With OCOMP enabled the Model 2701 performs one normal resistance measurement and then loops back to perform a second resistance measurement with the internal current source set to its lowest level The offset compensated ohms reading is then calculated as shown in Figure D 2 NOTE For details on OCOMP measurements see Offset compensated ohms page 3 24 Filter The filter is used to stabilize noisy readings With the filter enabled the specified number of readings are averaged to yield a single filtered reading There are two types of filters moving and repeating A filter stack is used to temporarily store the specified number of readings to be averaged In general for the moving filter each measurement process adds a reading to the stack oldest reading discarded and then averages the stack to yield a filtered reading For the repeating filter each measurement process
43. SENSe 1 DATA FRESh 3 60 SENSe 1 DATA LATest 3 61 Examples 3 61 Measurements Basic 3 51 Capabilities 3 2 Considerations E 1 Current see Current measurements DCI and ACI Frequency and period see Frequency and period measurements One shot mode 13 7 Ranges 4 2 Resistance see Resistance measurements 942 and 344 3 20 Setting speed 4 10 Temperature see Temperature measure ments Voltage see Voltage measurements DCV and ACV 3 8 Menus CARD 2 30 Message exchange protocol 10 27 Messages Program 10 24 Response 10 27 Status and error C 1 Meter loading E 10 Minimizing source resistance noise E 5 Minimum and maximum buffer statistics 6 7 Model 7700 Card configuration schematic A 6 Module installation 2 4 Schematic diagram 2 37 Simplified schematic 2 38 Switching module 2 36 3 8 Ratio and channel average calculations 3 10 Monitor channel 7 18 Monitor scan example 7 36 Multiple channels Control commands 2 20 Controlling 2 17 Corrupt measurements 2 17 Operation 2 16 Anomalies 2 22 mX b math function 5 8 Configuration 5 8 Rel 5 9 Setting units 5 13 Network Interface Card 10 9 Noise Johnson noise equation E 5 Lowest settings 4 8 Source resistance E 5 vs speed characteristics 4 8 NPLC setting 4 10 Offset compensated ohms 3 24 3 25 3 26 3 28 3 30 3 32 Enabling disabling 3 24 Performing measurements 3 25 OPEN key 2 12 2 19 Open thermocouple detector 3 43 OPEN ALL 2 12 2 19 OPEN MULTI 2 19
44. Sensor Thermocouple Thermocouple Junction See Note See Note Open detector No off No off Type K K Units Timestamp No effect No effect Triggering Continuous One shot v Delay Auto Auto Source Immediate Immediate Reading hold Off Off Window 196 196 Count 5 5 1 26 Getting Started Table 1 4 continued Model 2701 User s Manual Default settings Setting Factory RST Set Diff Voltage AC and DC dB Off Off Reference 1 0 1 0 Digits AC 51 digits 51 digits Digits DC 61 digits 61 digits Filter On Off Window 0 1 0 1 Count 10 10 Type Moving Repeat v Range Auto Auto Rate DC Slow 5 PLC Slow 5 PLC Rel Off Off Note With a Model 7700 7706 or 7708 installed the default sensor junction is Internal Otherwise the Simulated 23 C junction is selected Remote programming default and user setups Default and user setup commands are listed in Table 1 5 NOTE The SYSTem PRESet and RST defaults are listed in the SCPI tables in Section 15 Table 1 5 Default setup commands Commands Description SYSTem PRESet Restore SYSTem PRESet defaults RST Restore RST defaults SAV lt NRf gt Save settings as user setup lt NRf gt 0 1 2 3 or 4 RCL lt NRf gt Restore user saved setup lt NRf gt 0 1 2 3 or 4 SYSTem POSetup name Specify power on setup lt name gt RST PRESet SAVO SAV1 SAV2 SAV3 or SAVA Programming exa
45. Set sample count to 10 Trigger store and request readings 9 Limits and Digital O Limits Explains how to perform limit tests on measured readings Digital I O Covers the digital I O port Explains how the five digital outputs respond to the results of limit tests Remote programming limits and digital output Summarizes the commands to perform limit tests and control the digital I O port Application sorting resistors Provides an application to test the tolerances of 100Q resistors Provides the digital output response to the various pass fail combinations of the limit tests 9 2 Limits and Digital I O Model 2701 User s Manual Limits NOTE Limits cannot be used with the CONT function When using limits you can set and control the values that determine the HIGH IN LOW status of subsequent measurements The limit test is performed on the result of an enabled Rel Math Ratio or Channel Average operation NOTE The various instrument operations including Limits are performed on the input signal in a sequential manner See Signal processing sequence page D 2 for details It includes flow charts showing where in the processing sequence that Limits are tested There are two sets of limits Limit 1 uses high and low limits and LOI as does Limit 2 HI2 and LO2 The HIGH IN LOW status indication applies to the first limit limit 1 or limit 2 that fails Figure 9 1 illustrates the following lim
46. Setting Factory RST Set Diff Limits Off Off LO Limit 1 1 1 HI Limit 1 1 1 LO Limit 2 2 2 HI Limit 2 2 2 Line Synchronization Off Off Math mX B Off Off Scale Factor 1 0 1 0 Offset 0 0 0 0 Units x x Percent Off Off Reference 1 0 1 0 1 X Reciprocal Off Off Monitor Off Off Output Beeper Never Never Digital Output Off Off Logic Sense High High Pulse No off No off Ratio Off Off Resistance Q2 and 04 Digits 6 digits 6 digits Filter On Off v Window 0 1 0 1 Count 10 10 Type Moving Repeat v Offset compensation OCOMP Off Off Range Auto Auto Rate Slow 5 PLC Slow 5 PLC Rel Off Off Model 2701 User s Manual Table 1 4 continued Getting Started 1 25 Default settings Setting Factory RST Set Diff RS 232 No effect No effect Baud rate No effect No effect Flow control No effect No effect Terminator No effect No effect Scanning Disabled Disabled Auto scan No off No effect Type Simple or Advanced No effect No effect Simple scan Minimum channel 101 201 301 401 or 501 101 201 301 401 or 501 Maximum channel No effect No effect Timer Off Off Reading count No effect No effect Advanced scan Setup No effect No effect Immediate trigger On On Limit triggers Off Off Timer Off Off Reading count No effect No effect Temperature Digits 5 digits 5 digits Filter On Off v Window 0 1 0 1 Count 10 10 Type Moving Repeat v Rate Slow 5 PLC Slow 5 PLC Rel Off Off
47. TEMP RJUN RSEL INT 8101 CALC3 LIM1 UPP 30 80101 CALC3 LIM1 STAT ON 0101 ROUT CLOS 8101 CAV ON 80101 FUNC VOLT 80102 104 VOLT RANG 10 102 104 VOLT AVER COUN 20 102 104 VOLT AVER STAT ON 102 104 ROUT SCAN 101 104 ROUT SCAN TSO HLIM1 ROUT MON POIN 4 ROUT MON 101 ROUT MON STAT ON 7 38 Scanning Model 2701 User s Manual 8 Triggering Trigger model Explains the various components of the front panel trigger model which controls the triggering operations of the instrument Reading hold Explains the Reading Hold feature which is used to screen out readings that are not within a specified reading window External triggering Explains external triggering which allows the Model 2701 to trigger and be triggered by other instruments Remote programming triggering Covers remote operation for triggering including the trigger model and the commands 8 2 Triggering Model 2701 User s Manual Trigger model Idle The flow chart in Figure 8 1 summarizes triggering as viewed from the front panel It is called a trigger model because it is modeled after the SCPI commands used to control triggering NOTE For scanning the trigger model has additional control blocks such as a Timer These are described in Section 7 Figure 7 1 and Figure 7 2 The complete trigger model which is based on bus operation is shown and discussed in Remote programming trigg
48. Temperature measurement procedure 3 45 Frequency and period measurements 3 46 Trigger t n etiaai etie eed 3 46 Gate time iaa eode tede a 3 46 ei dtr e deer ne ra o so dO e Meo 3 47 Frequency and period measurement procedure 3 48 Gontin ity testing see reir PR Den Ph 3 48 GONNECHONS i ente e ete cn de nete endi odes 3 49 Continuity testing procedure sssssseseeneennns 3 50 Remote programming for basic 3 51 Basic measurement commands sese 3 51 Basic measurement programming examples 3 57 Measurement queries 3 58 m ee 3 58 jp EE 3 59 MEAGSure function essen 3 60 SENSe 1 EDATA ERESh eee net eer 3 60 SENSe 1 DATA LATeSt 3 61 cho 3 61 4 Range Digits Rate Bandwidth and Filter 4 1 lai m 4 2 Measurement ranges and maximum readings 4 2 Manual rangirig e eee eee eee Y Cere ee ETE
49. Teo T 273 15 298 15 273 15 25 C F 8 Temperature Equations Model 2701 User s Manual RTD equations The temperature vs resistance readings listed in the RTD reference tables are calculated using the Callendar Van Dusen equation There are two equations based on different temperature ranges There is an equation for the 200 to 0 C range and one for the 0 to 630 C range Equation for 200 to 0 C temperature range Ro 1 AT BT CT T 100 where is the calculated resistance of RTD Rg is the known RTD resistance at 0 C T is the temperature in C alpha 1 delta 100 B 1 alpha delta 1e 4 C 1 alpha beta 1e 8 The alpha beta and delta values are listed in Table F 10 Equation for 0 to 630 C temperature range Ro 1 AT BT where is the calculated resistance of RTD Rg is the known RTD resistance at 0 C T is the temperature in C alpha 1 delta 100 B 1 alpha delta 1e 4 The alpha and delta values are listed in Table F 10 Model 2701 User s Manual Temperature Equations F 9 RTD parameters for equations The RTD parameters for the Callendar Van Dusen equations are listed in Table F 10 Table F 10 RTD parameters Type Standard Alpha Beta Delta 34 at 0 PT100 ITS 90 0 00385055 0 10863 1 49990 10024 D100 ITS 90 0 003920 0 10630 1 49710 10024 F100 ITS 90 0 003900 0 11000 1
50. and CALC DATA will return the basic reading 3 FETCh CALC DATA and DATA do not trigger readings They simply return the last reading If you again send one of these commands before triggering a new reading the old reading will be returned 4 DATA FRESh can only be used once to return the same reading Sending it again without first triggering a new reading will cause error 230 data corrupt or stale 1 40 Getting Started Model 2701 User s Manual Figure 1 9 Exercise 5 Trigger and return multiple readings TRAC CLE INIT CONT OFF TRIG COUN 1 Set 2701 to perform x SAMP COUN x number of measurements x 2 to 450000 INIT Penne READ TRAC DATA 1 In order to trigger and return multiple readings the buffer must first be cleared of readings that were stored by the TRACe command or front panel operation see Section 6 for details on buffer operation 2 INIT triggers the measurements and FETCh returns the readings Again sending FETCh without first sending INIT will return old readings 3 READ performs an INIT to trigger the measurements and then FETCh to return the reading s Clear buffer Place 2701 in non continuous trigger state Trigger Configuration Trigger and Return Readings 3 Trigger and Return j Readings Return Stored Readings 4 Triggered readings are automatically stored in the buffer Statistics for buffer readings are also stored in the buffer CALC2 c
51. and then press ENTER Model 2701 User s Manual Remote Operations 10 31 The commands to select and configure the RS 232 interface are listed in Table 10 3 Table 10 3 SYSTem commands to configure RS 232 Command Description COMMunicate Ethernet and RS 232 serial commands SELect name Select communications mode SERial or ETHernet SERial RS 232 BAUD n Set baud rate 300 600 1200 2400 4800 9600 19200 38400 57600 or 115200 BAUD Query baud rate PACE lt name gt PACE TERMinator lt name gt TERMinator CONTrol RTS lt name gt RTS SEND data ENTer Control Xon Xoff flow control XON on or NONE off Query state of flow control Select output terminator CR LF CRLF or LFCR Query output terminator Control RTS CTS hardware handshaking Enable IBFull or RFR or disable OFF hardware handshaking Query state of hardware handshaking Send data serial port to another instrument Read data from serial port 10 32 Remote Operations Model 2701 User s Manual RS 232 connections The RS 232 serial port 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 ready to send RTS clear to send CTS and signal ground GND lines of the RS 232 standard Figure 10 11 shows the rear panel connector for the RS 232
52. b lt clist gt Enable or disable filter Note 4 STATe lt clist gt Query state of digital filter IDIVider lt b gt Enable or disable 1OMQ input divider OFF Sec 3 IDIVider Query state of input divider 15 10 SCPI Reference Tables Model 2701 User s Manual Table 15 5 continued SENSe command summary Default Command Description parameter Ref SCPI SENSe 1 VOLTage AC Path to configure AC voltage Sec 3 v APERture lt n gt lt clist gt Set integration rate in seconds Note 2 Sec 4 3 333333e 5 to 1 APERture lt clist gt Query aperture integration rate NPLCycles n lt clist gt Set integration rate in line cycles 60Hz 5 0 Sec 4 v 0 002 to 60 50Hz 0 002 to 50 NPLCycles lt clist gt Query line cycle integration rate v RANGe Path to set measurement range Sec 4 v UPPer n lt clist gt Select range 0 to 757 5 750 UPPer lt clist gt Query range AUTO lt b gt lt clist gt Enable or disable auto range ON AUTO lt clist gt Query state of auto range DIGits n lt clist gt Specify measurement resolution 4 to 7 6 Sec4 DIGits lt clist gt Query resolution REFerence n lt clist gt Specify reference 757 5 to 757 5 0 Sec 5 v STATe lt b gt lt clist gt Enable or disable reference OFF STATe lt clist gt Query state of reference ACQuire lt clis
53. channel 1 paired to channel 11 channel 2 paired to channel 12 and so on As shown in Figure 3 3C one DC voltage source is connected to a primary channel i e 104 and the other source is connected to its paired channel i e 114 NOTE The ratio and channel average calculations are covered in Section 5 Figure 3 3 DCV and ACV connections using Model 7700 switching module Caution Maximum input 300VDC or RMS 1A switched 60W 125VA maximum Model 7700 Switching DC Voltage Module Source A DCV Connections Model 7700 itchi AC Voltage Switching E Module B ACV Connections DC M odel 7700 DC Voltage _ Switching Voltage Source Module Source C Ratio and Channel Average Connections DCV Note Thelow connections for channels 1 through 10 do not need to be referenced to the low connections for channels 11 through 20 Model 2701 User s Manual Basic DMM Operation 3 11 Volts measurement procedure NOTE Make sure the INPUTS switch is in the correct position To use front panel inputs it must be in the F out position For switching modules it must be in the R in position 1 Ifa switching channel is presently closed displayed press OPEN to open it 2 Select the volts measurement function by pressing DCV or ACV 3 Use the RANGE and keys to select a measurement range consistent with the expected voltage or press AUTO to select autoranging AUTO annunciator turns on Deta
54. empty slot For the last half inch or so press in firmly to mate the module connector to the mainframe connector On each side of the module there is a mounting screw Tighten these two screws to secure the module to the mainframe Do not overtighten Reconnect the power line cable and any other cables to the rear panel When you turn on the Model 2701 the model number of the switching module will be briefly displayed Model 2701 User s Manual Connections WARNING WARNING WARNING WARNING Close Open Switching Module Channels 2 5 Connection information for switching modules is intended for qualified ser vice personnel Do not attempt to connect DUT or external circuitry to a switching module unless qualified to do so To prevent electric shock that could result in serious injury or death adhere to the following safety precautions Before making or breaking connections to the switching module make sure the Model 2701 is turned off and power is removed from all external circuitry Donotconnect signals that will exceed the maximum specifications of switching modules Each module is provided with its own unique specifications If both the front panel terminals and the switching module terminals are connected at the same time the test lead insulation must be rated to the highest voltage that is connected For example if 1000V is connected to the front panel input the test lead insulation for the switching module mu
55. the following command words select range and digits RANGe UPPer n Specify expected reading RANGe AUTO p Enable ON or disable OFF auto range DIGits Set display resolution 3 5 4 5 5 5 or 6 5 digits The following examples demonstrate how to include the function name in the command string for configuration commands VOLT RANG 10 Select 10V range for DCV RES RANG AUTO ON Enable auto range for CURR DIG 4 5 Set DCI for 4l5 digit resolution NOTE See Section 4 for details on setting range digits rate bandwidth and filter 1 30 Getting Started Exercise 1 Basic DMM measurements Model 2701 User s Manual The exercise in Table 1 6 measures ACV on the 10V range and stores 15 readings in the buffer Table 1 6 Exercise 1 Measure AC volts store readings in buffer Front panel operation Command sequence For front panel operation proceed to step 2 For remote programming clear the buffer 2 Restore defaults Press SHIFT gt press SETUP gt select RESTORE FACT 3 Select ACV function Press ACV 4 Select 10V range Press RANGE a to display RANGE 10V 6 Store 15 readings in buffer Press STORE set for 000015 RDGS press ENTER 7 Recall buffer readings Press RECALL gt use edit keys to display readings Press EXIT to exit recall mode TRAC CLE RST FUNC VOLT AC VOLT AC RANG 10 SAMP COUN 15 READ CALC1 DATA
56. 0 parameter value with the individual command to program the register NOTE SYSTem PRESet and RST have no effect on status structure registers and queues Table 11 1 Common and SCPI commands to reset registers and clear queues Commands Description Notes Reset registers CLS Reset all bits of the following event registers to 0 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 1 Operation Event Enable Register Measurement Event Enable Register Questionable Event Enable Register Clear error queue CLS Clear all messages from Error Queue 2 STATus QUEue CLEar Clear messages from Error Queue 3 SYSTem CLEar Clear messages from Error Queue 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 11 10 2 STATus PRESet has no effect on the Error Queue 3 Use either of the two clear commands to clear the Error Queue Model 2701 User s Manual Status Structure 11 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 pa
57. 1 101 or the highest available channel i e 220 Perform the following steps to configure a simple scan 1 While in the normal measurement mode set up the instrument for your test This setup will be used for all selected channels in the scan Press SHIFT and then CONFIG to access the scan setup menu Press the or key to display INT SIMPLE and press ENTER Set the minimum channel MIN CHAN for the scan and press ENTER Set the maximum channel MAX CHAN for the scan and press ENTER Enable YES or disable NO the timer and press ENTER See STEP and SCAN keys for details on timer operation AAR WN 7 14 Scanning Model 2701 User s Manual If you enabled the timer set the timer interval using the hour minute second for mat The timer can be set from 0 001 sec 00H 00M 00 0015 to 99 hrs 99 min 99 999 sec 99H 99M 99 999S Note that pressing the AUTO key sets the timer to 0 001 sec With the desired interval displayed press ENTER The displayed reading count RDG CNT sets the number of channels to scan STEP or the number of scans to run SCAN You can change the reading count to any finite value from 2 to 450000 or you can select infinite continuous scanning To select infinite set the reading count to 000000 to display INF See Trigger models page 7 4 for details on reading count With the desired reading count setting displayed press ENTER to return to the normal measurement display state
58. 1 101 is only valid if scan channel 101 is set for the ACV function 2 DC is optional for the commands to set DCV and DCI range Model 2701 User s Manual Range Digits Rate Bandwidth and Filter 4 5 Manual ranging The range is selected by specifying the expected reading as an absolute value using the n parameter for the appropriate RANGe command The Model 2701 will then go to the most sensitive range for that expected reading For example if you expect a reading of approximately 3V let the parameter n equal 3 to select the 10V range Auto ranging The RANGe AUTO command is coupled to the command to select range manually CRANGe lt n gt When auto range is enabled the parameter value for RANGe n changes to the automatically selected range value When auto range is disabled the instrument remains at the selected range When a valid RANGe n command is sent auto ranging disables Range programming examples NOTE The following examples can be run from the KE2700 Instrument Driver using the example named MultiRange in Table G 1 of Appendix G Example 1 The following commands select range for DCV 2 and DCI VOLT RANG 0 5 Select 1V range for DCV RES RANG 2e3 Select 10kQ range for 02 CURR RANG 0 1 Select 100mA range for DCI Example 2 The following command sequence configures channel 101 of the Model 7700 to select the 10VDC range when it is scanned FUNC VOLT 101
59. 1 continued Visual Basic and CVI C examples KE2700 Instrument Driver Examples G 5 Name Manual Reference Brief Description Advance6 None Use Case 6 Scan 160 channels using 7703 module see NOTE Type K thermocouple TC temperature measurements Reference junction Simulated Measurement speed rate 0 01 plc Filter Disabled no filtering Buffer Store 160 reading strings Buffer elements include reading and channel Triggering Bus control source Data retrieval Continuously store data into buffer Retrieve data for every 32 readings NOTE When using a module that has a built in cold junction use the Internal reference junction Keep in mind that the buffer and data retrieval will have to be modified to accommodate the number of scanned channels Modules that have cold junction include 7700 and 7706 modules 20 available TC channels 7708 module 40 available TC channels Advance7 None Use Case 7 Ten 40 channel scans using 7702 module Channel 1 uses an external reference junction Measurement speed rate 1 plc Filter Repeat 25 readings Channels 2 through 40 are connected to type K thermocouples Measurement speed rate 1 plc Filter Disabled no filtering Open thermocouple detection Enabled Buffer Store 400 reading strings Buffer elements include reading real time clock a
60. 2 The following command sequence configures channels 103 and 105 for the ratio and channel average calculations When channel 103 is scanned the ratio calculation is based on DCV measurements of channels 103 and 113 When channel 105 is scanned the channel average calculation is based on TEMP measurements of channels 105 and 115 NOTE The following example be run from the KE2700 Instrument Driver using the example named Ratio2 in Table G 1 of Appendix G FUNC VOLT 0103 Set 103 for DCV RAT ON 80103 Set 103 for ratio on FUNC TEMP 8105 Set 105 for TEMP CAV ON 8105 Set 105 for channel average on 5 20 Rel Math Ratio Channel Average dB Model 2701 User s Manual dB Expressing DC or AC voltage in dB makes it possible to compress a large range of measurements into a much smaller scope The relationship between dB and voltage is defined by the following equation V dB 20log Rum REF where Vy is the DC or AC input signal Veer is the specified voltage reference level The instrument will read OdB when the reference voltage level is applied to the input If a relative value is in effect when dB is selected the value is converted to dB then REL is applied to dB If REL is applied after dB has been selected dB has REL applied to it NOTE The dB calculation takes the absolute value of the ratio Vi Vpgp The largest negative value of dB is 160dB This will accommodate a ratio of dB confi
61. 2 while system commands for the RS 232 interface are provided in Table 10 3 NOTE The Model 2701 has an internal web page From this web page you can send commands to the 2701 and take readings See Internal web page for details Also supplied TestPoint Runtime start up software can be used to control the Model 2701 See Section 4 in the Model 2701 Instrument Networking Instruction Manual for details 10 4 Remote Operations Model 2701 User s Manual Password A user defined password can be used to disable protected commands Most Model 2701 commands are protected When the use of password is enabled there are commands to either disable or enable the protected commands At the factory the Model 2701 is assigned the following password name DEFAULT The password is case sensitive and must be enclosed in quotes as shown above NOTE From the front panel the password can be cleared When cleared the use of password is disabled and the password name resets to DEFAULT The password can be cleared using the SETUP menu as follows Press SHIFT Press SETUP Use the edit keys to display CLR PASSWORD N or Y where N no do not clear and Y yes clear Press ENTER The password commands are listed in Table 10 1 The password commands are used to perform the following operations Disable or enable the use of a password Disabling the use of a password enables all protected commands SYSTem PASSword ENABle OFF Disable passw
62. 2 FORMat and Misc SYSTem Commands Model 2701 User s Manual FORMat commands The commands in this subsystem Table 14 1 are used to select the elements for acquired readings and to select the data format for reading status event registers NOTE Details on the FORMat SREGister command are provided in Section 11 see Programming and reading registers Table 14 1 SCPI commands data format Command Description Default FORMat ELEMents item list Specify data elements READing UNITs TSTamp All RNUMber CHANnel LIMits FORMat SREGister lt name gt Select data format for reading status event registers ASCii ASCii HEXadecimal OCTal or BINary FORMat ELEMents lt item list gt Parameters READing reading UNITs Units TSTamp Timestamp RNUMber Reading number CHANnel Channel number LIMits Limits reading The specified elements are included in the data string in response to FETCh READ MEASure and TRACe DATA Note that each element in the item list must be separated by a comma i e send FORMat ELEMents READing UNITs TSTamp RNUMber CHANnel LIMits to include all elements in the data string The elements for the ASCii format are shown in Figure 14 1 An overflow reading is returned as 9 9E37 When a specified data element has invalid data associated with it NAN Not A Number will be the response NAN is returned as 9 9 37 Timestamp Timestamp references the ret
63. 20 channels of 4 pole input It also has two 2 pole channels used exclusively for current input Model 7703 This differential multiplexer provides 32 channels of 2 pole input or 16 channels of 4 pole input Getting Started Model 2701 User s Manual Model 7705 This control module provides 40 independent 1 pole switching SPST channels that are isolated from the internal DMM Model 7706 This all in one module provides 20 10 channels of 2 4 pole input 16 digital outputs two analog outputs and one 32 bit counter with gating and totalizer Model 7707 This module provides 10 channels of 2 pole input or 5 channels of 4 pole input Also provides four independent 8 byte digital I O channels Model 7708 This differential multiplexer provides 40 channels of 2 pole input or 20 channels of 4 pole input The internal cold junction allows direct connection of thermocouples for temperature measurements Model 7709 This module is configured as a 6 x 8 matrix six rows eight columns The matrix consists of 48 crosspoint channels and two backplane isolation channels For system channel operation row 1 8 channels is connected to DMM Input For 4 wire measurements rows 1 and 2 4 system channels are connected to the DMM Model 7710 This differential multiplexer provides 20 channels of 2 pole input or 10 channels of 4 pole input The internal cold junction allows direct connection of thermocouples for temperature measure
64. 24 and 25 you will isolate the input signal from the DMM of Model 2701 Multiple channel operation allows any channel or channels in the test system to be closed or opened It allows more than one measurement channel to be closed at the same time It also allows individual control of non measurement channels such as backplane isolation channels Multiple channel operation should only be performed by experienced test system engineers WARNING Careless multiple channel operation could create an electric shock hazard that could result in severe injury or death Improper operation can also cause damage to the switching modules and external circuitry Multiple channel operation should be restricted to experienced test engineers who recognize the dangers associated with multiple channel closures NOTE Multiple channel operation cannot be used to perform thermocouple temperature measurements using the internal or external reference junction The simulated reference junction will instead be used and the integrity of the temperature reading will be questionable ERR annunciator turns on See Temperature measurements page 3 33 for details Some other key points for multiple channel operation include the following Closing a channel using multiple channel operation has no affect on other closed channels Whatever channels were previously closed remain closed Achannel closed using multiple channel operation is not displayed on the Mod
65. 30 seconds Do not attempt to communicate with the Model 2701 during this time period Turn on the Model 2701 by pressing in the front panel POWER button While booting up the following messages will be briefly displayed LOADING FPGA LOADING MAIN If Ethernet is the presently selected interface the following will be displayed for 10 to 15 seconds LOAD ETHRNET 1 18 Getting Started Model 2701 User s Manual The instrument then briefly displays all display characters and annunciators and performs self tests If all self tests pass the firmware revision levels are displayed An example of this display is REV A01 A01 where First AOI is the main board ROM revision Second 01 is the display board ROM revision If Ethernet is the presently selected interface the IP address will be displayed briefly Example ETHERNET 192 168 000 002 If RS 232 is the presently selected interface the baud rate will be displayed briefly RS 232 MODE BAUD 9600 Installed switching modules are then displayed For example if there is a Model 7700 switching module installed in both slots the following messages will be displayed 1 7700 2 7700 If a slot is empty the message NONE will be displayed instead If the saved power on setup is not the factory defaults setup SYSTem POSetup PRESet a message to identify the setup will be briefly displayed Defaults and user setups page 1 21 After the power up sequence t
66. 4 22 Hold 8 6 Limits and digital outputs programming example 9 14 Math programming examples 5 14 Multiple channel remote programming example 2 21 Program and read register set programming example 11 19 Range programming examples 4 5 Rate and bandwidth programming examples 4 13 Ratio and channel average programming examples 5 19 Read error queue 11 23 Rel programming examples 5 6 Scanning 7 32 Scanning programming example 7 32 Set MSS B6 when error occurs 11 10 Sytem channel remote programming example 2 14 Triggering programming example 8 20 EXT TRIG input 8 8 External triggering 8 7 Example 8 11 With BNC connections 8 14 Features Model 2701 1 6 Filter 4 14 RST disables filter 4 18 RST disables filter state to off 4 21 Characteristics 4 14 Commands 4 20 Control and configuration 4 18 Count 4 14 Example 4 16 Filter channel 4 19 Moving and repeating 4 15 4 17 Programming examples 4 22 Remote programming 4 20 Scanning 4 19 Type 4 14 Window 4 15 FILTER key 4 18 FORMat commands 14 2 FORMat ELEMents lt item list gt 14 2 Summary 15 6 FREQ and PERIOD connections for front panel inputs 3 47 Frequency and period measurements 3 46 Connections 3 47 Front panel input 3 47 Model 7700 switching module 3 47 Gate time 3 46 Procedure 3 48 Trigger level 3 46 Front panel Buffer 6 2 Inputs 1 13 1 29 Summary 1 10 Trigger model 8 2 Fuse Ratings 1 17 Replacing 1 16 Gate time 3 46 General bus commands 10 15
67. 4 6 Filter commands Commands Description Default DCY filter commands SENSe 1 Optional root command VOLTage DC AVERage TCONtrol name Select filter type lt name gt MOVing or Note 2 REPeat VOLTage DC AVERage WINDow lt NRf gt Set filter window in NRf 20to10 01 VOLTage DC AVERage COUNt n clist Specify filter count n 1 to 100 10 VOLTage DC AVERage STATe lt b gt clist Enable or disable the filter Note 3 filter commands SENSe 1 Optional root command VOLTage AC AVERage TCONtrol lt name gt Select filter type lt name gt MOVing or Note 2 REPeat VOLTage AC AVERage WINDow lt NRf gt Set filter window in lt NRf gt 0to 10 01 VOLTage AC AVERage COUNt n clist Specify filter count n 1 to 100 10 VOLTage AC AVERage STATe lt b gt clist Enable or disable the filter Note 3 DCI filter commands SENSe 1 Optional root command CURRent DC AVERage TCONtrol lt name gt Select filter type lt name gt MOVing or Note 2 REPeat CURRent DC AVERage WINDow lt NRf gt Set filter window in NRf 20to 10 0 1 CURRent DC AVERage COUNt n Specify filter count n 1 to 100 10 clist CURRent DC AVERage STATe lt b gt clist Enable or disable the filter Note 3 ACI filter commands SENSe 1 Optional root command CURRent AC AVERage TCONtrol lt name gt Select filter type lt name gt MOVing or Note 2 REPe
68. 702 05 x 107 2 121 69 10718 1 172 72 x 1079 5 392 80 x 10724 7 981 56 x 107 0 03 C to 0 02 C 1 972 485 x 10 3 300 943 x 107 3 915 159 x 107 9 855 391 x 10 1 274 371 x 10 16 7 767 022 x 10 22 0 02 C to 0 04 C too Co t c4E c4E dee c E where tog is the calculated temperature in C E is the measured voltage in microvolts Temperature Equations F 5 Model 2701 User s Manual Table F 6 Type R inverse function polynomial 50 C to 250 C 226uV to 1 9234 V 250 C to 1 200 C 1 923uV to 13 228u V 1 064 C to 1 664 5 C 11 361uV to 19 7394 V 1 664 5 C to 1 768 1 C 19 739uV to 21 1030 V Co Co C5 C6 c Cg Co C10 Error 0 0 1 889 138 0 x 107 9 383 529 0 x 10 1 306 861 9 x 107 2 270 358 0 x 10710 3 514 565 9 x 10 3 895 390 0 x 10716 2 823 947 1 x 10 1 1 260 728 1 x 107 3 135 361 1 x 10726 3 318 776 9 x 10730 0 02 C to 0 02 C 1 334 584 505 10 1 472 644 573 10 1 844 024 844 x 10 4 031 129 726 x 10 6 249 428 360 x 10713 6 468 412 046 x 107 4 458 750 426 x 10 1 994 710 149 x 1025 5 313 401 790 x 10730 6 481 976 217 x 105 0 005 C to 0 005 C 8 199 599 416 x 10 1 553 962 042 107 8 342 197 663 x 106 4 279 433 549 x 10 19 1 191 577 910 x 10 14 1 492 290 091 x 107 0 001 C to 0 0005 C 3 406 177 836 x 104 7 023 729 171 5 582 903 813
69. 7700 pseudocard in slot 2 Pseudocards for other switching modules can instead be installed Details on installing other pseudocards are provided in Section 2 There are SCPI commands to query the capabilities of the installed switching modules For example the following queries are provided to determine which channels of a Model 7700 in slot 1 are available for volts 2 wire ohms and which channels are available for amps Note that the returned values for the Model 7700 switching module are shown in parenthesis SYSTem CARD1 VCHannel STARt SYSTem CARD1 VCHannel END SYSTem CARD1 ACHannel STARt SYSTem CARD1 ACHannel END Query first volt 22 channel 7700 1 Query last volt Q2 channel 7700 20 Query first amps channel 7700 21 Query last amps channel 7700 22 All the commands to query switching module capabilities are covered in Table 15 7 Model 2701 User s Manual Scanning 7 3 Channel assignments A switching module has a certain number of channels For example the Model 7700 switching module has 22 channels 1 through 22 When you encounter a 1 or 2 digit channel number in this manual the switching module channel is the point of discussion A switching module can be installed in one of two slots of the mainframe Therefore to close open or scan a channel it is necessary to specify the slot location and channel number of the switching module This is accomplished by using a 3 digit chan
70. Available amp Logical AND OR Logical OR 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 Status Byte Register Model 2701 User s Manual Status Structure 11 9 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 Bl Not used e Bit B2 Error Available EAV Set summary bit indicates that an error or status message is present in the Error Queue e 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 message is present in the Output Queue Bit B5 Event Summary Bit ESB Set summary bit indicates that an enabled standard event has occurred Bit B6 Master Summary Status MSS Set bit indicates that an enabled summary bit of the Status Byte Register is set Bit B7 Operation Summary OSB Set summary bit indicates that an e
71. BUS or EXTernal TRIGger TIMer n Set timer interval 0 to 999999 999 sec 0 1 TRIGger COUNt lt NRf gt Set trigger count 1 to 450000 or INFinity Note 2 TRIGger DELay n Set delay 0 to 999999 999 sec 0 TRIGger DELay AUTO b Enable or disable auto delay TRIGger SIGNal Loop around control source g SAMPIe COUNt lt NRf gt Set sample count 1 to 450000 1 h SENSe 1 Optional root command for HOLD commands i HOLD WINDow lt NRf gt Set Hold window in 96 lt NRf gt 0 01 to 20 1 HOLD COUNt lt NRf gt Set Hold count lt NRf gt 2 to 100 5 HOLD STATe lt b gt Enable or disable Hold OFF SYSTem BEEPer STATe lt b gt Enable or disable the beeper ON RST Restore RST defaults see Default column of this table Places 2701 in the idle state Notes 1 SYSTem PRESet enables continuous initiation RST disables continuous initiation 2 SYSTem PRESet sets the trigger count to INF infinity RST sets the count to 1 6 20 Triggering Model 2701 User s Manual Reference a ABORt With continuous initiation disabled the 2701 goes into the idle state With continuous initiation enabled operation continues at the top of the trigger model INITiate Whenever the instrument is operating within the trigger model sending this command causes an error and will be ignored INITiate CONTinuous b With continuous initiation enabled you cannot use the READ command or set sample
72. COUN 10 Set to scan 10 channels ROUT SCAN 101 110 Set scan list channels 101 through 110 ROUT SCAN TSO IMM Start scan when enabled and triggered ROUT SCAN LSEL INT Enable scan READ Trigger scan and request the readings Scanning examples The following scanning examples assume that the Model 7700 switching module is installed in slot 1 of the mainframe Tables are used for the procedure steps to configure and run scan examples The left side of the table provides the front panel procedure while the right side shows the equivalent remote programming commands Where appropriate menu sequences are provided to summarize a front panel operation or selection For example SHIFT SETUP RESTORE FACT For the above menu sequence press SHIFT and then SETUP to access the menu Use the edit keys 4 and to display RESTORE FACT and then press ENTER to select it External trigger scan For this example an external instrument is used to trigger the start of the 2 channel scan Trigger pulse requirements and trigger cable connections are covered in Section 8 NOTE For this example the front panel TRIG key can be used in place of an external input trigger Each time the TRIG key is pressed the 2 channel scan will run One channel 101 measures temperature and the other channel 102 measures resistance The two readings are stored in the buffer Each time the scan is run the two readings will be appended adde
73. COUN to 1 The trigger count spec ifies the number of scans to be performed 2 ROUT SCAN LSEL INT enables the scan and INIT trigger the start of the scan 1 38 Getting Started Model 2701 User s Manual Trigger and return readings remote programming There are several commands used to trigger and return readings The proper commands and sequence to use depend on the trigger state continuous or non continuous and what you are trying to accomplish Presented here are three fundamental command sequences that can be used to trigger and return readings These three command sequences exercises will accommodate most basic measurement scenarios Simply use the command sequence exercise that satisfies your needs e Exercise 4 Trigger and return a single reading e Exercise 5 Trigger and return multiple readings Exercise 6 Return a single reading continuous triggering Details on the commands to trigger and return readings are provided in other sections of this manual For details refer to the following sections Section 3 See Trigger and retrieve readings in Table 3 7 Section 7 For scanning see Trigger commands in Table 7 1 Section 8 Explains the triggering process Section 13 Covers Signal Oriented Measurement Commands i e FETCh READ Section 15 See Table 15 9 Trigger command summary Appendix D Shows how trigger and read commands control data flow wit
74. D converter The A D Conversion Process measures the DC signal voltage and internal voltages that correspond to offsets zero and amplifier gains For TC temperature measurements using a switching module that has an internal reference junction i e Model 7700 the internal temperature is also measured These measurements are used in an algorithm to accurately calculate the reading of the input signal The voltage current resistance frequency or period or temperature reading is then displayed by the Model 2701 NOTE The multiple measurement process used by the A D converter is known as autozeroing It can be disabled to increase speed only the signal is measured However stability and accuracy will be affected over time and changes in temperature Figure D 1 Basic signal processing Input Signal Signal Conditioning A D Conversion Process Display Reading Model 2701 User s Manual Signal Processing Sequence and Data Flow D 3 Signal processing using instrument features Figure D 2 shows the processing sequence for an input signal with various instrument features enabled If a feature is not enabled the reading simply falls through to the next enabled feature or to the display Figure D 2 Signal processing using instrument features Input Signal Signal Conditioning H A D Conversion Process OComp OComp reading AV AI O utput trigger pulse VM C Rel
75. DCI or ICI is selected If an amps function DCI or ACT is selected and you attempt to close a system channel the message NO AMPS CHAN will be displayed briefly For remote programming error 222 Parameter data out of range is generated Example SYST PRES Restores system preset defaults SENS FUNC CURR DC Selects DCI function ROUT CLOS 101 Attempts to close system channel 101 Generates error 222 If a system channel is already closed and you attempt to select the DCI or ACI function the message INVALID FUNC will be displayed briefly For remote programming error 221 Settings conflict is generated Example SYST PRES Restores system preset defaults ROUT CLOS 9101 Close system channel 101 SENS FUNC CURR DC Attempts to select DCI function Generates error 221 Model 2701 User s Manual Close Open Switching Module Channels 2 15 Making amps measurements In order to perform amps measurements you must use the front panel inputs of the 2701 mainframe You can still use the non amps module for other aspects of the test but you must use multiple channel operation to close channels Example NOTE _ Inorder to use the front panel inputs make sure the INPUT switch is in the out F position SYST PRES Restores system preset defaults ROUT MULT CLOS 101 Closes channel 101 SENS FUNC CURR DC Selects DCI function Legal operation Non measure switchi
76. EE EE EE EE EE EE EE EE EE EE EE EE EE EE EE EE EE EE EE EE EE EE EE EE EE EE EE EE EE Model 2701 User s Manual Table C 1 continued Status and error messages Status and Error Messages Number Description Event 158 String data not allowed EE 154 String too long EE 151 Invalid string data EE 150 String data error EE 148 Character data not allowed EE 144 Character data too long EE 141 Invalid character data EE 140 Character data error EE 128 Numeric data not allowed EE 124 Too many digits EE 123 Exponent too large EE 121 Invalid character in number EE 120 Numeric data error EE 114 Header suffix out of range EE 113 Undefined header EE 112 Program mnemonic too long EE 111 Header separator error EE 110 Command header error EE 109 Missing parameter EE 108 Parameter not allowed EE 105 GET not allowed EE 104 Data type error EE 103 Invalid separator EE 102 Syntax error EE 101 Invalid character EE 100 Command error EE 000 No error SE C 3 C 4 Status and Error Messages Table C 1 continued Status and error messages Model 2701 User s Manual Number Description Event 101 121 122 123 124 125 126 161 171 174 180 301 302 303 304 305 306 307 308 309 310 311 312 313 314 Operation complete Device calibrating Device settling Device ranging Device sweeping Device measuring Device c
77. Immediate The count values of the Trigger Model are set to one The delay of the Trigger Model is set to zero The Model 2701 is placed in the idle state e math calculations are disabled Buffer operation is disabled A storage operation presently in process will be aborted e Autozero is enabled Programming examples Programming example 1 The following command configures scan list channels 101 through 105 for 4 wire resistance measurements on the IMQ range CONF FRES 1e6 101 105 Programming example 2 The following command selects the DCV function 10V range 3 2 digit resolution and performs the no lt clist gt CONFigure operations CONF VOLT 10 3 5 13 6 SCPI Signal Oriented Commands Model 2701 User s Manual FETCh Description This command requests the latest post processed reading After sending this command and addressing the Model 2701 to talk the reading is sent to the computer This command does not affect the instrument setup This command does not trigger a measurement The command simply requests the last available reading FETCh can also be used to return more than one reading When returning more than one reading the readings are automatically stored in the buffer In order to return multiple reading strings continuous initiation must be disabled INIT CONT OFF so that the sample count SAMPle COUNt which specifies the number of measurements to be performed can
78. Ls 4 3 AUTO EE 4 3 fo Taie R 4 3 Remote programming range seen 4 4 EE 4 6 SCannlrid 5t tdem eed te te a eed e eet 4 6 Remote programming digits 4 6 Rate and bandwidth eiae testo ed titre prre recte na 4 8 nct IEEE 4 8 Bandwidth reet meer tete re er t e Ee EINER 4 10 SCANNING epe EE 4 10 Remote programming rate and 4 11 ale H 4 14 Filter characteristics eacoir ana EA A AEA ETER 4 14 Remote programming filter ee 4 20 5 Relative Math Ratio Channel Average and dB 5 1 EIL 5 2 Document Number 2701 900 01 Rev F August 2011 iii Table of Contents Model 2701 Ethernet Based DMM Data Acquisition System Basic operatlOn tere dt cere re itte eyes 5 2 Remote programming 5 4 tree tee esie hand sebo 5 7 ITDCED x decedat eee xy ee aes wea ey ae iin OA ue uou ene 5 8 PON CON iis iit niti eere oie gei M Re ERU san dias ESI E 5 9 Reciprocall 1 X oret e ten gece eet cepe te eta 5 10 e er RR P RR ER RD 5 11 Remote programming math sese 5 12 Ratio and channel average 5 15 Basic operatilOn Ete epp ER ERE ei EP en EE
79. MUX Support multiplexer channels 1 yes 0 no ISOLated Support isolated channels 1 yes 0 no Model 2701 User s Manual SCPI Reference Tables 15 21 Table 15 7 continued SYSTem command summary Default Command Description parameter Ref SCPI SYSTem CARDX TCOMpensated Built in temperature sensors for T C cold junction 1 yes 0 no VCHannel Path to query volts 2 wire channels STARt Request lowest numbered volts 2 wire channel usually 1 0 voltage measurements not supported END Request highest numbered volts 2 wire channel 0 voltage measurements not supported ACHannel Path to query amps channels STARt Request lowest numbered amps channel 0 amps measurements not supported END Request highest numbered amps channel 0 amps measurements not supported CHannel Path to query isolated channels An isolated channel includes 2 4 pole and backplane relays STARt Request the first isolated channel 0 no isolated channels END Request the last isolated channel 0 no isolated channels AOUTput Path to query analog output channels STARt Request highest numbered analog output channel 0 analog output not supported END Request lowest numbered analog output channel 0 analog output not supported DOUTput Path to query digital output channels STARt Request lowest numbered digital output channel 0 digital output not supporte
80. Manual Table G 2 continued LabVIEW examples Manual Name Reference Brief Description Advance8 None Use Case 8 7706 module in slot 1 and 7702 module in slot 2 7706 module Output analog output values to analog output channels Output digital output values to digital output channels 7702 module Scan 120 DCV channels Measurement speed rate 1 plc Filter Disabled no filtering e Math mX b m 0 555 b 17 778 Limits Limit 1 all channels 100 Limit 2 180 Buffer Store 320 reading strings Buffer elements include reading channel and limit code Triggering Bus control source trigger delay 0 125 seconds Data retrieval SRQ when buffer 4 1 2 34 and full Simplel None Use Case 1 30 channel scan using 7708 module 30 channels DCV 10V range 10 channels type T thermocouple temperature Measurement speed rate 1 plc Filter Disabled no filtering Buffer Store 120 reading strings Buffer elements include reading only Triggering Bus control source Simple2 None Use Case 2 40 channel scan using 7708 module 30 channels DCV 15 on 100mV range 15 on 10V range 9 channels ACV 1V range e 1 channel 4 wire RTD temperature Measurement speed rate 1 plc Filter Disabled no filtering Buffer Store 120 reading strings Buffer elements include reading only Trig
81. Measurement methods 3 25 Constant current 3 26 Effects of open test leads 3 30 Ratiometric 3 28 Offset compensated ohms 3 24 3 25 3 26 3 28 3 30 3 32 Resistors Sorting 9 14 Response messages 10 27 Multiple 10 27 Sending 10 27 Terminator RMT 10 27 RJ 45 connector 10 10 RS 232 Connections 10 32 Connector 1 14 RS 232 interface Baud rate 10 28 Connector 10 32 Operation 10 28 Selecting and configuring 10 30 Sending and receiving data 10 28 Signal handshaking flow control 10 29 Terminator 10 30 RTD equation F 8 Safety precautions High energy circuits 3 3 Safety symbols and terms 1 2 SCAN 7 17 Operation overview 7 7 Scan Advanced 7 14 Commands 7 27 Scanning 5 17 7 1 Advanced 7 14 Advanced scan setup procedure 7 16 Allowed settings per channel 7 2 Auto scan 7 21 Basic scan 7 22 Buffer 7 22 Configuration 7 11 dB 5 20 Digital outputs 9 11 Digits 4 6 Examples 7 32 External trigger scan example 7 32 Filter 4 19 Fundamentals 7 2 Limits 9 4 Manual external trigger scan 7 23 Math 5 11 Monitor scan 7 35 Monitor scan analog trigger 7 24 Operation 7 21 Process 7 4 Range 4 3 Rate and bandwidth 4 10 Ratio and channel average 5 17 Relative 5 3 Remote programming 7 26 Remote programming example 7 32 Reset 7 13 Resume scan after power up 7 21 Sequential and non sequential 7 3 Simple 1 35 7 13 SCPI commands see FORMat commands SCPI reference tables SCPI signal oriented measurement commands an
82. Model 2701 User s Manual Table 7 1 Scanning commands Commands Description Default Ref Scan commands ROUTe SCAN lt clist gt Specify list of channels to be scanned a ROUTe SCAN Returns list of channels to be scanned ROUTe SCAN TSOurce lt list gt Select trigger s to start scan lt list gt IMMediate or IMM b HLIMitl LLIMitl HLIMit2 LLIMit2 ROUTe SCAN NVOLatile b Enable or disable auto scan b ON or OFF Note 1 ROUTe SCAN LSELect lt name gt Enable disable scan lt name gt INTernal or NONE NONE off ROUTe MONitor lt clist gt Specify one channel to be monitored c ROUTe MONitor POINts lt NRf gt Specify number of channels to scan lt NRf gt 2 to Note 3 450000 ROUTe MONitor STATe b Enable disable monitor b ON or OFF OFF ROUTe MONitor DATA Returns the most recent monitor reading ROUTe CLOSe ACONfigure b Enable or disable auto channel configuration Limits commands CALCulate3 LIMit UPPer n Set high limit 1 for monitor n 4294967295 to 1 0 14294967295 CALCulate3 LIMit1 LOWer n Set low limit 1 for monitor n 4294967295 to 1 0 14294967295 CALCulate3 LIMit2 UPPer n Set high limit 2 for monitor n 4294967295 to 2 0 14294967295 CALCulate3 LIMit2 LOWer n Set low limit 2 for monitor n 4294967295 to 2 0 14294967295 CALCulate3 LIMit1 STATe lt b gt Enable disable limit 1 test b ON or OFF OFF
83. O AMPS O LO o Model 2701 User s Manual Channel 25 See N ote Backplane Isolation O O O Input O O o LO Channel 24 See Note Backplane Isolation O HI Sense Model 2701 o 0 0L0 Backplane AMPS Notes Channels 23 and 25 in this schematic refer to the designations used for control and are not actual available measurement channels If the module is not to be internally connected to the DMM channels 24 and 25 can be opened using multiple channel operation Basic DMM Operation DMM measurement capabilities Summarizes the measurement capabilities of the Model 2701 and covers maximum signal levels for switching modules High energy circuit safety precautions Provides safety information when performing measurements in high energy circuits Performance considerations Covers some considerations that affect overall performance including warm up autozero and line synchronization Channel list parameter lt clist gt Summarizes the use of the lt clist gt parameter which is used throughout this manual to configure scan channels Voltage measurements DCV and ACV Provides detailed information for making basic DC and AC voltage measurements Current measurements DCI and ACI Provides detailed information for making basic DC and AC current measurements Resistance measurements Provides detailed information for making resistance measurements
84. O Model 2701 User s Manual Remote Operations Operation enhancements Summarizes some of the more important operations that can only be performed using remote operation System commands Summarizes the commands used to select and configure an interface for remote programming Also covers other system commands that pertain to remote operation Ethernet setup Shows some typical Ehternet systems covers connections and explains how to select and configure the Ethernet Front panel aspects of Ethernet operation Summarizes 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 2701 10 2 Remote Operations Model 2701 User s Manual Operation enhancements There are some operations you can do over the Ethernet and RS 232 interface that you cannot do from the front panel The more important ones are summarized below Pseudocards Using remote operation you can assign a pseudocard to an empty switching module slot With a pseudocard installed the Model 2701 will operate as if the switching module is installed in the Model 2701 This feature allows you to configure your system without having the actual switching module installed in the unit There is a pseudocard for every Keithley Model 7700 series switching module A single SCP
85. ON or OFF OFF lt clist gt VOLTage DC REFerence ACQuire lt clist gt Use input signal as rel value Rel commands for ACV SENSe 1 Optional root command VOLTage AC REFerence lt n gt lt clist gt Specify rel value lt n gt 757 5 to 757 5 0 V VOLTage AC REFerence STATe lt b gt Enable disable rel lt b gt ON or OFF OFF lt clist gt VOLTage AC REFerence ACQuire lt clist gt Use input signal as rel value Rel commands for DCI SENSe 1 Optional root command CURRent DC REFerence n lt clist gt Specify rel value n 3 1 to 3 1 A 0 CURRent DC REFerence STATe lt b gt Enable disable rel b 2 ON or OFF OFF lt clist gt CURRent DC REFerence ACQuire clist Use input signal as rel value Rel commands for ACI SENSe 1 Optional root command CURRent AC REFerence n lt clist gt Specify rel value lt n gt 3 1 to 3 1 A 0 CURRent AC REFerence STATe lt b gt Enable disable rel b ON or OFF OFF lt clist gt CURRent AC REFerence ACQuire lt clist gt Use input signal as rel value Model 2701 User s Manual Rel Math Ratio Channel Average dB 5 5 Table 5 1 continued Rel commands Commands Description Default Rel commands for Q2 SENSe 1 Optional root command RESistance REFerence lt n gt lt clist gt Specify rel value n 0 to 120e6 Q 0 RESistance REFeren
86. Peak Peak to Peak Value No Time No Date Min At XX Minimum Value Time Date Max At XX Maximum Value Time Date Buffer statistics 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 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 where yis the average X is a stored reading n is the number of stored readings 6 8 Buffer Model 2701 User s Manual Standard deviation This mode displays the standard deviation of buffered readings The following equation is used to calculate standard deviation n n 2 22 X 11 i n 1l 1 1 n 1 where y is the standard deviation X is a stored reading n is the number of stored readings NOTE Ifthe standard deviation calculation is being performed on a buffer that has more than 1000 readings the CALCULATING message will flash to indicate that the Model 2701 is busy While busy with the calculation front panel keys will not operate It will take approximately five seconds to calculate standard deviation on 450 000 readings Remote programming buffer NOTE When readings are stored in the buffer by the TRACe command or by front panel data store operatio
87. Read the event register Note 2 NDN or lt NRf gt Program the enable register Note 3 v 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 v NEXT Read the most recent error message Note 4 v ENABle lt list gt Specify error and status messages for Note 5 v queue ENABle Read the enabled messages v DISable lt list gt Specify messages not to be placed in Note 5 queue DISable Read the disabled messages CLEar Clears all messages from Error Queue Notes 1 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 of the registers STATus PRESet No effect Enable Registers Error Queue Power up and STATus PRESet Clears all bits of the registers CLS No effect Power up and CLS Clears the Error Queue STATus PRESet No effect Enable Disable Error Queue Messages The format for the response message decimal hexadecimal octal or binary is set by the FORMat SREGister command Power up Clears list of messages CLS and STATus PRESet No effect 15 20 SCPI Reference Tables Model 2701 User s Manual Table 15 7 SYSTem command summary Default Command Desc
88. Request URQ Set bit indicates that the LOCAL key on the Model 2701 front panel was pressed Bit B7 Power On PON Set bit indicates that the Model 2701 has been turned off and turned back on since the last time this register has been read Model 2701 User s Manual Status Structure 11 13 Operation event register The bits of the Operation Event Register Figure 11 5 are described as follows Bits BO through B3 Not used Bit B4 Measuring Meas Set bit indicates that the instrument is performing a measurement Bit B5 Waiting for Trigger Trig Set bit indicates that the Model 2701 is in the trigger layer waiting for a trigger event to occur Bits B6 and B7 Not used Bits B8 Filter Settled Filt Set bit indicates that the filter has settled or the filter is disabled Bit B9 Not used Bit B10 Idle State Idle Set bit indicates the Model 2701 is in the idle state Bits B11 through B15 Not used Figure 11 5 Operation event status O peration Condition Register O peration Event Register panon O peration Bit O S8 of E Idle Filt Trig Meas EE Status Byte B15 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 BO Register Register Idle Idle state amp Logical AND Filt Filter Settled or Disabled OR Logical OR Trig Triggering Meas Measuring 11 14 Status Structure Model 2701 User s Manual
89. Select DCV for channel 101 VOLT REF 1 8101 Set 1V rel value VOLT REF STAT ON 8101 Enable rel Model 2701 User s Manual Rel Math Ratio Channel Average dB 5 7 Math Example 3 The following command sequence configures channel 101 of the Model 7700 to zero correct the DCV input when it is scanned NOTE The following example can be run from the KE2700 Instrument Driver using the example named Relative3 in Table G 1 of Appendix G FUNC VOLT 80101 ROUT CLOS 6101 VOLT REF ACQ 80101 VOLT REF STAT ON 0101 Select DCV for channel 101 Close channel 101 Use input to channel 101 as rel value Enable rel The Model 2701 has three built in math calculations that are accessed from the MATH menu mX b percent and reciprocal 1 X Figure 5 1 shows the MATH menu tree Note that the settings shown in the menu tree are the factory defaults NOTE The various instrument operations including Math are performed on the input signal in a sequential manner See Signal processing sequence page D 2 for details It includes flowcharts showing where in the processing sequence that the Math operation is performed Figure 5 1 MATH menu tree SHIFT PERCENT REF 41 000000 1 X M 1 000000 B 00 00000 m UNITS X NOTE A Math operation can be used with the ratio and channel average calculation The ratio or channel average reading will be used in the calculation for the selected math functio
90. Table 15 6 STATus command summary Table 15 7 SYSTem command summary Table 15 8 TRACe command summary Table 15 9 Trigger command summary Table 15 10 UNIT command summary General notes e 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 are used to indicate parameter type Do not use angle brackets in the program message The Boolean parameter lt b gt is used to enable or disable an instrument operation 1 or ON enables the operation and 0 or OFF disables the operation e Upper case characters indicate the short form version for each command word Default Parameter Listed parameters are both the RST and SYSTem PRESet defaults unless noted otherwise Parameter notes are located at the end of each table Ref The reference column indicates where to find detailed information on the command s e SCPI A checkmark v indicates that the command and its parameters are SCPI confirmed An unmarked command indicates that it is an SCPI command but does not conform to the SCPI standard set of commands It is not a recognized command by the SCPI consortium SCPI confirmed commands that use one or more non SCPI parameters are explained by notes Model 2701 User s Manual SCPI Reference Tables 15 3 Table 15 1 CALCulate command summary Default Com
91. The BNC cables are labeled VMC trigger line 1 and EXT TRIG trigger line 2 Figure 8 9 shows how a Keithley Model 220 Current Source can be connected to the Trigger Link of the Model 2701 using the adapter cable When used with the STEP mode of the Model 220 you can perform synchronized source measure operations without the use of a computer Whenever the Model 220 receives a trigger from the Model 2701 it will step to the next current source value Model 2701 User s Manual Triggering 8 15 Figure 8 9 DIN to BNC trigger cable Model 220 Current Source 8503 DIN to Trigger Cable External Trigger Link x oP ERATOR SERVICABLE PARTS SERVICE BY QUALIFIED PERSONNEL ONLY RT DES KEITHLEY MADE MA eame DIGITAL TRIGGER ETHERNET EXT TRIG LINK 10 100 BaseT Lr 3B KEITHLEY SLOT COVER CAUTION roR CONTINUED PROTECTION AGAINST FIRE HAZARD REPLACE FUSE WITH SAME TYPE AND RATING Model 2701 8 16 Triggering Model 2701 User s Manual Remote programming triggering Trigger model remote operation The following paragraphs describe how the Model 2701 operates for remote operation The flow chart in Figure 8 10 summarizes operation over the bus The flow chart is called the trigger model because operation is controlled by SCPI commands from the Trigger subsystem Key SCPI commands are included in the trigger model Idle and initia
92. Thermocouple Copper wire to thermocouple wire connection one of two Ice Bath A Simulated reference junction front panel inputs Model 7700 Switching Module Copper wires Thermocouple Copper wire to thermocouple wire connection one of two Ice Bath B Simulated reference junction Model 7700 Model 7700 Switching Module EN Model 7700 O Switching Module Thermocouple Thermocouple D Channel average calculation internal reference junction Model 7700 3 40 Basic DMM Operation Model 2701 User s Manual Table 3 2 Color codes thermocouple wires T C type Positive Negative T C type Positive Negative J U S White Red E U S Purple Red British Yellow Blue British Blue DIN Red Blue DIN Red Black Japanese Red White Japanese Red White French Yellow Black French Yellow Blue U S Yellow Red U S Black Red British Brown Blue British White Blue DIN Red Green DIN Red White Japanese Red White Japanese Red White French Yellow Purple French Yellow Green N U S Orange Red S U S Black Red British British White Blue DIN DIN Red White Japanese Japanese Red White French French Yellow Green T U S Blue Red B U S Gray Red British White Blue Brtish DIN Red Brown DIN Red Gray Japanese Red White Japanese Red Gray French Yellow
93. User s Manual Channel setup The clist parameter is used to set up scan channels For example the following examples show how to set up scan channel 101 FUNC VOLT 9101 Set VOLT RANG 10 9101 Set VOLT DIG 4 5 0101 Set Set VOLT NPLC 3 9101 NOTE Buffer 101 101 101 101 Scanning 7 27 for DCV for 10V range for 4 digit resolution rate for 3 PLC In the above command sequence channel 101 is first set for DCV before sending the other commands to set range digits and rate If channel 101 was instead set to a different function i e RESistance the VOLT commands to set range digits and rate would generate error 700 Invalid function in scanlist For front panel scanning the reading count specifies the number of readings to store in the buffer For remote scanning the sample count specifies the number of readings to store in the buffer Readings stored in the buffer by the TRAC command or by front panel data store operation must be cleared before sending INITiate or READ to take the instrument out of idle The following command clears the buffer TRACe CLEar Clear buffer Scanning commands Scanning commands are listed in Table 7 1 Additional information on these commands follow the table NOTE Query commands and optional command words are not included in Table 7 1 The unabridged SCPI tables are provided in Section 15 7 28 Scanning
94. V Ou V to 76 3730 V Co 0 0 0 0 1 697 7288 10 1 705 703 5 x 10 c 4 3514970x 107 2 330 175 9 x 107 1 585 960 7 x 10719 6 543 558 5x 10 c4 92502871x 10 7 356 274 9 x 1017 cs 2 6084314 x 107 1 789 600 1 x 10 c6 4 136 019 9 x 10 8 403 616 5 x 10726 c 2 3 403 403 0 x 10725 1 373 587 9 x 10730 cg 1 1564860 107 1 062 982 3 x 105 Cg 3 244 708 7 x 107 Error 0 03 C to 0 01 C 0 02 C to 0 02 C too Co 2 c4E s where tog is calculated temperature in C E is the measured voltage in microvolts F 3 Table F 3 Type J inverse function polynomial 210 C to 0 C 0 C to 760 C 760 C to 1 200 C 8 095uV to Ou V to 42 919 42 919uV to 69 5530 V co 0 0 0 0 3 113 581 87 x 10 cy 1 952 826 8 x 107 1 978 425 x 10 3 005 436 84 x 10 c 1228 6185 x 106 2 001 204 x 1077 9 947 732 30 x 109 1 075217 8x 10 1 036 969 x 1071 1 702 766 30 x 10 10 c4 5 908 693 3 x 10712 2 549 687 x 10 16 1 430 334 68 x 10715 ce 1 725 6713x 19 19 3 585 153 x 10 4 738 860 84 x 10 cg7 2 813 1513 10720 5 344 285 10726 c 2 396 3370 107 5 099 890 1073 cg 8 382 332 1 x 107 Error 0 03 to 0 05 0 04 C to 0 04 C 0 03 C to 0 05 C tog Co CyE 2 c4E cE where tog is the calculated temperature in C E is the measured voltage in microvolts
95. a channel that is in the scan list Method 1 1 Use the CLOSE key or 4 and gt keys to close the channel that you want to be the monitor 2 Press SHIFT and then MONITOR MON annunciator turns on Method 2 1 Ifa channel is closed press OPEN to open it 2 Press SHIFT and then MONITOR 3 Usethe lt gt keys to display the monitor channel i e MONITOR 101 and press ENTER The monitor channel closes and the MON annunciator turns on To disable monitor again press SHIFT and then MONITOR MON annunciator turns off Once enabled you can change the monitor channel using the CLOSE key or the and keys If you open the monitor channel the monitor does not disable but it does become inactive MON annunciator turns off When a channel is closed monitor becomes active MON annunciator turns on While in the normal measurement state the present monitor channel dictates which channel in the scan list is the monitor Therefore if you change the monitor channel the scan list monitor channel also changes When you change the monitor channel while in the normal measurement state the instrument setup does not change If you want the monitor channel to assume the setup of the scan list channel you must disable the monitor and then re enable it 7 20 Scanning Model 2701 User s Manual Auto channel configuration Auto channel configuration allows you to recall scan list setups With auto channel configu
96. always use test leads that are rated for the available voltage and current NOTE When using the front panel inputs the INPUTS switch must be in the F out position For switching modules it must be in the R in position Front panel input When using the front panel input terminals connect the test leads to the INPUT HI and LO terminals as shown in Figure 3 2 Model 2701 User s Manual Basic DMM Operation 3 9 Figure 3 2 DCV and ACV connections using front panel inputs Model 2701 ewe HI DC Voltage Source Input Resistance 2 10M Q on 1000V and 100V ranges gt 10GQ on 10V 1V and 100mvV ranges Caution Maximum Input 1000V peak A DCV Connections Model 2701 SENSE Q4 WIRE A HI ls NA Voltage Source LO INPUTS Input Impedance 1M O lt 100pF Caution Maximum Input 750V RMS 1000V peak 8 x 107V Hz B ACV Connections 3 10 Basic DMM Operation Model 2701 User s Manual Model 7700 switching module Connections for the Model 7700 switching module are shown in Figure 3 3 For basic DCV and ACV measurements Figure 3 3A and B channels 1 through 20 can be used Ratio and channel average calculations Ratio calculates the reading ratio of two chan nels while channel average calculates the reading average of two channels For these cal culations paired switching channels are used Primary channels 1 through 10 are paired to channels 11 through 20
97. and RST default is READ UNIT RNUM and TST Table 15 4 ROUTe command summary Default Command Description parameter Ref SCPI ROUTe MONitor lt clist gt Specify one channel to be monitored Sec 7 STATe lt b gt Enable or disable channel monitoring OFF STATe Query state of channel monitoring DATA Returns the most recent monitor reading POINts lt NRf gt For a monitor scan specify number of channels Note 1 to scan 2 to 450000 POINts For a monitor scan query number of channels to scan MONitor Query the channel to be monitored CLOSe lt clist gt Close the one specified channel all others will Sec 2 open STATe lt clist gt Query closed channels in specified list 1 closed ACONfigure lt b gt Enable or disable auto configure Note 2 ACONfigure Query state of auto configure COUNC lt clist gt Query closure count for specified channels Sec 2 INTerval Set count update interval in minutes 10 to 1440 Note 3 lt NRf gt INTerval Query relay count update interval CLOSe Returns a lt clist gt of closed channels OPEN ALL Open all channels Sec2 Model 2701 User s Manual SCPI Reference Tables 15 7 Table 15 4 continued ROUTe command summary Default Command Description parameter Ref SCPI ROUTe MULTiple Path to control multiple channels Sec2 OPEN lt clist gt Open channel s specified in list Unlisted channels not affected C
98. and configuration for that function or range Model 2701 User s Manual Range Digits Rate Bandwidth and Filter 4 19 Figure 4 4 Filter configuration flow chart 0 0196 0 196 WINDOW 196 NONE 001 t 100 REPEAT TYPE MOVNG AV The moving filter cannot be used when scanning A scan channel cannot be configured to use the moving filter Also the filter window is not used when scanning When a simple scan is configured the present filter count and state will apply to all channels in the scan The window setting is ignored effectively set to NONE and if the moving filter is selected the filter will not enable when the scan is run For the advanced scan filter state on or off and count can be set for each channel You cannot set unique filter count type and window settings from the advanced scan setup menu For remote programming the lt clist gt parameter is used to set filter count and state for each channel in the scan You cannot set unique filter type and window settings NOTE Details on configuring a scan using filtering in a scan are provided in Section 7 4 20 Range Digits Rate Bandwidth and Filter Model 2701 User s Manual Remote programming filter Filter commands The filter commands are listed in Table 4 6 Additional information on these commands follow the table NOTE Query commands are not included in Table 4 6 All commands for the SENSe subsystem are provided in Table 15 5 Table
99. and factory defaults can be saved and recalled Offset compensated ohms A two measurement process for 4 wire ohms to cancel the effects of thermal EMFs Available for the 1000 1kQ and 10 ranges e Math mX b percent and reciprocal 1 X calculations provide mathematical manipulation of readings Relative Null offsets or establish baseline values Ratio and channel average Ratio and average calculations for two switching module channels Buffer Store up to 450 000 readings in the internal buffer Model 2701 User s Manual Getting Started 1 7 Limits Two sets of high and low reading limits to test devices Digital I O port Five digital limit test output lines to control external circuitry The digital trigger link and hardware interlock input can also be accessed at this port Monitor The Model 2701 can monitor a selected channel A scan can be trig gered to start when the Monitor detects a reached reading limit Remote interface Model 2701 can be controlled using the 10BaseT and 100BaseTX autosensing Ethernet or the RS 232 interface Plug in switching modules Up to two Keithley Model 77xx series switching modules can be installed in the Model 2701 A side by side comparison of the switching modules is provided in Table 1 1 Basic close open operation for switching module channels is provided in Section 2 while scanning is covered in Section 7 Connection information fo
100. and peak to peak values Remote programming buffer Summarizes the commands to control the data store and provides a programming example 6 2 Buffer Model 2701 User s Manual Buffer overview The Model 2701 has a data store buffer to store from 2 to 450 000 readings The instrument stores the readings that are displayed during the storage process Each timestamped reading includes the buffer location number and a timestamp The data store also provides statistical data on the measured readings stored in the buffer These include minimum maximum average peak to peak and standard deviation NOTE When scanning the readings are automatically stored in the buffer NOTE The various instrument operations including buffer operation are performed on the input signal in a sequential manner See Signal processing sequence page D 2 for details It includes flowcharts showing where in the processing sequence that buffer operations occur Front panel buffer Auto clear With buffer auto clear enabled the buffer is cleared readings lost before a new storage operation starts The buffer can be manually cleared by setting the number of readings to store buffer size to 000000 NOTE When editing the reading count over the front panel press AUTO to reset the count to 000000 You can then press ENTER to clear the buffer When buffer auto clear is disabled the buffer is not cleared and the buffer size is set to 450000 Each s
101. are provided in Table 2 1 and Table 2 2 Model 2701 User s Manual Close Open Switching Module Channels 2 7 System channel operation The system channel is a closed measurement channel that is internally connected to the internal DMM Input of the Model 2701 The system channel number is displayed on the Model 2701 For a 4 wire function i e Q4 the paired channel for the system channel is internally connected to DMM Sense The paired channel is not displayed on the Model 2701 When triggered the DMM performs a measurement and displays it on the Model 2701 The system channel is selected by closing a measurement channel using the system channel close keys These include the and keys or the CLOSE key SINGLE menu option See Controlling the system channel page 2 10 for details Other important points about system channel operation include the following There can only be one system channel This is the channel that is presently displayed and closed on the Model 2701 When a channel is not displayed there is no system channel When a measurement channel is closed the input backplane isolation channel also closes to connect the system channel to DMM input For a 4 wire function the paired channel and the sense backplane isolation channel also close to make the sense connections to the DMM e When a different measurement channel is closed the previous system channel opens The newly closed and displayed measurement
102. at the next channel If the reading count is set to infinity INF the scan will continuously repeat until you stop it NOTE One counter is used for STEP operation As shown in Figure 7 1 reading count sets the Trigger Counter SCAN operation When a scan is started one or more complete scans will be performed The number of channels in the scan list determines the number of channels for each scan The reading count determines the number of scans to perform and is best explained by an example Assume there are 10 channels in the scan list If you set the reading count to 10 or less one scan of the 10 channels will be performed If you set the reading count to any value from 11 to 20 two scans will be performed A reading count from 21 to 30 gives you three scans and so on If the reading count is set to infinity INF the scan will continuously repeat until you stop it NOTE As shown in Figure 7 2 two counters are used for SCAN operation The Trigger counter controls the number of scans and the Sample Counter controls the number of channels for each scan The number of channels in the scan list and the programmed reading count automatically sets the Trigger Counter and the Sample Counter The Sample Count is equal to the scan list length For example if channels 101 102 and 103 are programmed to be scanned the Sample Count is 3 Output trigger STEP operation After each channel is scanned an output trigger is applied
103. b LO 1 i Backplane i ag t Isolation og Dog 1 System channel operation Relay to l Close channel 101 Channel tdg i 23 2 Pole 4 Pole n p closed position Relay Pos rog 1 shown Dod 1 Pod m Channel 11 to i Relay Channel 24 ty i HI CO HI 1 Channel 11 o Sense 1 LO OLO ii E Backplane i Isolation l i 2 10 Close Open Switching Module Channels Model 2701 User s Manual Controlling the system channel When a measurement channel is closed a previous system channel and for a 4 wire function its paired channel is first opened The closed measurement channel becomes the system channel When a 4 wire function is selected the paired channel for the system channel also closes and keys These front panel keys Figure 2 3 can be used to select the next or previous measurement channel as the system channel If there are no measurement channels available one of the following messages will be briefly displayed when one of these keys is pressed NO SCAN CARD This message indicates that there are no switching modules or pseudocards installed both slots are empty NO MEAS CARD This message indicates that none of the installed switching modules or pseudocards have measurement channels For example the Model 7705 switching module does not have any measurement channels Those channels cannot be internally connected to the DMM NOTE The 4 and keys can also
104. be calculated and displayed The ratio calculation can be done on the DCV function and the channel average calculation can be done on the DCV and TEMP thermocouples only functions Ratio and channel average are calculated as follows Ratio Chan A Chan B Channel Average anh where is the selected closed channel Chan B is the paired channel for the installed switching module Ratio and Channel Average is the displayed result of the respective calculation Paired channels are used for ratio and channel average For example the Model 7700 switching module has 20 channels that can use ratio and channel average The primary channels 1 through 10 are linked to the paired channels 11 through 20 Channel 1 is paired to channel 11 channel 2 is paired to channel 12 and so on When ratio or channel average is enabled the Model 2701 measures the closed primary channel It then opens the primary channel and closes and measures the paired channel Ratio or channel average is then calculated from the two readings and displayed If the Model 2701 is configured for continuous measurements the two channel scan will continue to repeat and refresh the display with each new calculated reading The ratio or channel average calculation can only be enabled if a valid switching channel is closed If no channel is closed when you attempt to enable one of these calculations the message CLOSE A CHAN message will be disp
105. be set gt 1 After INITiate is sent to trigger the measurements FETCh will return the reading strings FETCh is automatically asserted when the READ or MEASure command is sent NOTE FETCh can repeatedly return the same reading Until there is a new reading this command continues to return the old reading When an instrument setting that is relevant to the readings in the sample buffer is changed the FETCh command will cause error 230 data corrupt or stale or a bus time out to occur To get FETCh working again a new reading must be triggered Model 2701 User s Manual READ SCPI Signal Oriented Commands 13 7 Description This command is typically used with the instrument in the one shot NOTE NOTE measurement mode to trigger and acquire a specified number of readings The SAMPle COUNt command is used to specify the number of readings see Trigger Subsystem Note that with sample count gt 1 the readings are stored in the buffer When this command is sent the following commands execute in the order they are presented ABORt INITiate FETCh When ABORt is executed the instrument goes into the idle state if continuous initiation is disabled If continuous initiation is enabled the operation re starts at the beginning of the Trigger Model If the instrument is in the idle state INITiate takes the instrument out of the idle state If continuous initiation is enabled INITiate CONTinuous ON then th
106. be the same The Node Designators must be different However the Subnet mask must be the same for the 2701 and the PC Local intranet address Using Internet Explorer a local intranet address is used to open the web page The web page address is the same as the IP Address of the Model 2701 Assuming the default IP Address is being used the following intranet address will open the web page http 192 168 0 2 If the use of password is enabled you will be prompted to enter the password If you for got the password you can either contact your network administrator for the password or you can clear the password from the front panel of the Model 2701 To clear the password and open the web page perform the following Model 2701 Press LOCAL gt press SHIFT gt press SETUP gt display CLR PASSWORD Y gt press ENTER Clearing the password disables its use and resets it to DEFAULT With the web page open the use of password can be enabled and changed if desired Configuration summary The configuration summary shown in Figure 10 9 provides the various details about the Model 2701 You will see Instrument Information Installed Cards Network Settings where you can input the IP Adress Subnet Mask Gateway and IP Mode and the Instru ment Settings The Instrument Settings is where you enter the Date Time and Enable a password by choosing Yes or No no will disable the password option Once you have established you
107. be used to open all channels in the mainframe Simply increment or decrement the channel number until there is no channel displayed Figure 2 3 System channel operation closing next or previous measurement channel TX Close previous Close next measurement measurement channel channel CLOSE key SINGLE menu option The SINGLE menu option for the CLOSE key can be used to select a measurement channel as the system channel Figure 2 4 Perform the following steps to select the system channel 1 Press the CLOSE key CLOSE SINGLE message will be displayed NOTE Ifthe CLOSE MULIT message is instead displayed when CLOSE is pressed it indicates that there are no measurement modules installed in the mainframe See Multiple channel operation page 2 16 to close the channels of a non measurement module i e Model 7705 Model 2701 User s Manual Close Open Switching Module Channels 2 11 2 Press ENTER to display the prompt to close a channel CLOSE CH XXX 3 Using lt gt and key in the three digit channel you want to select 4 Press ENTER The channel closes and the CHAN annunciator turns on Figure 2 4 System channel operation specifying measurement channel to close O PEN CLOSE Press CLOSE key Display SINGLE option CLOSESINGLE arid press ENTER Specify channel number XXX eee and press ENTER An invalid channel cannot be closed and will cause one of the following error mess
108. between noise performance and speed is acceptable e SLOW sets integration time to 5 PLC SLOW provides better noise performance at the expense of speed For the AC functions ACV ACV dB and ACI the RATE key sets integration time and bandwidth As listed in Table 4 4 FAST sets NPLC to 1 while the MEDium and SLOW NPLC settings are ignored see Bandwidth page 4 10 for details Table 4 4 Rate and bandwidth settings Rate and bandwidth Function Fast Medium Slow DCV DCI NPLC 0 1 NPLC 1 NPLC 5 ACV ACI NPLC 1 BW 300 NPLC X BW 30 NPLC X BW 3 O4 NPLC 0 1 NPLC 1 NPLC 5 FREQ PERIOD APER 0 01s APER 0 1s 15 Continuity NPLC 0 01 N A N A Notes NPLC number of power line cycles BW lower limit of bandwidth in Hz APER aperture in seconds N A not available X setting ignored From the front panel setting the rate for one function affects all the other functions For example if you set DCV for medium speed the other functions will also set to medium speed For remote programming each function can have its own unique rate setting 0 002 to 50 or 60 PLC NOTE Rate cannot be set for continuity It is fixed at 0 01 PLC 4 10 Range Digits Rate Bandwidth and Filter Model 2701 User s Manual Setting rate FAST MED or SLOW The RATE key is used to set rate measurement speed from the front panel Simply press RATE until the desired speed annunciator FAST MED
109. buffer is then routed to other enabled data flow blocks The data in the sample buffer remains there until data from another measurement cycle overwrites the buffer NOTE The trigger count TRIG COUN determines how many measurement cycles are performed However only the data arrays for the last measurement cycle end up in the sample buffer For example assume TRIG COUN 2 and SAMP COUN 20 The first measurement cycle stores 20 data arrays in the sample buffer The second measurement cycle then overwrites the 20 data arrays in the sample buffer Model 2701 User s Manual Signal Processing Sequence and Data Flow D 9 SENS 1 DATA LATest SENS 1 DATA FRESh These commands are used to return read the last processed data array stored in the sample buffer SENS 1 DATA LA Test This command returns reads one data array It returns the last processed data array stored in the sample buffer If for example 10 data arrays are stored in the sample buffer only the last 108 data array is returned DATA does not affect data in the sample buffer Therefore subsequent executions of DATA acquires the same data array In order to return a new reading you must first trigger a new reading s and then use DATA When using DATA to retrieve data it is good practice to include reading numbers in the data arrays Reading numbers that do not change will indicate that the same data array is being returned NOTE The FORMat ELEMe
110. channel 102 repeat step 1 above to open all channels and then use the key the 6102 command to close and display channel 102 This closes channel 102 which is the system channel and channel 125 to connect it to the DMM Input Model 2701 User s Manual Close Open Switching Module Channels 2 23 Anomaly 2 example opening the paired channel Assume 4 wire connections to resistor using channels 1 and 11 of the Model 7700 switching module Also assume the 4 function is selected The following procedure dem onstrates how careless multiple channel operation can cause an overflow reading even though everything else from the front panel looks right 1 Use the ALL option for the OPEN key OPEN ALL to open all channels in the mainframe Remote programming ROUT OPEN ALL 2 Pressthe key to close and display channel 101 The following channels close see Figure 2 2 Channel 101 system channel e Channel 125 connects channel 101 to DMM Input Channel 111 paired channel for 4 wire measurements Channel 124 connects channel 111 to DMM Sense e Channel 123 isolates channel 101 from channel 111 The Model 2701 will display the 1 reading for system channel 101 Remote programming ROUT CLOS 8101 3 Using the MULTI option for the OPEN key open channel 111 This opens the connection to DMM Sense and causes an OVRFLW reading Keep in mind that channel 101 is still closed and disp
111. circuits including the power transformer test leads and input jacks must be purchased from Keithley Instruments Standard fuses with applicable national safety approvals 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 a data acquisition board for installation into a computer should never require cleaning if handled according 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 Section Topic Page 1 Getting Started 1 1 General information nete Dti audi denied abies 1 2 Contact information esses nennen 1 2 Safety symbols and terms 1 2 nSpOCtlOr dex e ree y Hee er de exe pede
112. close the appropriate channels for the DUT make the measurement and then open the channels 8 After the last DUT is tested repeat step 1 to open all channels 2 30 Close Open Switching Module Channels Model 2701 User s Manual Identifying installed modules and viewing closed channels On power up the model numbers of installed switching modules are displayed briefly If a Model 7700 7701 7702 7703 7705 7708 or 7709 switching module is removed while the Model 2701 is on the instrument will operate as if the module is installed That is the Model 2701 will operate as if the pseudocard is installed NOTE Ifa Model 7706 or 7707 is removed while power is on error 523 Card hardware error will occur and the module will be removed from the system NOTE In general it is not recommended to install or remove switching modules with the power on CARD menu The CARD menu identifies the switching modules installed in the mainframe and is used for the following operations Configure digital inputs digital outputs and analog outputs for switching modules that have one or more of those capabilities 1 e Models 7706 and 7707 e View the analog input channels that are presently closed Also read digital input ports digital output ports and analog output values for switching modules that have one or more of those capabilities Menu navigation keys Once in the menu structure the manual range keys 4 and and the curs
113. command after the TRG command subsequent commands will not executed until the pointer for the Trigger Model has finished moving in response to TRG and has settled at its next state Programming example The following command sequence shows how to use the WAI command to allow the 2701 to wait for the programmed measurements to be completed before requesting a reading SYST PRES Returns 2701 to default setup INIT CONT OFF Disables continuous initiation ABORt Aborts operation Places 2701 in idle TRIG COUN 1 These two commands configure the 2701 SAMP COUN 30 to perform 30 measurements INIT Starts measurement process WAI Sends the WAI command Program waits for 2701 to go into idle before executing next command DATA Requests one reading 13 SCPI Signal Onented Measurement Commands Model 2701 User s Manual 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 When measurements are performed the readings are fed to other enabled operations Appendix D explains Data flow remote operation and provides additional information on using FETCh READ and MEASure to acquire 13 2 SCPI Signal Oriented Commands summarized in Table 13 1 NOTE readings Table 13 1 Signal oriented measurement command summary Command Description CONFigure function lt rang gt lt res gt
114. 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 third level it can be typed in without repeating the entire path name Notice that the leading colon for enab is not included in the program message If a colon were included the path pointer would reset to the root level and expect a root comman
115. connections Channel 1 Channels 2 19 E Thermocouple HI Channel 20 LO Figure B 6 2 Wire and thermistor connections HI Channel 1 LO Channels2 19 Resistor or i e Thermistor HI Channel 20 LO Model 2701 User s Manual Model 7700 Connection Guide B 9 Figure B 7 Wire and RTD connections Resistor or da 4 Wire RTD LO Channels 2 9 i HI Resistor or 4 Wire RTD LO HI Channel 11 LO Figure B 8 Current connections AC or DC Channel 21 HI Channel 22 LO B 10 Model 7700 Connection Guide Model 2701 User s Manual Figure B 9 Voltage connections DC or AC DC Voltage AC Voltage HERPES HI Channel 1 L Lo Channels 2 19 e Jl e HI Channel 20 LO iti EET lt Connection log Make a copy of Table B 1 and affix it to the cover of the Model 7700 Use this to record connection information and channel descriptions as needed Model 2701 User s Manual Table B 1 Connection log Model 7700 Model 7700 Connection Guide Channel Color Description AMPS COM INPUT SENSE CHI CH2 CH3 CH4 CHS CH6 CH7 CH8 CH9 CH10 11 12 CH13 CH14 CHI15 CH16 CH17 CH18 CH19
116. digital filter places a specified number of A D conversions Filter count into a memory stack These A D conversions must occur consecutively within a selected reading window Filter Window The readings in the stack are then averaged to yield a single filtered reading The stack can be filled in two ways Filter Type moving or repeating Details on digital filter characteristics are provided as follows Filter type There are two digital filter types moving and repeating The moving average filter uses a first in first out stack where the newest reading conversion replaces the oldest An aver age of the stacked reading conversions yield a filtered reading After the specified number of reading conversions Filter count fill the stack the moving filter gives a new reading for every new conversion This process is depicted in Figure 4 2A The repeating filter takes a specified number of conversions averages them and yields a filtered reading It then flushes its stack and starts over This character is useful when scanning readings for other channels are not averaged with the present channel The stack is then cleared and the process starts over see Figure 4 2B NOTE The moving filter cannot be used when scanning If a scan channel is set up to use the moving filter the filter will not turn on Scanning is covered in Section 7 Filter count The filter count specifies how many consecutive A D conversions within the filter win
117. e dee aeu 1 2 sistere ine CRAT QU BUR AE SERES RR ER YU ERR Xa 1 3 5 5 eene 1 3 Model 2701 features nennen nennen nnne 1 6 Plug in switching modules seen 1 7 Pseudocards onsite uit PURI IE 1 7 Identifying installed switching modules 1 7 Front and rear panel familiarization QS1 1 10 Front panel RE ERAKAR 1 10 Rear panel summary 1 13 istituito icu tpe del teen en QS2 1 15 Line power connection 1 15 LIME TE QUONICY es iioi e i eI ERES OR EE DO ien count ka eee etes 1 16 Setting line voltage and replacing 1 16 Power up sequence TAREA 1 17 M 1 19 Display LC 1 19 Status and error messages 1 19 Remote programming 1 19 Defaults and user setups 1 21 Saving and restoring 5
118. explosive nature in a high energy circuit can cause severe personal injury or death If the multimeter is connected to a high energy circuit when set to a current range or low resistance range the cir cuit is virtually shorted Dangerous arcing can result even when the multi meter is set to a voltage range if the minimum voltage spacing is reduced in the external connections As described in the International Electrotechnical Commission IEC Standard IEC 664 the Model 2701 measurement inputs are measurement Category I and signal lines must not be directly connected to AC mains When making measurements in high energy circuits use test leads that meet the following requirements Test leads should be fully insulated Only use test leads that can be connected to the circuit e g alligator clips spade lugs etc for hands off measurements Do not use test leads that decrease voltage spacing These diminish arc protection and create a hazardous condition WARNING For the front panel inputs the maximum common mode voltage voltage between INPUT LO and the chassis ground is 500V peak For a switching module the maximum common mode voltage is 300VDC or 300V RMS 425V peak for AC waveforms Exceeding these values may cause a breakdown in insulation creating a shock hazard Use the following sequence when testing power circuits 1 De energize the circuit using the regular installed connect disconnect device for example by r
119. function Setting limits 1 Press SHIFT and then LIMITS to display the high limit for Limit 1 2 Use lt gt and to key in the limit and press ENTER When editing a reading use the range designator m K M or G as a multiplier With the cursor on the range designator each press of or will increase or decrease the reading by a factor of 10 3 Key in the low limit for Limit 1 LO1 and press ENTER Key in the high limit for Limit 2 HI2 and press ENTER 5 Key in the low limit for Limit 2 LO2 and press ENTER The instrument will return the normal measurement state Beeper settings The beeper is configured from the OUTPUT menu shown in Table 9 1 as follows 1 Press SHIFT and then OUTPUT 2 Usethe or key to display the present beeper BEEP setting NEVER INSIDE or OUTSIDE 3 Press to position the cursor on the present beeper setting use the or key to display the desired setting and press ENTER The instrument will return to the normal measurement state NOTE Remote programming cannot be used to set the beeper It can only be set from the front panel Enabling disabling limits Press SHIFT and then ON OFF to display the present state off or on of limits To enable limits use the or key to display LIMITS ON and press ENTER To disable limits again press SHIFT and then ON OFF select LIMITS OFF and press ENTER Model 2701 User s Manual Limits and Digital I O 9
120. how to calculate the actual readings limits for dB with a user defined VREF of 10V you must calculate the voltage accuracy and apply it to the above equation To calculate a 60dB measurement assume 10mV RMS for a VREF of 10V Using the 100mV range one year 10Hz 20kHz frequency band and SLOW rate the voltage limits are as follows Accuracy 0 06 of reading 0 03 of range 0 0006 x 10mV 0 0003 x 100mV 6u V 30u V 36u V Thus the actual reading accuracy is 10mV 36mV or 10 036mV to 9 964mV Applying the voltage reading accuracy into the dB equation yields dBm 201og10036mV 59 96879aB 10V dBm 2019g2264mV _60 031334 10V Thus the actual reading accuracy is 60dB 0 031213dB to 60dB 0 031326dB dBm and dB for other voltage inputs can be calculated in exactly the same manner using pertinent specifications ranges and other reference voltages Additional derating factors In some cases additional derating factors must be applied to calculate certain accuracy values For example an additional derating factor of 0 02ppm V must be added to DCV specifications for voltages over 500V Before calculating accuracy study the associated specifications very carefully to see if any derating factors apply A 10 Specifications Model 2701 User s Manual Optimizing measurement accuracy The configurations listed below assume that the multimeter has had factory setups restored NOTE For maximum
121. in the scan setup menu 2 Forsome channel specific setups you have to configure them from a menu For example to set up and enable mX B you have to use MATH menu While in that menu the CHAN annunciator will flash to indicate that you are editing the mX b math setup for that channel in the scan list When you exit from the mX b setup menu the CHAN annunciator stops flashing 3 Paired channels A paired channel function or operation can only be selected for a primary channel For the Model 7700 channels 1 through 10 are the primary channels Trying to select a paired channel function or operation for channels 11 through 22 will result in INVALID CHAN 4 Function changes When you press a function key the selected channel assumes the mainframe setup for that function Also available channels for the specified slot that follow will assume that setup Model 7700 example If you press DCV for channel 101 channels 101 through 120 will assume the DCV setup Note that channels for slot 2 are not affected When you press the function key for a primary channel the subsequently paired channels will be displayed briefly Model 7700 example If you press for channel 108 channels 109 and 110 will also assume the function and the message 118 120 PRD will be displayed to indicate the paired channels A channel that is paired to a primary channel is not affected by function changes Model 7700 example Assume channel 102
122. installed in slot 1 To install a 7700 pseudocard in slot 1 send the following command SYST PCAR1 C7700 System channel operation is used to connect input channels to the DMM of the Model 2701 e For a 2 wire function i e DCV closing a system channel connects the input to DMM Input of the Model 2701 Figure 1 4 shows system channel 1 closed For the 2 function the resistance DUT would be connected to DMM Input as shown Figure 1 4 For a 4 wire function i e Q4 a channel pair is connected to the DMM when a system channel is closed The system channel is connected to DMM Input and the paired channel is connected to DMM Sense Figure 1 5 shows system channel 6 closed For a 4 wire function the paired chan nel also closes For the Model 7700 channels 1 through 10 are paired to channels 11 through 20 When channel 6 is closed channel 16 also closes Figure 1 5 shows how the DUT is connected to the DMM for the 4 wire function NOTE Figure 1 4 and Figure 1 5 show simplified schematics of the switching module They show a single switch closed to connect an input channel to the DMM In reality multiple switching is used to make proper connections to the DMM However for system channel operation the user need not be concerned about which switches in the module close Figure 1 4 Connection to DMM for 2 wire function system channel 101 closed Switching Module Switching Module _ DMM i Ch 1 i i Input DUT
123. interface and Table 10 4 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 10 11 RS 232 interface connector 5 43 2 1 e muy 9876 Rear Panel Connector Table 10 4 RS 232 connector pinout Pin Description No connection TXD transmit data RXD receive data No connection GND signal ground Not used RTS ready to send CTS clear to send No connection 00 10 Model 2701 User s Manual Remote Operations 10 33 Table 10 5 provides pinout identification for the 9 pin DB 9 or 25 pin DB 25 serial port connector on the computer PC Table 10 5 PC serial port pinout Signal DB 9 pin DB 25 pin DCD data carrier detect 1 8 RXD receive data 2 3 TXD transmit data 3 2 DTR data terminal ready 4 20 GND signal ground 5 7 DSR data set ready 6 6 RTS request to send 7 4 CTS clear to send 8 5 RI ring indicator 9 22 Error messages See Appendix C for RS 232 error messages 800 through 808 10 34 Remote Operations Model 2701 User s Manual Status Structure Overview Provides an operational overview of the status structure for the Model 2701 Clearing registers and queues Covers the actions that clear reset registers and queues Pro
124. is paired to channel 112 Now select channel 103 and press DCV All following channels except channel 112 will assume the DCV setup Channel 112 remains paired to channel 102 However if you select channel 101 and press DCV channel 102 will change to DCV and not be paired to channel 112 anymore Therefore all 20 channels will assume the DCV setup 5 Setting changes When you press a key to change a setting i e range rel digits etc only the selected scan channel is affected Model 7700 example If you make arange change for channel 103 the range settings for other channels are not affected NOTE Only one USER RTD per scan list 7 16 Scanning Model 2701 User s Manual Advanced scan setup procedure Step 1 Select the advanced scan configuration menu 1 Press SHIFT and then CONFIG to access the scan setup menu 2 Press the or key to display INT ADVANCED and press ENTER Step 2 Edit scan channels Usethe or gt key to select channel 101 SETUP V 101 factory default NOTE The CLOSE key can instead be used to select a scan channel to be edited Press CLOSE use the or keys to display the channel and then press ENTER 2 You can disable the channel or use it in the scan Perform step a or step b a If you do not want to use the channel press SHIFT and then CH OFF to disable the channel Available channels that follow will also disable Note however that channels for slot 2 are not affected b Ifyou wa
125. isolation channels 124 and 125 and the 2 pole 4 pole channel 123 Figure 2 2 shows the backplane isolation channels and the 2 pole 4 pole channel for the Model 7700 Perform the following steps to open all channels 1 Press the OPEN key to display OPEN ALL 2 Press OPEN a second time or press ENTER to open all channels NOTE Opening the system channel disables Ratio or Channel Average Ratio and Channel Average operation are covered in Section 5 Figure 2 5 System channel operation opening all channels in mainframe eren cios Press O PEN key Display ALL option and press OPEN again OPEN ALL Remote programming system channel control commands The commands to close and open the system channel are listed in Table 2 1 When a system channel reading is returned the system channel number will be included in the data string if the CHANnel data element is selected The FORMat ELEMents command is used to specify the data elements to be included in the data string see FORMat commands in Section 14 Model 2701 User s Manual Close Open Switching Module Channels 2 13 Table 2 1 System channel control commands Commands Description Ref ROUTe CLOSe lt clist gt Specify one measurement channel to close a ROUTe CLOSe STATe lt clist gt Query closed channels in specified list b 1 closed ROUTe CLOSe Returns a clist of closed measurement channels ROUTe OPEN ALL Open all channels
126. it can be started by a reached reading limit detected by the monitor channel For immediate the IMMediate command must be the only parameter in the list To use reading limits each limit must be separated by a comma Model 2701 User s Manual Scanning 7 31 Examples ROUT SCAN TSO IMM Start scan when it is enabled and triggered ROUT SCAN TSO HLIM1 LLIM1 Enable high limits 1 and low limits 1 Note that any reached limit will start the scan c ROUTe MONitor clist The channel that you specify as the monitor must be a channel that is in the scan list If it is not the first channel in the scan list will automatically become the monitor channel If the lt clist gt has more than one channel error 223 too much data occurs and the command is not executed d ROUTe MONitor POINts Use this command to specify the number of channels to scan each time the monitor scan is triggered to start For example assume the monitor scan list has 10 channels To scan that list once send ROUT MON POIN 10 To scan that list twice use parameter value 20 For three scans send parameter value 30 and so on e SAMPIe COUNt and TRIGger COUNt Sample count specifies the number of readings to scan and store in the buffer while the trigger count specifies the number of scans to perform If the sample count is greater than the number of channels in the scan list scan list length operation wraps around to the beginning of the scan l
127. line Trigger 1 the A D conversion starts with the positive going zero crossing of the power line cycle If the next trigger Trigger 2 occurs during the negative cycle then the measurement process also starts with the positive going zero crossing Figure 3 1 Line cycle synchronization lt 1PLC gt Reading Reading Done Done e lt AID gt lt gt Conversion Conversion Perform the following steps to enable or disable line cycle synchronization 1 Press SHIFT and then LSYNC to display the present state of line synchronization OFF or ON 2 Use the key to display LINESYNC ON LINESYNC OFF 3 Press ENTER The instrument returns to the normal display state NOTE Line synchronization is not available for the AC functions ACV ACI FREQ or PERIOD and for integration rates 1 PLC regardless of the LSYNC setting 3 6 Basic DMM Operation Model 2701 User s Manual Remote programming autozero and LSYNC Autozero and LSYNC commands The commands to control autozero and line synchronization are listed in Table 3 1 Table 3 1 Autozero and LSYNC commands Commands Autozero command SYSTem AZERo STATe lt b gt Line synchronization command SYSTem LSYNc STATe lt b gt OFF OFF Description Enable or disable autozero lt b gt ON or Enable or disable LSYNC lt b gt ON or Default ON OFF
128. lt clist gt Set LO2 limit lt NRf gt 4294967295 to 2 4294967295 CALCulate3 LIMit2 STATe lt b gt lt clist gt Enable disable Limit 1 test b ON or OFF a CALCulate3 LIMit2 FAIL Query test result 0 pass in 1 fail b high or low CALCulate3 LIMit2 CLEar Clear fail indication CALCulate3 LIMit2 CLEar AUTO lt b gt Enable disable auto clear lt b gt ON or OFF ON Digital output commands CALCulate3 OUTPut LSENse lt name gt Set logic sense name AHIGh ALOW AHIGh CALCulate3 OUTPut STATe lt b gt Enable disable digital outputs lt b gt ON or OFF OFF CALCulate3 OUTPut PULSe TIMe lt NRf gt Set output pulse time in secs lt NRf gt 0 001 0 002 to 99999 999 CALCulate3 OUTPut PULSe STATe lt b gt Enable disable pulse output lt b gt ON or OFF OFF CALCulate3 MLIMit LATChed lt b gt Enable disable master limit latch OFF Channel list parameter lt clist gt SCH Examples 101 Slot 1 Channel 1 where S Mainframe slot number 1 or 2 CH Switching module channel number must be 2 digits 101 203 Slot 1 Channel 1 and Slot 2 Channel 3 101 110 Slot 1 Channels 1 through 10 The lt clist gt parameter is used to configure one or more channels for a scan Model 2701 User s Manual Limits and Digital I O 9 13 NOTE When measurements are performed the readings are fed to other enabled operations including Limits Appendix D explains
129. master limit remains latched when a reading limit is reached or exceeded When disabled the master limit line releases immediately when the reading is inside all four limits Table 9 1 OUTPUT menu Menu item Setting Description DOUTPUT ON or OFF Enable disable digital outputs PULSE YES or NO Enable disable digital pulse output LSENSE HIGH or LOW Select logic sense BEEP NEVER INSIDE or OUTSIDE Set beeper for limits see Limits for details MASTR LATCH Y or N Enable disable master limit latch Perform the following steps to enable and configure digital outputs 1 2 Scanning While limits can be configured on a per scan channel basis the digital output configura tion cannot Therefore for all scan channels that are set to use limits the digital output will function according to how the Model 2701 is set up when the scan is run Press SHIFT and then OUTPUT If the digital output is already on DOUTPUT ON proceed to step 3 Otherwise press gt to move the cursor to the right press or key to display ON and press ENTER Use the key to display the master limit latch MASTR LATCH setting N no or Y yes If you want to retain the present master limit setting proceed to step 5 Otherwise press to move the cursor to the right press or key to display Y or N and press ENTER Use the key to display the present logic sense LSENSE setting HIGH or LOW If you want to
130. measurement To cancel the affects of the unwanted thermal voltage the thermocouple circuit requires a reference junction that is at a known temperature Reference junctions A reference junction is the cold junction in a thermocouple circuit which is held at a stable known temperature It is at the cold junction where dissimilar wire connections must be made As long as the temperature of the cold junction is known the Model 2701 can factor in the reference temperature to calculate the actual temperature reading at the thermocouple The standard reference temperature is the ice point 0 C The ice point can be precisely controlled and the National Bureau of Standards uses it as the fundamental reference for its voltage to temperature conversion tables However other known temperatures can be used There are two ways for the Model 2701 to acquire the cold junction temperature It can measure the cold junction using a thermistor or 4 wire RTD or the known temperature value can be entered by the user There are three reference junction types supported by the Model 2701 simulated reference junction internal reference junction and external reference junction These reference junctions are explained in the following paragraphs NOTE When using multiple channel operation ROUT MULT command to connect a switching module input channel to the DMM the SIMulated reference junction will be used if the INTernal or EXTernal reference junction i
131. message is displayed select a higher range until a normal reading is displayed Use the lowest possible range for the best resolution To measure other switching channels repeat steps 5 and 6 8 When finished press OPEN if there is a channel closed Continuity testing The instrument can test continuity using the 2 wire range After selecting continuity you will be prompted to enter the threshold resistance level 1 to 10009 When the measured circuit is below the set threshold level the instrument will beep and display the resistance readings When the measured circuit is above the threshold level the instrument Model 2701 User s Manual Basic DMM Operation 3 49 will not beep and either display the resistance reading or the message OPEN If the reading is below 11000 it will be displayed If the reading is 1100Qbr above OPEN will instead be displayed NOTE The reading rate for continuity is fixed at 0 01 PLC Limits and digital outputs cannot be used when testing continuity with the conti nuity CONT function If you need to use these operations use the 2 function to test continuity Connections NOTE When using the front panel inputs the INPUTS switch must be in the F out position For switching modules it must be in the R in position Front panel input When using the front panel input terminals connect the test leads to the INPUT HI and LO terminals as shown in Figure 3 19A Mod
132. number 1 or 2 CH Switching module channel number must be 2 digits Examples 101 Slot 1 Channel 1 101 203 Slot 1 Channel 1 and Slot 2 Channel 3 101 110 Slot 1 Channels 1 through 10 Notes 1 The lt clist gt parameter is used to configure one or more channels for a scan Each channel in the lt clist gt must be set to the function specified by the command If not a conflict error 221 will occur For example RESistance NPLCycles 1 101 is only valid if scan channel 101 is set for the 22 function 2 For 60Hz line power x 60 For 50Hz line power x 50 9 For 60Hz line power the default is 16 67msec For 50Hz line power the default is 20msec 4 Commands to set rate for ACV and ACI are only valid if bandwidth is set to 300 300Hz to 300kHz See Rate and bandwidth conflict error page 4 13 for details 5 The instrument will actually accept a parameter value up to 10e6 but it will default to 3e5 6 DC is optional for the commands to set DCV and DCI integration rate Aperture Aperture is a different way to specify the integration rate As previously explained 1 PLC sets the integration rate to 16 67msec assuming 60Hz line power You can instead use an APERture command as follows to set the same integration rate APERture 16 67e 3 Bandwidth There are three bandwidth settings for ACV and ACI measurements 3 3Hz to 300kHz 30 30Hz to 300kHz and 300 300Hz to 300k
133. or K Select temperature measurement units C F or K 2 SENS THRMSTR Select the thermistor transducer 3 TYPE 22000 50000 or 10kQ Select thermistor resistance 3 44 Basic DMM Operation Model 2701 User s Manual 4 wire RTD temperature measurement configuration The Alpha Beta Delta and Qat 0 C parameters for the five basic RTD types are provided in Table 3 5 Note that these parameters can be modified using remote programming Table 3 5 RTD parameters Type Standard Alpha Beta Delta Qat 0 C PT100 ITS 90 0 00385055 0 10863 1 49990 10092 D100 ITS 90 0 003920 0 10630 1 49710 1000 F100 ITS 90 0 003900 0 11000 1 49589 10092 385 IPTS 68 0 003850 0 11100 1 50700 1000 PT3916 IPTS 68 0 003916 0 11600 1 50594 1000 The steps to configure 4 wire RTD measurements are provided in Table 3 6 After pressing SHIFT and then SENSOR the menu starts at step 1 to select measurement units Each time you press ENTER to make a selection the menu will automatically go to the next selection After pressing ENTER for the last step the instrument will return to the normal measurement state NOTE As shown in Table 3 6 you can select the USER sensor type but you cannot change the USER parameters from the front panel The parameters for the USER type can only be set using remote programming see TEMPerature FRTD commands in Table 3 7 Table 3 6 4 wire RTD temperature measurement configuration Step Men
134. power on setup NOTE Atthe factory the factory default setup is saved as the SAVO SAVI SAV2 SAV3 or SAV4 setup Saving and restoring setups Saving a user setup 1 Configure Model 2701 for the desired measurement application 2 Press SHIFT and then SAVE to access the save setup menu 3 Press to place the cursor on the present setup SAVO SAVI SAV2 SAV3 SAV4 4 Use key to display the desired setup and press ENTER The instrument returns to the normal measurement state 1 22 Getting Started Model 2701 User s Manual WARNING _ If you make firmware upgrades you will lose all your saved settings Saving a power on setup 1 Configure Model 2701 for the desired measurement application 2 Press SHIFT and then SAVE to access the save setup menu 3 Press the key to display the present power on PWR ON setup FACT RST SAVO SAV2 SAV3 or SAVA 4 Press to place the cursor on the present power on setup 5 Usethe key to display the desired setup and press ENTER The instrument returns to the normal measurement state Restoring a setup 1 Press SHIFT and then SETUP to access the restore setup menu 2 Press to place the cursor on the present RESTORE setup FACT RST SAVO SAV1 SAV2 SAV3 or SAVA 3 Use the key to display the desired setup and press ENTER The instrument returns to the normal measurement state NOTE Ifthe settings for a user setup or power on setu
135. programming the gate time can be set from 0 01 to 1 0 sec using the FREQuency APERture and PERiod APERture commands Table 3 7 Note however that if you set a gate time other than 1 0 0 1 or 0 01 sec the SLOW MED and FAST annunciators will be off The Model 2701 completes a reading when it receives its first zero crossing after the gate time expires In other words the reading is completed 1 2 cycle after the gate time has expired For example to sample a 3Hz frequency you may wait up to three seconds before the Model 2701 returns a reading Model 2701 User s Manual Basic DMM Operation 3 47 Connections NOTE When using the front panel inputs the INPUTS switch must be in the F out position For switching modules it must be in the R in position Front panel input When using the front panel input terminals connect the test leads to the INPUT HI and LO terminals as shown in Figure 3 17 Figure 3 17 FREQ and PERIOD connections for front panel inputs Model 2701 HWE maA EX AUI AC Voltage e Source Lo 500V Q Input Impedance 1MQ in parallel with lt 100pF Caution Maximum Input 1000V peak 8 x 10 V Hz Model 7700 switching module Connections for the Model 7700 switching module are shown in Figure 3 18 For this 2 wire measurement channels 1 through 20 can be used Figure 3 18 FREQ and PERIOD connections using Model 7700 switching module M odel 7700 AC Switching Voltage Module Sou
136. reading is outside Limit 1 but inside Limit 2 the beeper will sound at a lower pitch The beeper will not sound for readings outside both limits For the limits shown in Figure 9 1 a 0 5V read ing will sound the beeper at its normal pitch a 1 5V reading will sound the beeper at a lower pitch and for a 2 5V reading the beeper will not sound Tips to use Limit 2 test Limits 1 Limits 2 When the set limits for Limit 1 are less than the limits for Limit 2 i e Figure 9 1 use the INSIDE beeper As previously explained when the reading is between Limit 1 and Limit 2 the beeper will sound raspy Limits 1 gt Limits 2 When the set limits for Limit 1 are greater than the limits for Limit 2 use the OUTSIDE beeper When the reading is between Limit 1 and Limit 2 the beeper will sound raspy 9 4 Limits and Digital I O Model 2701 User s Manual Scanning When a simple scan is configured the present limit values and state will apply to all channels in the scan When an advanced scan is configured each channel can have its own unique limits configuration Details to configure and run a scan are provided in Section 7 For remote programming the lt clist gt parameter is used to configure channels for a scan Basic limits operation The limits configuration is the same for all functions For example if a reading limit is set to 1 that will equate to 1V for a voltage function for a current function and 1Q for an ohms
137. resistor Its resistance changes non linearly with changes in temperature Most thermistors have a negative temperature coefficient As temperature increases the resistance decreases The Model 2701 measures the resistance of the thermistor and calculates the temperature reading Of all the temperature transducers the thermistor is the most sensitive It can quickly detect minute changes in temperature It is a good choice when measuring very small changes in temperature The downside for this increased sensitivity is the loss of linearity Since they are especially non linear at high temperatures it is best to use them for measurements below 100 C NOTE Curve fitting constants are used in the equation to calculate thermistor temperature The thermistor manufacturer s specified curve fitting constants may not be exactly the same as the ones used by the Model 2701 Thermistor equation page F 6 provides the equation and the constants used by the Model 2701 It also explains how to select a thermistor when the manufacturer 5 constants and the ones used by the Model 2701 do not match Model 2701 User s Manual Basic DMM Operation 3 37 4 wire RTDs For 4 wire RTDs the temperature measurement range is 200 C to 630 C 0 01 C resolution RTD types that are supported include D100 F100 PT385 and PT3916 A USER type is available to modify RTD parameters such as the resistance at 0 C The USER type can be enabled from the front panel but th
138. retain the present logic sense setting proceed to step 7 Otherwise press gt to move the cursor to the right press or key to display HIGH or LOW and press ENTER Use the key to display the present PULSE mode setting NO or YES To retain the present pulse mode setting press ENTER Otherwise press to move the cursor to the right press or key to display NO or YES and press ENTER 9 12 Limits and Digital I O Model 2701 User s Manual Remote programing limits and digital output Limits and digital output commands The limits and digital output commands are provided in Table 9 2 Table 9 2 Limits and digital I O commands Commands Description Def Ref Limit 1 commands CALCulate3 LIMit1 UPPer lt NRf gt lt clist gt Set HII limit lt NRf gt 4294967295 to 1 4294967295 CALCulate3 LIMit1 LOWer lt NRf gt lt clist gt Set LOI limit lt NRf gt 4294967295 to 1 4294967295 CALCulate3 LIMit1 STATe b lt clist gt Enable disable Limit 1 test b 2 ON or OFF a CALCulate3 LIMit1 FAIL Query test result 0 pass in 1 fail b high or low CALCulate3 LIMit1 CLEar Clear fail indication CALCulate3 LIMitl CLEar AUTO lt b gt Enable disable auto clear lt b gt ON or OFF ON Limit 2 commands CALCulate3 LIMit2 UPPer lt NRf gt lt clist gt Set HI2 limit lt NRf gt 4294967295 to 2 4294967295 CALCulate3 LIMit2 LOWer lt NRf gt
139. saved setup E 0 1 2 3 or 4 SRE lt NDN3 gt Service request enable Programs the service request enable register Sec 11 or lt NRf gt command SRE Service request enable query Reads the service request enable register Sec 11 STB Status byte query Reads the status byte register Sec 11 TRG Trigger command Sends a bus trigger to Model 2701 G TST Self test query Performs a checksum test on ROM and returns H the result WAT Wait to continue command Wait until all previous commands are executed I Model 2701 User s Manual Common Commands 12 3 A DN identification query Reads identification code The identification code includes the manufacturer model number serial number and firmware revision levels and is sent in the following format KEITHLEY INSTRUMENTS INC Model 2701 xxxxxxx yyyyy zzz Where XXXXXXX is the serial number yyyyy zzzzz is the firmware revision levels of the digital board ROM and display board ROM B OPC Operation Complete Set the OPC bit in the standard event register after all pending commands are complete Description After the OPC command is sent the Operation Complete bit bit BO of the Standard Event Status Register will set immediately after the last pending command is completed If the corresponding bit Bit BO in the Standard Event Enable Register and Bit 5 Event Summary Bit of the Service Request Enable Register is set the MSS Master Summary Sta
140. scan example Monitor Mode Close Monitor Channel 101 M easure TEMP Scan Mode Close First Return to Channel Monitor Mode 4 M easurements O pen Last Chan Close N ext Chan M easure Model 2701 User s Manual Model 2701 User s Manual Table 7 3 Monitor scan example Scanning 7 37 Front panel operation Remote programming Restore defaults SHIFT SETUP RESTORE FACT For front panel operation proceed to step 3 For remote programming clear the buffer Configure advanced scan SHIFT CONFIG ADVANCED Channel 101 Select TEMP function Configure temperature SHIFT SENSOR Select Thermocouple sensor SENS TCOUPLE Select type K thermocouple TYPE K Select internal reference junction JUNC INT Set and enable high limit 1 Set limit to 30 SHIFT LIMITS gt 1 30 00000 Enable on limit SHIFT OFF ON gt LIMITS ON Close channel 101 Enable Channel Average SHIFT CH AVG Channel 102 103 and 104 Select DCV function Select 10V range Set filter count to 20 SHIFT TYPE gt 020 RDGS Enable filter FILTER Disable off channels 105 through 222 SHIFT CH OFF Disable immediate scan IMM SCAN N and enable high limit 1 HLIMI SCAN Y Disable timer TIMER NO Set reading count to 4 Select and enable monitor channel SHIFT MONITOR 2101 SYST PRES TRAC CLE FUNC TEMP 0101 TEMP TRAN TC 8101 TEMP TC TYPE K 8101
141. still enabled STEP or SCAN annunciator on When you press STEP or SCAN the scan will continue starting with the next channel With reading count set to infinite the scan will keep repeating While the scan is enabled STEP or SCAN annunciator on most front panel keys are inoperative and will cause the message HALT SCANNER to be displayed To disable the scan press SHIFT and then HALT To recall scanned readings stored in the buffer press RECALL and use the 4 gt 4 and keys to navigate through the buffer Note that the buffer can be read while the instru ment is storing readings See Section 6 for details on recalling buffer readings When fin ished make sure to exit from buffer recall by pressing the EXIT key NOTE Channels for an advanced scan be configured using different mX B units i e and Q temperature sensors i e 4 wire RTD and thermistor and measurement type i e OCOMP ohms and DCV However when readings are recalled from the buffer the display may not indicate the correct mX B units symbol or annunciator for each channel For example assume one channel used OCOMP ohms while a second used Q2 When the readings are recalled the OCOMP annunciator may remain on for both channels This display anomaly is due to memory limitations Preserving the mX B units and annunciators for each channel would reduce the number of readings that could be stored in the buffer Model 2701 User s Manu
142. the Model 7700 are to be performed by qualified service personnel This information is provided in Appendix B Model 7700 Connection Guide Switching module capabilities Channels 1 through 20 The Model 7700 can multiplex one of twenty 2 pole signals or one of ten 4 pole signals into the input of the Model 2701 Channels 21 and 22 The Model 7700 can multiplex one of two 2 pole current signals into the input of the Model 2701 CAUTION To prevent damage to the Model 7700 switching module do not exceed these maximum signal levels Channels 1 20 300VDC or 300V RMS 425V peak for AC waveforms 1A switched 60W 125VA Channels 21 22 60VDC or 30 RMS switched 60W 125VA NOTE System channel operation Of the 22 measurement channels only one channel or channel pair can be closed at the same time When you close a channel or channel pair all other measurement channels will open The user has no control of channels 23 24 and 25 The open close state of these channels are determined by the selected function The Model 7700 has six temperature transducers to monitor the cold junction temperature at the screw terminals For temperature measurements this internal reference junction allows thermocouples to be connected directly to the screw terminals of the module When the Model 2701 is on the DCV ACV 2 CONT 04 FREQ PERIOD or TEMP function channels 1 through 20 are available When on a current function
143. the master limit line will not release until operation within the trigger model returns to and passes the control source see Section 7 for details on triggering When scanning the latched master limit line will not release until the scan is finished and another scan is started For example if after testing a resistor network the master limit line did set then the network has passed all tests 9 8 Limits and Digital I O Model 2701 User s Manual Sink mode controlling external devices Each output can be operated from an external supply voltage range from 5V to 33V applied through the external device being driven The high current sink capacity of the output driver allows direct control of relays solenoids and lamps no additional circuitry needed As shown in Figure 9 3 each of the digital open collector outputs includes a built in pull up resistor connected to 5V The output transistor is capable of sinking 250mA from voltages up to 33V Each output channel contains a fly back diode for protection when switching inductive loads such as a low power solenoid or relay coils To use these fly back diodes connect the external supply voltage to pin 7 of the digital I O port Make sure the external supply voltage is between 5V and 33V and the current required by the device does not exceed 250mA CAUTION On pin 7 do not exceed 33V For the output lines do not exceed the maximum sink current The maximum sink current for
144. the questionable event clears Model 2701 User s Manual Status Structure 11 17 Figure 11 7 Questionable event status Warn Cal Temp Q uestionable E Condition B15 B14 B13 B9 8 B7 B5 4 B3 BO Register Questionable Event Register Questionable Event Enable Summary Bit Register Q SB of Status BUS Hegel Warn Command Warning amp Logical AND Cal Calibration Summary OR Logical OR Temp Temperature Summary Condition registers As Figure 11 1 shows each status register set except the Standard Event Register set has a condition register A condition register is a real time read only register that constantly updates to reflect the present operating conditions of the instrument For example while the Model 2701 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 11 4 For details on read ing registers see Reading registers page 11 7 Table 11 4 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 Note The format of the response messages for the above queries is set by the FORMatt SREGister comm
145. the screw terminals on the Model 7700 Channel designations for the screw terminals are contained in Figure B 3 Model 2701 User s Manual Model 7700 Connection Guide B 5 Figure B 2 Screw terminal access LOCK Figure B 3 Model 7700 screw terminal channel designations INPUT SENSE CH1 CH2 CH3 CH4 CH5 CH6 CH7 CH8 CH9 CH10 HL HL HL HL HL HL HL HLHLHLHL IS IS IS S v 2 WIRE 9 Mallia aaa DOH LH LH L H LH LH L H LH LH LH L CH21 CH22 27 CH11 CH12 CH13 CH14 CH15 CH16 17 CH18 CH19 CH20 B 6 Model 7700 Connection Guide Model 2701 User s Manual Wiring procedure Use the following procedure to wire the Model 7700 module Make all connections using correct wire size up to 20 AWG Also make sure to add supplementary insulation around the harness for voltages above 42V peak Figure B 4 WARNING All wiring and supplementary insulation must be rated for the maximum voltage in the system For example if 1000V is applied to the front terminals of the DMM the plug in module wiring m
146. the specified number of reading conversions for a moving average filter is reached After a reading Rdg is procured operation proceeds to Hold Hold The Hold feature is used to screen out reading anomalies When enabled the user selects a window and count for Hold In general when a reading is outside the window it is rejected operation loops back to the beginning of the Device Action as shown in Figure 8 2 The hold count specifies how many readings have to be within the window before it is accepted See Reading hold autosettle page 8 6 for operation details After a Hold Reading is acquired operation proceeds to Channel Closure Channel Closure When scanning the last device action is channel control Using the hold feature provides an auto settling time for switching relays Each open close transition will restart the hold process and a reading for each channel will not occur until the relay settles Output trigger After the device action an output trigger occurs and is available at the rear panel Trigger Link connector This trigger can be used to trigger another instrument to perform an operation e g select the next channel for an external scan 6 6 Triggering Model 2701 User s Manual Reading hold autosettle With hold enabled HOLD annunciator on the first processed reading becomes the seed reading and operation loops back within the device action block After the next reading is processed it is chec
147. to 1 and SYSTem PRESet sets count to INFinity 3 The default value depends on which switching module is installed Reference a ROUTe SCAN lt clist gt Channels will be scanned in the order that they are listed The following example shows the proper format for specifying channels in a scan list for a sequential scan ROUT SCAN 101 110 201 204 206 For the above scan list the scan will run starting with the lowest numbered channel 101 and then sequence up forward to the highest numbered channel 206 Remote programming can also be used to run non sequential scans Any scan list configured to scan backward is considered a non sequential scan The following examples configure non sequential scan lists Example 1 ROUT SCAN 101 105 103 106 110 Example 2 ROUT SCAN 110 101 Example 1 The scan starts with channel 101 and proceeds to channel 105 After channel 105 is scanned the unit backs up to scan channel 103 then proceeds forward to scan channels 106 through 110 Example 2 The scan starts with channel 110 then proceeds backward to channel 101 7 30 Scanning Model 2701 User s Manual NOTE Non sequential scanning is only intended to be performed using remote programming Unexpected results may occur if a non sequential scan is run from the front panel There must be at least two channels in the scan list Creating a scan list that has only one channel will generate error 221 settings confl
148. to 10000 TEMPerature FRTD ALPHa lt NRf gt Specify constant for USER type 0 00385 lt clist gt lt NRf gt 0 to 0 01 TEMPerature FRTD BETA lt NRf gt Specify constant for USER type 0 111 lt clist gt lt NRf gt 0 to 1 00 TEMPerature FRTD DELTa lt NRf gt Specify constant for USER type 1 507 lt clist gt lt NRf gt 0 to 5 00 FREQ function SENSe 1 Optional root command FREQuency THReshold VOLTage Select threshold voltage range 10 f RANGe lt n gt lt clist gt n 0 to 1010 FREQuency APERture n lt clist gt Set gate time for FREQ measurements 1 0 g Model 2701 User s Manual Basic DMM Operation 3 53 Table 3 7 continued Basic measurement commands Commands Description Default Ref PERIOD function PERiod THReshold VOLTage RANGe Select threshold voltage range 10 f n lt clist gt n 0 to 1010 PERiod APERture n lt clist gt Set gate time for PERIOD measurements 1 0 g in secs n 0 01 to 1 0 CONT function SENSe 1 Optional root command CONTinuity THReshold lt NRf gt Set continuity threshold in ohms 10 lt NRf gt 1 to 1000 SYSTem BEEPer lt b gt Enable disable beeper lt b gt ON or OFF ON Set temperature measurement units UNIT TEMPerature lt name gt Set temperature units lt name gt C CEL h F FAR or K Trigger and retrieve readings i INITiate CONTinuous lt b gt Enable disable continuous initi
149. to select either the real time clock timestamp or the relative timestamp NOTE Changing the timestamp will clear the buffer if a storage is in process The message BUF CLEARED will be displayed to indicate the buffer readings were lost If no storage is in process changing the timestamp will not clear the buffer 1 Press SHIFT and then SETUP 2 Usethe a and keys to display TSTAMP 3 Press the key to place the cursor on the presently selected timestamp REL or RTCL 4 Use the or key to display the relative REL or real time clock RTCL and press ENTER Storing readings Perform the following steps to store readings 1 Setup the Model 2701 for the desired configuration 2 Press the STORE key 3 Usethe lt gt keys to specify the number of readings to store in the buffer 2 to 450000 Pressing the AUTO key sets the readings count to 000000 NOTE With buffer auto clear disabled the only valid buffer size values are 450000 and 000000 which clears the buffer Any other buffer size value is ignored 4 Press ENTER The asterisk annunciator turns on to indicate the buffer is enabled It will turn off when the storage is finished 5 The buffer can be stopped at any time by pressing EXIT NOTE Stored readings are not lost when the instrument is turned off To clear the buffer set the reading value to 000000 and press ENTER For remote programming the continuous storage mode ca
150. trigger via the Trigger Link line EXT TRIG is received The front panel TRIG key is pressed The Model 2701 must be taken out of remote before it will respond to the TRIG key Use the LOCAL key or send SYSTem LOCal over the Ethernet RS 232 Trigger command TRG is received over the Ethernet or RS 232 Delay auto or manual A programmable delay is available after event detection It can be set manually or an auto delay can be used With auto delay selected the instrument automatically selects a delay period that will provide sufficient settling for function changes autorange changes and multi phase measurements Normal measurement state With auto delay selected and the External or Bus control source selected the Model 2701 selects a delay based on the selected voltage range The auto delay period cannot be adjusted by the user The auto delays are listed in Table 8 1 With one of the other control sources selected the auto delay is 0 0005 for all functions and ranges 6 4 Triggering Model 2701 User s Manual Scanning When scanning the nominal delay will be long enough to allow each switch ing module channel relay to settle before making the measurement When scanning the auto delay times in Table 8 1 are valid for all control sources Table 8 1 Auto delay settings Function Range and delay DCV 100mV 1V 10V 100V 1000V lms lms lms Sms Sms ACV 100mV 1V 10V 100V 750V 25ms 25ms 25ms 2
151. user setups is covered in Section 1 see Defaults and user setups on page I 21 Model 2701 User s Manual Scanning 7 13 Scan reset From the scan configuration menu you can reset the scan configuration to the default setup for a simple scan For the Model 7700 switching module channels 21 and 22 are turned off not used and channels 1 through 20 are configured as follows Function DCV Range Auto Rate Slow All other multimeter features and functions are disabled When the scan is run by pressing STEP or SCAN channels 1 through 20 will be scanned and the 20 DCV readings will be stored in the buffer Perform the following steps to reset the scan configuration 1 Press SHIFT and then CONFIG to enter the scan configuration menu 2 Press the or key to display INT RESET and press ENTER After briefly displaying LIST RESET the instrument returns to the normal measure ment state Simple scan For a simple scan you specify a starting channel MIN CHAN and an ending channel MAX CHAN for the scan These settings determine the number of channels in the scan For example if you set MIN CHAN to 101 and MAX CHAN to 110 there will be 10 channels in the scan list The starting channel number must be lower than the ending channel number If you enter an invalid value the message TOO SMALL or TOO LARGE will be displayed briefly The displayed channel number will default to the lowest available channel
152. v 0 002 to 60 50Hz 0 002 to 50 NPLCycles Query line cycle integration rate v DIGits n lt clist gt Specify measurement resolution 4 to 7 6 Sec 4 DIGits lt clist gt Query resolution REFerence n lt clist gt Specify reference in C 328 to 3310 0 Sec 5 v STATe lt b gt lt clist gt Enable or disable reference OFF v STATe lt clist gt Query state of reference v ACQuire lt clist gt Use input signal as reference REFerence lt clist gt Query reference value v AVERage Path to configure and control filter Sec 4 TCONtrol lt name gt Select filter type MOVing or REPeat Note 3 TCONtrol Query filter type WINDow lt NRf gt Set filter window in of range 0 1 0 to 10 WINDow Query filter window COUNt n lt clist gt Specify filter count 1 to 100 10 COUNC lt clist gt Query filter count STATe b lt clist gt Enable or disable filter Note 4 STATe lt clist gt Query state of digital filter TRANsducer lt name gt Select temperature transducer TCouple TCouple Sec 3 lt clist gt TRANsducer lt clist gt FRTD or THERmistor Query transducer type 15 16 SCPI Reference Tables Table 15 5 continued SENSe command summary Model 2701 User s Manual DELT2 lt clist gt Query delta Default Command Description parameter Ref SCPI SENSe 1 TEMPeratur
153. wire function such as requires that another measurement channel be paired to the system channel For example if the switching module has 20 measurement channels channels 1 through 10 can be used as the system channel while channels 11 through 20 are used as the paired channel For a switching module that has 20 measurement channels channel 1 is paired to channel 11 channel 2 is paired to channel 12 channel 3 is paired to channel 13 and so on Figure 2 2 shows an example of system channel connections for a 4 wire function Assume a Model 7700 switching module is installed in slot 1 of the mainframe and a 4 wire function such as 4 is selected When channel 101 is closed using the system channel close keys the Channel 1 relay and the input backplane isolation relay Channel 25 closes to connect the channel to DMM Input Also the Channel 11 relay and the sense backplane isolation relay Channel 24 close to connect the paired channel to DMM Sense Also note in Figure 2 2 that the Channel 23 relay closes to isolate channel 1 from channel 11 The complete simplified schematic of Model 7700 is provided in Figure 2 12 Relay i Figure 2 2 4 wire system channel connections to Model 2701 DMM M Model 2701 slot 1 i Mk dris kn dida C a i ea seers Ss 1 Model 7700 Switching Module DMM i n i Channel 1 i Relay Channel 25 tg T HI KOHI 1 Channel 1 1 Input
154. x 104 1 952 394 635 x 108 2 560 740 231 x 10 0 002 C to 0 001 C too Co cE c4E wa c E where tog is the calculated temperature in C E is the measured voltage in microvolts Table F 7 Type S inverse function polynomial 1 064 C to 1 664 5 C 1 664 5 C to 1 768 1 C 50 C to 250 C 250 C to 1 200 C 10 332uV to 17 536uV to 235uV to 1 8744 V 1 8740 V to 11 9500 V 17 5360 V 18 693u V co 0 0 1 291 509 199 x 10 8 087 801 117x 10 5 333 875 126 x 10 1 849 49460 x 10 1 466298 863 x 10 1 621 573 104 x 10 1 235 892 298 x 10 8 005 050 62 x 10 1 534 713 402 x 10 8 536 869 453 x 10 1 092 657 613 x 10 c3 1 02237430 x 107 3 145 945 973 x 10 4 719 686 976 x 10719 4 265 693 686 x 108 c4 1 522 485 92 x 10719 4 163 257 839 x 107 1 441 693 666 x 104 6 247 205 420 x 10 5 1 888213 43 x 107 3 187 963 771 x 10 2 081 618 890 x 10 c6 1 590859 41 x 10716 1 291 637 500 x 10 c 8230278 80x 10720 2 183 475 087 x 10726 cg 2 341 819 44 x 10723 1 447 379 511 x 107 2 797 862 60x 1077 8 211 272 125 x 10 6 Error 0 02 C to 0 02 C 0 01 C to 0 01 C 0 0002 C to 0 0002 C 0 002 C to 0 002 C tog Co cE t c4E oe c E where tog is the calculated temperature in C E is the measured voltage in microvolts F 6 Temperature Equations Table
155. x 20 36 The filter window for the 20 window is 36 C Filter example Filter Type Moving Filter Window 0 01 of range Filter Count 10 Filter State On Ten readings fill the stack to yield a filtered reading Now assume the next reading which is the 11 is outside the window A reading will be processed displayed however the stack will be loaded with that same reading Each subsequent valid reading will then displace one of the loaded readings in the stack The FILT annunciator will flash until 10 new readings fill the stack NOTE 8 of the Operation Event Status Register sets when the filter window has properly settled or the filter is disabled See Section 11 Status Structure for details Model 2701 User s Manual 1 of range Range Digits Rate Bandwidth and Filter Windows Violation 1 4 of range 1 of range 4 17 Integration Time Figure 4 3 Filter window Voltage B A Conversions Filter configuration Ai Type Moving jd Count 5 i Window None p Rdg 1 Filter configuration 1 Moving Count 5 Window 1 Rdg 1 Filter configuration A1 Type Repeating A Count 5 p Window None A1 Filter configuration 1 Repeating fo Count 5 Ai Window 1 4 18 Range Digits Rate Bandwidth and Filter Model 2701 User s Manual Filter control and configuration The FILTER key toggles the state of the Filter When
156. 0 When a 2 wire function i e DCV is selected channel 23 opens 2 pole position to allow any of the 20 channels to be connected to the input backplane When a 4 wire function is selected channel 23 closes 4 pole position to isolate channels 1 through 10 from channels 11 through 20 With a system channel 1 through 10 closed its paired channel 11 through 20 will also close to connect the sense channel to the sense backplane For the two current channels 21 and 22 signal HI and LO are routed directly to the backplane when the channel is closed As shown in Figure 2 12 there are also screw terminals labeled Input Sense and Amps The Input and Sense terminals are connected to the inputs of channels 24 and 25 isolation relays If channels 1 through 20 are not intended to be connected to the internal DMM channels 24 and 25 can be controlled independently using multiple channel operation The Amps terminals are connected directly to the DMM 2 38 Close Open Switching Module Channels Figure 2 12 Model 7700 simplified schematic HI o Input LO o Sense H LO o Cold Junction Ref x3 HI o oT Channel 1 RUN d LO e Channels 2 9 i oof o MNT Channel 10 Lolllll 2l 2 Channel 23 2 Pole O pen AM AS 4 Pole Closed See Note 0 0 Cold Junction Ref x3 H Channel 11 3A O HI Oo o Channel 22 LO o O
157. 00 installed in the main frame the instrument can scan channels that are valid for the selected function For front panel operation Figure 1 7 shows the three basic steps to configure and run a simple scan The differences between the STEP function and the SCAN function involve the reading count and the timer Reading count RDG CT For both STEP and SCAN the reading count specifies the number of readings to store in the buffer For STEP the reading count determines the num ber of channels to scan For SCAN the reading count also determines the number of scans to perform and is best explained by an example Assume there 10 channels in the scan list 1 101 through 110 If you set the reading count to 10 or less one scan of the 10 channels will be per formed If you set the reading count to any value from 11 to 20 two scans will be per formed A reading count from 21 to 30 gives you three scans and so on Timer interval TIMER For the STEP function the timer specifies the time delay between scanned channels For the SCAN function the interval specifies the time delay between scans The timer starts when the scan is started For SCAN the next scan will not start until the timer interval expires NOTE The Model 2701 can also be configured to run an advanced scan For an advanced scan each channel can have its own unique setup i e function range etc Advanced scanning is covered in Section 7 1 36 Gettin
158. 00 000 With the cursor on the polarity sign the and keys toggle polarity 4 Press ENTER The MATH annunciator will turn on and the result of the calculation will be displayed Note that the calculation will be applied to all measurement functions 5 To disable mX b again press SHIFT and then MATH The MATH annunciator will turn off NOTE The result of the percent calculation is positive when the input exceeds the reference and negative when the input is less than the reference The result of the percent calculation may be displayed in exponential notation For example a displayed reading of 2 500E 03 is equivalent to 250096 2 5K 5 10 Rel Math Ratio Channel Average dB Model 2701 User s Manual Reciprocal 1 X The reciprocal of a reading is displayed when the reciprocal 1 X math function is enabled Reciprocal 1 X where X is the normal input reading The displayed units designator for reciprocal readings is R This units designator cannot be changed Example Assume the normal displayed reading is 2 5Q The reciprocal of resistance is conductance When the reciprocal math function is enabled the following conductance reading will be displayed 0 4R Reciprocal 1 X configuration 1 Press SHIFT and then MATH to display the math menu 2 Press the RANGE key to display 1 X and press ENTER The MATH annunciator will turn on and the result of the calculation will be displayed Note
159. 1 User s Manual Thermocouple equation The Model 2701 uses the ITS 90 inverse function coefficients for the polynomial to calculate thermocouple temperature The Model 2701 measures the thermocouple voltage and then calculates temperature in C as follows tog Co c4E c E t c4E 5 cE where tog is the calculated temperature in C Co C are the coefficients for the thermocouple type is the thermocouple voltage in microvolts u V The coefficients for each thermocouple type are listed in Table F 1 through Table F 8 Table F I Type B inverse function polynomial 250 C to 700 C 700 C to 1 820 C 291 pV to 2 310 V 2 431pV to 13 8204 V co 9 842 332 1 10 2 131507 1 1 x 10 cy 6 997 1500 107 2 851 0504 1 x 10 8476 5304 x 10 5 274 288 7 1 x 10 1 005 2644x 10 9 916 080 4 1 x 10 c4 8 334 595 2 10 1 1 296 530 3 1 10 cs 4 550 8542 10 1 119 587 0 1 x 10716 cg 1 552303 7 x 10716 6 062 519 9 1 x 10 c7 2 9886750 x 10720 1 866 169 6 1 x 10725 cg 2474286 0 x 107 2 487 858 5 1 x 10730 Error 0 03 C to 0 02 C 0 02 C to 0 01 C tog Co c4E oe cE where tog is the calculated temperature in C E is the measured voltage in microvolts Model 2701 User s Manual Temperature Equations Table F 2 Type E inverse function polynomial 200 C to 0 C 0 C to 1 000 C 8 825uV to Ou
160. 14 FORMat commands e CHANnel References the reading to a switching module channel If the reading is not for a switching module channel 000 will be returned UNITs Identifies the measurement function 1 e VDC e RNUMber References the reading to the buffer reading number TSTamp Timestamps the reading ABSolute or DELTa timestamp as set by the TRACe TSTamp FOR Mat command e FORMat ELEMents READing CHANnel UNITs RNUMber TSTamp LIMits 6 14 Buffer Model 2701 User s Manual Choose the elements to be outputted with each DATA or each buffer reading in a TRAC DATA RNUMber is reading number TSTamp is Timestamp as set by the SYST TSTamp TYPE command The other elements should be self explanatory The query acts the same as 2000 except there are six possible elements instead of 3 Therefore if only READ is selected then FORM ELEMents returns the string READ The LIMits are returned in ASCII format as a four bit number abcd where a corresponds to High Limit 2 b is Low Limit 2 c is High Limit 1 and d is Low Limit 1 A zero in the bit position indicates a passing limit while a 1 indicates failure In the binary formats the limit information must be decoded from the value 0 15 returned where the MSB is High Limit 2 and the LSB is Low Limit 1 For example a value of 10 returned in the limits field would indicate that High Limit 2 and High Limit 1 both failed Real time timestamps
161. 1OMQ reference resistor 3 26 Basic DMM Operation Model 2701 User s Manual Constant current source method For the 100 2to IMO ranges the Model 2701 uses the constant current method to measure resistance The Model 2701 sources a constant current Isoup to the DUT and measures the voltage Resistance is then calculated and displayed using the known current and measured voltage VwgAs Igoug The constant current method is shown in Figure 3 10 The test current sourced to the DUT depends on the selected measurement range For example for the 1000 range the test cur rent is ImA Since the voltmeter of the Model 2701 has very high input impedance gt 10GQ virtually all the test current 1mA flows through the DUT For DUT 4kQ 4 wire ohms measurements should be used as shown in Figure 3 10B The voltage is measured at the DUT This eliminates IR drop in the test leads which could be significant when measuring low ohm DUT Model 2701 User s Manual Basic DMM Operation 3 27 Figure 3 10 Constant current method to measure ohms 100Qto IMQranges A 2 wire ohms Q2 measurements 1000 through 1M9 ranges Input Hi i Input Lo ee ee ee eee ee eee eee eee eee ees Input Lo Sense Lo 3 26 Basic DMM Operation Model 2701 User s Manual Ratiometric method For the 10MQ and 100MQ ranges the ratiometric method is used to measure resistance Test current for this method is g
162. 2 16 Controlling multiple channels eee 2 17 Multiple channel operation anomalies 2 22 Dual independent multiplexers eeeeeeenee 2 24 Identifying installed modules and viewing closed eerte 2 30 CARD MON Uses 2 30 Switching module queries remote 2 32 Relay closure Courit lee Eee dre e bina s 2 34 Reading relay closure count 2 35 Setting count update 2 35 Model 7700 switching module sseeeenn en 2 36 Switching module capabilities 2 36 Schematic 2 37 3 Basic DMM Operation sss 3 1 DMM measurement 3 2 High energy circuit safety precautions 3 3 Performance considerations sse 3 4 Warm Up ETE 3 4 PULOZ ONO HE 3 4 LSYNC line cycle synchronization 3 5 Remote programming autozero and LSYNC 3 6 Channel list parameter clist sse 3 7 Voltage measurements DCV and 3 8 input divider enne 3 8 Ger
163. 220 when the scan is run See Section 1 for details on power on default settings 7 12 Scanning Model 2701 User s Manual There are two scan configurations simple and advanced When you configure the simple scan the instrument uses the present instrument setup for each channel in the scan For the advanced scan each channel can have its own unique setup As explained in Trigger models page 7 4 there is a user set delay auto or manual that is in effect for both the simple and advanced scan Channel setup considerations Rel In order to use an acquired rel value for an advanced scan channel the rel value has to be acquired with the instrument in the normal measurement state Details to set rel for scan channels are provided in Relative page 5 2 Scanning examples front panel and remote programming at the end of this section demonstrate how to set rel values for scan channels Filter The moving filter cannot be used in a scan only the repeat filter can be used If you configure a channel or channels to use the moving filter the filter will be off when the scan is run See Section 4 for details on filter Hold Reading hold cannot be used with scanning Do not set up a scan channel to use hold and do not run a scan with hold enabled NOTE When in the scan setup menu use the edit keys 4 a and to make selections and set values Displayed selections and settings are entered by pressing the ENTER key Savin
164. 2700 Instrument Driver Examples Table G 1 continued Visual Basic and CVI C examples Model 2701 User s Manual Name Manual Reference Brief Description Advance4 None Use Case 4 Two scans using 7708 module 40 channel DCV scan 1V range Configuration saved in User Setup 1 20 channel scan Configuration saved in User Setup 2 e Models 2700 and 2701 1000 range e Model 2750 10Q range dry circuit ohms enabled Setup 1 or Setup 2 recalled to perform scan Measurement speed rate 0 1 plc DCV input divider Enabled LOMQ input impedance Filter Disabled no filtering Buffer Store 40 reading strings 20 reading strings Buffer elements include reading only Limits DCV scan Limit 1 all channels 20mV Master Latch enabled Triggering Bus control source Data retrieval SRQ if limit fails Advance5 None Use Case 5 32 channel scan using 7701 module Common side 4 wire ohms measurements CSIDe mode Dry circuit ohms option for Model 2750 Install jumpers to connect Input Hi and Sense Hi directly to DUT common side bus Install jumpers to connect channel 35 to Sense Lo and Input Lo Buffer Store 32 reading strings Buffer elements include reading only Triggering Immediate control source Data retrieval SRQ when buffer full Model 2701 User s Manual Table G
165. 49589 10024 PT385 IPTS 68 0 003850 0 11100 1 50700 100 PT3916 IPTS 68 0 003916 0 11600 1 50594 100 Example 1 Calculate the resistance of a PT100 RTD at 100 C T The following Rp Qat 0 C alpha and delta values are used for the PT 100 RTD Table F 10 100 C Ro Qat 0 C 1000 alpha 0 003850 delta 1 49990 Using the above alpha and delta values A and B are calculated as follows A 0 00385 1 1 4999 100 0 00385 1 014999 0 003907746 B 0 00385 1 4999 1e 4 1 0 005774615 1e 4 5 774615 7 The resistance of the RTD at 100 C is then calculated as follows Rioo AT BT 100 1 0 003907746 100 5 774615e 7 1007 100 1 0 3907746 0 005774615 100 1 385 138 50 F 10 Temperature Equations Model 2701 User s Manual Example 2 Calculate the resistance of a D100 RTD at 100 C T The following R Qat 0 C alpha beta and delta values are used for the D100 RTD Table F 10 T 100 C Ro Qat 0 C 100 alpha 0 003920 beta 0 10630 delta 1 49710 Using the above alpha and delta values A and B are calculated as follows A 0 003920 1 1 49710 100 0 003920 1 014971 0 003978686 B 1 0 003920 1 49710 1e 4 1 0 005868632 1e 4 5 868632e 7 1 0 003920 0 10630 1e 8 1 0 000416696 1e 8 4 16696e 12 The resistance of the RTD at 100 C Rj go is then calculated as follows
166. 5 Model 2701 s Digital I O port is accessed at a male DB 9 connector located on the rear panel The connector location and pin designations are shown in Figure 9 2 Figure 9 2 Digital I O port Model 2701 WARNING no INTERNAL OPERATOR SERVICABLE PARTS SERVICE BY QUALIFIED PERSONNEL ONLY Link Act_1006T EIC BUT cu WAS E dE emo 1 Digital Output 1 low limit 1 2 Digital Output 2 high limit 1 3 Digital Output 3 low limit 2 4 Digital Output 4 high limit 2 6789 Es MNT 5 master limit Ext Trig input DIGITAL I O 7 Diode Clamp 8 Hardware Interlock input 9 Digital chassis Ground 12345 Digital input trigger link input When enabled the Trigger In pin 6 and Digital Ground pin 9 can be used as the trigger link input for external triggering Pin 6 is physically connected to the input line pin 2 of the TRIG LINK connector Pin 8 of the digital I O is used to enable or disable Trigger In Trigger In is enabled by leaving pin 8 open or pulling it high 45V Trigger In is disabled by setting pin 8 low 0V NOTE External triggering is covered in Section 8 9 6 Limits and Digital I O Model 2701 User s Manual Digital outputs The digital I O port has five digital outputs Each digital output can be used as a sink to control devices e g relays or as a source to provide input to external logic TTL or CMOS circuitry The simplified schematic
167. 57 6k 38 4k e 19 2k 9600 e 4800 2400 1200 e 600 e 300 The factory selected baud rate is 9600 When you choose a baud rate make sure that the programming terminal that you are connecting to the Model 2701 can support the baud rate you selected Both the multimeter and the other device must be configured for the same baud rate Model 2701 User s Manual Remote Operations 10 29 Signal handshaking flow control Signal handshaking between the controller and the instrument allows the two devices to communicate to each other regarding being ready or not ready to receive data Software flow control Software flow control is in the form of X ON and X OFF characters and is enabled when XonXoFF is selected from the RS232 FLOW menu When the input queue of the Model 2701 becomes more than I full the instrument issues an X OFF command The control program should respond to this and stop sending characters until the Model 2701 issues the X ON which it will do once its input buffer has dropped below half full The Model 2701 recognizes X ON and X OFF sent from the controller An X OFF will cause the Model 2701 to stop outputting characters until it sees an X ON Incoming commands are processed after the CR character is received from the controller NOTE For RS 232 operation OPC or OPC should be used with slow responding commands A list of the slowest responding commands and details on OPC and OPC are provided
168. 5ms 25ms FREQ and 100mV 1V 10V 100V 750V PERIOD lms lms lms lms lms DCI 20mA 100mA 1A 3A 2ms 2ms 2ms 2ms ACI 1A 3A 400ms 400ms 2 OA 100Q 1kQ 10kQ 100kQ IMQ 10MQ 100MQ 3ms 3ms 13ms 25ms 100ms 150ms 25025 Continuity 1kQ 3ms TEMP The auto delay for thermocouples is 1ms For thermistors and 4 wire RTDs the auto delay period is the same as the delay for the resistance range that is used for the measurement The delay function is accessed by pressing SHIFT and then DELAY The present delay setting AUTO or MANual is displayed Press the or key to display the desired setting and press ENTER If MANual is chosen also enter the duration of the delay in the hour minute second format using the 4 gt a and keys The maximum is 99H 99M 99 999S Note that pressing the AUTO key sets the delay to 0 001 sec Press ENTER to accept the delay or EXIT for no change Model 2701 User s Manual Triggering 8 5 Device action The primary device action is a measurement However the device action block could include the following additional actions Figure 8 2 Figure 8 2 Device action From Delay Block To Output Trigger of Figure 8 1 Block of Figure 8 1 Filter DEVICE ACTION Filtering If the repeating filter is enabled the instrument samples the specified number of reading conversions to yield single filtered reading Only one reading conversion is performed if the filter is disabled or after
169. 701 User s Manual Buffer 6 13 TRACe NOTify lt NRf gt Specify number of readings that will set Trace Notify bit lt NRf gt 1 to 449999 Use this command to specify the number of stored readings that will set bit B6 Trace Notify of the measurement event register See Section 11 for details on status structure The maximum valid parameter value for this command is one less than the present buffer size which is set by the TRACe POINTs command For example TRACe POINts 450000 sets the buffer size to 450 000 readings For this buffer size the maximum valid parameter value for TRACe NOTify is 449999 450000 1 When an invalid parameter value is specified the command is ignored and causes error 222 parameter data out of range 1 FORMat ELEMents lt item list gt Select elements for TRACe DATA lt item list gt READing CHANnel UNITs RNUMber TSTamp The data returned by TRACe DATA can include from one to all five data elements shown in the above item list For example if you want the units and reading number included with the reading you would send this command FORMat ELEMents READing UNITs RNUMber Only the elements defined by the list are used Elements not included in the list are not used You can specify the elements in the list in any order but they must be separated by commas The data elements that can accompany the reading are summarized as follows More details on data elements are provided in Section
170. 8 2 Front panel scan 7 4 Idle 8 2 Idle and initiate 8 16 Operation 8 18 Remote operation 8 16 Remote scan 7 26 With SCAN function 7 6 Trigger models With STEP function 7 5 Triggering 8 1 Commands 8 19 External see External triggering Programming example 8 20 Remote programming 8 16 User setups see Setups Visual Basic examples G 2 Voltage measurements DCV and ACV 3 8 Connections 3 8 Front panel input 3 8 Model 7700 switching module 3 10 DCV input divider 3 8 Procedure 3 11 Voltmeter complete 8 10 Warm up 3 4 Specifications are subject to change without notice All Keithley trademarks and trade names are the property of Keithley Instruments Inc All other trademarks and trade names are the property of their respective companies KEITHLEY A GREATER MEASURE CONFIDENCE Keithley Instruments Inc Corporate Headquarters 28775 Aurora Road Cleveland Ohio 44139 440 248 0400 Fax 440 248 6168 1 888 KEITHLEY www keithley com 12 06
171. 95 CALCulate 1 KMATh PERCent AC Quire Use input signal as reference value CALCulate 1 STATe lt b gt lt clist gt Enable or disable calculation b Note 2 CALCulate 1 DATA LATest CALCulate 1 DATA FRESh or OFF Return last result of calculation Return last fresh result of calculation Channel list parameter lt clist gt SCH where S Mainframe slot number 1 or 2 Examples 101 Slot 1 Channel 1 CH Switching module channel number must be 2 digits 101 203 Slot 1 Channel 1 and Slot 2 Channel 3 101 110 Slot 1 Channels 1 through 10 1 The lt clist gt parameter is used to configure one or more channels for a scan 2 RST default is ON SYSTem PRESet is OFF Model 2701 User s Manual Rel Math Ratio Channel Average dB 5 13 Setting mX b units The char parameter for CALCulate K MATh MUNits must be one character enclosed in single or double quotes It can be any letter of the alphabet the degrees symbol or the ohms symbol Q The ohms symbol Q and the degrees symbol are not ASCII characters and therefore must be substituted with the and V characters as follows CALCulate KMAth MUNIits P Use ohms symbol Q as units designator CALCulate KMAth MUNits V Use degrees symbol as units designator Percent reference The PERCent lt NRf gt command specifies the reference value for the percent calculat
172. ASK value MASK GATeway value GATeway DHCP b Select communications mode ETHernet or SERial Ethernet Set IP address of 2701 n n n n Query IP address of 2701 Sets the subnet mask Query subnet mask Set the Ethernet gateway n n n n Query the Ethernet gateway Enable or disable Dynamic Host Control Protocol DHCP 15 24 SCPI Reference Tables Model 2701 User s Manual Table 15 7 continued SYSTem command summary Default Command Description parameter Ref SCPI SYSTem COMMunicate ETHernet DHCP Query state of DHCP MAC Returns MAC address of 2701 6 hexadecimal values separated by colons 00 60 1A 00 04 0B SERial RS 232 BAUD n Set baud rate 300 600 1200 2400 4800 9600 19200 38400 57600 115200 BAUD Query baud rate PACE name Control Xon Xoff flow control XON on or NONE off PACE Query state of flow control v TERMinator lt name gt Select output terminator CR LF CRLF or LFCR TERMinator Query output terminator v CONTrol Control RTS CTS hardware handshaking v RTS lt name gt Enable IBFull or RFR or disable OFF hardware handshaking RTS Query state of hardware handshaking v SEND data Send data from serial port to another instrument ENTer Read data from serial port Note 1 Tf there is no card in the specified slot error 241 Hardware Missing wi
173. After enabling autozero you can update the internal reference points immediately by setting the integration rate to 0 002 PLC and then back to the desired setting see NPLC commands in Section 4 Model 2701 User s Manual Basic DMM Operation 3 7 Channel list parameter lt clist gt Channels of one or more switching modules installed in the Model 2701 can be scanned Each scan channel can have its own unique setup For example a channel could be set to measure DCV on the 10V range while another channel can be set to measure ACV on the 1V range From the front panel scan channels are configured from the scan configuration menu as explained in Section 7 For remote programming the lt clist gt parameter is used to configure scan channels Channel list parameter lt clist gt SCH where S Mainframe slot number 1 or 2 CH Switching module channel number must be 2 digits Examples 101 Slot 1 Channel 1 101 203 Slot 1 Channel 1 and Slot 2 Channel 3 101 110 Slot 1 Channels 1 through 10 Throughout this manual you will encounter commands that can use the lt clist gt parameter The lt clist gt simply indicates that the associated command can be used to configure a scan channel For example SENSe FUNCtion VOLTage AC Select ACV function SENSe FUNCtion VOLTage AC 101 Configure scan channel 101 for ACV While in the normal measurement display state the first command simply
174. BO 0 0 1 0 0 0 0 0 Mask to read B5 decimal 32 When a returned value for STB is AND ed with the above mask it will read 0 OPC clear or 32 OPC set NOTE More information on OPC is provided in Section 12 11 22 Status Structure Model 2701 User s Manual Queues The Model 2701 uses two queues which are first in first out FIFO registers e Output Queue Used to hold reading and response messages e Error Queue Used to hold error and status messages The Model 2701 status model Figure 11 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 bit in the Status Byte Register An appropriate query command is used to read a message from the Output Queue 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
175. Blue French Thermistor connections A thermistor can be connected directly to the front panel inputs or to any of the 20 input channels of the Model 7700 switching module as shown in Figure 3 15 Model 2701 User s Manual Basic DMM Operation 3 41 Figure 3 15 Thermistor connections Model 2701 Input HI Thermistor B Model 7700 switching module Module Thermistor 4 wire RTD connections Shown in Figure 3 16 are 4 wire RTD connections to the Model 2701 For the Model 7700 switching module paired channels are used to perform the 4 wire measurement The two input leads of the RTD are connected to a primary channel 1 through 10 while the two sense leads are connected to its paired channel 11 through 20 Channel 1 is paired to channel 11 channel 2 is paired to channel 12 and so on Figure 3 16 4 wire RTD connections Model 2701 SENSE SPN eur A m A AC Voltage Source Lo 500V INPUTS EAS 5 A Joh E FRONTIREAR 3A25 iov AMPS Input Impedance 1MQ in parallel with 100pF Caution Maximum Input 1000V peak 8 x 10 V Hz 3 42 Basic DMM Operation Model 2701 User s Manual Temperature measurement configuration The Model 2701 is configured to measure temperature from the temperature measurement configuration menu Use the following general rules to navigate through the menu structure e Press SHIFT and then SENSOR to enter the menu structure Cursor position is indica
176. C APERture n lt clist gt Set rate for DCI in secs n 3 333e 5 to 1 Note 3 CURRent AC NPLCycles n lt clist gt Set rate for ACI in PLCs n 0 002 to xd 5 0 CURRent AC APERture n lt clist gt Set rate for ACI in secs n 3 333e 5 to js Note 3 RESistance NPL Cycles n lt clist gt Set rate for Q2 in PLCs n 0 002 to x 5 0 RESistance APERture n lt clist gt Set rate for Q2 in secs n 3 333e 5 to 1 Note 3 FRESistance NPLCycles n lt clist gt Set rate for in PLCs n 0 002 to x 5 0 FRESistance APERture n lt clist gt Set rate for in secs n 3 333e 5 to 1 Note 3 TEMPerature NPLCycles n lt clist gt Set rate for TEMP in PLCs n 0 002 to 2 5 0 TEMPerature APERture n lt clist gt Set rate for TEMP in secs n 3 333e 5 to 1 Note 3 4 12 Range Digits Rate Bandwidth and Filter Table 4 5 continued Rate and bandwidth commands Model 2701 User s Manual lt NRf gt lt clist gt lt NRf gt 3 to 3e5 gt Commands 6 Description Default Bandwidth commands SENSe 1 VOLTage AC DETector B ANDwidth Set AC bandwidth for ACV in Hertz lt NRf gt 30 lt NRf gt lt clist gt 3 to 3e52 CURRent AC DETector BAND width Set AC bandwidth for ACI in Hertz 30 Channel list parameter lt clist gt SCH where S Mainframe slot
177. CALCulate3 LIMit2 STATe lt b gt Enable disable limit 2 test b ON or OFF OFF Trigger commands TRIGger SOURce name Select control source lt name gt IMMediate TIMer IMM MANual BUS or EXTernal TRIGger TIMer n Set timer interval in sec n 0 001 to 999999 999 0 1 TRIGger COUNt lt NRf gt Set trigger count lt NRf gt 1 to 450000 or INFinity Note 2 TRIGger DELay lt n gt Set delay in sec n 0 to 999999 999 0 TRIGger DELay AUTO lt b gt Enable disable auto delay lt b gt ON or OFF ON SAMPle COUNt lt NRf gt Set sample count lt NRf gt 1 to 450000 1 e SAMPle COUNt Query sample count INITiate CONTinuous lt b gt Enable disable continuous initiation lt b gt ON or OFF f INITiate Initiate one scan cycle f READ Initiate one scan cycle and request sample readings f Model 2701 User s Manual Scanning 7 29 Table 7 1 continued Scanning commands Commands Description Default Ref Buffer commands TRACe DATA Read buffer readings TRACe CLEar Clear buffer Channel list parameter lt clist gt SCH where S Mainframe slot number 1 or 2 CH Switching module channel number must be 2 digits Examples 101 Slot 1 Channel 1 101 203 Slot 1 Channel 1 and Slot 2 Channel 3 101 110 Slot 1 Channels 1 through 10 Notes 1 Not affected by RST and SYSTem PRESet Front panel factory default is OFF 2 RST sets count
178. Channel 1 and Slot 2 Channel 3 101 110 Slot 1 Channels 1 through 10 The lt clist gt parameter is used to configure one or more channels for a scan Enabling disabling ratio or channel average As with front panel operation enabling ratio disables channel average and conversely enabling channel average disables ratio Ratio and channel average delay RATio DELay or CAVerage DELay sets the delay between the two channel measure ments for the enabled calculation This delay is applied after the trigger delay in the trigger model see Section 8 for details This delay cannot be set from the front panel The 0 5s default delay keeps the relays from cycling too fast Setting a shorter delay may shorten the life of the relays It does not matter which of the two commands you use to set the delay The set delay affects both ratio and channel average Model 2701 User s Manual Rel Math Ratio Channel Average dB 5 19 Ratio and channel average programming examples Example 1 The following command sequence performs the ratio calculation using pri mary channel 102 of the Model 7700 NOTE The following example can be run from the KE2700 Instrument Driver using the example named Ratiol in Table G 1 of Appendix G RST One shot measure mode FUNC VOLT Select DCV function ROUT CLOS 80102 Close channel 102 RAT ON Enable the ratio calculation READ Read the result of the calculation Example
179. D 1 V A CF 1 When 0 5 D lt 1 BENE ID 1 Triangular sawtooth Ve RMS Vrms 0 557V CF 21 733 0 Vp A Model 2701 User s Manual Basic DMM Operation 3 15 Low level considerations For sensitive measurements external considerations beyond the Model 2701 affect the accuracy Effects not noticeable when working with higher voltages are significant in microvolt signals The Model 2701 reads only the signal received at its input therefore it is important that this signal be properly transmitted from the source The following paragraphs indicate factors that affect accuracy including stray signal pick up and thermal offsets Shielding AC voltages that are extremely large compared with the DC signal to be measured may produce an erroneous output Therefore to minimize AC interference the circuit should be shielded with the shield connected to the Model 2701 input low particularly for low level sources Improper shielding can cause the Model 2701 to behave in one or more of the following ways e Unexpected offset voltages nconsistent readings between ranges e Sudden shifts in reading To minimize pick up keep the voltage source and the Model 2701 away from strong AC magnetic sources The voltage induced due to magnetic flux is proportional to the area of the loop formed by the input leads Therefore minimize the loop area of the input leads and connect each signal at only one point Thermal EMFs T
180. Data flow remote operation and the commands used to read the result of limit tests Reference a CALCulate3 LIMitl STATe b lt clist gt CALCulate3 LIMit2 STATe b lt clist gt Unlike front panel operation Limit 1 and Limit 2 can be controlled on off separately for remote programming The front panel limit indicators are affected as follows Limit 1 enabled The front panel HIGH IN LOW indicators work the same as they do for front panel operation Limit 1 disabled and Limit 2 enabled The status indicators pertain to Limit 2 When the reading is within Limit 2 the message I2 is displayed When the reading reaches or exceeds the high or low limit the HIGH or LOW annunciator will turn on and the number 2 will be displayed NOTE When limits are disabled from the front panel both Limit 1 and Limit 2 disable for remote operation b CALCulate3 LIMit FAIL CALCulate3 LIMit2 FAIL These commands are used to query the results of Limit 1 and Limit 2 0 Passing reading within the high and low limits 1 Failing reading has reached or exceeded the high or low limit The 1 response message does not tell you which limit high or low has been reached To determine which limit has failed you will have to read the measurement event register Section 12 c CALCulate3 LIMit1 CLEar CALCulate3 LIMitl CLEar AUTO lt b gt CALCulate3 LIMit2 CLEar CALCulate3 LIMit2 CLEar AUTO lt b gt These co
181. Dus 5 16 Remote programming ratio and channel average 5 18 REA EO EE ERA MEE RI E S 5 20 Remote programming dB ssessssseeee 5 20 6 jc na i ences 6 1 Buffer oveni E 6 2 Front panel DURST a a mie Ea EAER 6 2 e eased ANE A AEA A a NEAN EE 6 2 PE E E T mm 6 4 Storing readirgs Ene 6 5 Recalling readings mir aE Taa a 6 6 Bufer Statuses aa EE 6 7 Remote programming buffer sse 6 8 Butfer comiriands 5 iue iter eee c te Fo Tete sordes teeta esti te 6 8 Programming example sse eene 6 15 7 SCanbihgm ouod 7 1 Scanning fundamentals eene nnns 7 2 Channel assignments 7 3 Sequential and non sequential 7 8 SCAN DrOCGSs dresses calet sce Dr eerie reet cose A Lue Ci 7 4 Trigger models met ect entier aet reca a ee priam 7 4 Scan 7 11 SCAM ESCH 7 13 Simple Scan i tdeo eva ama cds 7 13 AOVANCOC SCAM MER 7 14 Setting delay acci uoce ee een fale ie eti ode dts 7 18 Monitor channel aserrea netr eE RERE EE EEEE EE EEA re ie TEER RKRN 7 18 Auto channel configuration 7 20 SAVING SCL
182. Dwidth lt NRf gt Set AC detector bandwidth in Hertz 30 lt clist gt 3 to 3e5 BANDwidth lt clist gt Query bandwidth Model 2701 User s Manual SCPI Reference Tables 15 13 Table 15 5 continued SENSe command summary Default Command Description parameter Ref SCPI SENSe 1 RESistance Path to configure resistance Sec 3 v APERture n lt clist gt Set integration rate in seconds Note 2 Sec 4 3 333333e 5 to 1 APERture lt clist gt Query aperture integration rate NPLCycles n lt clist gt Set integration rate in line cycles 60Hz 5 0 Sec 4 v 0 002 to 60 50Hz 0 002 to 50 NPLCycles lt clist gt Query line cycle integration rate v RANGe Path to set measurement range Sec 4 v UPPer n lt clist gt Select range 0 to 120e6 120e6 UPPer lt clist gt Query range v AUTO lt b gt lt clist gt Enable or disable auto range ON AUTO lt clist gt Query state of auto range v DIGits n lt clist gt Specify measurement resolution 4 to 7 7 Sec 4 DIGits lt clist gt Query resolution REFerence n lt clist gt Specify reference 0 to 120e6 0 Sec 5 v STATe lt b gt lt clist gt Enable or disable reference OFF v STATe lt clist gt Query state of reference v ACQuire lt clist gt Use input signal as reference REFerence lt clist gt Query reference value v AVERage Path to configure and control filt
183. E CALCulate2 STATe lt b gt Enable disable statistic calculation lt b gt ON or OFF OFF m CALCulate2 IMMediate Calculate data in buffer m CALCulate2 IMMediate Calculate data and read result m CALCulate2 DATA Read the selected buffer statistic m Notes 1 SYSTem PRESet and RST have no effect on TRACe commands The listed defaults for TRACe commands are set at the factory 2 The SYSTem PRESet and RST default is READ UNIT RNUM and TST 6 10 Buffer Model 2701 User s Manual SYSTem TIME lt hr min sec Set clock time Use to set the clock time in the 24 hour format hr min sec Seconds can be set to 0 01 sec resolution Examples SYST TIME 13 23 36 Set time to 1 23 36 PM SYST TIME 3 25 28 5 Set time to 3 25 28 5 AM The SYSTem TIME command can be used to read the time Note that it returns the actual clock time and not the time parameter specified by the TIME command SYSTem DATE yr mo day Set clock date Use to set the clock date in the year month day format When setting the year a 4 digit value must be used Example SYSTem DATE 1999 11 10 Set clock date to November 10 1999 SYSTem TSTamp TYPE RELative RTClock Select timestamp SYSTem TSTamp TYPE Query timestamp type next storage TRACe TSTamp TYPE Query timestamp type readings in buffer SYSTem TSTamp TYPE name Use to select the relative timestamp or the real time timestamp Note that changing the timestamp will clear the buffe
184. E Query timestamp type for readings presently in buffer c TRACe CLEar Clear the buffer immediately d TRACe CLEar AUTO lt b gt Enable disable buffer auto clear lt b gt ON or OFF ON d TRACe FREE Query bytes available and bytes in use e TRACe POINts lt NRf gt Specify size of buffer lt NRf gt 2 to 450000 100 f TRACe POINts Query size of buffer f TRACe POINts ACTual Query number of readings stored in buffer f TRACe TSTamp FOR Mat Select timestamp format lt name gt ABSolute or ABS g lt name gt DELTa TRACe FEED lt name gt Select source of readings name SENSe 1 CALC h CALCulate 1 or NONE TRACe FEED CONTrol Set buffer control lt name gt NEVer NEXT or NEV h lt name gt ALWays TRACe DATA Read all readings in the buffer i TRACe DATA SELected Specify readings to be returned lt start gt starting j lt start gt lt count gt point lt count gt number of readings TRACe NEXT Query buffer location for next stored reading j TRACe NOTify lt NRf gt Specify number of stored readings that will set Trace k Notify bit B6 of measurement event register lt NRf gt 1 to 449999 must be less than TRACe POINts value FORMat ELEMents lt item list gt Specify elements for TRACe DATA response Note 2 1 message lt item list gt READing CHANnel UNITs RNUMber and TSTamp CALCulate2 FORMat name Select buffer statistic lt name gt MINimum NONE m MAXimum MEAN SDEViation PKPK or NON
185. Event Status Measurement Event Status and Questionable Event Status Model 2701 User s Manual Status Structure 11 11 Register bit descriptions Standard event register The used bits of the Standard Event Register Figure 11 4 are described as follows Bit BO Operation Complete OPC Set bit indicates that all pending selected device operations are completed and the Model 2701 is ready to accept new com mands This bit only sets in response to the OPC query command See Section 12 for details on OPC and OPC PON URQ EXE DDE QYE OPC B15 B8 B7 B6 B5 B4 B3 B2 B1 BO Figure 11 4 Standard event status ESR Standard Event Status Register To Event Summary Bit ESB of Status Byte Register ESE PON URQ EXE DDE QYE OPC ESE B15 8 B7 B6 B5 B4 B3 B2 B1 BO Register PON Power On Query Error URQ U ser Request Operation Complete Command Error EXE Execution Error amp Logical AND DDE Device D ependent Error OR Logical OR Bit BI Not used Bit B2 Query Error QYE Set bit indicates that you attempted to read data from an empty Output Queue 11 12 Status Structure Model 2701 User s Manual e Bit B3 Device Dependent Error DDE Set bit indicates that an instrument operation did not execute properly Some of the errors specifi
186. F 8 Type T inverse function polynomial 200 C to 0 C 5 603uV to Ou V 0 C to 400 C Ou V to 20 872u V 5 C7 Error 0 0 2 594 9192 x 10 2 131 696 7 x 107 7 901 869 2 x 10 10 4 252 7777 x 10 1 330 447 3 x 10716 2 024 144 6 x 10 29 1 266 817 1 x 10724 0 04 C to 0 02 C 0 0 2 592 800 x 10 7 602 961 x 107 4 637 791 x 10 2 165 394 x 1015 6 048 144 x 1029 7 293 422 x 10 25 0 03 C to 0 03 C tog Co 2 c4E ves where tog is calculated temperature in C E is the measured voltage in microvolts Thermistor equation Model 2701 User s Manual Temperature in Kelvin is calculated using the Steinhart Hart equation as follows T 1 K ear SM R BInR C InR where Ty is the calculated temperature in Kelvin InR is the natural log of the measured resistance of the thermistor A B and C are the curve fitting constants The constants for the three thermistor types used by the Model 2701 are listed in Table F 9 Table F 9 Model 2701 curve fitting constants for thermistors 2252Q at 25 C 5000Qat 25 C 10kQat 25 C Constant Series 44004 Series 44007 Series 44006 A 0 0014733 0 001288 0 0010295 B 0 0002372 0 0002356 0 0002391 C 1 074e 7 9 557e 8 1 568e 7 Selecting a thermistor The thermistor manufacturers specified curve f
187. F or LF CR The command processor will hang if your computer does not provide this termination The following example shows how a multiple command program message must be terminated trig coun 1 lt PMT gt Command execution rules Commands execute in the order that they are presented in the program message Aninvalid command generates an error and of course is not executed e Valid commands that precede an invalid command in a multiple command program message are executed e Valid commands that follow an invalid command in a multiple command program message are ignored Model 2701 User s Manual Remote Operations 10 27 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 Multiple response messages If you send more than one query command in the same program message see Multiple command messages page 10 25 the multiple response messages for all the queries are sent to the computer 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 Each response is terminated wit
188. FT and then TEST Refer to the Model 2701 Service Manual for details Status and error messages Status and error messages are displayed momentarily During operation and programming you will encounter a number of front panel messages Typical messages are either of status or error variety as listed in Appendix C Remote programming display Using remote programming the Model 2701 can display a custom ASCII message up to 12 characters Also the front panel display and controls can be disabled Display commands The commands are listed in Table 1 3 Details on these commands follow the table 1 20 Getting Started Model 2701 User s Manual NOTE Optional command words and queries are not included in Table 1 3 Table 15 2 provides an unabridged list of all display commands Table 1 3 Display commands Command Description Default DISPlay TEXT DATA lt a gt Define message lt a gt ASCII characters none up to 12 DISPlay TEXT STATe lt b gt Enable or disable message mode lt b gt ON OFF or OFF DISPlay ENABle lt b gt Enable or disable the front panel display ON lt b gt ON or OFF SYSTem PRESet and RST have no effect on DISPlay commands The listed defaults are power on defaults DISPlay TEXT DATA lt a gt Define text message This command defines the text message for display A message can be as long as 12 char acters A space counts as a character Excess message characters r
189. H annunciator will turn on and the result of the calculation will be displayed Note that the calculation will be applied to all measurement functions 9 To disable mX b again press SHIFT and then MATH The MATH annunciator will turn off Model 2701 User s Manual Rel Math Ratio Channel Average dB 5 9 mX b rel The mX b function can be used to manually establish a rel value To do this set the scale factor m to 1 and set the offset b to the rel value Each subsequent reading will be the difference between the actual input and the rel value offset Percent This math function determines percent deviation from a specified reference value The percent calculation is performed as follows Input Reference Percent Reference x 100 where Input is the normal display reading Reference is the user entered constant Percent is the displayed result NOTE When using Rel the rel ed reading of the input signal is used by the percent calculation Percent configuration Press SHIFT and then MATH to display the math menu 2 Press the RANGE and key to display PERCENT and press ENTER to dis play the present reference value REF 41 000000 factory default 3 Keyinthe reference value The and keys control cursor position and the 4 and keys increment decrement the digit value To change range place the cursor on the multiplier and use the 4 keys m x0 001 a x 1 K x 1000 and M x 1 0
190. HIFT SETUP External triggers accessed from EX TRIG Buffer enabled and set to store 400 readings 8 12 Triggering Model 2701 User s Manual Model 7002 Factory defaults restored Scan list 1 1 1 400 Number of scans 1 Channel spacing TrigLink Figure 8 7 Trigger link connections Model 7002 Trigger Link oye D ge oye em Trigger Link Cable 8501 KEITHLEY Link Act 4100bT DIGITAL VO TRIGER ETHERNET EXT TRIG LINK 10 100 BaseT KEIMHLEY SLOT COVER CAUTION rFOR CONTINUED PROTECTION AGAINST FIRE HAZARD REPLACE FUSE WITH SAME TYPE AND RATING Model 2701 Model 2701 User s Manual Triggering 8 13 1 Press EX TRIG to place the Model 2701 in the external trigger mode 2 Press STEP on the Model 7002 to take it out of idle and start the scan The scanner s output pulse triggers the Model 2701 to take a reading store it and send a trigger pulse The following explanation on operation is referenced to the operation model shown in Figure 8 8 Figure 8 8 Operation model for triggering example Model 7002 Press STEP to start scan Model 2701 Press EX TRIG Wait for Wait for Trigger Link Trigger Link Trigger Trigger r 1 Scan Channel 1 Make Measurement Trigger Trigger Output AEN T 4 Output Trigger Uu Uu Trigger Scanned 400 Channels A Pressing EX TRIG
191. Hz To achieve the best accuracy for ACV and ACI measurements use the bandwidth setting that best reflects the frequency of the input signal For example if the input signal is 40Hz then a bandwidth setting of 30 should be used Model 2701 User s Manual Range Digits Rate Bandwidth and Filter 4 13 To set bandwidth simply specify approximately the frequency of the input signal The instrument will automatically set the bandwidth as follows lt NRf z3to29 3Hz to 300kHz 30 to 299 30Hz to 300kHz 300 to 300e3 300Hz to 300kHz NOTE rate command NPLCycles or APERture for ACV and ACT is only valid if the bandwidth for that AC function is set to 300 300Hz to 300kHz See Rate and bandwidth conflict error page 4 13 for details Rate and bandwidth conflict error For bandwidth settings of 3 and 30 the normal A D conversion method is not used for ACV and ACI measurements Therefore integration rate commands NPLCycles and APERture for these bandwidth settings will cause a settings conflict error 221 and not be executed For a bandwidth setting of 300 the normal A D conversion method is used therefore the integration rate commands can be used The default bandwidth setting is 30 for both ACV and ACI If you want to set an integration rate for an AC function you will have to first set the bandwidth to 300 Rate and bandwidth programming examples NOTE The following examples be run from the KE2700 I
192. I command SYSTem PCARdX where X 1 or 2 is used to install a pseudocard in an empty switching module slot Details are provided in Section 2 A pseudocard cannot be installed from the front panel However once it is installed you can take the Model 2701 out of remote and use the front panel When the instrument is turned off the pseudocard will be lost uninstalled Autozero Autozero is part of the normal measurement process to assure stable accurate measurements Autozero can be disabled to increase measurement speed However the readings will eventually become inaccurate over time and temperature changes Autozero can only be disabled using remote programming It cannot be disabled from the front panel Autozero is covered in Section 3 dB calculation Using remote programming you can select the dB calculation for DC or AC voltage The dB calculation makes it possible to compress a large range of measurements into a much smaller scope See Section 5 to select and configure the dB calculation You cannot select dB from the front panel However once it is selected you can take the Model 2701 out of remote and use the front panel When the instrument is reset to default conditions or turned off dB will be lost Model 2701 User s Manual Remote Operations 10 3 Separate function setups A few settings from the front panel are global That is the setting on one function also applies to the other functions For example if you se
193. INITiate external trigger SENSe DATA FRESh enter reading This step will time out if the trigger has not occurred 4 Range Digits Rate Bandwidth and Filter Range Provides details on measurement range selection Includes the commands for remote programming Digits Provides details on selecting display resolution Includes the commands for remote programming Rate and bandwidth Provides details on integration rate and bandwidth for AC measurements Includes the commands for remote programming Filter Provides details on filtering Includes the commands for remote programming 4 2 Range Digits Rate Bandwidth and Filter Model 2701 User s Manual Range The range setting is remembered by each measurement function When you select a function the instrument will return to the last range setting for that function Measurement ranges and maximum readings The selected range affects both accuracy of the measurement as well as the maximum level that can be measured The measurement ranges and maximum readings for all functions except FREQ PERIOD and TEMP are listed in Table 4 1 Input values that exceed the maximum readings cause the message OVERFLOW to be displayed Table 4 1 Measurement ranges and maximum readings Maximum Function Ranges reading DCV 100mV 10V 100V 1000V 1010V ACV 100mV 1V 10V 100V 750V 757 5N DCI 20mA 100mA 1A 3A 3 1A ACI 1A
194. Keithley will give you the MAC address of your unit After you have the address press SHIFT and then ETHERNET to bring up the MAC address edit mode You can then enter the new address in decimal Model 2701 User s Manual Remote Operations 10 13 Front panel Ethernet setup The front panel Ethernet menu provides two options VIEW and SET The VIEW is used to check the present Ethernet settings Settings cannot be changed from this menu stucture The SET option is used to change the Ethernet settings VIEW Ethernet settings Use the flowchart in Figure 10 7 to check the Ethernet settings Figure 10 7 shows the settings set at the factory All but the MAC address can be changed by the user using the SET menu SET Ethernet Ethernet settings can be changed using the flowchart in Figure 10 8 For the IP Address Subnet and Gateway the setting is divided into four parts 1 through 4 The settings shown in Figure 10 8 are the values set at the factory Figure 10 7 Flowchart to VIEW Ethernet settings Press SHIFT Press ETH ERN ET Press A or V to display C 2 Prompt for an action Displayed message or setting ETH ERN ET VIEW Press ENTER Press A or V to display VIEW MAC Press EN TER VIEW ADDRESS VIEW SUBNET VIEW GATEWAY Press ENTER Press ENTER Press EN TER 192 168 000 002 255 255 255 000 192 168 000 001 00 60 1A 00 04 0B d 4 NOTE Press EXIT to exit the menu str
195. LOSe lt clist gt Close channel s specified in list Unlisted channels not affected STATe lt clist gt Query closed channels in specified list 1 closed CLOSe Return list of all closed channels SCAN Path to configure scan Sec 7 v INTernal lt clist gt Specify list of channels to be scanned v INTernal Query scan list TSOurce lt list gt Select trigger source to start the scan IMM IMMediate HLIMitl HLIMit2 LLIMitl1 and LLIMit2 TSOurce Query trigger source for scan NVOLatile lt b gt Enable or disable nonvolatile memory for Note 2 scanning autoscan NVOLatile Query nonvolatile memory setting LSELect lt name gt Enable INTernal or disable NONE scan NONE LSELect Query state of scan Notes 1 Default value depends on which switching module is installed 2 Not affected by RST and SYSTem PRESet Front panel factory default is OFF 3 Not affected by RST and SYSTem PRESet Interval set to 15 minutes at the factory 4 The ROUT MULT CLOS command cannot be used to measure thermocouple temperature using the internal or external refer ence junction The simulated reference junction will instead be used See Temperature measurements page 3 33 for details 15 8 SCPI Reference Tables Model 2701 User s Manual Table 15 5 SENSe command summary Default Command Description parameter Ref SCPI SENSe 1 FUNCtion name Select function VOLTage DC VOLT DC Sec 3 v
196. Mat NONE or CALCulate S TATe OFF the raw reading will be retrieved by CALC DATA and CALC DATA FRESh 5 14 Rel Math Ratio Channel Average dB Model 2701 User s Manual Math programming examples Example 1 The following command sequence performs the mX b calculation for channels 101 and 102 of the Model 7700 NOTE The following example can be run from the KE2700 Instrument Driver using the example named Linear in Table G 1 of Appendix G CALC FORM MXB Select mX b calculation CALC KMAT MMF 2 Set m factor to 2 CALC KMAT MBF 100 Set Ip factor to 100 CALC STAT ON Enable math calculation ROUT CLOS 80101 Close channel 101 CALC DATA Read mX b result for channel 101 ROUT CLOS 80102 Close channel 102 CALC DATA Read mX b result for channel 102 Example 2 The following command sequence configures channels 101 through 110 of the Model 7700 to perform the percent calculation when they are scanned NOTE The following example can be run from the KE2700 Instrument Driver using the example named Percent in Table G 1 of Appendix G CALC FORM PERC 101 110 Select percent calculation CALC KMAT PERC 100 101 110 Set reference to 100 CALC STAT ON 101 110 Enable math calculation Model 2701 User s Manual Rel Math Ratio Channel Average dB 5 15 Ratio and channel average With a switching module installed in the Model 2701 the ratio or average of two channels can
197. Number 2701 900 01 Rev F August 2011 Model 2701 Ethernet Based DMM Data Acquisition System Table of Contents Visual Basic and CVI C G 2 LabVIEW examples ee e eie hee td ete G 12 Document Number 2701 900 01 Rev F August 2011 ix Table of Contents Model 2701 Ethernet Based DMM Data Acquisition System x Document Number 2701 900 01 Rev F August 2011 1 Getting Started Quick Start Of the following section topics three can be used immediately to quickly acquaint yourself with fundamental instrument operations Use QS1 to familiarize your self with front panel controls use QS2 to power up the instrument and finally use QS3 to perform exercises to operate the instrument QS1 QS2 General information Covers general information that includes contact infor mation safety symbols and terms inspection and available options and accesso ries Model 2701 features Summarizes the features of Model 2701 Plug in switching modules Summarizes the capabilities of the Keithley Model 77xx series switching modules Front and rear panel familiarization Summarizes the controls and connectors of the instrument Rack mounting Covers the options available for rack mounting the Model 2701 in a standard 19 inch rack Power up Covers line power connection line voltage setting fuse replacement power line frequency an
198. Prog Ex ConfigChan Page 3 58 Ex 4 Demonstrates configuring channels CTMMV Page 3 57 Ex 1 Demonstrates continuous AC volts measurement Digits Page 4 7 Ex 1 amp 2 Demonstrates setting display resolution Digout See 7706 packing list Demonstrates setting the digital outputs on a 7706 module Get1 Reading None Demonstrates retrieving one reading from the instrument Limits Page 9 14 Demonstrates limits and digital outputs Linear Page 5 14 Ex 1 Demonstrates an mX b linear calculation MAFilter Page 4 22 Ex 1 Demonstrates moving filter use Model 2701 User s Manual Table G 1 continued Visual Basic and CVI C examples KE2700 Instrument Driver Examples G 7 Name Manual Reference Brief Description MultiRange Page 4 5 Ex 1 amp 2 Demonstrates various range and function settings Ohmm Page 3 57 Ex 2 Demonstrates measuring offset compensated ohms in one shot trigger mode Percent Page 5 14 Ex 2 Demonstrates percent calculation PollSQR Page 11 10 Prog Demonstrates serial poll operation and use of SRQs Prmr Page 11 19 Prog Ex Demonstrates reading the measurement condition and event registers RAFilter Page 4 22 Ex 2 Demonstrates use of repeating filter RateBandwidth Page 4 13 Ex 1 amp 2 Demonstrates rate and bandwidth settings Ratiol Page 5 19 Ex 1 Demonstrates ratio calculation Ratio2 Page 5 19 Ex 2 Demonstrates r
199. RACe FREE 6 10 TRACe NEXT 6 12 TRACe NOTify 6 13 TRACe POINts 6 11 TRACe TSTamp FORMat 6 11 Front panel 6 2 Overview 6 2 Programming example 6 15 Remote programming 6 8 Standard deviation 6 8 Statistics 6 7 Wrap around buffer 6 11 Cables 1 5 Leakage 3 23 CARD menu 2 30 CARD CONFIG 2 31 CARD VIEW 2 31 Tree 2 31 Carrying case 1 6 Channel average 5 15 5 18 Basic operation 5 16 Commands 5 18 Delay 5 18 Enabling disabling 5 18 Programming examples 5 19 Remote programming 5 18 Scanning 5 17 Channel list parameter clist 3 7 Channels Assignments 2 6 7 3 Auto channel configuration 7 20 Average see Channel average Closing and opening 1 31 2 1 Monitor 7 18 Multiple see Multiple channels Numbering 2 6 Setup 7 27 Setup considerations 7 12 System see System channel CLOSE key 2 10 2 18 CLOSE MULTI 2 10 CLOSE SINGLE 2 10 Color codes Thermocouple wires 3 40 Command words 10 21 Commands Autozero and LSYNC 3 6 Basic measurement 3 51 Buffer 6 8 Common see Common commands Condition register 11 17 dB 5 20 Digits 4 6 Display 1 19 Error queue 11 23 Event enable registers 11 19 Event register 11 18 Execution rules 10 26 Filter 4 20 General bus see General bus commands Limits and digital output 9 12 Math 5 12 Multiple channel control 2 20 Range 4 4 Ratio and channel average 5 18 Rel 5 4 Scanning 7 27 SCPI see FORMat commands SCPI refer ence tables and SYSTem commands Setups 1 26 Status byte and service requ
200. ROUTe MONitor POINts command to specify the number of channels to scan Table 7 1 4 While in the normal measurement state select and enable the monitor channel as explained in Scan configuration Monitor channel page 7 18 When the reading limit for the monitor channel is reached the scan will be triggered to start When the monitor channel is scanned the display will show the reading that triggered the scan If the reading limit event is still present on the monitor channel when the scan finishes the scan will be triggered to run again Note that the scan can also be run by pressing STEP or SCAN 5 To disable the monitor scan perform the following steps a To disable monitor press SHIFT and then MONITOR MON annunciator turns off b disable limits press SHIFT and then ON OFF Press or to display LIMITS OFF and press ENTER 7 26 Scanning Model 2701 User s Manual Remote programming scanning NOTE Scanning examples remote programming and front panel operation are provided at the end of this section Trigger model The trigger model for bus operation is shown in Figure 7 2 Bus operation is similar to front panel SCAN operation with the following significant differences Idle The instrument goes into the idle state measurements halted after the last scan channel is measured For front panel operation the instrument stays in idle until the next scan is started For bus operation the instrume
201. Rioo R 1 AT BT 100 100 1 0 003978686 100 5 868632e 7 1002 4 16696e 12 1003 100 100 100 1 0 3978686 0 005868632 0 000833392 100 0 5954294 59 542940 a G KE2700 Instrument Driver Examples G 2 KE2700 Instrument Driver Examples Model 2701 User s Manual Introduction An IVI style Instrument Driver is provided with the Models 2700 2701 and 2750 The driver supports programming in LabView LabWindows CVI Visual Basic and C Test examples provided by the KE2700 Instrument Driver are listed in Table G 1 and Table G 2 Some of the examples demonstrate the simple command sequence examples that are used throughout this manual These examples include a reference to appropriate manual section in the References column of the tables Visual Basic and CVI C examples Table G 1 lists the Visual Basic and CVI C examples and Use Cases that are provided with the KE2700 Instrument Driver By default Visual Basic examples are installed in Program Files Keithley Instruments KE2700 Examples VB and CVI examples are installed in Program Files Keithley Instruments KE2700 Examples CVI Model 2701 User s Manual Table G 1 Visual Basic and CVI C examples KE2700 Instrument Driver Examples G 3 Name Manual Reference Brief Description Advancel None Use Case 1 40 channel scan using 7708 module 30 channels DCV 10V range 10 chann
202. SER type 0 to 1 507 lt clist gt 5 00 Model 2701 User s Manual SCPI Reference Tables 15 17 Table 15 5 continued SENSe command summary Default Command Description parameter Ref SCPI SENSe 1 FREQuency Path to configure frequency Sec 3 APERture n lt clist gt Sets gate time for frequency 1 0 Sec4 measurements in seconds 0 01 to 1 0 APERture lt clist gt Query frequency gate time DIGits lt n gt lt clist gt Specify measurement resolution 4 to 7 7 Sec 4 DIGits lt clist gt Query resolution REFerence n lt clist gt Specify reference 0 to 1 5e7 0 Sec 5 STATe lt b gt lt clist gt Enable or disable reference OFF STATe lt clist gt Query state of reference ACQuire lt clist gt Use input signal as reference REFerence lt clist gt Query reference value THReshold Path to select the threshold voltage range Sec 3 v VOLTage v RANGe n lt clist gt Select threshold range 0 to 1010 10 RANGe lt clist gt Query threshold range PERiod Path to configure period Sec 3 APERture n lt clist gt Sets gate time for period measurements in 1 0 Sec4 seconds 0 01 to 1 0 APERture lt clist gt Query period gate time DIGits n lt clist gt Specify measurement resolution 4 to 7 7 Sec4 DIGits lt clist gt Query resolution REFerence n lt clist gt Specify reference 0 to 1 0 Sec 5 STATe lt b gt lt c
203. STem RWLock is in effect LOCAL will be locked out If TRIGger SOURce is set to manual the TRIG key will be active in remote 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 11 Status Structure for more information 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 SYSTem RWLock command is in effect the LOCAL key is also inoperative Model 2701 User s Manual Remote Operations 10 21 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 Sections 12 through 15 for more details on common and SCPI commands 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 SYSTem BEEPer lt b gt Parameter lt b gt required SYSTem PRESet No paramet
204. Set 101 for DCV function VOLT RANG 1 5 0101 Set 101 for 10V range 4 6 Di Range Digits Rate Bandwidth and Filter Model 2701 User s Manual gits The DIGITS key sets display resolution for the Model 2701 from 31 2 to 6 digits From the front panel setting digits for one function affects all the other functions For example if you set DCV for 3 digits the other functions will also set to 3 digits For remote pro gramming each mainframe input function can have its own unique digits setting Digits has no effect on the remote reading format The number of displayed digits does not affect accuracy or speed Speed is set by the RATE key Setting display resolution To set display resolution press the DIGITS key until the desired number of digits is displayed Scanning When a simple scan is configured the present digits setting will apply to all channels in the scan When an advanced scan is configured each channel can have its own unique digits setting Details to configure and run a scan are provided in Section 7 For remote programming the lt clist gt parameter is used to configure channels for a scan Remote programming digits Digits commands The commands to control display resolution digits are listed in Table 4 3 Additional information on these commands follow the table NOTE Query commands are not included in Table 4 3 All commands for the SENSe subsystem are provided in Table 15 5 Mode
205. TERnal reference junction the scan channel 101 201 301 401 or 501 to be used for the measurement must already be configured to use a thermistor or 4 wire RTD transducer Otherwise a settings conflict error 221 will occur The TEMPerature TRANsducer command is used to select the transducer NOTE The following command can instead be used to select the reference junction TEMPerature RJUNction RSELect lt name gt lt clist gt Model 2701 User s Manual Basic DMM Operation 3 55 TEMPerature TCouple RJUNction SIMulated n lt clist gt The units for the simulated reference temperature depend on the present temperature measurement units as set by UNIT TEMPerature see Ref h NOTE The following command can instead be used to set the simulated reference temperature TEMPerature RJUNction SIMulated n lt clist gt TEMPerature FRTD RZERo lt NRf gt lt clist gt TEMPerature FRTD ALPHa NRf lt clist gt TEMPerature FRTD BETA NRf lt clist gt TEMPerature FRTD DELTa lt NRf gt lt clist gt These commands are used to set the parameters for the USER RTD type Note that the RZERo command sets the Qat 0 C parameter When any of these commands are sent the USER RTD type is automatically selected FREQuency THReshold VOLTage RANGe n lt clist gt PERiod THReshold VOLTage RANGe n lt clist gt These commands are used to specify the expected input level The in
206. Tem CARDx VMAX Request maximum allowable voltage for CARDx where x is the slot number for the module For system channel operation the instrument will display the OVERFLOW message when the maximum allowable voltage for the module is being exceeded However for multiple channel operation the OVERFLOW message will not occur until the maximum voltage of the mainframe not module is exceeded Therefore the OVERFLOW message would occur only if 1010V is exceed Careless multiple channel operation could create an electric shock hazard that could result in severe injury or death Improper operation can also cause damage to the switching modules and external circuitry Multiple channel operation should be restricted to experienced test engineers who recognize the dangers associated with multiple channel closures Model 2701 User s Manual NOTE NOTE Close Open Switching Module Channels 2 3 The Model 2701 can scan switching module channels Each channel in the scan can have its own unique setup configuration Scanning is covered in Section 7 When a setup is saved as a user setup SAVO SAV1 SAV2 SAV3 or SAV4 closed channels are also saved When the setup is restored those channels and only those channels will be closed see Defaults and user setups page 1 21 2 4 Close Open Switching Module Channels Model 2701 User s Manual Switching module installation and connections In order to exercise
207. Top Row Unshifted DCV Selects DC voltage measurement function ACV Selects AC voltage measurement function DCI Selects DC current measurement function ACI Selects AC current measurement function 2 Selects 2 wire resistance measurement function A Selects 4 wire resistance measurement function FREQ Selects frequency measurement function TEMP Selects temperature measurement function Model 2701 User s Manual Shifted MATH OUTPUT RATIO CH AVG CONT OCOMP PERIOD SENSOR Middle Row Unshifted EXTRIG TRIG STORE RECALL FILTER REL and Shifted DELAY HOLD LIMITS ON OFF TYPE MONITOR CH OFF CARD Bottom Row Unshifted OPEN CLOSE STEP SCAN DIGITS RATE EXIT ENTER Shifted SAVE SETUP CONFIG HALT TEST LSYNC ETHERNET RS 232 Getting Started 1 11 Configures and controls mX b percent or reciprocal 1 X calculation Configures and controls digital and audio beeper output for limits Enables disables channel ratio Enables disables channel average Configures and controls continuity test Enables disables offset compensated ohms with function selected Selects period measurement function Configures temperature measurements Selects external triggering as the trigger source Triggers a measurement when in external triggering EX TRIG Sets the number of readings to store and enables the buffer Displays stored readings and buffer statistics Use the 4 a and keys to navig
208. User s Manual Basic DMM Operation 3 43 Table 3 3 Thermocouple temperature measurement configuration Step Menu structure Description UNITS Select temperature measurement units C F or K 2 SENS TCOUPLE Select the thermocouple transducer 3 TYPE J K T E S or N Select thermocouple type 4 JUNC SIM INT or EXT Select the SIMulated INTernal or EXTernal reference junction SIM 000 C to 065 C For the SIMulated reference junction set the reference junction 273K to 338K or temperature The displayed units depend on the present UNITS 032 F to 149 F setting 5 OPEN DET Y or N Enable Y or disable N the open thermocouple detector When using multiple channel operation ROUT MULT command to connect a switching module input channel to the DMM the SIMulated reference junction will be used if the INTernal or EXTernal reference junction is selected Thermistor temperature measurement configuration The steps to configure thermistor measurements are provided in Table 3 4 After pressing SHIFT and then SENSOR the menu starts at step 1 to select measurement units Each time you press ENTER to make a selection the menu will automatically go to the next selection After pressing ENTER for the last step the instrument will return to the normal measurement state Table 3 4 Thermistor temperature measurement configuration Step Menu structure Description UNITS E
209. Y QUALIFIED PERSONNEL ONLY KEITHLEY WARNING No INTERNAL OPERATOR SER CATI MADE IN e pe DIGITAL 1 0 TRIGGER ETHERNET RS 232 EXT TRIG LINK 10 100 BaseT LinkAci 190bT KEITHLEY SLOT COVER gt CAUTION rFOR CONTINUED PROTECTION AGAINST FIRE HAZARD REPLACE FUSE WITH SAME TYPE AND RATING TE 10 12 Remote Operations Model 2701 User s Manual Ethernet settings NOTE Ethernet fundamentals and details on the valid Ethernet settings are provided in the Model 2701 Instrument Networking Manual The following information explains how to use the front panel Ethernet menu and SCPI commands to check and or change Ethernet settings Ethernet settings include the following Dynamic Host Control Protocol DHCP Enable or disable IP address Subnet mask Ethernet gateway MAC address of the 2701 This fixed address for the 2701 cannot be changed Ethernet settings can be made from either the front panel or remote programming NOTE Error code 550 Unitialized Ethernet module will occur on power up if the Ethernet settings are corrupt or the MAC address is FF FF FF FF FF FF Contact Keithley immediately if this error occurs Make sure to have the serial number of you Model 2701 handy when you call The serial number is displayed from the SETUP menu Press SHIFT and then SETUP to access the menu then use the up RANGE key to display the serial number SNUM When you call
210. ables 4 in computer RJ 45 male male lt Up to 100 meters 2 Keithley 2701 Figure 10 4 Enterprise wide or internet network system PC with NIC installed Enterprise wide or Internet Router or Servers RJ 45 RJ 45 Outlet Outlet p Cables RJ 45 male male e ug I F Keithley 2701 Unlimited length 10 10 Remote Operations Model 2701 User s Manual Ethernet connections The Model 2701 is connected to the Ethernet using a male to male RJ 45 Ethernet cable see Figure 10 5 The Ethernet connector for the Model 2701 is shown in Figure 10 6 With power off connect one end of the cable to the Model 2701 and connect the other end to the Ethernet connector of the PC hub or receptacle Figure 10 5 RJ 45 Ethernet cable male male Ethernet Cable T RJ 45 male to male RJ 45 connector status LEDs The female RJ 45 connector shown in Figure 10 6 has two status LEDs located at the top of the connector These LEDs provide the following status LED State Ethernet status Link Act Off Network NOT connected Link Act On Network connected Link Act Blinking Traffic is traversing the port 100bT Off 10 mb s network speed 100bT On 100 mb s network speed Model 2701 User s Manual Remote Operations 10 11 Figure 10 6 Model 2701 Ethernet connector Link Act 100bT 10bT status LED 100bT status LED ETHERNET 10 100 BaseT BLE PARTS SERVICE B
211. age Sec 3 v APERture lt n gt lt clist gt Set integration rate in seconds Note 2 Sec 4 3 333333e 5 to 1 APERture lt clist gt Query aperture integration rate NPLCycles n lt clist gt Set integration rate in line cycles 60Hz 5 0 Sec 4 v 0 002 to 60 50Hz 0 002 to 50 NPLCycles lt clist gt Query line cycle integration rate v RANGe Path to set measurement range Sec 4 v UPPer n lt clist gt Select range 0 to 1010 1000 v UPPer lt clist gt Query range v AUTO lt b gt lt clist gt Enable or disable auto range ON v AUTO lt clist gt Query state of auto range v DIGits n lt clist gt Specify measurement resolution 4 to 7 7 Sec 4 DIGits lt clist gt Query resolution REFerence lt n gt lt clist gt Specify reference 1010 to 1010 0 Sec 5 v STATe lt b gt lt clist gt Enable or disable reference OFF v STATe lt clist gt Query state of reference v ACQuire lt clist gt Use input signal as reference REFerence lt clist gt Query reference value v AVERage Path to configure and control filter Sec 4 TCONtrol lt name gt Select filter type MOVing or REPeat Note 3 TCONtrol Query filter type WINDow lt NRf gt Set filter window in of range 0 1 0 to 10 WINDow Query filter window COUNt n lt clist gt Specify filter count 1 to 100 10 COUNC lt clist gt Query filter count STATe
212. ages to be briefly displayed INVALID CHAN This message indicates that the channel is not a valid measurement channel The following actions will cause this error Trying to close a non measurement channel such as a backplane isolation channel a channel that sets the pole mode or a channel that cannot be internally connected to the DMM Trying to close an amps channel while on a non amps function The DCI or ACI function must be selected in order to close an amps channel Trying to close a paired channel while on a 4 wire function For the Model 7700 channels 1 through 10 are paired to channels 11 through 20 for a 4 wire function If for example you try to close channel 12 while on the function the INVALID CHAN error will occur Trying to close a switching module channel that does not exist TOO SMALL or TOO LARGE These messages also indicate an invalid channel TOO SMALL indicates that the specified channel and any other lower numbered channel is invalid TOO LARGE indicates that the specified channel and any other higher numbered channel is invalid 2 12 Close Open Switching Module Channels Model 2701 User s Manual OPEN key ALL menu option The ALL menu option of the OPEN key opens all channels for all switching modules installed in the Model 2701 Figure 2 5 For example if a Model 7700 switching module is installed in slot 1 OPEN ALL will open all measurement channels 101 to 120 121 and 122 the backplane
213. airing is disabled NOTE Channels closed by ROUT MULT CLOS are not displayed The ROUT MULT CLOS command cannot be used to perform thermocouple temperature measurements using the internal or external reference junction The simulated reference junction will instead be used and the integrity of the temperature reading will be questionable ERR annunciator on See Temperature measurements page 3 33 for details NOTE OPC or OPC should be used with ROUT MULT CLOS if the lt clist gt is large Details on OPC and OPC are provided in Section 12 Model 2701 User s Manual Close Open Switching Module Channels 2 21 ROUTe MULTiple OPEN lt clist gt With this command you can open one or more switching module channels When you send this command to open the channels specified in the lt clist gt only those listed channels will open Channels not specified are not affected NOTE OPC or OPC should be used with ROUT MULT OPEN if the lt clist gt is large Details on OPC and OPC are provided in Section 12 ROUTe OPEN ALL This command functions the same as the front panel OPEN key ALL menu option It simply opens all channels including non measurement channels in the mainframe ROUTe MULTiple CLOSe This query command returns a lt clist gt of all closed channels including non measurement channels and paired channels for 4 wire functions ROUTe MULTiple CLOSe STATe lt clist gt This query return
214. al Scanning 7 23 Manual external trigger scan The only difference between a manual external trigger scan and the basic scan is control The basic scan runs as soon as the STEP or SCAN key is pressed The manual external trigger scan is controlled by the front panel TRIG key or by triggers received from another instrument NOTE For the following procedure the Model 2701 can be triggered by pressing the TRIG key or by receiving a trigger pulse from another instrument Section 8 provides details on triggering 1 If the scanner is presently enabled STEP or SCAN annunciator on press SHIFT and then HALT to disable it 2 Press the EX TRIG to place the instrument in the external triggering mode The TRIG annunciator turns on and the reading is blanked 3 Press STEP or SCAN to enable the scan STEP or SCAN annunciator turns on The TRIG key or input triggers control the scan as follows STEP operation In general each time the Model 2701 is triggered one channel is scanned When the STEP key is pressed to enable the scan the first channel in the scan list closes When the first trigger occurs a measurement is taken the channel opens and the next channel closes This process continues for each channel in the scan After the last channel in the scan list is scanned the first channel in the scan list closes The reading count determines how many channel measurements will be performed during the scan sequence If the reading c
215. alculating Program running Waiting in trigger layer Re entering the idle layer Filter settled Reading overflow Low limit 1 event High limit 1 event Low limit 2 event High limit 2 event Reading available Buffer user selectable event Buffer available Buffer half full Buffer full Buffer overflow Buffer one quarter full Buffer three quarters full Master limit event SE SE SE SE SE SE SE SE SE SE SE SE SE SE SE SE SE SE SE SE SE SE SE SE SE Model 2701 User s Manual Table C 1 continued Status and error messages Status and Error Messages Number Description Event Calibration messages 400 10vdc zero error EE 401 100vdc zero error EE 402 10vdc full scale error EE 403 10vdc full scale error EE 404 100vdc full scale error EE 405 100vdc full scale error EE 406 1k 2 w zero error EE 407 10k 2 w zero error EE 408 100k 2 w zero error EE 409 10M 2 w zero error EE 410 10M 2 w full scale error EE 411 10M 2 w open error EE 412 1k 4 w zero error EE 413 10k 4 w zero error EE 414 100k 4 w zero error EE 415 10M 4 w sense lo zero error EE 416 1k 4 w full scale error EE 417 10k 4 w full scale error EE 418 100k 4 w full scale error EE 419 1M 4 w full scale error EE 420 10M 4 w full scale error EE 421 10m adc zero error EE 422 100m adc zero error EE 423 10m adc full scale error EE 424 100m adc full scale error EE 425 1 adc full scale error EE 426 10 4 w zero e
216. alue see Table 11 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 11 2 Data format command for reading status registers Command FORMat SREGister lt name gt Description Select data format for reading status registers lt name gt ASCii Decimal format HEXadecimal Hexadecimal format OCTal Octal format BINary Binary format Default ASCii 11 8 Status Structure Model 2701 User s Manual Status byte and service request SRQ Service request is controlled by two 8 bit registers the Status Byte Register and the Service Request Enable Register Figure 11 3 shows the structure of these registers Figure 11 3 Status byte and service request SRQ Status Summary Message Service Request STB OSB MSS ESB MAV QSB EAV MSB Status Byte Generation B7 B6 B5 B4 B3 B2 B1 BO Register lt Read by STB ann a es OSB ESB MAV OSB B7 B6 B5 B4 B3 SRE EAV MSB Service Request SRE B2 B1 BO Enable Register OSB Operation Summary Bit QSB Questionable Summary Bit MSS Master Summary Status EAV Error Available ESB Event Summary Bit MSB Measurement Summary Bit Mav Message
217. amples Manual Name Reference Brief Description Simple7 None Use Case 7 Ten 40 channel scans using 7702 module Channel 1 uses an external reference junction Measurement speed rate 1 plc Filter Repeat 25 readings Channels 2 through 40 are connected to type K thermocouples Measurement speed rate 1 plc Filter Disabled no filtering Buffer Store 400 reading strings Buffer elements include reading only Triggering Bus control source Simple8 None Use Case 8 7706 module in slot 1 and 7702 module in slot 2 7706 module Output analog output values to analog output channels Output digital output values to digital output channels 7702 module Scan 120 DCV channels Measurement speed rate 1 plc Filter Disabled no filtering Buffer Store 320 reading strings Buffer elements include reading only Triggering Bus control source trigger delay 0 125 seconds G 20 KE2700 Instrument Driver Examples Model 2701 User s Manual Index Symbols SCPI signal oriented measurement MEASure lt function gt lt rang gt lt res gt 13 8 symbol 5 13 342 and 344 connections for front panel inputs 3 21 342 and 344 connections for Model 7700 switching module 3 22 Numerics 2 wire functions 2 8 4 wire functions 2 9 4 wire RTDs 3 37 Connections 3 41 Temperature measurement configuration 3 44 7700 Module Connectio
218. an be included in the scan list Make sure to list them from the lowest numbered channel to the highest For example to scan channels 1 through 8 of a Model 7700 installed in slot 1 send the following command to define the scan list ROUTe SCAN 101 108 Model 2701 User s Manual Getting Started 1 37 Exercise 3 Simple scanning The scanning example in Table 1 8 assumes a Model 7700 installed in slot 1 of the mainframe The scan will use default settings DCV to scan eight channels and store the readings in the buffer Table 1 8 Exercise 3 Simple scanning Front panel operation Command sequence 1 For front panel operation proceed to step 2 For remote programming clear the buffer TRAC CLE 2 Restore defaults Press SHIFT press SETUP select RESTORE FACT RST 3 Configure scan Press SHIFT press CONFIG select INT SIMPLE set MIN ROUT SCAN 101 108 gt set MAX CHAN 108 gt select TIMER NO gt set SAMP COUN 8 RDG CT 000008 4 Enable and start scan ROUT SCAN LSEL INT Press STEP INIT 5 Halt disable scanner Press SHIFT gt press HALT ROUT SCAN LSEL NONE 6 Recall the eight stored readings Press RECALL gt use edit keys to display readings Press EXIT CALCI DATA exit recall mode 7 Open all channels Press OPEN gt display OPEN ALL gt Press OPEN ROUT OPEN ALL 1 Factory and RST defaults opens all channels select the DCV function and sets TRIG
219. an channel are displayed the reading and annunciators pertain to that channel but that channel is no longer closed The next channel in the scan list is the one that is now closed Therefore the reading and annunciators pertains to the channel and does not necessarily indicate the present state of the Model 2701 If the display is blanked the displayed channel is closed and has not been measured Trigger models NOTE The following information on trigger model operations apply specifically to front panel operation Block diagrams known as trigger models are used to show the two fundamental scan functions STEP or SCAN These two scan functions are enabled by the STEP and SCAN keys respectively The trigger models for scanning are shown in Figure 7 1 and Figure 7 2 Model 2701 User s Manual Scanning 7 5 NOTE The trigger model in Figure 7 2 also applies for bus operation See Remote programming scanning page 7 26 for differences between front panel and remote scanning For the following discussion refer to Figure 7 1 for STEP operation and Figure 7 2 for SCAN operation Figure 7 1 Trigger model with STEP function Enable Scan Close First Chan in List Event Detection Immediate O pen Last Chan External Close N ext Chan Timer Timer in List Enabled Anothe Trigger Reading mm Counter Reading Count Control Source Delay Auto or Manual Rati
220. an make the following measurements DCV DC voltage measurements from 0 1uV to 1000V ACV AC voltage measurements from 0 1uV to 750V DCI DC current measurements from 10nA to 3A ACI AC current measurements from to 2 2 wire resistance measurements from 100uO to 120MQ 4 4 wire resistance measurements from 100uOto 120MQ FREQ Frequency measurements from 3Hz to 500kHz PERIOD Period measurements from 333ms to 2us TEMP Temperature measurements from 200 C to 1820 C CONT Continuity testing using the 1 range CAUTION When using a switching module do not exceed the maximum signal levels of the module To prevent damage to the Model 7700 switching module do not exceed these maximum signal levels Channels 1 20 300VDC or 300V RMS 425V peak for AC waveforms 1A switched 60W 125VA Channels 21 22 60VDC or 30V RMS switched 60W 125VA For the other switching modules the maximum signal levels are included with their specifications NOTE This section shows DUT connections to the front panel inputs of the Model 2701 and to the Model 7700 switching module Details on Model 7700 connections are provided in Appendix B Model 2701 User s Manual Basic DMM Operation 3 3 High energy circuit safety precautions To optimize safety when measuring voltage in high energy distribution circuits read and use the directions in the following warning WARNING Dangerous arcs of an
221. an output line is 250mA Exceeding these limits may cause damage to the instrument that is not covered by the warranty An externally powered relay connected to the digital output port is shown in Figure 9 4 Other externally powered devices can be similarly connected by replacing the relay with the device When the output line is pulled low 0V the output transistor sinks current through the external device In the high state the output transistor is off transistor switch open This interrupts current flow through the external device Model 2701 User s Manual Limits and Digital I O 9 9 Figure 9 4 Controlling externally powered relays Model 2701 Pin 7 Diode Clamp Digital Output 1 7 Flyback Diode A TR Pull Up Resistor External Power 5V to 33V Digital Output Control Line Pin 9 Digital Ground Equivalent Circuit External Power i 5V to 33V B Transistor Switch 9 10 Limits and Digital I O Model 2701 User s Manual Source mode logic control The digital outputs can be used as logic inputs to active TTL low power TTL or CMOS inputs For this mode of operation the output lines can source up to 200 CAUTION Each output line can source up to 200pA Exceeding 200uA may cause damage to Model 2701 that is not covered by the warranty Figure 9 5 shows how to connect a logic device to one of the output lines When the output line is pulled high the transistor will turn
222. and 11 16 Status Structure Model 2701 User s Manual Event registers As Figure 11 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 11 5 For details on reading registers see Reading registers page 11 7 Table 11 5 Event register commands Command Description ESR Read Standard Event Status Register STATus OPERation EVENt Read Operation Event Register STATus MEASurement EVENt Read Measurement Event Register STATus QUEStionable EVENt Read Questionable Event Register Notes 1 The format of the response messages for the above queries is set by the FORMatt SREGister command 2 Power up and CLS resets all bits of all event registers to 0 STATus PRESet has no effect Event enable registers As Figure 11 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 an
223. and measure 10 DUT An external source powers DUT while the DMM of the Model 2701 measures the output of the DUT To prevent overloading of the external source each DUT is powered and measured separately Figure 2 9 shows the connections for this application The external source is connected to the Sense terminals of the switching module and DUT is connected to channels 1 through 10 Channels 11 through 20 are used to connect external power to each DUT For this application the 2 pole 4 pole relay and backplane isolation relays of the switching module are to be controlled as follows Closing channel 23 connects the External Source to DUT via channels 11 through 20 Closing channel 23 also isolates measure channels 1 through 10 from the source channels 11 through 20 This channel must remain closed while testing DUT Opening channel 24 isolates the external source from the backplane of the Model 2701 This channel must remain open while testing DUT Closing channel 25 connects an input channel 1 through 10 to the DMM In Figure 2 9 channels 1 and 11 are closed to test DUT 1 A more detailed view of the test for DUT 1 is shown in Figure 2 10 The test for the other DUTS is similar except that different source and measure channels are closed Closed channels for each DUT test are listed as follows Tested Tested device Closed channels device Closed channels DUT 1 1 11 23 and 25 DUT 6 6 16 23 and 25
224. and disable ratio and channel d average Channel list parameter lt clist gt SCH where S Mainframe slot number 1 or 2 CH Switching module channel number must be 2 digits Examples 101 Slot 1 Channel 1 101 203 Slot 1 Channel 1 and Slot 2 Channel 3 101 110 Slot 1 Channels 1 through 10 Reference a ROUTe CLOSe lt clist gt This command functions the same as the front panel CLOSE key SINGLE menu option to select the system channel Only one measurement channel can be specified in the lt clist gt Trying to close an invalid channel such as a non measurement channel with this command will result in error 222 Parameter data out of range ROUTe CLOSe STATe lt clist gt This query returns a 0 open or 1 closed for every measurement channel specified in the lt clist gt For example assume lt clist gt 101 104 107 102 The response message 0 0 1 0 indicates that channel 107 is closed The state of non measurement channels cannot be checked with this command ROUTe CLOSe This query command returns a lt clist gt of closed measurement channels including paired channels for 4 wire functions This query command will not return non measurement channels such as backplane isolation channels and the pole mode channel ROUTe OPEN ALL This command functions the same as the front panel OPEN key ALL menu option It simply opens all
225. ands to select and configure Ethernet are listed in Table 10 2 NOTE Ethernet and RS 232 settings are not affected by RST or SYSTem PRESet The Ethernet settings set at the factory are shown in Figure 10 7 and Figure 10 6 Table 10 2 SYSTem commands for Ethernet Command Description SYSTem COMMunicate Ethernet and RS 232 commands SELect name Select communications mode ETHernet or SERial ETHernet Ethernet ADDRess value Set IP address of 2701 n n n n ADDRess Query IP address of 2701 MASK value Sets the subnet mask MASK Query subnet mask GATeway value Set the Ethernet gateway GATeway Query the Ethernet gateway DHCP lt b gt Enable or disable Dynamic Host Control Protocol DHCP DHCP Query state of DHCP MAC Returns MAC address of 2701 6 hexadecimal values separated by colons 00 60 1A 00 04 0B 10 16 Remote Operations Model 2701 User s Manual Internal web page The Model 2701 has an internal web page see Figure 10 9 and Figure 10 10 The web page is organized as follows e Configuration summary Network Settings You can view and or change the network settings of the Model 2701 Instrument Information Provides read only information about the Model 27701 revision levels serial numbers and calibration status Installed Cards Provides read only information about switching modules installed in the mai
226. anual Model 2701 User s Manual Specifications A 5 A 6 Specifications Model 2701 User s Manual Model 7700 20 Channel Differential Multiplexer Put 7700 specs here Model 2701 User s Manual Specifications A 7 Accuracy calculations The information below discusses how to calculate accuracy for both DC and AC characteristics Calculating DC characteristics accuracy DC characteristics accuracy is calculated as follows Accuracy ppm of reading ppm of range ppm parts per million and 10 0 001 As an example of how to calculate the actual reading limits assume that you are measuring 5V on the 10V range You can compute the reading limit range from one year DCV accuracy specifications as follows Accuracy 30ppm of reading 5ppm of range 30ppm x 5V 5ppm x 10V 150uV 50uV 200 V Thus the actual reading range is 5V 200uV or from 4 9998V to 5 0002V DC current and resistance calculations are performed in exactly the same manner using the pertinent specifications ranges and input signal values Calculating AC characteristics accuracy AC characteristics accuracy is calculated similarly except that AC specifications are given as follows Accuracy of reading of range As an example of how to calculate the actual reading limits assume that you are measuring 120V 60Hz on the 750V range You can compute the reading limit range from ACV one year accuracy specifications as follows
227. are not available for output data formats other than ASCII The element TSTamp can still be selected and will show up when FORM ELEM is que ried but no timestamp will be included in the output data CALCulate2 FORMat lt name gt Select buffer statistic CALCulate2 STATe ON OFF Control on off buffer statistic CALCulate2 IMMediate Calculate data in buffer CALCulate2 IMMediate Calculate and read result CALCulate2 DATA Read result of statistic calculation lt name gt MINimum MAXimum MEAN SDEViation PKPK NONE After the selected buffer statistic is enabled IMMediate or IMMediate must be sent to calculate the statistic from the data in the buffer The CALCulate2 DATA command does not initiate a calculate operation It simply returns the result of the last calculation If new data is stored in the buffer you must again send IMMediate or IMMediate to recalculate the statistic from that new data NOTE Ifthe standard deviation calculation is being performed on a buffer that has more than 1000 readings the CALCULATING message will flash to indicate that the Model 2701 is busy While busy with the calculation remote program ming commands will not execute NOTE Use OPC or OPC with CALC2 IMM and CALC2 IMM when performing the standard deviation calculation on a large buffer See Section 12 for details on OPC and OPC NOTE The Model 2701 should take 5 to 6 seconds to perform standard deviation on 450 000 rea
228. arrays stored in the sample buffer then all 20 data arrays will be sent to the computer when FETCh is executed With a math function mX B Percent or 1 X enabled the reading in each data array returned by FETCh is the result of the math calculation Note that FETCh does not affect data in the sample buffer Therefore subsequent executions of FETCh acquire the same data NOTE When an instrument setting that is relevant to the readings in the sample buffer is changed the FETCh command will cause error 230 data corrupt or stale or bus time out to occur To get FETCh working again a new reading must be triggered READ The READ command performs an INITiate and then a FETCh The INITiate triggers a measurement cycle which puts new data in the sample buffer With no math function enabled FETCh reads the data arrays from the sample buffer With a math function enabled the readings are the result of the math calculation The following conditions must be met in order to use READ Continuous initiation must be disabled It can be disabled by sending RST or INIT CONT OFF e are readings stored in the data store the sample count SAMP COUN must be set to 1 To use a sample count gt 1 the data store must be cleared empty It can be cleared by sending TRAC CLE Model 2701 User s Manual Signal Processing Sequence and Data Flow D 11 MEASure The MEASure command places the instrument in a one s
229. art Contact Keithley s Service Department to order this manual Battery The Model 2701 uses battery backed memory for the 450 000 reading buffer A fully charged battery will maintain storage of readings for 30 days at 23 C At 50 C the stor age period is degraded to approximately 15 days See Appendix A for specifications on the rechargeable lithium ion battery The battery is warranted for 90 days However at 23 C the battery will typically last three years See Section 3 of the Model 2701 Service Manual to replace the battery The Keithley part number for the battery is BA 52 Options and accessories Plug in switching modules NOTE Table 1 1 provides a side by side comparison of the following Keithley switch ing modules All multiplexer modules can be configured as two independent multiplexers NOTE The Model 77xx Series Switching Modules Instruction Manual provides operat ing and service information for the switching modules This manual is supplied with each switching module Model 7700 This differential multiplexer provides 20 channels of 2 pole input or 10 channels of 4 pole input The internal cold junction allows direct connection of thermo couples It also has two 2 pole channels used exclusively for current input Model 7701 This differential multiplexer provides 32 channels of 2 pole input or 16 channels of 4 pole input Model 7702 This differential multiplexer provides 40 channels of 2 pole input or
230. as 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 and 400Hz is 20msec 1 50 In general the fastest integration time 0 1 PLC from the front panel 0 002 PLC from the bus results in increased reading noise and fewer usable digits while the slowest integration time 5 PLC from the front panel 50 PLC from the bus provides the best common mode and normal mode rejection In between settings are a compromise between speed and noise The Model 2701 has a parabola like shape for its speed vs noise characteristics and is shown in Figure 4 1 The Model 2701 is optimized for the 1 PLC to 5 PLC reading rate At these rates lowest noise region in graph the Model 2701 will make corrections for its own internal drift and still be fast enough to settle a step response 100ms Figure 4 1 Speed vs noise characteristics Voltage Noise 33 33us 16 67ms 83 33ms 1s 0 002 PLC 1 PLC 5 PLC Aperture Time Model 2701 User s Manual Range Digits Rate Bandwidth and Filter 4 9 The front panel RATE key settings for all but the AC functions are explained as follow e FAST sets integration time to 0 1 PLC Use FAST if speed is of primary importance at the expense of increased reading noise and fewer usable digits e MEDium sets integration time to 1 PLC Use MEDium when a compromise
231. at CURRent AC AVERage WINDow lt NRf gt Set filter window in lt 0 10 01 CURRent AC AVERage COUNt n clist Specify filter count n 1 to 100 10 CURRent AC AVERage STATe lt b gt clist Enable or disable the filter Note 3 Model 2701 User s Manual Range Digits Rate Bandwidth and Filter 4 21 Table 4 6 continued Filter commands Commands Description Default filter commands SENSe 1 Optional root command RESistance AVERage TCONtrol lt name gt Select filter type lt name gt MOVing or Note 2 REPeat RESistance AVERage WINDow lt NRf gt Set filter window in NRf 20to10 01 RESistance AVERage COUNt n clist Specify filter count n 1 to 100 10 RESistance AVERage STATe lt b gt clist Enable or disable the filter Note 3 XX filter commands SENSe 1 Optional root command FRESistance AVERage TCONtrol lt name gt Select filter type lt name gt MOVing or Note 2 REPeat FRESistance AVERage WINDow lt NRf gt Set filter window in lt NRf gt 0to 10 0 1 FRESistance AVERage COUNt n clist Specify filter count n 1 to 100 10 FRESistance AVERage STATe lt b gt clist Enable or disable the filter Note 3 TEMP filter commands SENSe 1 Optional root command TEMPerature AVERage TCONtrol lt name gt Select filter type lt name gt MOVing or Note 2 REPeat TEMPerature AVERage WINDow l
232. ata retrieval SRQ when buffer 4 1 34 and full Model 2701 User s Manual Table G 2 continued LabVIEW examples KE2700 Instrument Driver Examples G 13 Name Manual Reference Brief Description Advance2 None Use Case 2 40 channel scan using 7708 module 30 channels DCV 15 on 100mV range 15 on 10V range 9 channels ACV 1V range e 1 channel 4 wire RTD temperature Measurement speed rate 1 plc Filter Disabled no filtering Buffer Store 160 reading strings Buffer elements include reading only Triggering Timer scan 40 channels every one minute Data retrieval SRQ when buffer 12 34 and full Advance3 None Use Case 3 Two scans using 7708 module 40 channel DCV 1V range scan 20 channel scan e Models 2700 and 2701 1000 range e Model 2750 10Q range dry circuit ohms enabled Measurement speed rate 0 1 plc DCV input divider Enabled 1OMQ input impedance Filter Disabled no filtering Buffer Store 40 reading strings 20 reading strings Buffer elements include reading only Limits DCV scan Limit 1 all channels 20mV Master Latch enabled Triggering Bus control source Data retrieval SRQ if limit fails G 14 KE2700 Instrument Driver Examples Model 2701 User s Manual Table G 2 continued LabVIEW examples Name Man
233. ate through buffer Enables disables filter for selected function Enables disables relative for selected function Dual function Manually scans switching channels When in a menu these keys control cursor position for making selections or change values Sets user delay between trigger and measurement Holds reading when the selected number of samples is within the selected tolerance Sets upper and lower limits for readings Enables disables limits Configures and enables filter for selected function Selects and enable disables monitor channel Disables channel for a scan must be in scan channel setup mode Identifies switching modules installed in mainframe Set up switching modules that require configuration View closed channels and channel settings for switching modules that require configuration Opens closed channel Closes specified channel Steps through channels sends a trigger after each channel Scans through channels sends a trigger after last channel Sets display resolution for all functions Sets measurement speed fast medium or slow for all functions Cancels selection moves back to measurement display Accepts selection moves to next choice or back to measurement display Saves up to five instrument setups for future recall and selects power on setup Restores a default setup factory or RST or a saved setup Enables disables buffer auto clear auto scan and auto channel configuration Sets t
234. ated RZV I and the reading is displayed For offset compensated ohms two measurements are performed one normal resistance measurement and one using the lowest current source setting The offset compensated ohms reading is then calculated as follows Offset compensated ohms reading AV AI where AV V2 VI AI 2 2 Il V1 is the voltage measurement with the current source at its normal level V2 is the voltage measurement using the lowest current source setting The above 2 point measurement process and reading calculation eliminates the resistance contributed by the presence of Vg Enabling disabling offset compensated ohms Offset compensated ohms is enabled by pressing SHIFT and then OCOMP When enabled the OCOMP annunciator is on Offset compensated ohms is disabled by again pressing SHIFT and then OCOMP Model 2701 User s Manual Basic DMM Operation 3 25 Performing offset compensated ohms measurements Offset compensated ohms can only be performed on the function using the 1000 1kQ or 10 range Make sure you use 4 wire connections to the DUT see Connections page 3 8 NOTE Make sure the INPUTS switch is in the correct position To use front panel inputs it must be in the F out position For switching modules it must be in the R in position 1 Ifa switching channel is presently closed displayed press OPEN to open it 2 Select the 4 wire ohms measurement function by pressing Enable offset comp
235. atio and channel average functions ReadError Page 11 23 Prog Ex Demonstrates reading the error queue Queue Relativel Page 5 6 Ex 1 Demonstrates acquiring and using a relative reference reading Relative2 Page 5 6 Ex 2 Demonstrates setting a relative reference value Relative3 Page 5 6 Ex 3 Demonstrates zero correction using relative value ScanChan Page 7 32 Prog Ex Demonstrates scanning 10 channels Simplel None Use Case 1 30 channel scan using 7708 module 30 channels DCV 10V range 10 channels type T thermocouple temperature Measurement speed rate 1 plc Filter Disabled no filtering Buffer Store 120 reading strings Buffer elements include reading only Triggering Bus control source G 6 KE2700 Instrument Driver Examples Table G 1 continued Visual Basic and CVI C examples Model 2701 User s Manual Name Manual Reference Brief Description Simple2 None Use Case 2 40 channel scan using 7708 module 30 channels DCV 15 on 100mV range 15 on 10V range 9 channels ACV 1V range 1 channel 4 wire RTD temperature Measurement speed rate 1 plc Filter Disabled no filtering Buffer Store 120 reading strings Buffer elements include reading only Triggering Bus control source Simple3 None Use Case 3 Two scans using 7708 module 40 channel DCV 1V range scan
236. ation Note 4 lt b gt ON or OFF INITiate Trigger one or more measurements SENSe 1 Optional root command DATA LATest Returns the last reading string DATA FRESh Returns the last fresh reading string FETCh Return reading s READ Trigger and return reading s Channel list parameter lt clist gt SCH where S Mainframe slot number 1 or 2 CH Switching module channel number must be 2 digits Examples 101 Slot 1 Channel 1 101 203 Slot 1 Channel and Slot 2 Channel 3 101 110 Slot 1 Channels 1 through 10 1 The lt clist gt parameter is used to configure one or more channels for a scan 2 When using multiple channel operation ROUT MULT command to connect a switching module channel to the DMM for thermocouple temperature measurements the SIMulated reference junction will be used if the INTernal or EXTernal reference junction is selected The ERR annunciator will turn on to indicate that the integrity of the temperature reading is questionable 3 With a Model 7700 7706 or 7708 installed the default sensor junction is Internal Otherwise the Simulated 23 C junction is selected 4 The RST default is OFF and the SYSTem PRESet default is ON 3 54 Basic DMM Operation Model 2701 User s Manual Reference a FUNCtion lt name gt lt clist gt Note that the name parameters in the table are enclosed in single quotes However double quote
237. ber 2701 900 01 Rev F August 2011 vii Table of Contents Model 2701 Ethernet Based DMM Data Acquisition System Connections and wiring eene B 4 Screw terminals ais tet Lime ee cee CE Dee dpa eae ate le B 4 Wiring procedure ARREN AARAA EE aA AROSE EIRA nnns nnne B 6 Typical connections eraser itina iei iii iii B 8 CONNECtON IOs re paaa Re TRAE PASA EXER AP aai Sai B 10 C Status and Error Messages C 1 D Signal Processing Sequence and Data Flow D 1 Signal processing sequence 2 D 2 Basic signal processing rocne ederent aiiiar kaiaia ni emen D 2 Signal processing using instrument features D 3 Signal processing using Ratio or Ch D 6 Data flow remote D 7 SENSe and sample buffer D 8 SENSI DATA LATES Z trt t ier tette ens D 9 SENS 1 DATA FRESR D 9 rre emm eh ten re D 10 8 9 m rite D 10 MEA SUC X D 10 GAEG TEDATA LAT6St ontario date ve t dece D 10 GAEG TEDATA ERESRD iiia iie tnt ie ree D 10 GALGS LIMT EAIE u
238. c to the Model 2701 that will set this bit include the following Error 516 Battery backed RAM error Data stored in RAM has been lost Replace the battery if frequent failures occur Error 517 Cannot resume scan Due to a card ID change auto scan has disabled The scan will not resume after a power interruption For details see Scan configuration Auto scan page 7 21 Error 520 Saved setup scancard mismatch Settings for a user setup or power on setup do not match the switching module types presently installed For details see Defaults and user setups page 1 21 Error 523 Card hardware error Communication with the microprocessor on a switching module card has been lost Error 524 Unsupported card detected The Model 2701 has detected an installed Model 77XX switching module that is not supported by the current version of firmware Bit B4 Execution Error EXE Set bit indicates that the Model 2701 detected an error while trying to execute a command Bit B5 Command Error CME Set bit indicates that a command error has occurred IEEE 488 2 syntax error Instrument received a message that does not follow the defined syntax of the IEEE 488 2 standard Semantic error Instrument received a command that was misspelled or received an optional IEEE 488 2 command that was not implemented The instrument received a Group Execute Trigger GET inside a program message Bit B6 User
239. can be assigned as a monitor channel When the monitor channel detects that a reading limit has been reached the scan will be triggered to start There are four reading limits that can be used to trigger the start of the scan low limit 1 LLIM1 high limit 1 HLIM1 low limit 2 LLIM2 and high limit 2 HLIM2 The scan will start when any enabled reading limit event is detected by the monitor channel Details on Limits are provided in Section 9 NOTE An overflow reading OVRFLW message displayed is interpreted by the Model 2701 as a positive reading even if the input signal is negative This could inadvertently trigger a monitor scan For example assume the monitor channel is monitoring a negative input signal and the instrument is configured to trigger a monitor scan if a positive input signal is detected If for some reason the negative input signal exceeds the measurement range the overflow reading will be interpreted as positive and trigger the start of the scan Perform the following steps to run a monitor scan NOTE The last enabled scan function STEP or SCAN will be used for the monitor scan 1 Perform Step 1 and Step 2 of the Advanced scan setup procedure page 7 16 to set up scan channels With the channel to be used as the monitor selected set and enable limits as follows Note that you only need to set values for limits that are going to be used a c Press SHIFT and then LIMITS to access th
240. ce STATe lt b gt lt clist gt Enable disable rel b ON or OFF OFF RESistance REFerence ACQuire lt clist gt Use input signal as rel value Rel commands for 4 SENSe 1 Optional root command FRESistance REFerence n lt clist gt Specify rel value n 0 to 120e6 Q 0 FRESistance REFerence STATe lt b gt clist Enable disable rel b ON or OFF OFF FRESistance REFerence ACQuire lt clist gt Use input signal as rel value Rel commands for TEMP SENSe 1 Optional root command TEMPerature REFerence n lt clist gt Specify rel value n 328 to 3310 C 0 TEMPerature REFerence STATe lt b gt Enable disable rel lt b gt ON or OFF OFF lt clist gt TEMPerature REFerence ACQuire lt clist gt Use input signal as rel value Rel commands for FREQ SENSe 1 Optional root command FREQuency REFerence n lt clist gt Specify rel value lt n gt 0 to 1 5e7 Hz 0 FREQuency REFerence STATe lt b gt lt clist gt Enable disable rel b ON or OFF OFF FREQuency REFerence ACQuire lt clist gt Use input signal as rel value Rel commands for PERIOD SENSe 1 Optional root command PERiod REFerence lt n gt lt clist gt Specify rel value lt gt 0 to 1 sec 0 PERiod REFerence S TATe lt b gt lt clist gt Enable disable rel b ON or OFF OFF PERiod REFerence ACQuire lt clist gt Use input signal as re
241. ce the voltage by a factor of 100 but the noise will be decreased only by a factor of 10 E 6 Measurement Considerations Model 2701 User s Manual Very often cooling the source is the only practical method available to reduce noise Again however the available reduction is not as large as it might seem because the reduction is related to the square root of the change in temperature For example to cut the noise in half the temperature must be decreased from 293K to 73 25K a four fold decrease Magnetic fields When a conductor loop cuts through magnetic lines of force a very small current is generated This phenomenon will frequently cause unwanted signals to occur in the test leads of a test system If the conductor has sufficient length or cross sectional area even weak magnetic fields such as those of the earth can create sufficient signals to affect low level measurements Three ways to reduce these effects are 1 reduce the lengths of the connecting cables 2 minimize the exposed circuit area and 3 change the orientation of the leads or cables In extreme cases magnetic shielding may be required Special metal with high permeability at low flux densities such as mu metal is effective at reducing these effects Even when the conductor is stationary magnetically induced signals may still be a problem Fields can be produced by various sources such as the AC power line voltage Large inductors such as power transformers ca
242. ced menu and enable rel for the primary and or paired channel See Relative page 5 2 for details on setting rel for scan channels 5 Settings such as NPLC aperture bandwidth OCOMP etc are ignored on the paired channel These settings are controlled by the primary channel 6 Forremote programming the clist parameter is used to configure channels for a scan Table 5 3 5 18 Rel Math Ratio Channel Average dB Remote programming ratio and channel average Ratio and channel average commands Model 2701 User s Manual The ratio and channel average are listed in Table 5 3 Details on these commands follow the table NOTE Queries are not included in Table 5 3 All the math commands are provided in Table 15 5 Table 5 3 Ratio and channel average commands Commands Description Def SENSe 1 Optional root command RATio STATe b lt clist gt Enable disable ratio lt b gt ON or OFF OFF RATio DELay lt NRf gt lt clist gt Set delay in secs lt NRf gt 0 to 99999 0999 0 5 CAVerage STATe lt b gt lt clist gt Enable disable channel average b ON or OFF OFF CAVerage DELay lt NRf gt lt clist gt Set delay in secs lt NRf gt 0 to 99999 0999 0 5 Channel list parameter lt clist gt SCH where S Mainframe slot number 1 or 2 CH Switching module channel number must be 2 digits Examples 101 Slot 1 Channel 1 101 203 Slot 1
243. channel becomes the system channel e The system channel close keys can only close measurement channels that will automatically connect to the DMM Non measurement channels cannot be closed by the system channel close keys NOTE Use the VIEW option of the CARD menu to display all closed channels in the mainframe see CARD menu page 2 30 2 8 Close Open Switching Module Channels Model 2701 User s Manual 2 wire functions Figure 2 1 shows an example of how the system channel is connected to the DMM Input of the Model 2701 Assume a Model 7700 switching module is installed in slot 1 of the mainframe When channel 101 is closed using the system channel close keys both the Channel 1 relay and the backplane isolation relay Channel 25 close to connect the channel to the DMM The complete simplified schematic of the Model 7700 is provided in Figure 2 12 Figure 2 1 2 wire system channel connections to Model 2701 DMM Close channel 101 Relay Pod i Model 2701 Slot 1 PUT TELE TURA EON TI L2 m a 1 LE CU OD E 1 1 Model 7700 Switching Module OGDMM tt 1 1 1 f od 1 Channel 1 ME T X Relay Channel25 T HI 00 7 0 0 7 0 Hl Channel 1 so Input i LO 90 0o 0 0o 0 0 LO Z hy Backplane n i System channel operation Isolation 1 a I Model 2701 User s Manual Close Open Switching Module Channels 2 9 4 wire functions paired channels A 4
244. channels including non measurement channels installed in the mainframe 2 14 Close Open Switching Module Channels Model 2701 User s Manual Remote programming example system channel operation The following example assumes a Model 7700 installed in slot 1 and the function of the Model 2701 is selected This command sequence connects channel 101 and its paired channel 111 to DMM Input and Sense as shown in Figure 2 2 ROUT OPEN ALL Open all channels ROUT CLOS 101 Close channels 101 111 123 124 and 125 Non amp and non measure switching modules There are Keithley switching modules that do not support current measurements and there are modules that do not support any measurements at all Non amps module With an amps function selected DCI or ACT system channel oper ation cannot be used to close channels on that module Non measure module For front panel operation system channel operation cannot be used to close channels For remote programming system channel operation can be used but only the one specified channel will close All other channels on the module will open Non amps switching modules NOTE Presently non amps Keithley modules include the Models 7701 7703 7706 7707 7708 and 7709 You can check the Keithley website www keithley com for new modules A non amp module does not support amps measurements System channel operation can not be used to close channels while an amps function
245. ching Module Channels e Close open overview Summarizes the two operating modes to control switching modules system channel operation and multiple channel operation Switching module installation and connections Explains how to install a switching module or pseudocard into the Model 2701 mainframe Also explains where to find connection information which should only be performed by qualified service personnel e Channel assignments Explains the format for specifying the mainframe channel assignment which is made up of the slot number and switching module channel number System channel operation Provides detailed information for using system channel operation Multiple channel operation Provides detailed information for using multiple channel operation Due to safety considerations this operating mode should only be used by experienced test engineers Identifying installed modules and viewing closed channels Explains how to use the CARD menu to identify installed switching modules and view closed channels Explains how to remotely identify installed modules OPT and summarizes other query commands that can be used to acquire information about the installed modules Model 7700 switching module Covers operating characteristics that are unique to the Model 7700 Also includes a simplified schematic diagram of the switching module 2 2 Close Open Switching Module Channels Model 2701 User s Manual
246. close open operations explained in this section a switching module or pseudocard must be installed in the mainframe A switching module can be installed by the user however external connections to the switching module are only to be performed by qualified service personnel NOTE For inexperienced users it is recommended that DUT and external circuitry not be connected to switching modules This will allow you to exercise close open operations without the dangers associated with live test circuits WARNING To prevent electric shock that could result in injury or death NEVER handle a switching module that has power applied to it Before installing or removing a switching module make sure the Model 2701 is turned off and disconnected from line power Ifthe switching module is already connected to DUT make sure power is removed from all external circuitry Module installation WARNING Slot covers must be installed on unused slots to prevent personal contact with high voltage circuits Perform the following steps to install a switching module into the Model 2701 mainframe 1 Turn the Model 2701 off and disconnect the power line cord and any other cable connected to the rear panel Position the Model 2701 so you are facing the rear panel Remove the slot cover plate from the desired mainframe slot Retain the plate and screws for future use With the top cover of the switching module facing up slide the module into an
247. clusively for the DCI and ACI functions For example the Model 7700 has channels 21 and 22 reserved for amps measurements With the DCI or ACI function selected only channels 21 and 22 can be closed These chan nels cannot be accessed on any other function Model 2701 User s Manual Getting Started 1 33 Figure 1 6 shows the front panel keys used to close and open system channels Figure 1 6 Front panel keys to close and open system channels Close next measurement channel Press OPEN key OPEN CLOSB Press CLOSE OPEN CLOSB Display ALL V CLOSE sINGLH DisPlay SINGLE option G5EN ALL option and press and press ENTER Close previous 5 CLOSE CH XX be XX c d 3 number an Sequencing through B Specifiying channel to close C Opening all channels channnels For remote programming the following three commands are used for basic system opera tion to open and close input channels ROUTe CLOSe clist Close specified system channell ROUTe CLOSe Query closed system channel ROUT OPEN ALL Open all channels 1 Only one channel can be specified in the clist For example to close input channel 3 for a module in slot 1 the following command would be sent ROUTe CLOSe 8103 2 Only the closed system channel is returned by ROUTe CLOSe The paired channel for a 4 wire function is not returned For example assume channel 2 in slot 1 is closed The
248. configured as VMC and line 2 as EXT TRIG The connector pinout is shown in Figure 8 3 8 8 Triggering Model 2701 User s Manual Figure 8 3 TRIG LINK pinout TRIG LINK Pin Number Description Pinout 1 Voltmeter Complete Output 2 External Trigger Input VOW 3 No Connection SA 4 No Connection C 5 No Connection 6 No Connection Pin2 Pin 1 7 Signal Ground External Voltmeter 8 Signal Ground Trigger Complete Input Output Digital O Pin 6 Ext Trig of the Digital I O can also be used as the external trigger input for the Model 2701 Line 2 of the TRIG LINK is physically connected to pin 6 of the Digital I O connector The Digital I O has a hardware interlock line pin 8 that allows the use of an external circuit to control input triggers When that line is left open or pulled high 45V input triggers are enabled When pulled low to OV input triggers are disabled When disabled the Model 2701 will not respond to an input trigger Details on the Digital I O are provided in Section 9 External trigger The EXT TRIG input requires a falling edge TTL compatible pulse with the specifications shown in Figure 8 4 In general external triggers can be used to control measure operations For the Model 2701 to respond to external triggers the trigger model must be configured for it Model 2701 User s Manual Triggering Figure 8 4 Trigger link input pulse specifications EXT TRIG Triggers on Leading Edge TTL High 2V 5V
249. count SAMPle COUNt greater than one FETCh READ See Section 3 Section 13 and Appendix D for details on using these commands to trigger and retrieve readings NOTE SENSe 1 DATA LATest and SENSe 1 DATA FRESh can be used to retrieve the last reading These commands are also explained in Section 3 Section 13 and Appendix D TRIGger SOURce name With the timer control source selected use the TRIGger TIMer command to set the interval DELay AUTO b The auto delay times are listed in Table 8 1 Disabling auto delay sets the delay time to 0 TRIGger SIGNal Send this action command to bypass the control source when you do not wish to wait for the programmed event to occur The instrument must be waiting at the control source for the event when this command is sent Otherwise an error occurs and the command is ignored SAMPIe COUNt A sample count gt 1 specifies how many readings will automatically be stored in the buffer However with continuous initiation enabled you cannot set the sample count greater than one SENSe 1 HOLD commands Hold cannot be set when the scanner is enabled ROUTe SCAN LSEL INT Sending a hold command will result in a settings conflict error 221 Programming example The following program fragment triggers and stores in the buffer 10 readings RST TRAC CLE TRIG DEL 0 5 SAMP COUN 10 READ Restore RST defaults Clear buffer Set delay for 0 5sec
250. d END Request highest numbered digital output channel 0 digital output not supported TCHannel Query the totalizer channel DINPut Path to query digital input channels STARt Request lowest numbered digital input port 0 digital input not supported END Request highest numbered digital output channel 0 digital input not supported 15 22 Table 15 7 continued SYSTem command summary SCPI Reference Tables Model 2701 User s Manual Default Command Description parameter Ref SCPI SYSTem CARDX SNOpen Query whether card is single no open type e 7711 1 yes 0 no BANKs For single no open card query number of banks If not single no open type error 221 settings conflict results SWOpen Query whether card is single with open type i e 7711 1 yes 0 no BANKs For single with open card query number of banks CSOhms Query whether card supports common side 4 wire ohms i e 7701 TIME hr min sec gt Set system time using 24 hour format Sec 6 TIME Query system time DATE yr mo day Set system date yr 20xx Sec 6 DATE Query system date TSTamp Path to set timestamp Sec 6 lt name gt Select timestamp type RELative or REL RTCLock TYPE Query timestamp type that will be used for the next buffer storage RELative Path to reset relative timestamp RESet Reset relative timestamp to 0 RNUMber Path t
251. d Since enab is not a root command an error would occur 10 26 Remote Operations Model 2701 User s Manual Command path rules Each new program message must begin with the root command unless it is optional e g SENSe If the root is optional simply treat a command word on the next level as the root For fastest operation do not send optional data Acolon can be used at the beginning of a program message However using the colon slows down execution time 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 back to the root level The path pointer can only move down It cannot move up a level Executing a command 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 are separated by semicolons A common command can be executed at any command level and will not affect the path pointer Example statoper enab lt NRf gt ESE lt NRf gt Program message terminator PMT Each program message must be terminated with an LF line feed CR carriage return CR L
252. d These include both measurement and non measurement channels The channels are built into a string that scrolls the display Four dots identify the end of the string Model 7700 example Slot 1 Assume the 4 function is selected and system channel 101 is closed The following string will scroll across the display 101 111 123 124 125 Channels 101 and 111 are the paired channels for the 4 wire measurement Channel 123 is the 4 pole relay setting and channels 124 and 125 connect input and sense to the DMM of the Model 2701 Figure 2 2 NOTE Some switching modules have analog outputs digital inputs and or digital outputs The values for these channels are also displayed from the VIEW menu item For details on a particular switching module refer to the packing list that was shipped with each module 2 32 Close Open Switching Module Channels Model 2701 User s Manual SLOTX 77XX Use to scroll the closed channels and channel settings if applicable for the switching module in Slot X where X or 2 Scrolling speed The scrolling speed of the channel string is adjustable or can be paused The key slows down scrolling speed and the key speeds it up The ENTER key pauses scrolling Press ENTER a second time to resume scrolling Exiting VIEW To exit from VIEW press the EXIT key Pressing an instrument setting key will also exit VIEW but it will also perform the operation associated with the key For example p
253. d then close the next higher or lower channel 6 Observe the displayed reading 7 To measure other switching channels repeat steps 5 and 6 8 When finished press OPEN if there is a channel closed 3 46 Basic DMM Operation Model 2701 User s Manual Frequency and period measurements The Model 2701 can make frequency measurements from 3Hz to 500kHz on voltage ranges of 100mV 1V 10V 100V and 750V Period 1 frequency measurements can be taken from 2 to 333ms on the same voltage ranges as the frequency Input impedance 1 MO 100pF AC coupled The instrument uses the volts input to measure frequency The AC voltage range can be changed with the RANGE keys The signal voltage must be greater than 10 of the full scale range CAUTION The voltage limit is subject to the 8 x 107 VHz product Trigger level Frequency and period use a zero crossing trigger meaning that a count is taken when the frequency crosses the zero level The Model 2701 uses a reciprocal counting technique to measure frequency and period This method generates constant measurement resolution for any input frequency The multimeter s AC voltage measurement section performs input signal conditioning Gate time The gate time is the amount of time the Model 2701 uses to sample frequency or period readings Use the RATE key to set the gate time SLOW sets the gate time to 1 0 sec MED sets it to 0 1 sec and FAST sets it to 0 01 sec For remote
254. d to the buffer A type K thermocouple is used to measure temperature Since the internal cold reference junction of the Model 7700 is being used the thermocouple can be connected directly to the screw terminals of the switching module Model 2701 User s Manual Scanning 7 33 Operation A simplified model of external trigger scan operation is shown in Figure 7 4 while the procedure steps and programming commands are listed in Table 7 2 As shown in the operation model when the scan is enabled channel 101 closes and the Model 2701 waits for an external trigger When the trigger is received channels 101 and 102 are measured Operation then returns to the control source where it waits for another trigger NOTE After the scan is enabled Table 7 2 step 5 the TRIG key can be used to trigger the scan Figure 7 4 External trigger scan example Enable Scan Close Chan 101 Wait For Trigger 2 M easurements O pen Last Chan Close Next Chan M easure 7 34 Scanning Model 2701 User s Manual Table 7 2 External trigger scan example Front panel operation Remote programming 1 Restore defaults Restore defaults SHIFT SETUP RESTORE FACT RST 2 For front panel operation proceed to step 3 For remote programming clear buffer and disable TRAC CLE buffer auto clear TRAC CLE AUTO OFF 3 Configure advanced scan SHIFT CONFIG gt ADVANCED a Channel 101 Select TEMP functi
255. d CH13 CH8 and CH18 CH4 and CH14 CH9 and CH19 CHS and CH15 CH10 and CH20 Model 2701 User s Manual Figure B 1 Simplified schematic for Model 7700 HI Input LO Cold Junction Ref x3 1 LO Channels 2 9 HI Channel 10 Cold Junction Ref f H Channel 11 Channels 12 19 i HI Channel 20 HI Channel 21 LO HI Channel 22 LO AMPS LO 2 Pole O pen th Channel 23 4 Pole Closed See N ote Model 7700 Connection Guide B 3 Channel 25 See N ote Backplane Isolation O 0 0 Input O O o LO Channel 24 See Note Backplane Isolation O 0 0 HI To Sense Model 2701 oT 0 oL0 Backplane AMPS N otes Channels 23 and 25 in this schematic refer to the designations used for control and are not actual available measurement channels If the module is notto be internally connected to the DMM channels 24 and 25 can be opened using multiple channel operation see Multiple channel operation in Section 2 for details B 4 Model 7700 Connection Guide Model 2701 User s Manual Connections and wiring WARNING WARNING WARNING WARNING Screw terminals The following information is intended for qualified service personnel Do not make or break switching module connections unless qualified to do so To prevent electric shock that could result in serious injury or death adhere to the following safety precauti
256. d SYSTem commands SCPI reference tables 15 1 15 2 CALCulate commmand summary 15 3 DISPlay command summary 15 5 FORMat command summary 15 6 ROUTe command summary 15 6 SENSe command summary 15 8 STATus command summary 15 19 SYSTem command summary 10 6 10 15 10 31 15 20 TRACe command summary 15 25 Trigger command summary 15 26 UNIT command summary 15 27 SCPI signal oriented measurement commands 13 1 CONFigure function lt rang gt lt res gt lt clist gt 13 4 FETCh 13 6 READ 13 7 Settings Default 1 21 1 23 Setups 1 21 Commands 1 26 Remote programming 1 26 Restoring 1 22 Saving 7 21 Saving power on 1 22 Saving user 1 21 Shielding 3 15 3 22 E 9 Signal handshaking 10 29 Signal processing Buffer D 5 Filter D 4 Limits D 5 Math D 5 OComp D 4 Output trigger pulse VMC D 4 Ratio and Ch Average D 6 Rel D 5 Signal processing sequence D 2 Slot numbering 2 6 Software 1 5 Source mode Logic control 9 10 Specifications A 1 Speed Setting measurement speed 4 10 vs noise characteristics 4 8 Standard deviation buffer statistic 6 8 Standard event status 11 11 Status and error messages C 1 Status byte and service request SRQ 11 8 Commands 11 10 Status indicators Ethernet 10 20 Status structure 11 1 Overview 11 2 STEP 7 7 7 17 Operation overview 7 7 Switching modules 1 3 1 7 Cables and connector kits 1 4 CARD commands 2 33 Closing and opening channels 1 31 2 1 Connections 2 4 2 5 D
257. d continuity tests However when limits or CONT is again selected the beeper will automatically enable Parameters lt b gt 0 Disable beeper Enable beeper Figure 14 2 Key press codes 1 2 3 4 5 6 7 8 16 11 SENSE awe INPUT m ETHERNET eae sen A ACQUISITION SYSTEM MATH OUWPUT CHWVG CONT OCWMP ncs SENSOR SHIFT RANGE DELAY HOLD LIMITS E MONITOR CH OFF CARD LE N us Eme 5 FILTER REL Lx gt ane ee RANGE CATI AMES POWER SETUP CONFIG HALT TEST __LSYNG WAHERNET RS 232 Bh D J OPEN OPEN stee scan Diets Rare ewres A 17 26 27 28 29 30 31 32 14 13 18 19 20 21 22 23 24 15 12 14 6 FORMat and Misc SYSTem Commands Model 2701 User s Manual 15 SCPI Reference Tables 15 2 SCPI Reference Tables Model 2701 User s Manual Reference tables Table 15 1 through Table 15 10 summarize the commands to operate the Model 2701 and Model 7700 switching module NOTE The commands listed in the following tables pertain to operation of the Model 2701 and the Model 7700 switching module For commands that are unique to operation of other switching modules refer to the packing list provided with each switch module Table 15 1 CAL Culate command summary Table 15 2 DISPlay command summary Table 15 3 FORMat command summary Table 15 4 ROUTe command summary Table 15 5 SENSe command summary
258. d 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 1000V 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 sources NEVER connect switching cards directly to AC mains When connecting sources to switching cards install protective devices to limit fault current and voltage to the card Before operating an instrument ensure that the line cord is connected to a properly grounded power receptacle Inspect the connecting 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
259. d read the event enable registers are listed in Table 11 6 For details on programming and reading registers see Programming enable registers page 11 5 and Reading registers page 11 7 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 Model 2701 User s Manual Status Structure 11 19 Table 11 6 Event enable registers commands Command Description ESE lt NDN gt or lt NRf gt Program Standard Event Enable Register ESE Read Standard Event Enable Register STATus OPERation ENABle lt NDN gt or lt NRf gt Program Operation Event Enable Register STATus OPERation ENABle Read enable register STATus MEASurement ENABle lt NDN gt or lt NRf gt Program Measurement Event Enable Register STATus MEASurement ENABle Read enable register STATus QUEStionable ENABle lt NDN gt or lt NRf gt Program Questionable Event Enable Register STATus QUEStionable ENABle Read enable register Parameters Hx Qx lt NRf gt 0to lt NDN gt Bxx x Binary format each x 1 or 0 Hexadecimal format x 0 to 7FFF Octal format x 0 to 77777 32767 Decimal format Notes 1 The format of the response messages for the above queries is set by the FORMatt SREGister command 2 Power up and STATus PRESet resets all bits of all enable registers to 0 CLS has no effect Programming examples Exa
260. d reading count setting dis played press ENTER The instrument returns to the normal measurement mode See Trigger models page 7 4 for details on reading count 7 18 Scanning Model 2701 User s Manual Setting delay As shown in Figure 7 1 and Figure 7 2 a delay auto or manual can be set by the user With auto delay selected the delay period depends on function and range Table 8 1 With manual delay selected the delay period can be set from 0 secs to 99 hrs 99 mins 99 999 secs Perform the following steps to set auto or manual delay 1 With the instrument in the normal measurement display state press SHIFT and then DELAY 2 Press or to display AUTO auto delay or MAN manual delay and press ENTER 3 If you selected MAN yo77xxu will be prompted to set the delay in the hour minute second time format Use the 4 gt and keys to set the delay NOTE Pressing the AUTO key sets the manual delay to 0 001 sec 4 With the desired manual delay displayed press ENTER For remote programming the TRIGer DELay NRf and TRIGger DELay AUTO b commands are used to set the delay See Table 7 1 for details NOTE The delay for ratio and channel average can only be set using remote programming Table 5 3 Monitor channel While in the normal measurement state a scan list channel can be used to monitor readings When a channel is selected to be the monitor it will assume the setup of the scan list c
261. d the power up sequence Display Provides information about the display of the Model 2701 Defaults and user setups Lists the RST and factory default settings and cov ers the three setup configurations available to the user Remote programming information Explains how SCPI commands are pre sented in this manual 1 2 Getting Started Model 2701 User s Manual QS3 Quick start exercises Provides abbreviated operating information and exer cises front panel and remote programming to acquaint a user with operation basics General 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 a Keithley Application Engineer at 1 800 348 3735 U S and Canada only Safety symbols and terms The following symbols and terms may be found on the instrument or used in this manual The A 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 personal injury or death Always read the associated information very carefully before performing the indicated procedure The CAUTION heading used in this man
262. date Keithley Model 77xx series switching modules The Model 2701 is shipped from the factory with slot covers installed Please note additional slot covers can be requested from Keithley Instruments WARNING _ Slot covers must be installed on unused slots to prevent personal con tact with high voltage circuits Model 2701 User s Manual Getting Started 1 15 Power up QSD The Model 2701 will operate properly using the following line power voltages and frequencies Line power voltages 100V 120V 220V and 240V Line power frequencies 45Hz to 66Hz and 360Hz to 440Hz Line power connection Follow the procedure below to connect the Model 2701 to line power and turn on the instrument 1 Check to see that the line voltage indicated in the window of the fuse holder assem bly Figure 1 3 is correct for the operating voltage in your area If not refer to Setting line voltage and replacing fuse page 1 16 CAUTION Operating the instrument on an incorrect line voltage may cause dam age to the instrument possibly voiding the warranty 2 Before plugging in the power cord make sure that the front panel power switch is in the off O position 3 Connect the female end of the supplied power cord to the AC receptacle on the rear panel Connect the other end of the power cord to a grounded AC outlet WARNING _ The power cord supplied with the Model 2701 contains a separate ground wire for use with grounded outlets When pro
263. dings Model 2701 User s Manual Programming example Buffer 6 15 The following command sequence stores 20 readings in the buffer and then calculates the mean for those readings NOTE The following example can be run from the KE2700 Instrument Driver using the example named BufStats in Table G 1 of Appendix G Store readings TRAC CLE AUTO ON TRAC POIN 20 TRAC FEED SENS TRAC FEED CONT NEXT TRAC DATA Calculate mean CALC2 FORM MEAN CALC2 STAT ON CALC2 IMM Enable buffer auto clear Set buffer size to 20 Select raw readings for storage Start storage process Request all stored readings Select mean calculation Enable mean calculation Perform calculation and request result 6 16 Buffer Model 2701 User s Manual scanning Scanning fundamentals Explains channel assignments slot channel programming format the difference between sequential and non sequential scans and the basic scan process Block diagrams known as trigger models are provided to help explain the STEP and SCAN operations Scan configuration Provides the step by step procedures to configure a simple scan or an advanced scan Covers other scan options including delay monitor auto configuration saving setups and auto scan Scan operation Provides the step by step procedures to perform a basic scan a manual external trigger scan and a monitor scan Remote programming scanning Provides the commands used f
264. dow to place in the memory stack When the stack is full the A D conversions are averaged to calculate the final filtered reading The filter count can be set from 1 to 100 Note that with a filter count of 1 no averaging is done However only readings within the Filter window will be displayed stored or transmitted Model 2701 User s Manual Range Digits Rate Bandwidth and Filter 4 15 NOTE While the filter processes readings the FILT annunciator blinks Readings that are being displayed while the FILT annunciator blinks are not final filtered readings When the FILT annunciator stops blinking the filter has settled Figure 4 2 Moving and repeating filters A Type Moving Average Readings 10 Conversion Conversion Average Reading 1 Conversion Conversion B Type Repeating Readings 10 Conversion Conversion Average Reading 1 Conversion Conversion Filter window Average Reading 2 Average Reading 2 Conversion Conversion Conversion Conversion Average Reading 3 Average Reading 3 The digital filter uses a noise window to control filter threshold As long as the input signal remains within the selected window A D conversions continue to be placed in the stack If the signal changes to a value outside the window the filter resets and the filter starts processing again starting with a new initial conversion value from the A D converter The n
265. e TCouple Path to configure thermocouple Sec 3 TYPE type Select T C type J K T E R S B N K lt clist gt TYPE lt clist gt Query T C type ODETect lt b gt Enable or disable T C open detector OFF ODETect Query state of T C open detector RJUNCtion Path to configure reference junction 6 RSELect name Select reference junction SIMulated Note 7 lt clist gt INTernal or EXTernal RSELect lt clist gt Query reference junction SIMulated n Set simulated reference temperature 23 lt clist gt 0 to 65 C 32 to 149 F or 273 to 338 K SIMulated lt clist gt Query simulated reference temperature THERmistor Path to configure thermistor Sec 3 TYPE lt NRf gt Set thermistor type in ohms 1950 to 5000 lt clist gt 10050 TYPE lt clist gt Query thermistor type FRTD Path to configure 4 wire RTD Sec 3 TYPE name Select FRTD type PT100 D100 F100 PT100 lt clist gt PT3916 PT385 or USER lt clist gt Query FRTD type RZERo lt NRf gt Specify constant for USER type 0 to 100 lt clist gt 10000 RZERO lt clist gt Query rzero ALPHa lt NRf gt Specify constant for USER type 0 to 0 00385 lt clist gt 0 01 ALPHa lt clist gt Query alpha BETA lt NRf gt lt clist gt Specify constant for USER type 0 to 0 111 1 00 BETA lt clist gt Query beta DELTa lt NRf gt Specify constant for U
266. e 3 8 Volts measurement procedure esse 3 11 AC voltage measurements and crest 3 12 Low level considerations sss 3 15 Current measurements and 3 17 tees cec tepore th ette eee ev tt Max eve T 3 17 Amps measurement procedure 3 18 AMPS fuse replacement front panel AMPS 3 19 Resistance measurements Q2 and 3 20 s pre Een eate ce ay rero ce vasi deo casa ae eO EMI 3 20 Standard resistance measurements sss 3 23 Offset compensated 3 24 Measurement methods 3 25 ii Document Number 2701 900 01 Rev F August 2011 Model 2701 Ethernet Based DMM Data Acquisition System Table of Contents 4 wire common side CSID ohms measurements 7701 module 3 32 Temperature measurements sssssssssssseeeeennen eene 3 33 Thermocouples ense creer trece ae repe cedido 3 33 Mulier m 3 36 AE wire 08 eo ien me E spe eta 3 37 2 E 3 38 Temperature measurement 3 42
267. e INITiate command generates error 213 init ignored If continuous initiation is enabled the READ command will generate error 213 init ignored It can be disabled by sending INITiate CONTinuous OFF The RST command can also be used to disable continuous initiation It also places the Model 2701 in the one shot measurement mode RST Disable continuous initiation and place 2701 in one shot mode READ Trigger and return one reading When readings are stored in the buffer by the TRACe command or by front panel data store operation INIT and multi sample READ queries are locked out With readings in the buffer that were stored in that manner you cannot use the INIT or READ command if sample count is gt 1 error 225 out of memory Buffer operation is covered in Section 6 The buffer of the Model 2701 is nonvolatile Therefore readings stored in the buffer are not lost when the instrument is turned off or when RST or SYSTem PRESet is sent When writing test programs that perform multi sample measurements SAMPle COUNT gt 1 you may want to add TRACe CLEar command at the beginning to clear the buffer However be careful not to inadvertently clear stored readings that are needed 13 8 SCPI Signal Oriented Commands Model 2701 User s Manual MEASure lt function gt lt rang gt lt res gt lt clist gt MEASure VOLTage DC lt rang gt lt res gt lt clist gt MEASure VOLTage AC
268. e RAV bit in the status model or by allowing sufficient time to pass for the reading to complete READ What it does This command performs three actions It will reset the trigger model to the idle layer equivalent to ABORt command take the trigger model out of idle equivalent to the INIT command and return a reading equivalent to a FETCh query This command will always return a new reading since aborting the trigger model will invalidate any old readings and trigger a new one This query will wait for a new reading to become available before the instrument sends a result back Limitations This command will not work if the trigger source is set for BUS or EXTERNAL This will cause a 214 Trigger deadlock error Under this condition use a FETCh query or a DATA FRESh query see page 3 60 If the trigger model is continuously initiating CINIT CONT ON sending this query may cause a 213 Init ignored error but it will still give a new reading When appropriate If the instrument receives a RST command then it defaults to INIT CONT OFF TRIG SOUR IMM and TRIG COUNT 1 Sending a READ query under these conditions will trigger a new reading 3 60 Basic DMM Operation Model 2701 User s Manual MEASure function What it does This query will reconfigure the instrument to the function specified in the query set the trigger source for immediate set the trigger count to 1 and configur
269. e Sense Hi terminal connected to the DUT but it does not need to be It can be left open The measurement method is similar to the ratiometric method for 2 but it performs an extra voltage measurement Vj pap to compensate for IR drop in the input test leads As stated in the specifications Appendix A to achieve rated accuracy the Input Hi and Input Lo test leads must have 10 matching of resistance To meet that criteria simply use similar type test leads that are the same length Keep in mind that VyAs includes the voltage drops of the input test leads Input Hi and Input Lo Therefore the actual voltage drop across the DUT is VygAs minus the two voltage drops in the test leads Since matched input leads are used the voltage drop for the two test leads are 2 x Vj gAp Therefore VMEAS 2 ViEADJ The Model 2701 still uses Eq 2 to calculate resistance but it uses in place of Vmeas This ratiometric method cancels the effects of input test lead resistance Model 2701 User s Manual Basic DMM Operation 3 29 Figure 3 11 Ratiometric method to measure ohms LOMQ and 100MQ ranges A 2 wire ohms 02 measurements 10M and 100M ranges _ i Q2 Function Eq 1 Isour Iner Ipur Vmeas V meas Rar Rout Eq 2 3 m V meas RREF DUT Isour Rrer Vmeas Vugss 10M Q 0 7uA 10M Q Vmeas Example B 4 wire ohms 04 measurements 10M and 100M Asume Vm
270. e Use Case 6 Scan 160 channels using 7703 module see NOTE Type K thermocouple TC temperature measurements Reference junction Simulated Measurement speed rate 0 01 plc Filter Disabled no filtering Buffer Store 160 reading strings Buffer elements include reading and channel e Triggering Bus control source Data retrieval Continuously store data into buffer Retrieve data for every 32 readings NOTE When using a module that has a built in cold junction use the Internal reference junction Keep in mind that the buffer and data retrieval will have to be modified to accommodate the number of scanned channels Modules that have cold junction include 7700 and 7706 modules 20 available TC channels 7708 module 40 available TC channels Advance7 None Use Case 7 Ten 40 channel scans using 7702 module Channel 1 uses an external reference junction Measurement speed rate 1 plc Filter Repeat 25 readings Channels 2 through 40 are connected to type K thermocouples Measurement speed rate 1 plc Filter Disabled no filtering Open thermocouple detection Enabled Buffer Store 400 reading strings Buffer elements include reading real time clock and channel e Triggering Bus control source Data retrieval SRQ when buffer 2 34 and full G 16 KE2700 Instrument Driver Examples Model 2701 User s
271. e first stored reading to return Note that the first stored reading in the buffer is 0 The lt count gt parameter specifies the number of readings to return When the storage process is aborted you can use TRACe NEXT to determine the buffer location for the next stored reading For example if the last reading is stored at memory location 36 TRACe NEXT will return the value 37 This query is useful when using the buffer in the continuous storage mode TRACe FEED CONTrol ALWays as demonstrated by the following example Example Assume the buffer is configured for continuous wrap around storage and the buffer size is 100 At some point you stop the storage process and want to return all the readings that were stored since the last time the buffer filled The following command will return the buffer location for the next stored reading TRACe NEXT Query buffer location for next stored reading Assume that the above query returned value 37 Now you can use that value as the count parameter for the following command to return the 37 readings 0 through 36 TRACe SELected DATA 0 36 Return buffer readings 0 through 36 NOTE When using the RS 232 interface the TRAC DATA SEL command should always be used when recalling more than 100 points of buffer data For large buffers the PC may lose synchronization and data can be lost To avoid this use this query command to recall buffer data in 100 point chunks Model 2
272. e limits menu Note that the CHAN annunciator flashes to indicate that the menu is being used to set up a scan channel Use the lt and keys to set high limit 1 HLIM1 and press ENTER Set low limit 1 LLIM1 and press ENTER Set high limit 2 HLIM2 and press ENTER Set low limit 2 LLIM2 and press ENTER The instrument returns to the scan setup menu Press SHIFT and then ON OFF to display the present state of LIMITS ON or OFF Again the CHAN annunciator flashes to indicate that the menu is for a scan channel Press the or key to display LIMITS ON and press ENTER The instrument returns to the scan setup menu Note that the HIGH and LOW annunciators are on to indicate that limits are enabled After all scan channels are set up press ENTER The present state of IMM SCAN is Y yes or N no Model 2701 User s Manual Scanning 7 25 2 Press the or key to display IMM SCAN N and press ENTER a Press the or key to enable or disable low limit 1 LLIMI SCAN N Y and press ENTER b Press the or key to enable or disable high limit 1 HLIM1 SCAN N Y and press ENTER c Press the or key to enable or disable low limit 2 LLIM2 SCAN N Y and press ENTER d Press the or key to enable or disable high limit 2 HLIM2 SCAN N Y and press ENTER 3 Finish configuring the scan by performing Step 4 and Step 5 of the Advanced scan setup procedure page 7 16 NOTE Fora remote programmed monitor scan use the
273. e settings can only be changed using remote programming The RTD has a metal construction typically platinum The resistance of the RTD changes with changes in temperature The Model 2701 measures the resistance and calculates the temperature reading When using default RTD parameters the resistance of the RTD will be 100 at 0 C Of all the temperature transducers the RTD exhibits the most stability and linearity The Model 2701 performs the 4 wire measurement using offset compensated ohms This provides the most accurate way to measure the low resistance of the RTD NOTE The equations used by the Model 2701 to calculate the temperature vs resistance readings listed in the RTD reference tables are provided in Appendix F NOTE Only one USER RTD per scan list 3 36 Basic DMM Operation Model 2701 User s Manual Connections NOTE When using the front panel inputs the INPUTS switch must be in the F out position For switching modules it must be in the R in position Thermocouple connections Connections for thermocouples are shown in Figure 3 14 Thermocouples are color coded to identify the positive and negative leads Table 3 2 Note that the negative lead for U S type T Cs is red For front panel inputs you need to use a simulated reference junction for thermocouple temperature measurements An ice bath as shown in Figure 3 144 serves as an excellent cold junction since it is relatively easy to hold th
274. e temperature to 0 C Notice that copper wires are used to connect the thermocouple to the Model 2701 input NOTE The positive lead of the type T thermocouple is made of copper Therefore that lead can be connected directly to the input of the Model 7700 It does not have to be maintained at the simulated reference temperature i e immersed in ice bath For the Model 7700 switching module you can also use a simulated reference junction as shown in Figure 3 14B or you can connect the thermocouple wires directly to the screw terminals internal reference junction as shown in Figure 3 14C Using a simulated reference junction may be inconvenient but it will provide more accurate temperature measurements assuming the user enters a precise reference temperature With open thermocouple detection disabled the Model 2701 can calculate the average temperature of two thermocouple channels using Channel Average see Section 5 for details As shown in Figure 3 14D one thermocouple is connected to a primary channel 1 through 10 and the other thermocouple is connected to its paired channel 11 through 20 Channel 1 is paired to channel 11 channel 2 is paired to channel 12 and so on Keep in mind that a simulated reference junction i e ice bath can instead be used for these thermocouple temperature measurements Model 2701 User s Manual Basic DMM Operation 3 39 Figure 3 14 Thermocouple connections Model 2701 Input HI Copper wires
275. e the measurement parameters to RST defaults It will then trigger a single reading and return the result Limitations This query is much slower than a READ or FETCh query because it has to reconfigure the instrument each time it is sent It will reset the NPLC autoranging and averaging to default settings When appropriate This is an ideal command for taking one shot measurements if the default settings for a measurement are appropriate and speed is not a requirement SENSe 1 DATA FRESh What it does This query is similar to FETCh in that it returns the latest reading from the instrument but it has the advantage of making sure that it does not return the same reading twice Limitations Like the FETCh query this command does not trigger a reading When appropriate This is a much better choice than the FETCh query because it cannot return the same reading twice This would be a good query to use when triggering by BUS or EXTERNAL because it will wait for a reading to complete if a reading is in progress The CALC DATA FRESh query is similar to the DATA FRESh query but applies to readings that have math applied to them e g MX B scaling Model 2701 User s Manual Basic DMM Operation 3 61 SENSe 1 DATA LATest What it does This query will return the last reading the instrument had regardless of what may have invalidated that reading such as changing ranges or functions Limitations This
276. each subsequent pass through the loop the Timer Bypass is disabled Operation is then delayed by the Timer or the Delay If the user set Timer interval is larger than the user set Delay the Timer will control the length of the delay Otherwise the length of the delay is controlled by the user set Delay period The Timer interval can be set from 0 to 999999 999 seconds The timer source is only available during scan operation The timer resets to its initial state when the instrument goes into the normal mode of operation or into the idle state e EXTernal Event detection is satisfied when an input trigger via the TRIG LINK connector is received by the Model 2701 BUS Event detection is satisfied when a bus trigger TRG is received by the Model 2701 Delay and Device Action These blocks of the trigger model operate the same for both front panel and remote operation See the front panel Trigger model page 8 2 for operating information on these trigger model blocks Also see Reading hold autosettle page 8 6 for details on Hold Counters Programmable counters are used to repeat operations within the trigger model For example if performing a 10 channel scan the sample counter would be set to 10 Operation will continue until all 10 channels are scanned and measured If you wanted to repeat the scan three times you would set the trigger counter to three For a sample count value gt 1 the sample readings will aut
277. eas 3 4V ranges Hi Roire 3 4V 10MQ 2701 zu 0 7uA 10M 9 3 4V i Input Hi 9 444MQ Q4 Function Vout Vmeas 2 Vieap Input Lo For Eq 1 Eq 2 and the Example E Vout is used in place of V meas Rout Sense Lo 3 30 Basic DMM Operation Model 2701 User s Manual Effects of open test leads on ohms readings The Model 2701 will display readings up to 120 of range Readings above 120 of range will cause the OVRFLW message to be displayed For example on the 1000 range readings up to 120Q will be displayed Above 1200 the OVRFLW message is displayed The Model 2701 will also display the OVRFLW message if a test lead is open during an ohms measurement A hardware H W detection circuit or software S W detection is used to detect an open input lead For an 4 measurement a software S W detection rou tine is used to detect an open sense lead Open test lead detection is illustrated in Figure 3 12 for an Q4 measurement of a 100Q resistor using the 100 range For an 2 measurement sense circuity is not used With the test leads properly connected as shown in Figure 3 12A 1mA is sourced through the 100 DUT The 100mV drop across the DUT appears on the Input Hi terminal Resistance is then calculated 100mV 1mA 100Q and displayed by the Model 2701 Open input lead detection 100Q through 1MQ ranges For the lower ohms ranges a hardware detector is used to detect an
278. ecify measurement resolution 4 to 7 7 Sec4 DIGits lt clist gt Query resolution REFerence n lt clist gt Specify reference 0 to 120e6 0 Sec 5 v STATe lt b gt lt clist gt Enable or disable reference OFF STATe lt clist gt Query state of reference ACQuire lt clist gt Use input signal as reference REFerence lt clist gt Query reference value AVERage Path to configure and control filter Sec4 TCONtrol lt name gt Select filter type MOVing or REPeat Note 3 TCONtrol Query filter type WINDow lt NRf gt Set filter window in of range 0 1 0 to 10 WINDow Query filter window COUNt n lt clist gt Specify filter count 1 to 100 10 COUNC lt clist gt Query filter count STATe b lt clist gt Enable or disable filter Note 4 STATe lt clist gt Query state of digital filter OCOMpensated lt b gt Enable or disable offset compensation OFF Sec 3 lt clist gt Model 2701 User s Manual SCPI Reference Tables 15 15 Table 15 5 continued SENSe command summary Default Command Description parameter Ref SCPI SENSe 1 TEMPerature Path to configure temperature Sec 3 v APERture lt n gt lt clist gt Set integration rate in seconds Note 2 Sec 4 3 333333e 5 to 1 APERture lt clist gt Query aperture integration rate NPLCycles n lt clist gt Set integration rate in line cycles 60Hz 5 0 Sec 4
279. ecution The execution of OPC is not completed until it has placed the 1 in the Output Queue Model 2701 User s Manual Common Commands 12 5 Programming example The following command sequence demonstrates how to use OPC to signal the end of a measurement process SYST PRES Returns 2701 to default setup INIT CONT OFF Disables continuous initiation ABORt Aborts operation Places 2701 in idle SAMP COUN 5 to perform five measurements INIT Starts measurement process TRIG COUN 1 These two commands configure the 2701 OPC Sends OPC command After all five measurements are performed and the instrument returns to the idle state an ASCII 1 will be placed in the Output Queue The 1 from the Output Queue is sent to the computer SYST PRES Returns 2701 to default setup NOTE The following commands take a long time to process and may benefit from using OPC or OPC e RST and SYST PRES RCL and SAV e ROUT MULT CLOS and ROUT MULT OPEN Only if the lt clist gt is long e CALC2 IMM and CALC2 IMM Only when performing the standard deviation calculation on a large buffer A 450 000 point buffer takes around 5 to 6 seconds OPT option query Query installed switching modules Use this query command to determine which switching modules are installed in the Model 2701 For example if a Model 7703 is installed in slot 1 and the other slot is empty the response message will lo
280. ed channel For details see Table 2 2 and related reference information Model 2701 User s Manual Close Open Switching Module Channels 2 33 SYSTem CARD commands There is a series of SYSTem CARD commands that can be used to acquire the following information about a switching module installed in the Model 2701 Return the serial number and firmware revision Determine the maximum allowable voltage Determine if the module supports multiplexer or isolated channels Determine if the module has built in temperature sensors for internal cold junction thermocouple temperature measurements Determine which channels are used for volts 2 wire measurements and which are used for amps Determine which channels are used for analog or digital output Determine the totalizer channel Model 7706 only The SYSTem CARD commands are covered in Table 15 7 2 34 Close Open Switching Module Channels Model 2701 User s Manual Relay closure count The Model 2701 keeps an internal count of the number of times each module relay has been closed The total number of relay closures are stored in EEPROM on the card This count will help you determine if and when any relays require replacement see module contact life specifications Relay closures are counted only when a relay cycles from open to closed state If you send multiple close commands to the same channel without sending an open command only the first closure will be counted Re
281. ed to type K thermocouples Measurement speed rate 1 plc Filter Disabled no filtering Buffer Store 400 reading strings Buffer elements include reading only Triggering Bus control source Model 2701 User s Manual Table G 1 continued Visual Basic and CVI C examples KE2700 Instrument Driver Examples G 11 Name Manual Reference Brief Description Simple8 None Use Case 8 7706 module in slot 1 and 7702 module in slot 2 7706 module Output analog output values to analog output channels Output digital output values to digital output channels 7702 module Scan 120 DCV channels Measurement speed rate 1 plc Filter Disabled no filtering Buffer Store 320 reading strings Buffer elements include reading only Triggering Bus control source trigger delay 0 125 seconds SOPC Page 12 4 Demonstrates operation complete query OPC SrSetup Page 12 6 Demonstrates saving and recalling user setup TCalibration 7706 Demonstrates 7706 temperature calibration TCTemperature None Demonstrates temperature measurement Totalizer 7706 Demonstrates reading the 7706 totalizer TrigReadings Page 8 20 Demonstrates instrument triggering VoltdB 1 Page 5 21 Ex 1 Demonstrates DCV dB measurement with 1V OdB level VoltdB2 Page 5 21 Ex 2 Demonstrates ACV dB measurement with 10V OdB level G 12 KE2700 Instrument Driver Examp
282. eed ing these limits could cause damage to the switching module 5 Ifusinga switching module use the and keys to close the desired amps channel for the Model 7700 21 or 22 All other channels will be open Model 2701 User s Manual Basic DMM Operation 3 19 6 Observe the displayed reading If the OVERFLOW message is displayed select a higher range until a normal reading is displayed or press AUTO for autoranging For manual ranging use the lowest possible range for the best resolution 7 To measure another amps channel repeat steps 5 and 6 8 When finished press OPEN if there is a channel closed NOTE When you have an amps only channel closed you cannot select a non amps function For example if channel 21 of the Model 7700 is closed you cannot select the DCV function INVALID FUNC displayed AMPS fuse replacement front panel AMPS input WARNING Make sure the instrument is disconnected from the power line and other equipment before replacing the AMPS fuse Turn off the power and disconnect the power line and test leads 2 From the front panel gently push in the AMPS fuse holder with a flat blade screwdriver and rotate the fuse holder one quarter turn counterclockwise 3 Remove the fuse and replace it with the same type 3A 250V fast blow 5 x 20mm The Keithley part number is FU 99 1 CAUTION Do not use a fuse with a higher current rating than specified or instrument damage may occur If t
283. el 2701 Also the CHAN annunciator does not turn on when a channel is closed Opening a channel using multiple channel operation has no affect on other closed channels Only the specified channel opens NOTE Use the VIEW option of the CARD menu to display closed channels see CARD menu page 2 30 Model 2701 User s Manual Close Open Switching Module Channels 2 17 Controlling multiple channels WARNING When using multiple channel operation you must be very careful when switching hazardous voltages If you inadvertently close the wrong channel s you could create a shock hazard and or cause damage to the equipment Most switching modules use latching relays That is closed channels remain closed when the Model 2701 is turned off Never handle a switching module that is connected to an external source that is turned on Turn off all power sources before 1 making or breaking connections to the module and 2 installing or removing the module into or out of the Model 2701 Avoiding corrupt measurements Aside from the safety issues improper use of multiple channel operation can result in corrupt measurements For example assume two Model 7700s installed in slots 1 and 2 and a 2 wire function selected If you use multiple channel operation to close channels 201 and 225 you will connect the input at channel 201 to the DMM for measurement If you then use system channel operation to close channel 101 channel 125 will also clo
284. el 7700 switching module Connections for the Model 7700 switching module are shown in Figure 3 19B Since this is a 2 wire ohms measurement channels 1 through 20 can be used Figure 3 19 Continuity connections Model 2701 Input HI Resistance Under Test Resistance Switching Under Test Module Note Source current flows from input high to input low B Model 7700 connections 3 50 Basic DMM Operation Model 2701 User s Manual Continuity testing procedure NOTE Make sure the INPUTS switch is in the correct position To use front panel NOTE inputs it must be in the F out position For switching modules it must be in the R in position Apply the resistance to be tested and if using a switching module close the appropriate channel Press SHIFT and then CONT to display the present threshold LEVEL Use 4 gt and to key in the desired level 1 to 10000 and press ENTER If the measured circuit is below the set threshold level the instrument will beep and display the resistance readings If the measured circuit is above the threshold level the instrument will not beep and either display the resistance reading or the message OPEN If the reading is below 11000 it will be displayed If the reading is 1100Qor above OPEN will instead be displayed To disable continuity testing select a different function i e press DCV The beeper can be disabled using the SYSTem BEEPer STATe OFF com
285. el inputs 3 9 Using Model 7700 switching module 3 10 DCV input divider 10 3 Default settings 1 21 1 23 Delay 7 9 8 3 Auto 7 9 Auto delay settings 8 4 Manual 7 9 Ratio and channel average 5 18 Ratio Chan Average 7 9 Setting 7 18 Timer Delay for STEP and SCAN 7 22 Device action 7 9 8 5 Digital I O 1 14 8 8 9 5 Digital input 9 5 Digital outputs 9 6 Commands 9 12 Logic sense 9 7 Master limit latch 9 7 Programming example 9 14 Pulse option 9 7 Remote programming 9 12 Scanning 9 11 Setting 9 10 Sink mode controlling external devices 9 8 Digits 4 6 Commands 4 6 Programming examples 4 7 Remote programming 4 6 Scanning 4 6 Setting 4 7 Display 1 19 Annunciators 1 12 Commands 1 19 DISPlay ENABle 1 20 DISPlay TEXT DATA 1 20 DISPlay TEXT STATe 1 20 Programming example 1 20 Remote programming 1 19 DMM measurements 1 29 Dual independent multiplexers 2 24 Dual multiplexer application 2 26 DUT test system 8 11 Error messages C 2 Ethernet Connections 10 10 Front panel aspects 10 20 Front panel setup 10 13 Front panel status indicators 10 20 Settings 10 12 Setup 10 7 Standards 10 7 Status LEDs 10 10 Ethernet systems 10 7 Examples Basic measurement programming examples 3 57 Buffer programming example 6 15 dB programming examples 5 21 Default and user setups programming example 1 26 Digits programming examples 4 7 Display programming example 1 20 External triggering 8 11 Filter 4 16 Filter programming examples
286. elay when designing test systems Model 2701 User s Manual Limits and Digital I O 9 7 Logic sense The selected logic sense active high or active low determines if an output is pulled high or low when the limit is reached If logic sense is set high the output line will be pulled high when the reading reaches or exceeds the limit If logic sense is set low the output line will be pulled low to OV when the reading reaches or exceeds the limit Pulse option Pulse option is available for the digital outputs When enabled an output line will pulse high or low depending on the logic sense setting for each reading that reaches or exceeds the limit The factory default time duration for the pulse is 2ms maximum but can be set from 0 001 to 99999 999 seconds using remote programming Pulse time cannot be set from the front panel NOTE The commands to set pulse time and enable disable pulse output are listed in Table 9 2 See Digital output commands in the table The pulse time does not affect measurement speed If a subsequent in limit reading occurs while the output line is being pulsed the line will be released immediately pulse terminated Master limit latch The master limit line is pulled high or low when one or more of the other four limits are reached or exceeded The master limit line can be programmed to release when a reading is inside all four limits or the master limit can be latched when a failure occurs When latched
287. eleased and the beeper sounds if enabled 7 Remove the hold condition by disconnecting the signal from the input Hold will then seek a new seed 8 disable HOLD press SHIFT and then HOLD Model 2701 User s Manual Triggering 8 7 Beeper control The beeper for Hold can be enabled or disabled from the OUTPUT menu as follows 1 Press SHIFT and then OUTPUT 2 Use the or key to display the present beeper BEEP state NEVER OUT SIDE or INSIDE 3 Perform step a or b a enable the beeper use the or key to display OUTSIDE or INSIDE b To disable the beeper use the or key to display NEVER 4 Press ENTER The instrument returns to the normal display state The instrument returns to the normal measurement state External triggering The EX TRIG key selects triggering from three external sources trigger link digital I O and the TRIG key When EX TRIG is pressed the TRIG annunciator lights and dashes are displayed to indicate the instrument is waiting for an external trigger From the front panel press the TRIG key to trigger a single reading Pressing the EX TRIG key again toggles back to continuous triggers The Model 2701 uses two lines of the TRIG LINK rear panel connector as External Trigger EXT TRIG input and Voltmeter Complete VMC output The EXT TRIG line allows the Model 2701 to be triggered by other instruments The VMC line allows the Model 2701 to trigger other instruments Line 1 is
288. els type T thermocouple temperature Measurement speed rate 1 plc Filter Disabled no filtering Buffer Store 160 reading strings Buffer elements include reading channel and real time clock Triggering Timer scan 40 channels every one minute Data retrieval SRQ when buffer 1 2 34 and full Advance2 None Use Case 2 40 channel scan using 7708 module 30 channels DCV 15 on 100mV range 15 on 10V range 9 channels ACV 1V range 1 channel 4 wire RTD temperature Measurement speed rate 1 plc Filter Disabled no filtering Buffer Store 160 reading strings Buffer elements include reading only Triggering Timer scan 40 channels every one minute Data retrieval SRQ when buffer 1 34 and full Advance3 None Use Case 3 Two scans using 7708 module 40 channel DCV 1V range scan 20 channel 4 scan e Models 2700 2701 100Qrange e Model 2750 10Q range dry circuit ohms enabled Measurement speed rate 0 1 plc e DCV input divider Enabled LOMQ input impedance Filter Disabled no filtering Buffer Store 40 DCV reading strings 20 reading strings Buffer elements include reading only Limits DCV scan Limit 1 all channels 20mV Master Latch enabled Triggering Bus control source Data retrieval SRQ if limit fails G 4 KE
289. emoving the device s power cord or by turning off the power switch Attach the test leads to the circuit under test Use appropriate safety rated test leads for this application If over 42V use double insulated test leads or add an additional insulation barrier for the operator Set the multimeter to the proper function and range Energize the circuit using the installed connect disconnect device and make measurements without disconnecting the multimeter De energize the circuit using the installed connect disconnect device Disconnect the test leads from the circuit under test 3 4 Basic DMM Operation Model 2701 User s Manual Performance considerations NOTE For maximum system performance it is recommended that all measurement cables be limited to less than 3 meters Warm up After the Model 2701 is turned on it must be allowed to warm up for at least two hours to allow the internal temperature to stabilize If the instrument has been exposed to extreme temperatures allow extra warm up time Autozero To help maintain stability and accuracy over time and changes in temperature the Model 2701 periodically measures internal voltages corresponding to offsets zero and amplifier gains For thermocouple temperature measurements using the internal reference junction i e Model 7700 switching module installed the internal temperature is also measured These measurements are used in the algorithm to calculate the reading of the i
290. enerated by a 0 7u A current source Iggyp in parallel with a 10MQ reference resistance Rpg as shown in Figure 3 11 Basic circuit theory dictates that the sum of the branch currents Ipgg and Ipyr is equal to the source current Since the voltmeter of the Model 2701 Vygas has very high input impedance gt 10GQ current through the voltmeter branch is insignificant and can be discounted Therefore as shown in Eq 1 Isour Ipgp Ipur Since I V R Eq 1 is modified using the V R equivalents in place of Ipgg and Ipyr Therefore Isour Vmeas Rrep Vmeas Eq 1 is then rearranged to solve for and is shown in Eq 2 of Figure 3 11 Keep in mind that VygAs is measured by the Model 2701 With Isour Rggp known the Model 2701 calculates the resistance of the DUT and displays the result NOTE 2 in Figure 3 11 assumes that is exactly 10 2 In reality the Model 2701 measures the resistance of and uses that value in the equation The Model 2701 routinely does a self calibration During this process the precision 0 7uA current is sourced through with an open input This reference voltage Vggp is measured and is then calculated Rrer O7 As shown in Figure 3 11B the function can also be used to measure ohms for the 10MQ and 100MQ ranges There are actually 3 wire ohm measurements Sense Hi is not used Figure 3 11B shows th
291. ensated ohms by pressing SHIFT and then OCOMP OCOMP annunciator turns on 3 Use the RANGE keys to select the 1000 1kQ or 10kQ range or press AUTO to enable auto range If using auto range offset compensated ohms measurements will not be performed if the instrument goes to the 100k or higher range 4 Perform steps 4 through 8 of the Standard resistance measurements page 3 23 procedure NOTE The OCOMP annunciator will flash when the instrument is on an invalid range 100kGthrough 100M ranges for offset compensated ohms Normal ohms measurements will instead be performed For buffer recall there is no way to distinguish between a normal ohms reading and an offset compensated ohms reading The OCOMP annunciator off on or flashing has no significance for recalled resistance readings that are displayed Buffer operation is covered in Section 6 With offset compensated ohms enabled it will be remembered by the 421 func tion after you change measurement functions i e DCV When 24 is again selected offset compensated ohms will be enabled Measurement methods The Model 2701 uses two methods to measure resistance e Constant current source method 1000 through 1MQ ranges Sources a constant current to the DUT Voltage is measured by the Model 2701and resistance is then calculated e Ratiometric method 10MQ and 100MQ ranges Test current is generated by a 0 7uA source in parallel with a
292. ents in a high humidity environment use Teflon insulated cables to minimize errors due to cable leakage Standard resistance measurements NOTE Make sure the INPUTS switch is in the correct position To use front panel inputs it must be in the F out position For switching modules it must be in the R in position Perform the following steps to measure resistance 1 Ifa switching channel is presently closed displayed press OPEN to open it 2 Select the ohms measurement function by pressing 2 or 3 Use the RANGE and keys to select a measurement range consistent with the expected resistance or press AUTO to select autoranging AUTO annunciator turns on Details on range are provided in Section 4 4 Connect the resistance s to be measured CAUTION Front panel inputs Do not apply more than 1000V peak between INPUT HI and LO or instrument damage may occur Model 7700 switching module Do not apply more than 300V DC or 300V RMS 425V peak for AC waveforms between input high H or input low L or switching module damage may occur 5 Ifusing a switching module perform the following steps to close the desired channel Keep in mind that for Q4 measurements you will close the primary INPUT channel 1 through 10 The paired channel will close automatically a Press the CLOSE key b Use lt gt and to key in the channel number and press ENTER The previously closed channel s if any w
293. ep in mind however that filtering may have detrimental effects such as increased settling time on the desired signal Model 2701 User s Manual Measurement Considerations E 7 Ground loops When two or more instruments are connected together care must be taken to avoid unwanted signals caused by ground loops Ground loops usually occur when sensitive instrumentation is connected to other instrumentation with more than one signal return path such as power line ground As shown in Figure E 2 the resulting ground loop causes current to flow through the instrument LO signal leads and then back through power line ground This circulating current develops a small but undesirable voltage between the LO terminals of the two instruments This voltage will be added to the source voltage affecting the accuracy of the measurement Figure E 2 Power line ground loops Signal Leads Instrument 1 Instrument 2 Instrument 3 Power Line Ground Figure E 3 shows how to connect several instruments together to eliminate this type of ground loop problem Here only one instrument is connected to power line ground Ground loops are not normally a problem with instruments like the Model 2701 that have isolated LO terminals However all instruments in the test setup may not be designed in this manner When in doubt consult the manual for all instrumentation in the test setup E 8 Measurement Considerations Model 2701 User s Manual Figure E 3 Eliminatin
294. equest Enable Register to 0 use 0 as the parameter value for the SRE command SRE 0 Table 11 3 Status Byte and Service Request Enable Register commands Command Description Default STB Read Status Byte Register SRE lt 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 second command in the following sequence enables EAV error available When an invalid command is sent line 4 bits B2 EAV and B6 MSS of the Status Byte Register set to 1 The last command reads the Status Byte Register To determine the exact nature of the error you will have to read the Error Queue see Queues on page 11 22 NOTE The following example can be run from the KE2700 Instrument Driver using the example named PollSRQ in Table G 1 of Appendix G CLS Clear Error Queue SRE 4 Enable EAV FORM SREG BIN Select binary format XYZ Generate error STB Read Status Byte Register Status register sets As shown in Figure 11 1 there are four status register sets in the status structure of the Model 2701 Standard Event Status Operation
295. er Sec 4 TCONtrol lt name gt Select filter type MOVing or REPeat Note 3 TCONtrol Query filter type WINDow lt NRf gt Set filter window in of range 0 1 0 to 10 WINDow Query filter window COUNt n lt clist gt Specify filter count 1 to 100 10 COUNC lt clist gt Query filter count STATe b lt clist gt Enable or disable filter Note 4 STATe lt clist gt Query state of digital filter 15 14 SCPI Reference Tables Table 15 5 continued SENSe command summary Model 2701 User s Manual OCOMpensated lt clist gt Query state of offset compensation Default Command Description parameter Ref SCPI SENSe 1 FRESistance Path to configure four wire resistance Sec 3 v APERture lt n gt lt clist gt Set integration rate in seconds Note 2 Sec 4 3 333333e 5 to 1 APERture lt clist gt Query aperture integration rate NPLCycles n lt clist gt Set integration rate in line cycles 60Hz 5 0 Sec 4 v 0 002 to 60 50Hz 0 002 to 50 NPLCycles lt clist gt Query line cycle integration rate v RANGe Path to set measurement range Sec 4 v UPPer n lt clist gt Select range 0 to 120e6 120e6 UPPer lt clist gt Query range AUTO lt b gt lt clist gt Enable or disable auto range ON AUTO lt clist gt Query state of auto range DIGits n lt clist gt Sp
296. er s Manual Scan process Basic scan For functions that use 2 wire measurements the basic scan process is to 1 open any closed channel 2 close a channel and then 3 perform the measurement This 3 step process is repeated for each channel in the scan The last scanned channel opens Channel pair scan For the functions that use 4 wire measurements O4 and 4 wire RTD TEMP the scan process uses paired channels The scan process is to 1 open any closed channels 2 close the paired channels and then 3 perform the 4 wire measurement The last scanned channel pair opens NOTE For the Model 7700 switching module primary channels 1 through 10 are paired to channels 11 through 20 Channel 1 is paired to channel 11 channel 2 is paired to channel 12 channel 3 is paired to channel 13 and so on Calculations using channel pairs Ratio and channel average performs measurements on two channels and then calculates and displays the result Therefore these 2 channel calculations also use paired channels The scan process is to 1 open any closed channels 2 close the primary displayed channel and perform a measurement 3 open the primary channel 4 close the paired channel and perform a measurement 5 calculate and display the result and finally 6 open the paired channel NOTE When scanning the displayed channel number i e 101 is not necessarily the channel that is presently closed If both a reading AND a sc
297. er test Safe operation requires the use of a lid interlock Ifa screw is present connect it to safety earth ground using the wire recommended in the user documentation The A symbol on an instrument means caution risk of danger The user should refer to the operating instructions located in the user documentation in all cases where the symbol is marked on the instrument The A symbol on an instrument means caution risk of danger Use standard safety precautions to avoid personal contact with these voltages The N symbol on an instrument shows that the surface may be hot Avoid personal contact to prevent burns The A symbol indicates a connection terminal to the equipment frame If this symbol is on a product it indicates that mercury is present in the display lamp Please note that the lamp must be properly disposed of according to federal state and local laws The WARNING heading in the user documentation 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 the user documentation explains hazards that could damage the instrument Such damage may invalidate the warranty 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
298. er 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 program message For example INITiate IMMediate These brackets indicate that IMMediate 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 IMMediate 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 b Boolean Used to enable or disable an instrument operation 0 or OFF disables the operation and 1 or ON enables the operation Example SYSTem LSYNc ON Enable line synchronization 10 22 Remote Operations name lt NRf gt lt n gt lt clist gt lt list gt Model 2701 User s Manual Name parameter Select a parameter name from a listed group Example name NEVer NEXt ALWays 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 exponent 2 3E6 Example SYSTem KEY 11 Press EXIT key from over the bus Numeric value A numeric value parameter can consist of an NRf n
299. eries NOTE For more information on read commands see Section 8 Triggering Section 13 SCPI Signal Oriented Measurement Commands and Appendix D Signal Processing Sequence and Data Flow FETCID What it does This command will simply return the latest available reading from an instrument Limitations If the instrument does not have a reading available indicated by dashes in the display sending this command will cause a 230 Data corrupt or stale error This query will not cause the box to trigger a reading nor will it wait for a result if a reading is in progress It is possible to get the same reading over and over using this query It will continue to give the same result until one of two things has happened new reading has been triggered e The old reading has been invalidated by changing ranges or by changing function Model 2701 User s Manual Basic DMM Operation 3 59 Where appropriate Since this query does not trigger a reading and can give duplicate results there are not many cases where this command should be used The DATA FRESh query see page 3 47 is often a better choice If this query is used the following conditions should be met A reading has been triggered either by free running INIT CONT ON and TRIG SOUR IMM by some event such as a remote trigger TRG or by an external trigger TRIG SOUR EXT 115 confirmed that the reading is completed either by the setting of th
300. ering page 8 16 Figure 6 1 Front panel trigger model without scanning Control Source Event Detection Output Trigger Immediate External Auto Delay or Manual Delay Device Action When not scanning and in the continuous trigger mode factory default setup the instrument will not stay in idle Operation will continuously fall through the idle state and proceed to the Event Detection block of the trigger model When in the one shot trigger mode RST default setup the TRIG key must be pressed to take the instrument out of idle After each measurement the instrument returns to idle and requires the TRIG key to be pressed to continue The FACT factory default setup or RST default setup is selected from the SHIFT gt SETUP menu see Defaults and user setups page 1 21 When scanning the unit is considered idle at the end of a scan operation when the reading for the last channel remains displayed To restore triggers press SHIFT and then HALT See Section 7 for details on scanning Model 2701 User s Manual Triggering 8 3 Control source and event detection The control source holds up operation until the programmed event occurs and is detected The control sources are described as follows Immediate With this control source event detection is immediately satisfied allowing operation to continue External Event detection is satisfied for any of the following three conditions Aninput
301. 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 11 7 When you read a message in the Error Queue 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 the appendices at the end of this manual Model 2701 User s Manual Status Structure 11 23 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 11 7 there are commands to enable and or disable messages For these commands the list parameter is used to specify which messages to enable or disable The messages are specified by their codes The following examples show various forms for using the list parameter lt list gt 110 Single message 110 222 Range of messages 110 t
302. est 11 10 System channel control 2 12 Triggering 8 19 Common commands 12 1 CLS 11 4 ESE 11 19 ESE 11 19 ESR 11 18 IDN 12 3 OPC 12 3 OPC 12 4 OPT 12 5 RCL 12 6 RST 12 6 SAV 12 6 TRG 12 7 TST 12 7 WAI 12 8 Common errors 3 11 Connections 2 wire system channel 2 8 4 wire RTDs 3 41 4 wire system channel 2 9 Continuity testing 3 49 Current measurements 3 17 Ethernet 10 10 Frequency and period measurements 3 47 Resistance measurements 3 20 RS 232 10 32 Temperature measurements 3 38 Thermistor 3 40 Thermocouple connections 3 38 Trigger link 8 12 Voltage measurements 3 8 Connectors DIGITAL I O 1 14 IEEE 488 1 14 10 10 RS 232 interface 1 14 10 32 TRIG LINK 1 14 Contact information 1 2 Continuity connections 3 49 Continuity testing 3 48 Connections 3 49 Front panel input 3 49 Model 7700 switching module 3 49 Procedure 3 50 Control sources 7 7 External trigger 7 8 Immediate 7 8 Timer 7 8 Crest factor 3 12 Current measurements DCI and ACI 3 17 AMPS fuse replacement front panel AMPS input 3 19 Amps measurement procedure 3 18 Connections 3 17 Front panel inputs 3 17 Model 7700 switching module 3 18 CVI C examples G 2 Data flow D 7 dB 5 20 Commands 5 20 Configuration 5 20 Programming examples 5 21 Remote programming 5 20 Scanning 5 20 dB calculation 10 2 DCI and ACI connections Using front panel inputs 3 17 Using Model 7700 switching module 3 18 DCV and ACV connections Using front pan
303. esults in an error The characters must be enclosed in either single quotes or double quotes DISPlay TEXT STATe ON OFF Control on off message for display This command enables and disables the text message mode When enabled a defined message is displayed When disabled the message is removed from the display A user defined text message remains displayed only as long as the instrument is in remote Taking the instrument out of remote by pressing the LOCAL key or sending can cels the message and disables the text message mode DISPlay ENABle ON OFF Control display circuitry This command is used to enable and disable the front panel display circuitry When dis abled the instrument operates at a higher speed While disabled the display is blanked All front panel controls except LOCAL are disabled Normal display operation can be resumed by using the ENABle command to enable the display or by putting the Model 2701 into local mode press LOCAL Programming example The following command sequence displays the text message TESTING DISP TEXT DATA TESTING Define text message DISP TEXT STAT ON Enable text message mode Model 2701 User s Manual Getting Started 1 21 Defaults and user setups Model 2701 can be restored to one of two default setup configurations FACTory or RST or five user saved SAVO SAVI SAV2 SAV3 or SAV4 As shipped from the factory Model 2701 powers up to t
304. et settings iet reet EE bine enun 10 12 Internal web page 3 encierra le ie ee ines 10 16 Opening the web 10 16 Front panel aspects of Ethernet operation 10 20 Error and status 10 20 Status indiGatots ioo dee ahi dede one oie vp ee qv dece 10 20 Hs c Nc M EHE 10 20 Programming Syntax rx nue degere eerie ei 10 21 Command words esses enne nennen nnne 10 21 Query commlands t or rette een t atte genie ERR Too 10 23 Gase Sensitivity arire ei ce ated aaa eae dete deu de 10 23 Long form and short form 10 23 Short form rules aid eoin seirinin d rete vede aa aaah 10 24 Program messagaS entren nnne nnne nnne nnns 10 24 Response messages nnne nennen nns 10 27 Message exchange 10 27 RS 232 interface operation 10 28 Sending and receiving data sss 10 28 Baud Tales etes a nee ep AS EEK REE re ste Eee eade Pune caste 10 28 Signal handshaking flow control 10 29 TermmlliatOr reete Eee Ee receta e RR Peri EE Ee paene ip 10 30 Selec
305. eue The coded result is sent from the output queue to the computer A returned value of zero 0 indicates that the test passed and a value of one 1 indicates that the test failed 12 8 Common Commands Model 2701 User s Manual WAJI Wait to Continue Prevent execution of commands until previous commands are completed Description Two types of device commands exist Sequential commands A command whose operations are allowed to finish before the next command is executed e Overlapped commands A command that allows the execution of subsequent commands while device operations of the Overlapped command are still in progress Use the WAI command to suspend the execution of subsequent commands until the device operations of all previous Overlapped commands are finished The WAI com mand is not needed for Sequential commands The Model 2701 has three overlapped commands INITiate INITiate CONTinuous ON e TRG NOTE See OPC OPC and TRG for more information The INITiate commands remove the Model 2701 from the idle state The device operations of INITiate are not considered complete until the Model 2701 returns to idle By sending the WAI command after the INITiate command all subsequent commands will not execute until the Model 2701 goes back into idle The TRG command issues a bus trigger that could be used to provide the arm scan and measure events for the Trigger Model By sending the WAI
306. fills the stack with new readings all previous readings discarded and then averages the stack to yield a filtered reading NOTE For details on filter operation see Filter page 4 14 Output trigger pulse VMC An output trigger pulse from the Model 2701 can be used to trigger an external instrument to perform an operation In general a trigger pulse is the output at this point in the flowchart for each processed reading An exception is the SCAN function for scanning For the SCAN function an output trigger is not output until after the specified number of channels as set by the sample counter are scanned NOTE For details on scan operation see Trigger models page 7 4 Model 2701 User s Manual Signal Processing Sequence and Data Flow D 5 Rel Next in the signal processing sequence is the Rel operation Rel is used to null offsets or subtract a baseline rel value from the reading With Rel enabled the Rel ed reading is calculated as shown in Figure D 2 NOTE For details on Rel operation see Relative page 5 2 Math Next in the signal processing sequence is a Math operation mX b Percent or Reciprocal These math operations allow you to mathematically manipulate the reading X that is applied to this block in the flowchart With one of the Math functions enabled the math result is calculated as shown in Figure D 2 NOTE For details on Math operations see Math page 5 7 Limits The reading that is appl
307. following response message will be returned 8102 1 34 Getting Started Model 2701 User s Manual Exercise 2 Closing and opening channels system channel operation The exercise in Table 1 7 demonstrates a sequence to close and open channels of a Model 7700 installed in slot 1 of the mainframe Table 1 7 Exercise 2 Close and open channels system channel operation Front panel operation Command sequence 1 Open all channels Press OPEN gt display OPEN ALL gt Press OPEN ROUT OPEN ALL 2 Select 2 function Press Q2 FUNC RES 3 Close system channel 101 Press the key Channel 1 connects to DMM Input see Figure 1 4 ROUT CLOS 8101 4 1 system channel 102 Press the key Channel 2 connects to DMM Input ROUT CLOS 8102 5 Close system channel 106 Press CLOSE gt select CLOSE SINGLE gt key in channel 106 gt press ROUT CLOS 106 ENTER Channel 6 connects to DMM Input 6 Select function Press 4W annunciator turns on and channels 6 and 16 connect to FUNC FRES DMM Input and Sense see Figure 1 5 7 Open all channels Press OPEN gt display OPEN ALL gt Press OPEN ROUT OPEN ALL It is a good safe practice to start and end a switching sequence by opening all channels Model 2701 User s Manual Getting Started 1 35 Simple scanning NOTE See Section 7 for details on scanning With at least one multiplexer switching module i e Model 77
308. for the digital outputs are shown in Figure 9 3 Note that this illustration shows the schematic for one digital output All five digital output circuits are identical Figure 9 3 Digital I O port simplified schematic Model 2701 Pin 7 5V to 33V Digital Output Flyback Diode Digital Output Control Line Pin 9 Digital Ground The five digital output lines pins through 5 are controlled by limit operations Each of these five outputs correspond to the following limit operations Digital Output 1 Low Limit 1 LO1 Digital Output 2 High Limit 1 HI1 Digital Output 3 Low Limit 2 LO2 Digital Output 4 High Limit 2 HI2 Digital Output 5 Master Limit logical OR of the four above limits When a limit LO1 HI2 LO2 HL2 is reached the digital output line for that limit will be pulled high or low When a reading is within the limit the output line is released Digital output 5 is the logical OR of the four limits Therefore if any of the four limits are reached or exceeded output 5 will be pulled high or low NOTE When the reading is taken and a limit has been reached there is a short delay before the digital output line is active As measured from the output trigger TLINK the delay is about 1Omsec when closing a channel and about 2msec without a channel closure Because of additional time needed for data conversion the delay can be up to 10 times longer for temperature readings Allow for this d
309. frame For details see Switching module installation and connections page 2 4 1 8 Getting Started Model 2701 User s Manual Table 1 1 Model 77xx series switching modules Model 7700 Model 7701 Model 7702 Model 7703 2 pole Operation 20 channels 32 channels 40 channels 32 channels 4 pole Operation 10 channel pairs 16 channel pairs 20 channel pairs 16 channel pairs Connector type Confi guration Unique features mechanical 2 female DB 50s Independent SPST channels Multiple channel operation only mechanical Mini screw terminal Multiplexer 16 digital outputs 2 analog outputs one counter totalizer 1 pole Operation N A N A N A N A Measure Volts 300V maximum 150V maximum 300V maximum 300V maximum Measure Amps Ch 21 amp 22 Max No Ch 41 amp 42 3A Max No Measure Ohms 2 4 wire 2 4 wire 2 4 wire 2 4 wire Thermocouple Yes No No No Cold Junction Relay Type Latching electro Latching electro Latching electro Non latching reed mechanical mechanical mechanical Connector type Oversized screw 1 female DB 50 Oversized screw ter 2 female DB 50s terminals 1 female DB 25 minals Configuration Multiplexer Multiplexer Multiplexer Multiplexer Unique features All DMM functions All DMM functions All DMM functions All DMM functions except amps except amps Model 7705 Model 7706 Model 7707 Model 7708 2 pole Operation N A 20 channels 10 channels 40 channels 4 pole Operati
310. g Started Figure 1 7 Simple scan operation Step 1 Configure simple scan Press SHIFT CONFIG SHIFTC STE SCAN Press CONFIG STEP Display SIMPLE option and press ENTER INT SIMPLE Specify minimum MIN CHAN XXX channel XXX and press ENTER Specify maximum MAX CHAN YYY channel YYY and press ENTER TIMER NO YES YES Display NO or YES and press ENTER XxH xxM xx xxxS press ENTER Specify reading count and press ENTER RDG CT xxxxxx Step 3 Disable scan mode Press SHIFT HALT SHIFT Press HALT Set timer interval in hr min sec format and Model 2701 User s Manual Step 2 Run simple scan Press STEP or SCAN to start scan STEF SCAN Timer interval specifies time between scans Reading count Specifies number of scans to be performed Specifies number of readings to store in buffer Timer interval specifies time between scanned channels Reading count Specifies number of channels to be scanned Specifies number of readings to store in buffer For remote programming the following commands are used for simple scanning ROUTe SCAN clist Define scan list TRIGger COUNt NRf Specify number of scans 1 to 450000 or INFinity SAMPle COUNt NRf Specify number of channels to scan 1 to 450000 ROUTe SCAN LSELect name Enable INT or disable NONE scan Any valid switching module channel c
311. g ground loops Instrument 1 Instrument 2 Instrument 3 Power Line Ground Model 2701 User s Manual Measurement Considerations E 9 Shielding WARNING Do not float input LO more than 30V rms 42 4V peak above earth ground with an exposed shield connected to input LO To avoid a possible shock hazard surround the LO shield with a second safety shield that is insulated from the inner shield Connect this safety shield to safety earth ground using 18 AWG minimum wire before use Proper shielding of all signal paths and sources being measured is important to minimize noise pickup in virtually any low level measurement situation Otherwise interference from such noise sources as line frequency and RF fields can seriously corrupt measurements rendering experimental data virtually useless In order to minimize noise a closed metal shield surrounding the source may be necessary as shown in the example of Figure E 4 This shield should be connected to input LO in most cases although better noise performance may result with the shield connected to chassis ground in some situations Figure E 4 Shielding example 2701 Noise Shield Safety Shield Connect noise shiald to Connect safety shield to a known safety earth ground using 18 AWG wire or higher WARNING Safety shield required when floating noise shield gt 30V rms above chassis ground E 10 Measurement Considerations Model 2701 User s Manual Meter load
312. g is normally performed with continuous initiation disabled INIT CONT OFF The sample count SAMP COUN 0 specifies the number of channels to scan and store in the buffers sample buffer and data store the trigger count TRIG COUNt specifies the number of scans to perform Note that if the trigger count is gt 1 the data for each subsequent scan will overwrite the data stored in the sample buffer and data store Once the scan is properly configured INIT or READ will start the scan READ also returns the scanned readings data arrays from the sample buffer or the CALCI block if Math is enabled FETCh will not start a scan but it will return the readings already stored While the scan is in process SENS DATA and CALC1 DATA commands can be used to return the latest data array When used after the scan is finished they will return the data array for the last stored reading D 14 Signal Processing Sequence and Data Flow Model 2701 User s Manual E Measurement Considerations E 2 Measurement Considerations Measurement considerations Model 2701 User s Manual Low level voltage measurements made using the Model 2701 can be adversely affected by various types of noise or other unwanted signals that can make it very difficult to obtain accurate voltage readings Some of the phenomena that can cause unwanted noise include thermoelectric effects thermocouple action source resistance noise magnetic fields and radio frequency inte
313. g the configured scan The configured scan can be saved in a user saved setup SAVO SAV2 SAV3 or SAV4 For a front panel configured scan the reading count and timer values are also saved B04 and later software However if the settings for a user setup or power on setup do not match the switching module type presently installed error 520 Saved setup scancard mismatch occurs when the setup is recalled The scan resets to the factory default settings and all channels will open The saved setup is still retained in memory and can be restored when the matching switching module is later installed The displayed front panel CONFIG menu operates differently from other menus when a saved front panel scan is recalled The reading count value in the menu may not reflect the actual reading count of the scan For example Assume a Model 7700 module configured for a10 channel scan and a reading count of 30 For this configuration the instrument will scan through the scan list three times Now assume the scan setup is saved in SAVI and is the power on default After cycling power press SCAN or STEP to run the scan The scan will run properly That is the 10 channels will be scanned three times However if you check the reading count in the front panel CONFIG menu the reading count will be 10 instead of 30 This is because the scan list length suggests the reading count value during the setup process NOTE Saving and recalling
314. gering Bus control source Model 2701 User s Manual Table G 2 continued LabVIEW examples KE2700 Instrument Driver Examples G 17 Name Manual Reference Brief Description Simple3 None Use Case 3 Two scans using 7708 module 40 channel DCV 1V range scan 20 channel scan e Models 2700 and 2701 1000 range e Model 2750 10Q range dry circuit ohms enabled Measurement speed rate 0 1 plc DCV input divider Enabled 1OMQ input impedance Filter Disabled no filtering Buffer Store 40 reading strings 20 reading strings Buffer elements include reading only Limits DCV scan Limit 1 all channels 20mV Master Latch enabled e Triggering Bus control source Simple4 None Use Case 4 Two scans using 7708 module 40 channel DCV scan 1V range Configuration saved in User Setup 1 20 channel 4 scan Configuration saved in User Setup 2 e Models 2700 and 2701 1000 range e Model 2750 10Q range dry circuit ohms enabled Setup 1 or Setup 2 recalled to perform scan e Measurement speed rate 0 1 plc DCV input divider Enabled 10MQ input impedance Filter Disabled no filtering Buffer Store 40 reading strings 20 reading strings Buffer elements include reading only Limits DCV scan Limit 1 all channels 20mV Master Latch enabled Triggering
315. gramming 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 11 2 Status Structure Model 2701 User s Manual Overview The Model 2701 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 11 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 indicate t
316. guration Remote programming must be used to configure the Model 2701 for dB measurements It cannot be configured from the front panel Scanning Typically a scan using dB is configured and run using remote programming However once dB is selected using remote programming a simple dB scan can be configured and run from the front panel When the simple scan is configured it will use the dB measurement setup for each channel in the scan Details on configuring and running a scan are provided in Section 7 NOTE See Section 7 to configure and run a scan Remote programming dB dB commands The dB commands are listed in Table 5 4 Details on these commands follow the table Model 2701 User s Manual Rel Math Ratio Channel Average dB 5 21 NOTE Queries are not included in Table 5 4 All the dB commands are provided in Table 15 10 Table 5 4 dB commands Commands Description Def DCV dB commands UNITs VOLTage DC lt name gt Select DCV measurements lt name gt V or DB V UNITs VOLTage DC DB REFerence n Set reference in volts n 1e 7 to 1000 1 ACV dB commands UNITs VOLTage AC lt name gt Select ACV measurements lt name gt V or DB V UNITs VOLTage AC DB REFerence n Set reference in volts n le 7 to 1000 1 Channel list parameter lt clist gt SCH where S Examples 101 Slot 1 Channel 1 Mainframe slot number 1 or 2 CH Switching module channel number m
317. gured as two independent multiplexers 3 The Models 7711 and 7712 have no measurement capabilities Latching relays hold their open close state after the mainframe is turned off When turned on all relays open after a few 1 10 Getting Started Model 2701 User s Manual Front and rear panel familiarization 081 Front panel summary The front panel of Model 2701 is shown in Figure 1 1 Figure 1 1 Model 2701 front panel KEITHLEY INTEGRA SERIES SENSE Q4WIRE 2701 ETHERNET MULTIMETER DATA ACQUISITION SYSTEM 7 MATH OUTPUT RATIO CHAVG CONT OCOMP PERIOD SENSOR QQ o0 Q A ex DELAY HOLD LIMITS _ ON OFF TYPE MONITOR CARD EX TRIG TRIG STORE RECALL FILTER REL CHED FRONTEN SAVE SETUP CONFIG HALT TEST LSYNC ETHERNET RS 232 Son OPEN CLOSE STEP SCAN DIGITS RATE EXIT J ENTER NOTE Most keys provide a dual function or operation The nomenclature on a key indi cates its unshifted function operation which is selected by pressing the key Nomenclature in blue above a key indicates its shifted function A shifted func tion is selected by pressing the SHIFT key and then the function operation key 1 Special keys and power switch SHIFT Use to select a shifted function or operation LOCAL Cancels remote mode SHIFT LOCAL disables keyclick POWER Power switch In position turns 2701 on I out position turns it off 2 Function and operation keys
318. h an LF line feed The following 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 2701 what to send to the computer The following two steps must always be performed to send information from the instrument to the computer 1 Send the appropriate query command s in a program message 2 Retrieve the data from the 2701 Rule 2 The complete response message must be received by the computer before another program message can be sent to the Model 2701 10 28 Remote Operations Model 2701 User s Manual RS 232 interface operation Sending and receiving data The RS 232 interface transfers data using eight data bits one stop bit and no parity Make sure the controller you connect to the multimeter also uses these settings You can break data transmissions by sending a C decimal 3 or X decimal 18 character string to the instrument This clears any pending operation and discards any pending output You can break an RS 232 transmission of buffer readings by pressing LOCAL and then EXIT The next command to send buffer data 1 e TRACe DATA will start at the beginning rather than where the transmission was halted Baud rate The baud rate is the rate at which the Model 2701 multimeter and the programming terminal communicate Choose one these available rates e 115 2k e
319. hannel NOTE Ifyou change the setup while a monitor channel is closed that setup will be copied to that channel in the scan list When a scan is started the first channel in the scan list will be briefly displayed While the scan is in progress the display will only show the reading s for the monitor channel After the last channel is scanned the scan will disable with the monitor channel closed Monitor can be used with limit testing to trigger the start of a scan When the monitor detects that a set reading limit has been reached the scan is triggered to start The detailed procedure to perform a monitor scan is provided in Scan operation Monitor scan page 7 35 Model 2701 User s Manual Scanning 7 19 NOTE overflow reading OVRFLW message displayed is interpreted by the Model 2701 as a positive reading even if the input signal is negative This could inadvertently trigger a monitor scan see Scan operation Monitor scan page 7 35 The monitor channel must be a channel that is in the scan list If the monitor channel is removed from the scan list the lowest channel in the scan list will become the monitor channel To set monitor the instrument can be in the normal measurement state or enabled while in the advanced scan menu There are two methods to select a monitor channel Method 1 selects it while a channel is closed and Method 2 selects it with no channels closed NOTE The monitor channel must be
320. hat 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 2701 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 messages occur they are placed in the Error Queue When a queue contains data it sets the appropriate summary bit of the Status Byte Register Model 2701 User s Manual Status Structure 11 3 Figure 11 1 Model 2701 status register structure Questionable Questionable Questionable Condition Event Event Enable Register Register Register DINIS Error Queue Standard Status Request Event Byte Enable Status Register Register Register Operation Complete Query Error Device Dependent Error Execution Error Command Error User Reques
321. he factory FACT default settings NOTE Closed channels can be saved in a user setup SAVO SAVI SAV2 SAV3 or SAV4 When the setup is restored those channels and only those channels will be closed FACT and RST defaults opens all channels The factory default setup provides continuous triggering while the RST default setup places the Model 2701 in the one shot trigger mode With one shot triggering a measure ment is performed whenever the TRIG key is pressed or an initiate command is sent over the remote interface The factory and RST default settings are listed in Table 1 4 Setting differences Set Diff between the two default setups are indicated by checkmarks v For remote programming the SYSTem PRESet and RST commands are used to reset the instrument The RST command returns the instrument to the RST defaults and for the most part the SYSTem PRESet command returns the instrument to the factory default conditions The exceptions are explained as follows e Auto scan and auto channel configuration FACTory defaults disable auto scan and auto channel configuration while SYSTem PRESet has no effect The RST defaults front panel and remote operation have no effect Memory buffer auto clear FACTory defaults enable buffer auto clear while SYSTem PRESet has no effect The RST defaults front panel and remote opera tion have no effect The instrument will power up to whichever default setup is saved as the
322. he instrument begins its normal display of readings NOTE The serial number of the Model 2701 can be displayed by selecting the SNUM item of the SETUP menu Press SHIFT and then SETUP to access the menu For remote operation the serial number can be read using the IDN command see Section 12 for details NOTE The serial number and revision levels can be accessed from the internal web page of the Model 2701 using the Internet Explorer For details see Internal web page in Section 10 Model 2701 User s Manual Getting Started 1 19 Keyclick Display With keyclick enabled an audible click will sound when a front panel key is pressed Per form the following steps to disable or enable keyclick 1 Press SHIFT and then LOCAL to display the present state of KEYCLICK ON OFF 2 Press or to display the desired keyclick state and press ENTER Remote programming The following command controls keyclick SYSTem KCLick b Enable or disable keyclick where b ON or OFF NOTE kKeyclick ON is the FACTORY RST and SYSTem PRESet default Readings are displayed in engineering units 1 100 23mV while annunciators indicate various states of operation See Front panel summary page 1 10 for a complete listing of display annunciators NOTE The display test allows you to test display digit segments and annunciators The key test checks the functionality of front panel keys These tests are accessed by pressing SHI
323. he instrument repeatedly blows fuses locate and correct the cause of the trouble before replacing the fuse 4 Install the new fuse by reversing the procedure above NOTE For the Model 7700 switching module and other similar modules that support the amps function there are solder mount amps fuses See the Model 2701 Service Manual for fuse replacement information 3 20 Basic DMM Operation Model 2701 User s Manual Resistance measurements 22 and The Model 2701 has seven ohms ranges to measure resistance from 100HQ to 120MQ Available measurement ranges include 1000 1kQ 10kQ 100k 1MQ 10M O and 100MQ Information for this topic is structured as follows Connections 2 wire or 4 wire connections can be made to the front panel input terminals of the mainframe or to a switching module such as the Model 7700 Standard resistance measurements The Model 2701 can make resistance measurements from 100uQ to 120MQ For resistances 1kQ the 2 function 2 wire is typically used for measurements For resistances 4 the function 4 wire is typically used The function should be used to cancel the effect of test lead and channel path resistances Offset compensated ohms OCOMP The presence of thermal EMFs voltages can adversely affect low resistance measurement accuracy To overcome these unwanted offset voltages you can use offset compensated ohms on the 1000 1kQ and 10kQ ranges for the function Mea
324. hen optimum speed is required Note that the AUTO key has no effect on temperature TEMP Up ranging occurs at 12046 of range The Model 2701 will down range when the reading is lt 10 of nominal range To disable auto ranging press AUTO This will leave the instrument on the present range You can also disable auto ranging by pressing the or key however a range change may occur Scanning When a simple scan is configured the present function and range setting will apply to all channels in the scan When an advanced scan is configured each channel can have its own unique range setting Details to configure and run a scan are provided in Section 7 For remote programming the lt clist gt parameter is used to configure channels for a scan 4 4 Range Digits Rate Bandwidth and Filter Model 2701 User s Manual Remote programming range Range commands The commands to set range are listed in Table 4 2 Additional information on these commands follow the table NOTE Query commands and some optional command words are not included in Table 4 2 All commands for the SENSe subsystem are provided in Table 15 5 Table 4 2 Range commands Commands 2 Description Default SENSe 1 Optional root command VOLTage DC RANGe n lt clist gt Select DCV range n 0 to 1010 V 1000 VOLTage DC RANGe AUTO lt b gt Control DCV auto range lt b gt ON or OFF ON lt clist gt VOLTage AC RANGe n
325. hermal EMFs thermoelectric potentials are generated by temperature differences between the junctions of dissimilar metals These can be large compared to the signal that the Model 2701 can measure Thermal EMFs can cause the following conditions Instability or zero offset is much higher than expected The reading is sensitive to and responds to temperature changes This effect can be demonstrated by touching the circuit by placing a heat source near the circuit or by a regular pattern of instability corresponding to changes in sunlight or the activation of heating and air conditioning systems To minimize the drift caused by thermal EMFs use copper leads to connect the circuit to the Model 2701 For front panel inputs a banana plug generates a few microvolts A clean copper conductor such as 10 bus wire is ideal for this application For switching modules use 20 AWG copper wire to make connections The leads to the Model 2701 may be shielded or unshielded as necessary Refer to Shielding page E 9 3 16 Basic DMM Operation Model 2701 User s Manual Widely varying temperatures within the circuit can also create thermal EMFs Therefore maintain constant temperatures to minimize these thermal EMFs A shielded enclosure around the circuit under test also helps by minimizing air currents The REL control can be used to null out constant offset voltages AC voltage offset The Model 2701 at 52 digits resolution will typ
326. hin the instrument NOTE Each exercise indicates the commands used to configure triggering Trigger configuration Once triggering is configured the commands to trigger and or return readings can be repeated as often as desired unless noted otherwise Model 2701 User s Manual Getting Started 1 39 Exercise 4 Trigger and return a single reading Exercise 5 Trigger and return multiple readings Trigger controlled measurements The instrument is typically used in a non continuous trigger mode In this mode commands are used to trigger one or more readings After the specified number of readings are completed the measurement process stops Exercise 4 in Figure 1 8 provides a command sequence to trigger and return one reading Exercise 5 in Figure 1 9 provides a command sequence to trigger and return multiple readings Figure 1 8 Exercise 4 Trigger and return a single reading Place 2701 in non continuous trigger state INIT CONT OFF TRIG COUN 1 Trigger Configuration Set 2701 to perform SAMP COUN 1 one measurement Trigger Reading READ Trigger and Return Trigger and Return Reading j FETCh DATA ending OR OR CALC DATA DATA FRESh Return result of MATH Return Basic Reading 4 calculation 2 3 1 If a MATH function mX B percent or 1 X is enabled the result of the calculation will be returned MATH functions are covered in Section 5 2 If there is no MATH function enabled FETCh
327. hot measurement mode which places one data array in the sample buffer and then performs a READ With no math function enabled the one data array in the sample buffer is read With a math function enabled the reading is the result of the math calculation CALC 1 DATA LATest CALC 1 DATA FRESh These two commands are similar to the LATest and FRESh commands for SENSel subsystem except that returned data arrays are the result of the math calculation See SENS 1 DATA LATest and SENS 1 DATA FRESh for details on the differences between LATest and FRESh With a math function enabled both CALC 1 DATA and CALC 1 DATA FRESh return a single data array whose reading is the result of the math calculation Note that the calculation is performed on the last data array stored in the sample buffer These commands do not affect data in the sample buffer Therefore subsequent executions of these commands return the same data With no math function enabled these commands return the last data array stored in the sample buffer CALC3 LIM1 FAIL CALC3 LIM2 FAIL Each reading applied to the CALC3 Limit Tests block is tested when Limits operations are enabled When comparing the reading to the programmed high and low limits of Limit 1 CALC3 LIM1 FAIL returns a 0 inside limits or a 1 outside limits Similarly CALC3 LIM2 FAIL compares the reading to the high and low limits of Limit 2 NOTE Each data array re
328. hrough 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 disable messages each listed message is removed from the enabled list NOTE prevent all messages from entering the Error Queue send the enable command along with the null list parameter as follows STATus QUEue ENABle Table 11 7 Error queue commands Command Description Notes STATus QUEue NEXT Read and clear oldest error status code and message 1 STATus QUEue ENABle lt list gt Specify error and status messages for Error Queue 2 STATus QUEue ENABle Read the enabled messages STATus QUEue DISable lt list gt Specify messages not to be placed in queue 2 STATus QUEue DISable Read the disabled messages STATus QUEue CLEar Clear messages from Error Queue SYSTem ERRor Read Error Queue 1 SYSTem 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 example can be run from the KE2700 Instrument Driver using the example named ReadErrorQu eue in Table G 1 of Appendix The following command reads the error queue STAT QUE 11 24 Status Structure Model 2701 User s Manual 12 Co
329. i eee edere D 11 GAEGS9 EIM2 EAIE 0 11 RAGS DATA Prot 0 11 CAEC2 IM M ie epu dio oen D 12 e Merl mm D 12 GALG2 DATA hh t tete toten erri E PE etn D 12 Continuous measurement D 12 SCANMMG Pd D 13 E Measurement Considerations sss E 1 Measurement considerations sssseseeeeen een E 2 Thermoelectric E 2 Thermoelectric E 3 Minimizing thermal eseeeeeennm emen E 4 Source resistance noise sssssssssesssseseeeneene ennt E 5 Magnetic fields erecti i dene ore deed E 6 Radio frequency E 6 Ground loops oe erect we nie D ere o P eee E 7 ohielding suite num reer te tree E 9 Meter loading ie eee ttd eet regenti sede cese Pune dendo E 10 F Temperature Equations F 1 Thermocouple F 2 Thermistor equation Eee Regu ua ae F 6 RID Cquations sa iode reb iar F 8 G KE2700 Instrument Driver Examples G 1 INTRODUCTION Dm G 2 viii Document
330. ically display 100 counts of offset on AC volts with the input shorted This offset is caused by the offset of the TRMS converter This offset will not affect reading accuracy and should not be zeroed out using the REL feature The following equation expresses how this offset V oppsgr is added to the signal input V i Displayed reading Vin 2 Example Range 1VAC Offset 100 counts 1 0mV Input 100mV RMS Displayed reading J 100mV 1 0mV J0 01V 1x 10 5v 0 100005V The offset is seen as the last digit which is not displayed Therefore the offset is negligible If REL were used to zero the display the 100 counts of offset would be subtracted from resulting in an error of 100 counts in the displayed reading Model 2701 User s Manual Basic DMM Operation 3 17 Current measurements DCI The Model 2701 can make DCI measurements from 10nA to 3A and ACI measurements from to RMS NOTE See the previous discussion about crest factor in Voltage measurements DCV and ACV page 3 8 Connections NOTE When using the front panel inputs the INPUTS switch must be in the F out position For switching modules it must be in the R in position WARNING prevent electric shock never make or break connections while power is present in the test circuit Front panel inputs When using the front panel input terminals connect the test leads to
331. ict Effects of function changes on the scan list NOTE avoid unexpected problems with scans as explained after this note it is recommended that the scan list ROUT SCAN be created AFTER scan channel functions are selected SENS FUNC Changing from a 2 wire function to a 4 wire function will change the scan list This is demonstrated as follows The following commands show the proper sequence to configure a simple 20 channel DCV scan using a Model 7700 installed in slot 1 SENS FUNC VOLT 8101 120 Set channels for DCV ROUT SCAN 101 120 Specify scan list When the scan is changed to a 4 wire function the scan list will change For example assume the above scan is changed to the 4 function as follows SENS FUNC FRES 101 110 For the 4 wire resistance function channels 101 through 110 will be paired to channels 111 through 120 ROUT SCAN returns the following scan list 101 110 Now assume the scan is returned to DCV function as follows SENS FUNC VOLT 101 120 The above command sets channels 101 through 120 for DCV However it will NOT affect the scan list ROUT SCAN still returns a 10 channel scan list 101 110 The following command will set the scan list for 20 channels ROUT SCAN 101 120 ROUTe SCAN TSOurce lt list gt lt list gt IMMediate HLIMitl HLIMit2 LLIMitl LLIMit2 As with front panel operation the scan can start immediately when it is enabled and triggered OR
332. ied for sine waves of different frequency ranges Additional error uncertainties are also specified for non sinusoidal waveforms of specific crest factors and frequencies The Model 2701 has capabilities of measuring AC waveforms of crest factors up to 5 Model 2701 User s Manual Basic DMM Operation 3 13 Figure 3 4 ACV measurements sine waves Sine Ve AC coupled RMS Crest Factor 0 Vams T 2 Vp Half Wave Rectified Sine Ve 0 Vnus Ve qD 2 CF D 9 T Vave where D duty cycle T AC coupled RM S WH lt T o v 55 V Vaus Ve 00 V V gt 1 1 D 2 2 V Ve t Ve D 2 1 2 Full Wave Rectified Sine M di d o 0 Vp D V AC coupled RMS 1 Y Y N V 1 2 2 Vans J Ve 2 e aV VeL 2 n Ve N2 2V p r C VETERES V 2Voe n Ve 1 2 4 n 2 3 14 Basic DMM Operation Figure 3 5 ACV measurements square pulse and sawtooth waves Model 2701 User s Manual Square vid AC coupled RM S Crest factor 0 Vnus Vp CF 1 Vp Rectified square Ve AC coupled RMS 0 Vrms ae CF 22 Pulse Ve AC coupled RM S Vrms 0 1 0 F 0 RMS e ND I D C Dab pur where D duty cycle AC coupled pulse AC coupled peak uds V V 1 D When 0 lt D lt 0 5 04 i V VP
333. ied to the Limits block in the flow chart is not modified and is the reading that is displayed on the Model 2701 With Limits enabled the reading is tested against two sets of high and low limits Along with the displayed reading annunciators and messages are used to indicate the result of the limits testing NOTE For details on Limits testing see Limits page 9 2 Buffer With the buffer data store enabled each displayed reading is stored and timestamped The buffer also provides statistics on the stored statistics Buffer statistics include minimum and maximum peak to peak average and standard deviation When buffer recall is enabled stored readings and the buffer statistics are displayed on the Model 2701 NOTE For details on the Buffer see Section 6 D 6 Signal Processing Sequence and Data Flow Model 2701 User s Manual Signal processing using Ratio or Ch Avg With a switching module installed the ratio or average of two channels can be calculated Figure D 3 shows where Ratio or Ch Avg is calculated in the signal processing sequence Figure D 3 Signal processing using Ratio or Channel Average Input Signals ChanAq oChanB Ratio Chan A Chan B Ch Avg Chan A Chan B 2 Ratio or Channel Average Calculation Y mX b M ath 2 mx b Percent Percent Reference 100 Referen or Reciprocal Reciprocal 1 X Store Buffer neca Display Reading With a channel clo
334. igger mode to perform a thermocouple temperature measurement at channel 101 Model 7700 switching module installed in slot 1 With channel 101 closed the INIT command triggers one measurement and the DATA command sends the measured reading to the computer RST One shot measurement mode INIT CONT OFF FUNC TEMP Select TEMP function UNIT TEMP F Select F TEMP units TEMP TRAN TC Select thermocouple transducer TEMP TC TYPE J Select type J thermocouple TEMP RJUN RSEL SIM Select simulated reference junction TEMP RJUN SIM 32 Set reference temperature to 32 F ice point ROUT CLOS 101 Close channel 101 INIT Trigger one measurement DATA Return measured reading 3 56 Basic DMM Operation Model 2701 User s Manual Example 4 Scan configuration Model 7700 The following commands configure scan channels 101 102 and 121 of a Model 7700 installed in slot 1 When channel 101 is scanned DCV will be selected When channel 102 is scanned will be selected When channel 121 is scanned DCI will be selected NOTE The following example be run from the KE2700 Instrument Driver using the example named ConfigChan in Table G 1 of Appendix G FUNC VOLT 09101 Configure scan channel 101 for DCV FUNC RES 102 Configure scan channel 102 for 92 FUNC CURR 09121 Configure scan channel 121 for DCI NOTE Detailed information on scanning is provided in Section 7 Measurement qu
335. ill open and the specified channel or channel pair will close NOTE While in the normal measurement state you can use the 4 and keys to close channels In general each key press will open the presently closed channel and then close the next higher or lower channel 6 Observe the displayed reading If the OVERFLOW message is displayed select a higher range until a normal reading is displayed or press AUTO for autoranging For manual ranging use the lowest possible range for the best resolution 7 To measure other switching channels repeat steps 5 and 6 8 When finished press OPEN if there is a channel closed 3 24 Basic DMM Operation Model 2701 User s Manual Offset compensated ohms The presence of thermal EMFs V gyp can adversely affect low resistance measurement accuracy To overcome these unwanted offset voltages you can use offset compensated ohms OCOMP Offset compensated ohms measurements can be performed on the 100Q 1kQ and 10kQ ranges for the function It cannot be done on the 2 function NOTE The various instrument operations including OCOMB are performed on the input signal in a sequential manner See Signal processing sequence page D 2 for details It includes a flowchart showing where in the processing sequence that the OCOMP operation is performed For a normal resistance measurement the Model 2701 sources a current T and measures the voltage V The resistance R is then calcul
336. ils on range are provided in Section 4 4 Apply the voltage s to be measured CAUTION Do not apply more than maximum input levels indicated in Figure 3 2 and Figure 3 3 or instrument damage may occur The voltage limit is subject to the 8 x 10 VHz product Model 7700 switching module The maximum allowable voltage is 300V DC or 300V RMS 425V peak for AC waveforms Exceeding these limits may cause damage to the switching module WARNING If both the front panel terminals and the switching module terminals connected at the same time the test leads must be rated to the highest voltage that is connected For example if 1000V is connected to the front panel input the test lead insulation for the switching module must also be rated for 1000V 5 Ifusing a switching module perform the following steps to close the desired channel a Press the CLOSE key b Use and to key in the channel number and press ENTER The previously closed channel if there is one will open and the specified channel will close NOTE While in the normal measurement state you can use the and keys to close channels In general each key press will open the presently closed channel and then close the next higher or lower channel 6 Observe the displayed reading If the OVERFLOW message is displayed select a higher range until a normal reading is displayed or press AUTO for autoranging For manual ranging use the lowest pos
337. imestamp date and time Displays serial number of Model 2701 Selects and configures a simple scan or an advanced scan Disables step scan Selects the calibration menu display test or the key press test Enables disables line cycle synchronization When enabled noise induced by the power line is reduced at the expense of speed Enables disables and configures Ethernet settings Enables disables RS 232 interface selects baud rate flow control and terminator 1 12 Getting Started 3 Range keys Unshifted and AUTO Model 2701 User s Manual Dual function Selects the next higher lower measurement range for the selected function When in a menu these keys make selections or change values Enables disables autorange for the selected function 4 Display annunciators asterisk lt more speaker p 4W AC AUTO BUFFER CHAN DELTA ERR FAST FILT HIGH HOLD LOW MATH MED MON OCOMP RATIO REAR REL REM SCAN SHIFT SLOW SRQ STAT STEP TIMER TRIG Readings being stored in buffer Indicates additional selections are available Beeper on for continuity or limits testing Digital input output or analog output active set to non default value 4 wire resistance or 4 wire RTD temperature reading displayed AC function selected ACV dB or ACT Auto range enabled Recalling readings stored in buffer Setup or reading for a switching channel displayed Channel average enabled Quest
338. in Section 12 XonXoFF is the FACT and RST default flow control setting If NONE is the selected flow control then there will be no signal handshaking between the controller and the Model 2701 Data will be lost if transmitted before the receiving device is ready NOTE Even with XonXoFF selected the computer may lose data from the Model 2701 if the return string is very large approximately 30 000 or more characters and one of the higher baud rates is selected With no flow control NONE selected the error occurs with a much smaller return string Your program could provide some type of error checking for these situations NOTE Another solution to the problem is to use the TRACe DATA SELected start count command to return small portions 100 points of a very large buffer With this command you specify a buffer location start and the number of readings to return count See Section 6 for details Hardware flow control Hardware handshaking can instead be used for flow control The RS 232 interface provides two control lines RTS and CTS for this purpose see Figure 10 11 and Table 10 4 When the 2701 is ready to send RTS data it will transmit when it receives the clear to send CTS signal from the computer 10 30 Remote Operations Model 2701 User s Manual Terminator The Model 2701 can be configured to terminate each program message that it transmits to the controller with any of the following combinat
339. ing Loading of the voltage source by the Model 2701 becomes a consideration for high source resistance values As the source resistance increases the error caused by meter loading increases Figure E 5 shows the method used to determine the percent error due to meter loading The voltage source Vg has a source resistance Rs while the input resistance of the Model 2701 is R and the voltage measured by the nanovoltmeter is Vy Figure E 5 Meter loading Rs Vs Source EE Voltage Voltage The voltage actually measured by the meter is attenuated by the voltage divider action of Rg and and it can be calculated as follows _ M R R This relationship can be modified to directly compute for percent error 100R Ri RS Percent error From the above equation it is obvious that the input resistance of the Model 2701 must be at least 999 times the value of source resistance if loading error is to be kept to within 0 1 Temperature Equations e Thermocouple equation Documents the ITS 90 inverse function polynomial and the coefficients to calculate thermocouple temperature e Thermistor equation Documents the Steinhart Hart equation which is used to calculate thermistor temperature e RTD equation Documents the Callendar Van Dusen equation which is used to calculate the temperature vs resistance readings listed in the RTD reference tables F 2 Temperature Equations Model 270
340. ins channels 1 through 10 while the second bank contains channels 11 through 20 Each channel of the 20 channel multiplexer card is wired with separate inputs for HI LO providing fully isolated inputs The Model 7700 also provides two channels of current input Channels 21 and 22 Although the Model 7700 relays are the latching type relays hold their state even after power has been removed all relay states are set to open a few seconds after either a power cycle or a RST command is issued Connections to DMM functions for system channel operation are provided through the card backplane connector e Current provided through two protected channels Channels 21 and 22 e INPUT connections SENSE 04 wire connections AMP and LO common connections to the DMM are also provided Channel 23 2W 4W Configuration Channel 24 Sense Isolation and Channel 25 Input Isolation are normally automatically configured by the 2701 for system channel operation However by using multiple channel operation refer to Section 2 channels can be individually controlled NOTE Connect 4 wire sense leads using channels 11 20 To disconnect channels 11 20 from channels 1 10 send ROUT MULT CLOS 0123 note opposite logic When automatically configured for 4 wire measurements including 4 wire RTD temperature Ratio and Channel Average the channels are paired as follows and CH11 CH6 and CH16 CH2 and CH12 CH7 and CH17 CH3 an
341. ion while the PERCent ACQuire command uses the input signal as the reference value The ACQuire command is only functional if a reading is available If the instrument is overflowed OVERFLOW or a reading has not been triggered an execution error 200 occurs when ACQuire is sent The PERCent lt NRf gt command is coupled to the PERCent ACQuire command When a reference value is set using PERCent lt NRf gt the PERCent query command returns the programmed value When reference is set using ACQuire the PERCent query com mand returns the acquired reference value Reading math result CALCulate 1 DATA LATest or CALCulate DATA FRESh can be used to retrieve the result of the selected math calculation These commands do not trigger a reading They simply return the last reading string The reading reflects the result of the calculation While the instrument is performing measurements you can use these commands to return the last reading If the instrument is not performing measurements CALC DATA will keep returning the same reading string CALC DATA FRESh can only be used once to return the same reading string That is the reading must be fresh Sending this command again to retrieve the same reading string will generate error 230 data corrupt or stale or cause the system to time out In order to again use DATA FRESP a new fresh reading must be triggered If math is disabled CALCulate FOR
342. ionable reading or invalid cal step Fast reading rate selected Filter enabled for selected function Reading has reached or exceeded the enabled high limit 2701 in hold mode Reading has reached or exceeded the enabled low limit mX b percent or reciprocal 1 X calculation enabled Medium reading rate selected Monitor channel displayed 4 wire offset compensated ohms enabled Channel ratio enabled Front panel input terminals disconnected Relative enabled for selected function Instrument in Ethernet remote mode Scanning operation being performed Accessing a shifted key Slow reading rate selected Service request over Ethernet or RS 232 Displaying buffer statistics Stepping operation being performed Timer controlled triggering in use External triggering selected 5 INPUTS switch Use to select front panel inputs out F position or switching module inputs in R position NOTE For remote programming the following command queries the INPUTS switch position SYSTem FRSWitch Query INPUTS switch 0 rear 1 front 6 Handle Pull out and rotate to desired position Model 2701 User s Manual Getting Started 1 13 7 Front panel inputs INPUT HI and LO Used for DCV ACV CONT FREQ PERIOD and thermocouple thermistor TEMP measurements SENSE HI and LO Use with INPUT HI and LO for and RTD TEMP measurements AMPS Use with INPUT LO for DCI and ACI measurements Amps fuse holder Ho
343. ions of CR and lt LF gt CR Carriage return lt CR LF gt Carriage return and line feed lt LF gt Line feed lt LF CR gt Line feed and carriage return Selecting and configuring RS 232 interface After selecting enabling the RS 232 interface you will then set the baud rate flow control and terminator 1 Press the SHIFT key and then the RS 232 key The RS 232 ON or RS 232 OFF message will be displayed 2 Ifthe RS 232 is already ON press ENTER and proceed to step 3 Otherwise press the key to place the cursor on OFF press the or key to display the ON state and then press ENTER NOTE Enabling ON the RS 232 interface disables OFF the Ethernet Disabling the RS 232 interface enables the Ethernet Changing the state reboots the Model 2701 3 To retain the presently displayed BAUD rate press ENTER and proceed to step 4 Otherwise press the key to place the cursor on the baud rate value use the or key to display the desired baud rate and then press ENTER 4 To retain the presently displayed FLOW control press ENTER and proceed to step 5 Otherwise press the key to place the cursor on the flow control setting use the or key to display the alternate flow control setting and then press ENTER 5 To retain the presently displayed terminator Tx TERM press ENTER Other wise press the key to place the cursor on the terminator setting use the or key to display the desired terminator
344. ist and continues For example assume the scan list is made up of channels 101 102 and 103 and the sample count is set to 4 After channels 101 102 and 103 are scanned operation loops around to scan channel 101 again The first and last readings in the buffer will be channel 101 When performing multiple scans trigger count gt 1 sample readings overwrite the readings stored for the previous scan Continuous initiation must be disabled in order to set the sample counter gt 1 see Reference c f INITiate CONTinuous INITiate and READ In order to initiate a single scan cycle using INITiate or READ continuous initiation must be disabled If you send INIT or READ with continuous initiation enabled error 213 Init ignored will occur You cannot use READ or INITiate if sample count gt 1 AND there are readings stored in the buffer by the TRAC command or by front panel data store operation error 225 out of memory Either set the sample count to one or clear the buffer TRACe CLEar 7 32 Scanning Model 2701 User s Manual Scanning programming example The following program will scan 10 channels 101 through 110 NOTE The following example be run from the KE2700 Instrument Driver using the example named ScanChan in Table G 1 of Appendix G TRAC CLE INIT CONT OFF Clear buffer Disable continuous initiation TRIG SOUR IMM Select the immediate control source TRIG COUN 1 Set to perform one scan SAMP
345. its which are the factory defaults Limit 1 1V and LOI 1V Limit 2 HD 2V and LO2 2V Keep in mind that a limit value for Limit 2 does not have to exceed the Limit value For example Limit 2 can be set to 1 V and Limit 1 can be set to 2V In this case Limit 2 will fail before Limit 1 Figure 9 1 Default limits A LOW ee N Me HIGH R cal 2V 1V OV 1V 2V LO2 LO1 HI2 Limit 1 Limit 2 When a reading is within both limits the message IN will be displayed When the read ing is high or low the HIGH or LOW annunciator turns on and the number 1 or 2 will replace the IN message A 1 indicates that Limit 1 has failed while 2 indicates that Limit 2 has failed However if the reading is outside both limits the number 1 will be displayed For the limits shown in Figure 9 1 a reading of 1 5V is outside Limit 1 but inside Limit 2 The HIGH annunciator will turn on and display the number 1 For a reading of 2 5V which is outside both Limit 1 and Limit 2 the same status indication HIGH 1 will be displayed since Limit 1 takes precedence Model 2701 User s Manual Limits and Digital I O 9 3 Overflow readings A reading that exceeds the present measurement range causes the OVRFLW message to be displayed The IN 1 and 2 messages are not displayed while in the overflow condition The HIGH annunciator will turn o
346. itting values A B and C may not be exactly the same as the ones used by the Model 2701 If they are not exactly the same perform the following steps to select a thermistor to use with the Model 2701 Model 2701 User s Manual Temperature Equations F 7 NOTE The specified thermistor temperature measurement accuracy of the Model 2701 see Appendix A is based on the curve fitting constants listed in Table F 9 If the thermistor manufacturer s curve fitting constants are not exactly the same as the ones listed in Table F 9 accuracy will be affected 1 Choose the thermistor type to be used 22520 5kQ or 10kQ 2 Compare the A B and C constants from the thermistor manufacturer with those used by the Model 2701 see Table F 9 3 Selecta thermistor that closely matches the A B and C constants in Table F 9 Analyze the differences between the two sets of curve fitting constants to determine the affect on measurement accuracy Converting K to C The temperature in Kelvin can be converted to C as follows Too Ty 273 15 where is the temperature in C Tx is the calculated Kelvin temperature Example Calculate the temperature for a Series 44007 thermistor that measures 5kQ InR In 5000 8 5172 0 001288 0 0002356 C 9 557 8 Tk 1 A BInR O nR 1 0 001288 0 0002356 8 5172 9 557e 8 8 5172 1 0 001288 0 002007 0 000059 1 0 003354 298 15
347. ked to see if it is within the selected hold window 0 01 0 1 1 or 10 of the seed reading If the reading is within the window operation again loops back within the device action block This looping continues until the specified number 2 to 100 of consecutive readings are within the window If one of the readings is not within the window the instrument acquires a new seed reading and the hold process continues When a hold reading is acquired an audible beep is sounded if enabled and the reading is considered a true measurement The reading is held on the display until an out of window reading occurs to restart the hold process For remote operation the hold process seeks a new seed once it has been satisfied and the reading has been released For basic front panel operation the hold process does not seek a new seed until the held condition is removed NOTE Hold cannot be used when scanning Hold example 1 Press SHIFT and then HOLD to display the present window 0 01 0 1 1 or 1096 2 To change the window press the or key to display the desired window 3 Press ENTER The present hold count is displayed 2 to 100 4 change the hold count use the lt and keys to display the desired count 5 Press DCV to measure DC voltage Apply the test signal to the input of the Model 2701 Once the signal becomes sta ble enough to satisfy the hold condition the reading is r
348. l 2701 User s Manual Range Digits Rate Bandwidth and Filter 4 7 Table 4 3 Digits commands Commands Description Default SENSe 1 Optional root command VOLTage DC DIGits n lt clist gt VOLTage AC DIGits n lt clist gt CURRent DC DIGits n lt clist gt Set of digits for DCV n 4 to 7 Set of digits for ACV n 4 to 7 Set of digits for DC1 n 4 to 7 CURRent AC RESistance DIGits n lt clist gt FRESistance DIGits n lt clist gt TEMPerature DIGits n lt clist gt FREQuency DIGits n lt clist gt PERiod DIGits n lt clist gt DIGits n lt clist gt Set of digits for ACI n 4 to 7 Set of digits for Q2 n 4 to 7 Set of digits for Q4 n 4 to 7 Set of digits for TEMP n 4 to 7 Set of digits for FREQ n 4 to 7 Set of digits for PERIOD n 4 to 7 Channel list para lt clist gt SCH where S Mainframe slot number 1 or 2 CH Switching module channel number must be 2 digits Examples 101 Slot 1 Channel 1 meter 101 203 Slot 1 Channel 1 and Slot 2 Channel 3 101 110 Slot 1 Channels 1 through 10 The lt clist gt parameter is used to configure one or more channels for a scan Each channel in the lt clist gt must be set to the function specified by the dig its command If no
349. l Scanning 7 17 Step 3 Enable immediate scan The present state of immediate scan IMM SCAN is displayed Y yes which is the factory and RST default or N no With immediate scan enabled the scan will start when you press the STEP or SCAN key Use the or key to display IMM SCAN Y and press ENTER NOTE Disable immediate scan IMM SCAN N when you wish to use a monitored reading limit to trigger the start of the scan This technique to start a scan is covered later in this section See Scan operation page 7 21 Step 4 Timer controlled scan The present state of the TIMER will be displayed NO or YES If you do not wish to use the timer use the or key to display TIMER NO which is the factory and RST default and press ENTER To use the timer use the or key to display TIMER YES and press ENTER The timer interval is displayed in the hour minute second format The timer can be set from 0 001 sec 00H 00M 00 001S to 99 hr 99 min 99 999 sec 99H 99M 99 999S Note that pressing the AUTO key sets the timer to 0 001 sec With the desired interval displayed press ENTER Step 5 Set the reading count The displayed reading count RDG CNT sets the number channels to scan STEP or the number of scans to run SCAN You can change the reading count to any finite value from 2 to 450000 or you can select infinite continuous scanning To select infinite set the reading count to 00000 to display INF With the desire
350. l is measured The scan pointer then loops back to the control source and waits for the next trigger event to occur SCAN operation When the trigger event is detected all the channels in the scan list are scanned The scan pointer then returns to the control source and waits for the next trigger event to be detected Model 2701 User s Manual Immediate control source With immediate triggering event detection is immediate allowing channels to be scanned Timer control source With the timer source enabled selected event detection is immediately satisfied On the initial pass through the loop the Timer Bypass is enabled allowing operation to bypass the Timer and continue to the Delay block On each subsequent pass through the loop the Timer Bypass is disabled Operation is then delayed by the Timer or the Delay If the user set Timer interval is greater than the user set Delay the Timer will control the length of the delay Otherwise the length of the delay is controlled by the user set Delay period The Timer interval can be set from 0 to 999999 999 seconds The timer resets to its initial state when the scan is completed STEP operation As shown in Figure 7 1 the timer control source affects the timing between scanned channels SCAN operation As shown in Figure 7 2 the timer control source affects the timing between scans It has no effect on the timing between scanned channels External trigger control source
351. l value Channel list parameter lt clist gt SCH where S Mainframe slot number 1 or 2 CH Switching module channel number must be 2 digits Examples 101 Slot 1 Channel 1 101 203 Slot 1 Channel 1 and Slot 2 Channel 3 101 110 Slot 1 Channels 1 through 10 The lt clist gt parameter is used to configure one or more channels for a scan Each channel in the lt clist gt must be set to the function specified by the rel reference command If not a conflict error 221 will occur For example VOLTage AC REFerence 1 101 is only valid if scan channel 101 is set for the ACV function 2 DC is optional for the commands to set DCV and DCI rel 5 6 Rel Math Ratio Channel Average dB Model 2701 User s Manual Pressing REL using rel commands When the front panel REL key is pressed the displayed reading is used as the rel value Subsequent readings are then the result of the actual input value and the rel value The REFerence ACQuire and REFerence STATe ON commands in that order can be used to press the REL key For example the following command sequence is the equivalent of pressing the REL key while on the DCV function VOLT REF ACQ Acquire reading as rel value VOLT REF STAT ON Enable rel Setting rel values The REFerence n command specifies the rel value for the specified function while the ACQuire command uses the input signal as the rel value The
352. lay closure count can only be read via remote operation The commands are summarized in Table 2 3 Details follow the table Table 2 3 Relay closure count commands Commands Description Default ROUTe CLOSe COUNt lt clist gt Query close count for specified channels ROUTe CLOSe COUNt INTerval Set count update interval in minutes Note lt NRf gt 10 to 1440 ROUTe CLOSe COUNt INTerval Query relay count update interval Channel list parameter lt clist gt SCH where S Mainframe slot number 1 2 3 4 or 5 CH Switching module channel number must be 2 digits Examples 101 Slot 1 Channel 1 101 203 Slot 1 Channel 1 and Slot 2 Channel 3 101 110 Slot 1 Channels 1 through 10 Note Relay count interval set to 15 minutes at the factory SYSTem PREset and RST have no effect on the set interval NOTE The relay closure count can be reset to zero For details see the Model 2701 Service Manual Plug in module relay closure count Model 2701 User s Manual Close Open Switching Module Channels 2 35 Reading relay closure count To determine the closure count of specific channels send this query via remote ROUTe CLOSe COUNt clist Here lt clist gt is the summary of channels For example to determine the closure count of channels 1 and 4 of a module in slot 1 the following query would be sent ROUT CLOS COUN 101 104 The following query would determine the closure coun
353. layed as the system channel Remote programming ROUT MULT OPEN 8111 4 Inan attempt to clear the overflow reading problem use the SINGLE option of the CLOSE key to again close channel 101 You might think that this will again close channel 111 to reconnect it to DMM Sense However that is not the case Since channel 101 is still the system channel selecting it again in this manner is a no action Channel 111 does not close Remote programming ROUT CLOS 8101 A simple way to resolve the above problem is to repeat step 1 to open all channels and then repeat step 2 to close channel 101 All the listed channels in step 2 will close to make the 4 wire connection to the 1kQ resistor 2 24 Close Open Switching Module Channels Model 2701 User s Manual Dual independent multiplexers Using multiple channel operation any multiplexer switching module can be configured as two independent multiplexers For example the Model 7700 is normally used as a single 1 x 20 multiplexer but it can also be configured as two 1 x 10 multiplexers NOTE Thermocouple temperature measurements using the internal or external reference junction cannot be performed when using multiple channel operation to connect an input channel to the DMM The simulated reference junction will instead be used resulting in invalid readings ERR annunciator turns on See Temperature measurements page 3 33 for details A multiplexer switching module is configured a
354. layed to remind you to first close a valid channel A primary channel must be closed before you can enable ratio or channel average If a paired channel is instead closed message INVALID CHAN will be displayed to indi cate the settings conflict NOTE The various instrument operations including Ratio or Channel Average are performed on the input signal in a sequential manner See Signal processing sequence page D 2 for details It includes a flowchart showing where in the processing sequence that Ratio or Ch Avg operation is performed 5 16 Rel Math Ratio Channel Average dB Model 2701 User s Manual Basic operation NOTE 1 NOTE Make sure the INPUTS switch is set to the REAR position in Select and configure range filter rel etc a valid measurement function For ratio the only valid function is DCV For channel average the only valid functions are DCV and TEMP TCs only Use the or key to select close a primary channel 101 through 110 for the Model 7700 The CLOSE key can also be used Apply one signal to the selected primary channel and apply the other signal to the paired channel For the Model 7700 if the closed primary channel is 101 the paired channel is 111 Enable Ratio or Channel Average Ratio Press SHIFT and then RATIO The RATIO annunciator will turn on to indicate that the displayed readings are the result of the ratio calculation e Channel Average Press SHIFT and the
355. lds current fuse for front panel amps input Rear panel summary The rear panel of Model 2701 is shown in Figure 1 2 As shown a slot cover is installed on slot 2 Figure 1 2 Model 2701 rear panel 1 2 3 4 a INTERNAL PARTS SERVICE BY QUALIFIED 4 ONLY mu omme 7 oe DIGITAL I O TRIGGER ETHERNET RS 232 EXT TRIG LINK 10 100 BaseT 1 KEITHLEY SLOT COVER gt CAUTION FOR CONTINUED PROTECTION AGAINST FIRE HAZARD REPLACE FUSE WITH SAME TYPE AND RATING 1 14 Getting Started Model 2701 User s Manual 1 DIGITAL I O EXT TRIG Male DB 9 connector for digital input trigger link in and digital outputs 2 TRIGGER LINK Eight pin micro DIN connector for sending and receiving trigger pulses among connected instruments Use a trigger link cable or adapter such as Models 8501 1 8501 2 8502 and 8503 3 ETHERNET RJ45 female connector for Ethernet operation Use an RJ45 male male cable for connection Two status LEDs are located at the top of the connector These LEDs indicate the status of the Ethernet see Section 10 Ethernet connections 4 RS 232 Female DB 9 connector for RS 232 operation Use a straight through not null modem DB 9 shielded cable 5 Power module Contains the AC line receptacle power line fuse and line voltage setting The instrument can be configured for line voltages of 100V 120V 220V 240VAC at line frequencies of 50 or 60Hz 6 Slot 1 and Slot 2 Two slots to accommo
356. le Therefore the AC coupled crest factor will differ from the DC coupled waveform The RMS function will calculate the RMS value based on the pulsed waveform with an average value of zero The reason to consider crest factor in accuracy of RMS measurements is because the meter has a limited bandwidth Theoretically a sine wave can be measured with a finite bandwidth because all of its energy is contained in a single frequency Most other common waveforms have a number of spectral components requiring an almost infinite bandwidth above the fundamental frequency to measure the signal exactly Because the amount of energy contained in the harmonics becomes smaller with increasing frequency very accurate measurements can be made with a limited bandwidth meter as long as enough spectral components are captured to produce an acceptable error Crest factor is a relative measurement of the harmonic content of a particular waveform and reflects the accuracy of the measurement For a rectangular pulse train the higher the crest factor the higher the harmonic content of the waveform This is not always true when making spectral comparisons between different types of waveforms A sine wave for example has a crest factor of 1 414 and a square wave has a crest factor of 1 The sine wave has a single spectral component and the square wave has components at all odd harmonics of the fundamental The Model 2701 RMS AC volts and AC amps accuracies are specif
357. le error 100 4 w dckt Ioff zero error 100 4 w dckt Ion zero error 100 4 w ocomp Ion zero error 100 4 w ocomp Ion full scale error 100 4 w dckt Ioff full scale error 100 4 w dckt Ion full scale error 10 4 w dckt Ioff zero error 10 4 w dckt Ion zero error 10 4 w dckt full scale error 10 4 w full scale error 10 4 w ocomp Ion zero error 10 4 w ocomp Ion full scale error EE EE EE EE EE EE EE EE EE EE EE EE EE EE EE EE EE EE EE EE EE EE EE EE EE EE EE EE EE EE EE EE EE EE EE EE EE EE EE EE Model 2701 User s Manual Table C 1 continued Status and error messages Status and Error Messages Number Description Event 496 1 4 w dckt Ioff zero error EE 497 1 4 w dckt Ion zero error EE 498 1 4 w dckt Ion full scale error EE 499 1V 10Hz frequency error EE 500 Calibration data invalid EE 510 Reading buffer data lost EE 512 Power on state lost EE 513 AC calibration data lost EE 514 DC calibration data lost EE 515 Calibration dates lost EE 516 Battery backed RAM error EE 517 Cannot resume scan EE 518 Card calibration data lost EE 519 Card calibration dates lost EE 520 Saved setup scancard mismatch EE 521 Card relay counts lost EE 523 Card hardware error EE 524 Unsupported card detected EE 525 Scancard memory pattern mismatch EE 550 Unitialized ethernet module EE 4555 Cannot charge battery EE 556 Battery removed EE 558 A D Timeout EE 610 Questionable calib
358. les Model 2701 User s Manual LabVIEW examples Table G 2 lists the LabVIEW examples and Use Cases that are provided with the KE2700 Instrument Driver LabVIEW examples are provided in the file Examples lIb Use cases are provided in the file Use Cases lIb By default these are installed in the Program Files National Instruments LabView X instr lib KE2700 directory In addition to the examples numerous supporting VIs are included in the library file Table G 2 LabVIEW examples Manual Name Reference Brief Description Read multi point None Demonstrates configuring and reading multiple data points from from channels switching module channels Read multi point None Demonstrates configuring and reading multiple data points from from front panel the front panel input Read single point None Demonstrates configuring and reading a single data point from from switching switching module channels module channel Read single point None Demonstrates configuring and reading a single data point from from front panel the front panel input Advancel None Use Case 1 40 channel scan using 7708 module 30 channels DCV 10V range 10 channels type T thermocouple temperature Measurement speed rate 1 plc Filter Disabled no filtering Buffer Store 160 reading strings Buffer elements include reading channel and real time clock Triggering Timer scan 40 channels every one minute D
359. ley Model 77XX series switching module A pseudocard cannot be installed from the front panel However once it is installed you can take the Model 2701 out of remote and use the front panel Pressing the LOCAL key takes the Model 2701 out of remote When the instrument is turned off the pseudocard will be lost uninstalled Use the following commands to install pseudocards SYSTem PCARd1 lt name gt Install pseudocard in slot 1 SYSTem PCARd2 lt name gt Install pseudocard in slot 2 lt name gt C7700 C7701 C7702 C7703 C7705 C7706 C7707 C7708 C7709 C7710 C7711 or C7712 Programming example The following command sets up the Model 2701 to operate as if a Model 7700 switching module is installed in slot 2 which must be empty You cannot assign a pseudocard to a slot that already has a switching module installed in it SYSTem PCAR2 C7700 Install pseudocard 7700 for slot 2 Channel assignments The Model 2701 has two slots for switching modules To control the appropriate switching module the slot number must be included with the switching module channel number when you specify a channel The channel assignment is formatted as follows SCH where Sis the slot number CH is the channel number Examples 101 Slot 1 Channel 1 210 Slot 2 Channel 10 For remote operation the 3 digit channel assignment is included in the channel list parameter for the commands Format examples for the channel list parameter
360. list gt Enable or disable reference OFF STATe lt clist gt Query state of reference ACQuire lt clist gt Use input signal as reference REFerence lt clist gt Query reference value THReshold Path to select the threshold voltage range Sec 3 VOLTage RANGe n lt clist gt Select threshold range 0 to 1010 10 RANGe lt clist gt Query threshold range 15 18 SCPI Reference Tables Model 2701 User s Manual Table 15 5 continued SENSe command summary Default Command Description parameter Ref SCPI SENSe 1 CONTinuity Path to configure continuity test Sec 3 THReshold lt NRf gt Set threshold resistance in ohms 10 1 to 1000 THReshold Query threshold resistance Notes 1 POPE CAVerage DELay and RATio DELay are coupled Changing the delay for channel average also changes the delay for channel ratio and vice versa For 60Hz line power the default for aperture is 83 33msec For 50Hz the default is 100msec REPeat is the RST default and MOVing is the SYSTem PRESet default From the front panel the factory default is MOVing OFF is the RST default and ON is the SYTem PRESet default The following commands can instead be used to select the reference junction and set the simulated reference temperature TEMPerature RJUNction RSELect lt name gt lt clist gt Select reference junction SIMulated INTernal or EXTernal TEMPerat
361. ll occur 2 If a pseudocard is installed in the slot the message will be returned when querying the serial number or firmware revision 3 Power up and CLS clears the error queue RST SYSTem PRESet and STATus PRESet has no effect on the error queue 4 Valid only when Ethernet is the selected interface Model 2701 User s Manual SCPI Reference Tables 15 25 Table 15 8 TRACe command summary Default Command Description parameter Ref SCPI TRACel DATA Use TRACe or DATA as root command Sec 6 CLEar Path to clear the buffer IMMediate Clear the buffer AUTO b Enable or disable buffer auto clear ON AUTO Query state of buffer auto clear FREE Query bytes available and bytes in use v POINts lt NRf gt Specify size of buffer 2 to 450000 100 v POINts Query buffer size ACTual Query number of readings stored in buffer v NOTify lt NRf gt Specify number of stored readings that will set 50 Trace Notify bit B6 of measurement event register 1 to 449999 Must be less than TRACe POINts value NOTify Query trace notify value NEXT Query buffer location for next stored reading TSTamp Path to set timestamp format FORMat lt name gt Select timestamp format ABSolute or DELTa ABS FORMat Query timestamp format Query timestamp type for readings presently in buffer FEED lt name gt Select source of readings SENSe 1 CALC CALCulate 1 or NONE CONTrol lt name gt Select b
362. lt rang gt lt res gt lt clist gt MEASure CURRent DC lt rang gt lt res gt lt clist gt MEASure CURRent AC lt rang gt lt res gt lt clist gt MEASure RESistance lt rang gt lt res gt lt clist gt MEASure FRESistance lt rang gt lt res gt lt clist gt MEASure FREQuency lt rang gt lt res gt lt clist gt MEASure PERiod lt rang gt lt res gt lt clist gt MEASure TEMPerature lt clist gt MEASure CONTinuity lt clist gt Parameters lt rang gt Range parameter Measure DCV Measure ACV Measure DCI Measure ACI Measure 2 Measure Measure FREQ Measure PERIOD Measure TEMP Measure CONT for the specified function For example for DCV range parameter value 10 selects the 10V range See the NOTES that follow Table 13 1 for additional information 0 1 0 01 0 001 0 0001 0 00001 0 000001 Tes i e 100 0 V 3 digits i e 10 00 V 3 digits i e 1 000 V 3 digits i e 1 0000 V 41 digits i e 1 00000 V 5 digits i e 1 000000 V 61 digits The resolution of the res parameter value and the selected range sets the number of display digits As shown above with the 100V range selected and res 0 1 a 100V reading will be displayed as 100 0 V 3 digits The display will default to 3H digits when using parameter values that attempt to set the display below 312 digits For example a 10V reading
363. main input power 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 cables 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 Always 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 information and as shown on the instrument or test fixture panels or switching card When fuses are used in a product replace with the same type and rating for continued protection against fire hazard Chassis connections must only be used as shield connections for measuring circuits NOT as safety earth ground connections If you are using a test fixture keep the lid closed while power is applied to the device und
364. mand However the beeper will automatically enable the next time the continuity testing function is selected Limits and digital outputs cannot be used when testing continuity with the continuity CONT function If you need to use these operations use the 2 function to test continuity Model 2701 User s Manual Basic DMM Operation Remote programming for basic measurements Basic measurement commands NOTE When measurements are performed the readings are fed to other enabled processing operations Appendix D explains Data flow remote operation and the commands used to return the various processed readings Commands to perform basic measurements are listed in Table 3 7 Table 3 7 Basic measurement commands Commands Description Select measurement function SENSe 1 FUNCtion lt name gt lt clist gt DCV function SENSe 1 VOLTage DC IDIVider lt b gt SAA function SENSe 1 FRESistance OCOMpensated b lt clist gt SYSTem FRESistance T YPEx lt name gt Optional root command Select measurement function lt name gt VOLTage DC VOLTage AC CURRent DC CURRent AC RESistance FRESistance CONTinuity FREQuency or PERiod Note DC is optional Optional root command Enable disable DCV input divider lt b gt ON or OFF Optional root command Root command for SYSTem subsystem Select 4
365. mand Description parameter Ref SCPI CALCulate 1 Subsystem to control CALC 1 Sec 5 v FORMat lt name gt Select math format NONE MXB PERCent or PERCent lt clist gt RECiprocal FORMa lt clist gt Query math format KMATh Path to configure math calculations MMFactor lt NRf gt Set factor for mx b 4294967295 to 1 lt clist gt 4294967295 MA1Factor lt NRf gt Set factor for mx b 4294967295 to 1 lt clist gt 4294967295 MMrFactor Query m factor lt clist gt MA1Factor Query m factor lt clist gt MBFactor lt NRf gt Set b factor for mx b 4294967295 to 0 lt clist gt 44294967295 MAOFactor lt NRf gt Set b factor for mx b 4294967295 to 0 lt clist gt 44294967295 MBFactor lt clist gt Query factor MAOFactor Query b factor lt clist gt MUNIts char Specify units for mx b reading x MUNIts Query mx b units PERCent lt NRf gt Set target value for PERCent calculation 1 lt clist gt 4294967295 to 4294967295 ACQuire Use input signal as target value PERCent lt clist gt Query percent STATe lt b gt lt clist gt Enable or disable kmath calculation Note 4 STATe lt clist gt Query state of kmath function v DATA Read result of kmath calculation v CALCulate2 Subsystem to control CALC 2 Sec 6 v FORMat lt name gt Select math format MEAN SDEViation
366. mands perform the same operations 3 For mX b units char one character A through Z degrees symbol or ohms symbol CQ 4 ON is the RST default parameter and OFF is the SYSTem PRESet default Table 15 2 DISPlay command summary Default Command Description parameter Ref SCPI DISPlay see Note Sec 1 WINDow 1 v TEXT Path to control user text messages v DATA lt a gt ASCII message up to 12 characters none DATA Query text message v STATe lt b gt Enable or disable message mode OFF v STATe Query text message state lt b gt Enable or disable the front panel display ON v Query state of the display v Note RST and SYSTem PRESet have no effect on commands in this subsystem The listed defaults are power on defaults 15 6 SCPI Reference Tables Model 2701 User s Manual Table 15 3 FORMat command summary Default Command Description parameter Ref SCPI FORMat ELEMents item list Specify data elements READing CHANnel see Note Sec l4 v UNITs RNUMber TSTamp and LIMits ELEMents Query data elements SREGister name Select data format for reading status registers ASCii Secll v name ASCii Decimal format HEXadecimal Hexadecimal format OCTal Octal format BINary Binary format SREGister Query data format for reading status registers v Note The SYSTem PRESet
367. ments This module provides high speed switching and uses long life relays Model 7711 The Model 7711 is a 50 2GHz single pole dual 1 x 4 RF Multiplexer module eight channels no measurement capability This 1 x 4 multiplexer is a cascad ing tree design one of the channels of each is always connected to a common out It can be used to connect one instrument to multiple devices or multiple instruments to a single device Model 7712 The Model 7712 is a 500 3 5GHz single pole dual 1 x 4 RF Multiplexer module eight channels no measurement capability This 1 x 4 multiplexer is a cascad ing tree design one of the channels of each is always connected to a common out It can be used to connect one instrument to multiple devices or multiple instruments to a single device Cables and connector kits for switching modules Model 7788 DB 50 connector kit Contains two male DB 50 solder cup connectors with strain relief connector shells These connectors mate to the female connectors of the Models 7703 and 7705 switching modules Model 7789 50 25 pin solder cup connector kit Contains one male DB 50 and one male DB 25 solder cup connectors These connectors mate to the female connectors on the Models 7701 and 7709 switching modules Model 7790 ribbon cable adapter kit Contains one female DB 50 one male DB 50 and one male DB 25 IDC ribbon cable connectors These connectors are used with the Models 7701 7707 and 7709 swi
368. mmands are used to clear the fail 1 indications for Limit 1 and Limit 2 If auto clear is enabled for a limit the fail indication clears when instrument operation enters the idle state With auto clear disabled the fail indication will remain until it is cleared by the CLEar command 9 14 Limits and Digital I O Model 2701 User s Manual Limits and digital outputs programming example The following command sequence configures the Model 2701 to perform Limit 1 test on a DCV reading If the 100mV limit is reached digital output 2 will be pulled low If the 100mV limit is reached digital output 1 will be pulled low NOTE The following example can be run from the KE2700 Instrument Driver using the example named Limits in Table G 1 of Appendix G RST CALC3 CALC3 CALC3 CALC3 CALC3 READ CALC3 Application sorting resistors LIMI LIMI LIM1 OUTP 0UTP 0 1 LOW 0 1 STAT ON LSEN ALOW ON FAIL One shot measurement mode DCV Set HI1 limit to 100mV Set 101 limit to 100mv Enable Limit 1 Set logic sense to active low Enable digital outputs Trigger and request reading Request result of limit 1 test For this application the idea is to sort a batch of 100Qresistors into three bins Bin 1 is for resistors that are within 1 of the nominal value Bin 2 is for resistors that exceed 1 tolerance but are within 5 Bin 3 is for resistors that exceed 5 tolerance
369. mmon Commands 12 2 Table 12 1 Common Commands Model 2701 User s Manual Common commands summarized in Table 12 1 are device commands that are common to all devices on the bus These commands are designated and defined by the IEEE 488 2 standard Common commands and queries Mnemonic Name Description Ref CLS Clear status Clears all event registers and error queue Sec 11 ESE NDN Event enable command Program the standard event enable register Sec 11 or lt NRf gt ESE Event enable query Read the standard event enable register Sec 11 ESR Event status register query Read the standard event enable register and Sec 11 clear it IDN Identification query Returns the manufacturer model number serial A number and firmware revision levels of the unit OPC Operation complete command Set the operation complete bit in the standard B event register after all pending commands have been executed OPC Operation complete query Places an ASCII 1 into the output queue when C all pending selected device operations have been completed OPT Option query Returns the model numbers of the switching D modules installed in the Model 2701 Returns if a slot is empty RCL lt NRf gt Recall command Returns Model 2701 to the user saved setup 0 E 1 2 3 or 4 RST Reset command Returns Model 2701 to the RST default F conditions SAV lt NRf gt Save command Saves the present setup as the user
370. mple SAV 2 Save present setup in memory location 2 SYST POS SAV2 Specify SAV2 setup as the power on setup RST Return 2701 to RST defaults RCL 2 Return 2701 to setup stored in memory location 2 Model 2701 User s Manual Getting Started 1 27 Remote programming information Remote programming information is integrated with front panel operation throughout this manual Programming commands are listed in tables and additional information that pertains exclusively to remote operation is provided after each table The tables may reference you to other sections of this manual NOTE Except for Section 11 through Section 15 most programming tables in this man ual are abridged That is they exclude most optional command words and query commands Optional command words and query commands are summarized as follows Optional command words In order to be in conformance with the IEEE 488 2 stan dard Model 2701 accepts optional command words Any command word that is enclosed in brackets is optional and does not have to be included in the program message Query commands Most command words have a query form A query command is identified by the question mark that follows the command word A query command requests queries the programmed status of that command NOTE For complete details see Programming syntax page 10 21 1 28 Getting Started Model 2701 User s Manual Quick start exercises 053 This section t
371. mple 1 Program and read a register set NOTE The following example be run from the KE2700 Instrument Driver using the example named Prmr in Table G 1 of Appendix The following command sequence programs and reads the measurement register set STAT MEAS ENAB 512 Enable BFL buffer full STAT MEAS COND Read Measurement Condition Register STAT MEAS Read Measurement Event Register NOTE Examples 2 and 3 demonstrate the proper method to read an individual bit of an event register In general the state of an event register bit is determined by enabling the event bit then reading the status byte STB 11 20 Status Structure Model 2701 User s Manual Example 2 Read RAV bit of measurement event register The following command sequence demonstrates the proper method to read the RAV bit of the measurement event register RST Put 2701 in one shot mode CLS Clear measurement event register STAT PRES Clear measurement event enable register STAT MEAS ENAB 32 Enable RAV bit B5 of the measurement event register INIT Trigger one measurement STB Read status byte register CLS and STAT PRES resets the measurement register bits to zero The ENAB command enables the reading available bit B5 RAV of the measurement event register When a reading is triggered and becomes available bit BO MSB of the status byte will set INIT triggers a reading and STB reads the status byte Since you a
372. ms measurements CSIDe mode Dry circuit ohms option for Model 2750 Install jumpers to connect Input Hi and Sense Hi directly to DUT common side bus Install jumpers to connect channel 35 to Sense Lo and Input Lo e Buffer Store 32 reading strings Buffer elements include reading only e Triggering Immediate control source G 10 KE2700 Instrument Driver Examples Model 2701 User s Manual Table G 1 continued Visual Basic and CVI C examples Name Manual Reference Brief Description Simple6 None Use Case 6 Scan 160 channels using 7703 module see NOTE Type K thermocouple TC temperature measurements Reference junction Simulated Measurement speed rate 0 01 plc Filter Disabled no filtering Buffer Store 160 reading strings Buffer elements include reading only Triggering Bus control source NOTE When using a module that has a built in cold junction use the Internal reference junction Keep in mind that the buffer will have to be modified to accommodate the number of scanned channels Modules that have cold junction include 7700 and 7706 modules 20 available TC channels 7708 module 40 available TC channels Simple7 None Use Case 7 Ten 40 channel scans using 7702 module Channel 1 uses an external reference junction Measurement speed rate 1 plc Filter Repeat 25 readings Channels 2 through 40 are connect
373. n 5 8 Rel Math Ratio Channel Average dB Model 2701 User s Manual mX b This math operation lets you manipulate normal display readings X mathematically according to the following calculation Y mX b where X is the normal display reading m and b are the user entered constants for scale factor and offset Y is the displayed result NOTE When using Rel the rel ed reading of the input signal is used by the mX b calculation mX b configuration 1 Press SHIFT and then MATH to display the math menu 2 Press the RANGE and key to display mX b and press ENTER to display the present scale factor M 1 000000 factory default 3 Key in the scale factor value The and keys control cursor position and the 4 and keys increment decrement the digit value To change range place the cursor on the multiplier and use the 4 and keys m x0 001 4 x 1 1000 and X 1 000 000 With the cursor on the polarity sign the 4 and keys toggle polarity 4 Press ENTER to enter the m value and display the offset b value b 00 00000 m factory default 5 Keyinthe offset value 6 Press ENTER to enter the b value and display the one character units designator UNITS X factory default 7 Use the cursor keys and the and key if you wish to change the units designator The character can be any letter in the alphabet A through Z the degree symbol or the ohms symbol Q 8 Press ENTER The MAT
374. n INIT and multi sample READ queries are locked out With readings in the buffer that were stored in that manner you cannot use the INIT or READ command if sample count is gt 1 error 225 out of memory NOTE The measurement event register can be read to check when the buffer becomes 14 12 3A or full Status registers are covered in Section 11 Example 3 Read BHF bit of measurement event register shows how to read the BHF buffer half full bit of the measurement event register Buffer commands NOTE When measurements are performed the readings are fed to other enabled operations including the Buffer Appendix D explains Data flow remote operation page D 7 and the commands used to read the buffer and buffer statistics The commands to perform buffer operations are listed in Table 6 1 Details on these commands follow the table NOTE Optional command words and most queries are not included in Table 6 1 The unabridged tables for all SCPI commands are provided in Section 15 Model 2701 User s Manual Buffer 6 9 Table 6 1 Buffer commands Command Description Default Ref SYSTem TIME lt hr min sec Set clock time in 24 hour format a SYSTem DATE yr mo day Set clock date yr specified as 20xx b SYSTem TSTamp TYPE Select timestamp name RELative RTCLock REL e name SYSTem TSTamp TYPE Query timestamp type that will be used for the next c buffer storage TRACe TSTamp TYP
375. n Set lower limit 4294967295 to 1 lt clist gt 414294967295 DATA lt clist gt Query lower limit STATe b Enable or disable limit test OFF v lt clist gt STATe lt clist gt Query state of limit test v FAIL Query test result 1 failing CLEAR Path to clear events v IMMediate Clear high and low events v AUTO lt b gt Enable or disable auto clear ON v AUTO Query auto clear Model 2701 User s Manual SCPI Reference Tables 15 5 Table 15 1 continued CALCulate command summary Default Command Description parameter Ref SCPI CALCulate3 LIMit2 Path to control LIMIT 2 test UPPer Path to configure upper limit v DATA n Set upper limit 4294967295 to 2 lt clist gt 4294967295 DATA lt clist gt Query upper limit LOWer Path to configure lower limit v DATA n Set lower limit 4294967295 to 2 v lt clist gt 414294967295 DATA lt clist gt Query lower limit v STATe b Enable or disable limit test OFF v lt clist gt STATe lt clist gt Query state of limit test FAIL Query test result 1 failing CLEAR Path to clear events IMMediate Clear high and low events AUTO lt b gt Enable or disable auto clear ON v AUTO Query auto clear v Notes 1 The MMFactor and MA1Factor commands perform the same operations 2 The MBFactor and MAOFactor com
376. n CHA AVG The DELTA annunciator will turn on to indicate that the displayed readings are the result of the channel average calculation To disable channel average again press SHIFT and then CH AVG When finished there are two ways to disable the calculation Press the OPEN key The calculation will disable and the channel will open e Press SHIFT and then RATIO to disable ratio or press SHIFT and then CHA AVG to disable channel average The calculation will disable but the channel will remain closed The paired channel number is not displayed when it is measured Only the primary channel is displayed during the 2 channel scan for the calculation Enabling ratio disables channel average and conversely enabling channel average disables ratio If either of the channel readings over range OVRFLW the result of the calculation will also be OVRFLW When using limits with ratio or channel average the limit values will be compared to the result of the calculation and not to the individual channels With ratio or channel average enabled pressing a function key will display the EXIT RATIO or EXIT CHA AVG message to indicate that the calculation must first be disabled as explained in step 5 of the above procedure Model 2701 User s Manual Rel Math Ratio Channel Average dB 5 17 Scanning Ratio and channel average can be used in an advanced scan The 2 channel scan for the calculation is performed for every primary cha
377. n Guide B 1 7700 module 342 Wire and Thermistor connections B 8 344 Wire and RTD connections B 9 Card configuration B 2 Connection Log B 10 Current connections AC or DC B 9 Simplified schematic B 3 Terminal Identification B 5 Thermocouple connections B 8 Typical connections B 8 Voltage connections DC or AC B 10 Wire dressing B 7 Wiring B 6 7710 module Connections and wiring B 4 AC voltage measurements Crest factor 3 12 AC voltage offset 3 16 Accessories 1 3 Adapters 1 5 AMPS fuse replacement front panel AMPS input 3 19 Amps measurement procedure 3 18 Annunciators 1 12 Flashing CHAN 7 15 Flashing OCOMP 3 25 REM 10 20 SRQ 10 20 Aperture 4 12 Applications Sorting resistors 9 14 Auto delay settings 8 4 Auto ranging 4 3 4 5 Autozero 3 4 10 2 Average buffer statistic 6 7 Bandwidth 4 10 Aperture 4 12 Commands 4 11 Programming examples 4 13 Rate conflict error 4 13 Remote programming 4 11 Scanning 4 10 Settings 4 9 Basic measurements 3 8 Basic operation 3 1 Overview 3 2 Baud rate 10 28 Beeper control 8 7 Buffer 6 1 7 27 Auto clear 6 2 Clear 6 11 Commands 6 8 CALCulate2 DATA 6 14 CALCulate2 FORMat 6 14 CALCulate2 MMediate 6 14 CALCulate2 MMediate 6 14 CALCulate2 STATe 6 14 FORMat ELEMents 6 13 SYSTem DATE 6 10 SYSTem TIME 6 10 SYSTem TSTamp TYPE 6 10 TRACe CLEar 6 10 TRACe CLEar AUTO 6 10 TRACe DATA SELected start count 6 12 TRACe DATA 6 12 TRACe FEED 6 11 TRACe FEED CONTrol 6 11 T
378. n be selected After the buffer fills operation wraps around to the beginning of the buffer location 0 and starts to overwrite old reading data see TRACe FEED CONTrol com mand in Table 6 1 6 6 Buffer Recalling readings Figure 6 1 Model 2701 User s Manual Readings stored in the buffer are displayed by pressing the RECALL key The readings are positioned at the left side of the display while the buffer location number reading number and timestamps are positioned at the right side Perform the following steps to view stored readings and buffer statistics 1 Press RECALL The BUFFER annunciator indicates that stored readings are being displayed The double arrow annunciator indicates that more data can be viewed with the 4 gt a and keys 2 As shown in Figure 6 1 and Figure 6 2 use gt a and keys to navigate through the reading numbers reading values statistics and timestamps For any of the buffer statistics standard deviation average peak to peak minimum and maximum the STAT annunciator is on NOTE longer you hold in the a or key the faster you will scroll through the buffer After a while scrolling speed will increase by incrementing or decrementing the buffer reading number by 100 and then finally by 1 000 When you get close to the desired reading number release the a or key Again press and hold in the a or key to scroll one reading at a time Recalling buffer data
379. n generate substantial magnetic fields so care must be taken to keep the Model 2701 voltage source and connecting cables a good distance away from these potential noise sources Radio frequency interference RFI Radio Frequency Interference is a general term used to describe electromagnetic interference over a wide range of frequencies across the spectrum Such RFI can be particularly troublesome at low signal levels but it can also affect measurements at high levels if the fields are of sufficient magnitude RFI can be caused by steady state sources such as radio signals TV signals or some types of electronic equipment microprocessors high speed digital circuits etc or it can result from impulse sources as in the case of arcing in high voltage environments In either case the effect on the measurement can be considerable if enough of the unwanted signal is present RFI can be minimized in several ways The most obvious method is to keep the Model 2701 voltage source and signal leads as far away from the RFI source as possible Additional shielding of the instrument signal leads sources and other measuring instruments will often reduce RFI to an acceptable level In extreme cases a specially constructed screen room may be required to sufficiently attenuate the troublesome signal The Model 2701 digital filter may help to reduce RFI effects in some situations In some cases additional external filtering may also be required Ke
380. n measure temperature using thermocouples thermistors and 4 wire RTDs When deciding which temperature sensor to use keep in mind that the thermocouple is the most versatile the thermistor is the most sensitive and the 4 wire RTD is the most stable Thermocouples For thermocouples temperature measurement range depends on which type of thermocouple is being used Thermocouples that are supported include types J K N T E R S and B Type Range Resolution J 200 C to 760 C 0 001 K 200 C to 1372 C 0 001 C N 200 C to 1300 C 0 001 C T 200 C to 400 C 0 001 C E 200 C to 1000 C 0 001 C R 0 C to 1768 C 0 1 C 5 0 to 1786 0 1 B 350 C to 1820 C 0 1 C When two wires made up of dissimilar metals are joined together a voltage is generated The generated voltage is a function of temperature As temperature changes the voltage changes The thermocouple voltage equates to a temperature reading This is the basic operation principle of the thermocouple NOTE The equation to calculate thermocouple temperature is provided in Appendix F 3 34 Basic DMM Operation Model 2701 User s Manual When you connect a thermocouple directly to the input of the Model 2701 at least one of those connections will be a junction made up of two dissimilar metals Hence another voltage is introduced and is algebraically added to the thermocouple voltage The result will be an erroneous temperature
381. n to indicate an out of limits reading The LOW annunciator is not used for an overflow reading An overflow reading is interpreted by the Model 2701 as a positive reading even if the input signal is negative That is the reason why the LOW annunciator does not turn on NOTE When a switching module channel is closed the message I replaces the message IN to indicate that the reading is inside both Limit 1 and Limit 2 For limit test readings that get stored in the buffer the limits status indicators are displayed for each recalled reading When a limit test reading is returned using remote programming limit test status can be included with the reading See Section 14 FORMat commands for details When using Limits with Ratio or Ch Avg the limit values will be compared to the result of the calculation and not to the individual channels Beeper A beeper is also available for limit testing There are three beeper options NEVER OUTSIDE and INSIDE These options are explained as follows NEVER With this option the beeper is disabled OUTSIDE With this option the beeper sounds when the reading is outside HIGH or LOW of Limit 1 or Limit 2 Again referring to Figure 9 1 a 1 5V reading is outside HIGH Limit 1 and the beeper will sound INSIDE With this option the beeper will sound when the reading is inside Limit 1 and or Limit 2 If the reading is inside Limit 1 the beeper will sound raspy If the
382. nabled operation event has occurred 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 MSS by the Status Summary Message bits BO B2 B3 B4 B5 and B7 of the Status Byte Register As shown in Figure 11 3 the summary bits are logically ANDed amp with the corresponding enable bits of the Service Request Enable Register When a set 1 summary 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 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 command The Service Request Enable Register clears when power is cycled or a parameter value of 0 is sent with the SRE command SRE 0 The commands to program and read the SRQ Enable Register are listed in Table 11 3 11 10 Status Structure Model 2701 User s Manual Status byte and service request commands The commands to program and read the Status Byte Register and Service Request Enable Register are listed in Table 11 3 For details on programming and reading registers see Programming enable registers and Reading registers NOTE To reset the bits of the Service R
383. nd channel Triggering Bus control source Data retrieval SRQ when buffer 1 34 and full G 6 KE2700 Instrument Driver Examples Table G 1 continued Visual Basic and CVI C examples Model 2701 User s Manual Name Manual Reference Brief Description Advance8 None Use Case 8 7706 module in slot 1 and 7702 module in slot 2 7706 module Output analog output values to analog output channels Output digital output values to digital output channels 7702 module Scan 120 DCV channels Measurement speed rate 1 plc Filter Disabled no filtering e Math mX b m 0 555 b 17 778 Limits Limit 1 all channels 100 Limit 2 180 Buffer Store 320 reading strings Buffer elements include reading channel and limit code Triggering Bus control source trigger delay 0 125 seconds Data retrieval SRQ when buffer 1 34 and full Analout See 7706 packing list Demonstrates setting the output value of the analog output channels of the 7706 module AOCalibration 7706 packing list Demonstrates how to remotely calibrate the analog output channels of the 7706 module BufStats Page 6 15 Prog Ex Demonstrates calculating the mean of 20 readings BusTrg Page 12 7 Demonstrates use of bus triggering TRG Prog Ex CloseChannels Page 2 21 Demonstrates closing channels multiple channel operation Remote
384. nel number for the mainframe The first digit 1 or 2 indicates the slot number and the next two digits indicate the channel number of the switching module Examples Channel 101 Slot 1 channel 1 Channel 112 Slot 1 channel 12 Channel 220 Slot 2 channel 20 Sequential and non sequential scans Only a sequential scan can be configured from the front panel For a sequential scan the scan proceeds from the lowest numbered channel to the highest For example assume channels 101 102 105 108 and 109 are selected for a scan The scan will run in this order 101 102 105 108 109 For remote programming a non sequential scan can be configured Channels are scanned in the order that they are listed in the scan list This allows backward scanning For example assume the following scan list 101 102 104 105 103 109 The above scan will run in this order 101 gt 102 gt 104 gt 105 gt 103 2109 Notice that after channel 105 is scanned the unit backs up to scan channel 103 It then proceeds forward to scan channel 109 Any scan that performs backward scanning is considered a non sequential scan For more information on non sequential scanning see the reference information for the ROUT SCAN command that follows Table 7 1 NOTE Non sequential scanning is only intended to be performed using remote programming Unexpected results may occur if a non sequential scan is run from the front panel Scanning Model 2701 Us
385. nflict 3 The present password and command protection state are not affected by RST or SYSTem PRESet Battery System settings such as remote programming interface settings are saved in non volatile memory The rechargeable lithium ion battery is used for the 450 00 reading buffer The system commands to acquire status information about the battery are listed in Table 10 1 Error codes associated with the battery 555 Cannot charge battery Will occur approximately one hour after power up if the battery cannot charge and needs to be replaced 556 Battery removed Will occur one time on power up Subsequent power ups will not repeat this error NOTE Details on the rechargeable lithium ion battery are provided in Section I see Battery page 1 3 10 6 Remote Operations Model 2701 User s Manual Miscellaneous system commands Also included in Table 10 1 are system commands to control remote local operation re boot the 2701 and acquire the serial number and revision of the main PC board System commands not covered in this section are provided in Section 14 All SYSTem commands are listed in Table 15 7 Table 10 1 SYSTem commands Command Description SYSTem LOCal Take 2701 out of remote and restore operation of front panel controls REMote Place 2701 in remote RWLock Lockout front panel controls RESet Immediately re boots the 2701 BOARd PC board SNUMber Acquire serial number of PC board REVi
386. nframe revision level serial number and calibration sta tus Instrument Settings Establish the date time and enable yes or disable no the use of password Interactive control panel From the control panel the user can send commands and queries to Model 2701 Also with the click of button the instrument will continuously take readings Readings responses to queries and any error messages are displayed in the control panel Measurements Click Initiate to start continuous readings SCPI Programming Type in the edit field a command or query and click Send Opening the web page System requirements Internet Explorer IE 5 0 or greater is needed to open the 2701 web page Make sure the PC and Model 2701 is properly set for Ethernet operation Details on using the Ethernet is provided in the Model 2701 Instrument Networking Instruction Manual The following example demonstrates correct settings for the Model 2701 and the PC Example Assume the 2701 is using the default IP Address and Subnet mask Model 2701 settings IP Address 192 168 000 002 192 168 000 is the Network ID 002 is the Node Designation Subnet mask 255 255 255 000 PC settings IP Address 192 168 000 004 192 168 000 is the Network ID 004 is the Node Designator Subnet mask 255 255 255 000 Model 2701 User s Manual Remote Operations 10 17 As shown above for the IP Address the Network ID of the 2701 and PC must
387. ng modules NOTE Presently non measure Keithley modules include the Models 7705 7711 and 7712 You can check the Keithley website www keithley com for new modules Keep the following in mind when using a non measure module Fora non measure card no channels are connected to the internal DMM the channels cannot be connected to the backplane Multiple channel operation should be used to close channels on a non measure module For remote operation the ROUT MULT commands are used to close channels Front panel system single channel operation cannot be used to close channels on a non measure module For front panel operation system channel operation will cause message NO MEAS CARD to be displayed Anon measure module may have open close operations that are specific only to that module Refer to the appropriate module manual packing list for details on operation Inorder to perform measurements you must use the front panel inputs of the 2701 mainframe You can still use the non measure module to control other operations 2 16 Close Open Switching Module Channels Model 2701 User s Manual Multiple channel operation The capability to individually control channels provides you with added flexibility in how you use a switching module For example assume you want to route a signal into channel 1 and out channel 20 of a Model 7700 switching module You would do this by closing channels 1 20 and 23 If you open channels
388. nnel that is scanned For example assume the Model 7700 is installed in slot 1 and is configured to perform the ratio calculation for 10 channels When channel 101 is scanned measurements are performed on channels 101 and on its paired channel 111 The calculation is performed and the result is displayed When the next channel 102 is scanned measurements are performed on that channel 102 and on its paired channel 112 The calculation is performed and the result is displayed This process continues for each scanned channel When an advanced scan is configured each channel can have its own unique setup That is one or more channels can use ratio and other channel s can use channel average Details to configure and run a scan are provided in Section 7 Advanced scan configuration notes 1 When a calculation ratio or channel average is enabled for a primary scan chan nel the following setup actions occur The calculation enables for the paired channel The primary channel setup function range rel etc will be copied to the paired channel 2 The filter setup for both scan channels are controlled by the primary channel 3 After the calculation is enabled the range setting can be independently set for both the primary and paired channel 4 Before the calculation is enabled rel can be independently set for both the primary and paired channel In general set up rel from the normal measurement state then go into the advan
389. nner you cannot use the INIT or READ command if sam ple count is gt 1 error 225 out of memory Buffer operation is cov ered in Section 6 Model 2701 User s Manual Basic DMM Operation 3 57 Basic measurement programming examples Example 1 continuous triggering The following command sequence places the Model 2701 in a continuous trigger mode to measure ACV Whenever DATA is sent the last measured reading will be sent to the computer NOTE The following example can be run from the KE2700 Instrument Driver using the example named CTMMV in Table G 1 of Appendix G SYST PRES Continuous measurement mode INIT CONT ON FUNC VOLT AC Select ACV function DATA Request last measured reading Example 2 one shot triggering The following command sequence places the Model 2701 in a one shot trigger mode to measure offset compensated ohms Whenever READ is sent a measurement will be triggered and the measured reading will be sent to the computer NOTE The following example can be run from the KE2700 Instrument Driver using the example named Ohmm in Table G 1 of Appendix RST One shot measurement mode INIT CONT OFF FUNC FRES Select O4 function FRES RANG 1e3 Select 1kQ range FRES OCOM ON Enable offset compensated ohms READ Trigger and return one reading Example 3 temperature measurement using Model 7700 The following command sequence places the Model 2701 in a one shot tr
390. nput signal This process is known as autozeroing When autozero is disabled the offset gain and internal temperature measurements are not performed This increases the measurement speed However the zero gain and temperature reference points will eventually drift resulting in inaccurate readings of the input signal It is recommended that autozero only be disabled for short periods of time When autozero is enabled after being off for a long period of time the internal reference points will not be updated immediately This will initially result in inaccurate measurements especially if the ambient temperature has changed by several degrees NOTE To force a rapid update of the internal reference points set the integration rate to 0 002 PLC and then back to the desired rate i e 1 0 PLC The NPLC commands to set the integration rate are covered in Section 4 Remote programming can be used to enable or disable autozero see Table 3 1 Model 2701 User s Manual Basic DMM Operation 3 5 LSYNC line cycle synchronization Synchronizing A D conversions with the frequency of the power line increases common mode and normal mode noise rejection When line cycle synchronization is enabled the measurement is initiated at the first positive going zero crossing of the power line cycle after the trigger Figure 3 1 shows the measurement process that consists of two A D conversions If the trigger occurs during the positive cycle of the power
391. ns see Scanning fundamentals Sequential and non sequential scans page 7 3 For remote operation the ROUT CLOS ACON command is used to enable or disable auto channel configuration Table 7 1 Model 2701 User s Manual Scanning 7 21 Saving setup Up to five instrument setups can be saved in memory using the SHIFT SAVE menu SAVO SAV 1 SAV2 SAV3 or SAV4 A user saved setup can also be used as the power on setup A user saved setup can be restored from the SHIFT gt SETUP menu Details on user setups are covered in Section 1 Auto scan When auto scan is enabled the scan operation is saved in memory If power to the Model 2701 is interrupted the scan will resume when power is restored With auto scan enabled the last scan setup becomes the power on setup It takes precedence over the factory RST or user saved power on setup Perform the following steps to set auto scan 1 While in the normal measurement state press SHIFT and then SETUP 2 Use the and keys to display the auto scan AUTOSCAN setting N no or Y yes 3 change the setting press to place the cursor on the setting N or Y and press aor to change the setting 4 Press ENTER to exit from the menu structure NOTE With auto scan enabled DO NOT save the present setup as the power on default setup If you do so an interrupted scan will not resume If during the power up sequence the Model 2701 detects a card ID change for any sl
392. nstrument Driver using the example named RateBandwidth in Table G 1 of Appendix G Example 1 The following command sequence sets ACV rate to 5 PLC In order to set rate for an AC function bandwidth must first be set to 300 VOLT AC DET BAND 300 Set ACV bandwidth to 300 VOLT AC NPLC 5 Set ACV rate to 5 PLC NOTE VOLT AC DET BAND must be set to 300 before the VOLT AC NPLC command can be sent Example 2 The following command sequence configures channels 101 and 103 of the Model 7700 to set integration rate to 6 PLC when they are scanned FUNC VOLT 9101 103 Select DCV function VOLT NPLC 6 8101 103 Set rate to 6 PLC 4 14 Range Digits Rate Bandwidth and Filter Model 2701 User s Manual Filter The digital filter is used to stabilize noisy measurements The displayed stored or transmitted reading is a windowed average of a number of reading conversions from 1 to 100 The filter setup is remembered and can be unique for each measurement function DCV DCI ACI Q2 and TEMP When you select a function the instrument will return to the last filter setup for that function NOTE The various instrument operations including Filter are performed on the input signal in a sequential manner See Signal processing sequence page D 2 for details It includes flowcharts showing where in the processing sequence that filtering is performed Filter characteristics In general the
393. nt powers up to a setup that continuously measures DC volts Some of the default set tings for DCV function include auto range enabled 62 101 resolution filter enabled and slow reading rate These settings provide a good starting point and in many cases do not need to be changed Starting point default settings are also provided for the other measurement functions Therefore to perform basic measurements simply select the desired function and tweak the setup range rate filter digits etc as required For remote programming the instrument is typically used in a non continuous measure ment mode In this mode the user via remote command programming specifies the num ber of measurements to perform RST defaults place the instrument in a non continuous measurement mode Most of the other settings for factory and RST defaults are the same For remote programming the following command is used to select function NOTE Items in brackets are optional and do not need to be included Upper case characters are required Lower case characters are optional and need not be included SENSe 1 FUNCtion func Select measurement function func VOLTage DC DCV VOLTage AC ACV CURRent DC DCI CURRent AC ACI RESistance FRESistance FREQuency FREQ PERiod PERIOD TEMPerature TEMP Each function can have its own unique setup configuration i e range digits speed etc For example
394. nt the channel in the scan you can either use the presently selected function or select a valid measurement function When you press a function key i e DCV the channel assumes the setup of the selected function Available channels that follow will assume the same setup Note however that channels for slot 2 are not affected NOTE For the Model 7700 DCI and ACI cannot be selected for channels 101 through 120 and channels 201 through 220 DCI and ACI are the only functions that can be set for channels 121 122 221 and 222 3 If you did not disable the channel make your setup changes if any for the selected function These changes do not affect the following channels 4 Using the lt or gt keys or the CLOSE key to select the channel repeat Step 2 2 and Step 2 3 to set other channels 5 When finished setting up channels press ENTER to proceed to set up triggering NOTE lfthere are not at least two channels in the scan list two or more channels enabled the INVALID LIST message will appear briefly You will not be able to exit from the scan configure menu or finish the scan setup until you enable at least two channels NOTE The remaining steps are used to check or change the setups for triggering timer and reading count If you are not going to make changes to any of those setups you can exit from the scan setup menu by pressing EXIT twice The instrument returns to the normal measurement mode Model 2701 User s Manua
395. nt will not stay in idle unless continuous initiation is disabled There are two commands to disable continuous initiation INITitate CONTinuous OFF Disable continuous initiation RST Restore RST defaults The instrument will remain in idle until it receives an initiate command Typical commands to initiate one scan cycle include INITiate Initiate one scan cycle READ Initiate one scan cycle and request sample readings More information on using these commands is provided by Reference c that follows Table 7 1 Control sources For bus operation there are two additional control sources Bus and Manual For the Bus control source scan operation is controlled by bus triggers 1 TRG or by using the TRIG key For the Manual control source event detection is controlled solely by the TRIG key Note that the instrument has to be in local order to use the TRIG key The LOCAL key takes the instrument out of remote Trigger and sample counters For front panel SCAN operation the number of channels in the scan list and the programmed reading count automatically sets the trigger and sample counters For remote operation these two counters are set by the TRIGGer COUNt and SAMPle COUNt commands NOTE set sample count gt 1 continuous initiation must be disabled see Idle page 7 7 Note that only sample count readings are stored in the buffer See Section 8 for detailed information on the trigger model Model 2701
396. nto the buffer Math functions are covered in Section 5 NOTE In order to store readings in the buffer TRACe FEED cannot be set to NONE TRACe FEED CONTrol Selecting NEXT enables the buffer After the specified number of readings buffer size are stored buffer operation disables The ALWays parameter places the buffer into a continuous filling mode After the specified number of readings are stored operation wraps back to the first buffer location and overwrites the previous readings The NEVer parameter disables buffer operation 6 12 Buffer Model 2701 User s Manual TRACe DATA Read buffer Use TRACE DATA to retrieve all readings that are stored in the buffer You can send this command even if the instrument is still storing readings When TRACe DATA is sent it will return the readings stored up to that point in time Subsequent TRACe DATA commands will not retrieve readings already returned However once the buffer has filled and you have retrieved all buffer readings you can again send TRACe DATA to retrieve all the stored readings The data elements returned with each stored reading depends on which ones are selected with FORMat ELEMents command see Section 14 for details TRACe DATA SELected start lt count gt Specify readings to return TRACe NEXT Query location of last buffer reading Use the TRACe DATA SELected command to specify which stored readings to return The lt start gt parameter specifies th
397. nts command see Section 14 is used to include the reading number RNUM element in each data array SENS 1 DATA FRESh This command is similar to DATA L Test in that is also returns the last processed data array stored in the buffer However it can only be used once to retrieve the same data array That is the data array reading must be fresh Sending this command again to read the same stale data array will not work It will generate an error 230 data corrupt or stale or cause the Model 2701 to time out In order for DATA FRESh to respond you must first trigger a new fresh reading Using this command to retrieve data ensures that only new fresh readings are returned no readings are repeated However as previously noted problems may occur if a new reading is not ready available when this command is executed D 10 Signal Processing Sequence and Data Flow Model 2701 User s Manual FETCh READ MFEASure CALC 1 DATA LA Test CALC 1 DATA FRESh As shown in Figure D 4 these commands are used to read data arrays output from the CALCI Math block However if there is no math function enabled these commands read the data arrays in the sample buffer NOTE For more information on FETCh READ and MEASure see Section 13 SCPI Signal Oriented Measurement Commands FETCh With no math function enabled this command reads the data arrays stored in the sample buffer If for example there are 20 data
398. o Chan Average Delay O utput Trigger Device Action M easurement Process 7 6 Scanning Model 2701 User s Manual Figure 7 2 Trigger model with SCAN function Enable Scan Close First Chan in List No Yes Another Trigger Control Event Source Detection Scan Counter Immediate External Timer Manual imer O utput vk Timer gt Dela No y Yes Sample Counter Delay Auto or M anual O pen Last Chan Close N ext Chan Ratio Chan in List Average Delay Device Action M easurement Process Remote programming only Model 2701 User s Manual Scanning 7 7 STEP operation overview When the STEP key is pressed the Model 2701 leaves the idle state closes the first channel and waits for the programmed trigger event After the trigger is detected the instrument may be subjected to one or more delays before performing the measurement After a reading is taken and stored in the buffer the Model 2701 outputs a trigger pulse opens the closed channel and then closes the next channel in the scan list The instrument then waits for another trigger event to measure the channel After the last channel is scanned the instrument returns to the idle state with the first channel in the scan list closed SCAN operation overview When the SCAN key is pressed the Model 2701 leaves the idle state closes the first channel and waits for the programmed trigger event After the trigger i
399. o reset reading number Sec 14 RESet Reset reading number Next reading will be 1 ERRor Query Error Queue Note 3 Sec 11 Clears messages from the Error Queue Sec 11 VERSion Query rev level of SCPI standard Sec 14 v LOCal Take 2701 out of remote and restore operation of front panel controls REMote Place 2701 in remote RWLock Lockout front panel controls RESet Immediately reboots the 2701 Model 2701 User s Manual SCPI Reference Tables 15 23 Table 15 7 continued SYSTem command summary Default Command Description parameter Ref SCPI SYSTem BOARd PC board SNUMber Acquire serial number of PC board REVision Acquire revision level of PC board BATTery Battery PRESent Is a battery installed 0 no 1 yes STATus Returns OK MEMORY LOST or CHARGING FAILURE Memory is lost when the battery is not installed and upon a reset after a firmware upgrade A charging failure occurs when it is time for a new battery PASS word Password ENABlIe lt b gt Enables or disables the use of password Query password use CDISable password Disables protected commands CENable password Enables protected commands STATe lt b gt Returns 0 if password protected commands are disabled Returns 1 if enabled NEW password Set new password COMMunicate Ethernet and RS 232 commands SELect name ETHernet ADDRess value ADDRess M
400. ocedure shows how to configure a scan channel to use rel 1 While in the normal measurement state select the appropriate function and close the appropriate channel For example if scan channel 101 is going to be configured for DCV and use rel select DCV and close channel 101 2 Apply the DCV signal to be rel ed to the closed channel This could be an offset or a baseline level 3 Press the REL key to enable rel REL annunciator on The input signal level is used as the rel value 4 When configuring the advanced scan as explained in Section 7 select the desired channel press DCV and then press REL REL annunciator on When the channel is scanned rel will enable using the rel value established in step 3 For remote programming the lt clist gt parameter is used to configure channels for a scan 5 4 Rel Math Ratio Channel Average dB Remote programming rel Rel commands Model 2701 User s Manual The rel commands to set range are listed in Table 5 1 Additional information on these commands follow the table NOTE Query commands are not included in Table 5 1 All commands for the SENSe subsystem are provided in Table 15 5 Table 5 1 Rel commands Commands Description Default Rel commands for DCV SENSe 1 Optional root command VOLTage DC REFerence n lt clist gt Specify rel value n 1010 to 1010 0 V VOLTage DC REFerence STATe lt b gt Enable disable rel b 2
401. off transistor switch open to provide a reliable logic high output 23 75V When the output line goes low the transistor turns on transistor switch closed to route current to digital ground As a result a low logic output 0V is provided at the output If the second input B of the NAND gate is connected to another output line of the port the output of the NAND gate will go to logic 0 when both digital outputs are set high Figure 9 5 NAND gate control Model 2701 Logic Device 4 75kQ Pull Up Resistor Control Line Setting digital output The OUTPUT menu shown in Table 9 1 is used to control and configure digital outputs Menu items for the digital output include DOUTPUT Use to enable ON or disable OFF the digital outputs e PULSE Use to enable YES or disable NO the pulse option for the digital outputs NOTE The factory default pulse time is 2ms maximum Using remote programming pulse time can be set from 0 001 to 99999 999 sec It cannot be set from the front panel Model 2701 User s Manual Limits and Digital I O 9 11 LSENSE Use to select the logic sense active HIGH or active LOW With active high selected an output will be at approximately 5V when a reading is at or exceeds the limit Conversely with active low selected an output will be at OV when a reading reaches or exceeds the limit MASTR LATCH Use to enable Y or disable N the master limit latch When enabled the
402. oise window which is expressed as a percentage of range or maximum temperature reading allows a faster response time to large signal step changes e g scanned 4 16 Range Digits Rate Bandwidth and Filter Model 2701 User s Manual readings A reading conversion outside the plus or minus noise window fills the filter stack immediately If the noise does not exceed the selected window the reading is based on the average of the reading conversions If the noise does exceed the selected window the reading is a single reading conversion and new averaging starts from this point The noise window for the two filter types are compared in Figure 4 3 The five window selections from the front panel are 0 01 0 1 1 10 and NONE no window For remote programming the window can be set to any value from 0 01 to 1096 or NONE For voltage current and resistance the filter window is expressed as a percent of range For example on the 10V range a 10 window means that the filter window is 1V For temperature the filter window is expressed as a percent of the maximum temperature reading The maximum temperature depends on which thermocouple is being used For example for a Type J thermocouple the maximum reading is 760 C a 1096 window means that the filter window is 76 C For temperatures below 0 C the overflow point is 200 C so a 10 filter window is 20 C If using F units a 20 filter window is calculated as follows 9 5
403. ok like this 7703 NONE Note that the model number of an installed pseudocard is returned in the same manner See Section 2 for details on pseudocards 12 6 Common Commands Model 2701 User s Manual E SAV NRf save Save present setup in memory RCL lt NRf gt recall Return to setup stored in memory Parameters Memory location 0 0 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 A saved setup is approximately 4k bytes in size Model 2701 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 NOTE OPC or OPC should be used with SAV and RCL which are slow responding commands Details on OPC and OPC are provided in this section Programming example SAV 2 Save present setup in memory location 2 RST Return 2701 to RST defaults RCL 2 Return recall 2701 to setup stored in memo location 2 RST reset Return Model 2701 to RST defaults When the RST command is sent Model 2701 performs the following operations 1 Returns Model 2701 to
404. omatically be stored in the buffer For example with sample count set to 5 the five measured readings will be stored in the buffer If the trigger model is configured to repeat the sample readings i e trigger count 2 those five new readings will overwrite the original five readings in the buffer Model 2701 User s Manual Triggering 8 19 Output Trigger The Model 2701 will send one or more output triggers The output trigger is applied to the Trigger Link connector on the rear panel It can be used to trigger an external instrument to perform an operation The trigger model can be configured to output a trigger after the completion of a series of measurements or after every measurement For example with the sample counter set to 10 and the trigger counter set to one a trigger will be sent after the 10 measurements are performed If instead the trigger counter is set to 10 and the sample counter is set to 1 a trigger will be sent after each measurement Triggering commands Commands for triggering are summarized in Table 8 2 Table 8 2 SCPI commands triggering Commands Description Default Ref ABORt Reset trigger system a INITiate IMMediate Initiate one trigger cycle b INITiate CONTinuous b Enable disable continuous initiation ON or OFF Note 1 c FETCh Request the last reading s d READ Perform an ABORt INITiate and a FETCh d TRIGger SOURce name Select control source IMMediate TIMer MANual IMM e
405. ommands are used to calculate and return buffer statistics see Section 6 for details Model 2701 User s Manual Getting Started 1 41 Exercise 6 Return a single reading continuous triggering Readings can be returned while the instrument is in the continuous measurement trigger mode Each time a read command is sent the latest reading is returned Exercise 6 in Figure 1 10 provides a command sequence to return a single reading while in the continu ous trigger state Figure 1 10 Exercise 6 Return a single reading continuous triggering SAMP COUN 1 Place 2701 in continuous Trigger configuration INIT CONT ON trigger state FETCh i OR Return readings CALC DATA DATA OR DATA FRESh Return result of MATH Return basic reading calculation 2 1 If a MATH function mX B percent or 1 X is enabled the result of the calculation will be returned If there is no MATH function enabled FETCh and CALC DATA will return the basic reading MATH functions are covered in Section 5 2 None of these read commands trigger measurements They simply return the lastest reading If FETCH CALC DATA or DATA is again sent before a new reading is triggered the 3 DATA FRESh can only be used once to return the same reading Sending it again before a new reading is triggered will cause error 230 data corrupt or stale 1 42 Getting Started Model 2701 User s Manual 2 Closing and Opening Swit
406. on FUNC TEMP 101 Configure temperature SHIFT SENSOR Select thermocouple sensor SENS TCOUPLE TEMP TRAN TC 0101 Select type K thermocouple TYPE K TEMP TC TYPE K 101 Select internal reference junction JUNC INT TEMP RJUN RSEL INT 101 b Channel 102 Select 2 function FUNC RES 102 Select 1MQ range RES RANG 1e6 102 c Disable off channels 103 through 122 SHIFT CH OFF ROUT SCAN 8101 102 d Enable immediate scan IMM SCAN Y ROUT SCAN TSO IMM e Disable timer TIMER NO f Set reading count to infinity RDG CNT INF TRIG COUN INF SAMP COUN 2 4 Select external trigger control source Press EX TRIG TRIG SOUR EXT 5 Enable scan Press SCAN ROUT SCAN LSEL INT INIT Model 2701 User s Manual Scanning 7 35 Monitor scan For this example channel 101 of the Model 7700 is used to monitor temperature When the temperature reading reaches 30 C it will start the scan For this 4 channel scan channel 101 measures temperature while channels 102 103 and 104 measure DCV This example uses the channel average feature to measure temperature With channel average enabled two temperature measurements will be taken one at channel 101 and another at its paired channel 111 The two measured readings are then averaged to yield a single reading It is this averaged temperature reading that will start the scan when it reaches 30 C Refer to Section 5 for details on channel a
407. on N A 10 channel pairs 5 channel pairs 20 channel pairs 1 pole Operation 40 channels N A N A N A Measure Volts 300V maximum 300V maximum 300V 300V maximum Measure Amps No No No No Measure Ohms No 2 A wire 2 A wire 2 A wire Thermocouple No Yes No Yes Cold Junction Relay Type Latching electro Latching electro Latching electro Latching electro mechanical 1 male DB 50 lfemale DB 25 Multiplexer 32 digital inputs out puts mechanical Oversized screw terminals Multiplexer All DMM functions except amps Model 2701 User s Manual Table 1 1 continued Model 77xx series switching modules Models 7711 Model 7709 Model 7710 and 7712 2 pole Operation 8 channels 20 channels N A 4 pole Operation 4 channel pairs 10 channel pairs N A 1 pole Operation N A N A 8 channels Measure Volts 300V maximum 60V maximum No Measure Amps No No No Measure Ohms 2 4 wire 2 4 wire No Thermocouple No Yes No Cold Junction Relay Type Latching electro Solid state opto cou High frequency mechanical pled FET electromechanical Connector type 1 female DB 50 3 5mm removable 10 SMA 1 female DB 25 screw terminals Configuration 6 x 8 matrix Multiplexer Multiplexer Unique features Rows 1 amp 2 connect High speed switch 50Q RF dual 1 x 4 to DMM system ing and long life multiplexer channel operation relays Max Frequency 7111 2GHz 7112 3 5GHz seconds 2 All multiplexers can be confi
408. on the Model 2701 places it at point A in the flowchart where it is waiting for an external trigger B Pressing STEP on the Model 7002 takes it out of the idle state and places operation at point B in the flow chart C For the first pass through the model the scanner does not wait at point B for a trigger Instead it closes the first channel 6 14 Triggering Model 2701 User s Manual D After the relay settles the Model 7002 outputs a Channel Ready pulse Since the instrument is programmed to scan 400 channels operation loops back up to point B where it waits for an input trigger E amp F Model 2701 operation is at point A waiting for a trigger The output Channel Ready pulse from the Model 7002 triggers the Model 2701 to measure DUT 1 point E After the measurement is complete the Model 2701 outputs a comple tion pulse point F and then loops back to point A where it waits for another input trigger The trigger applied to the Model 7002 from the Model 2701 closes the next channel in the scan This triggers the Model 2701 to measure the next DUT The process continues until all 400 channels are scanned measured and stored in the buffer External triggering with BNC connections An adapter cable is available to connect the micro DIN Trigger Link of the Model 2701 to instruments with BNC trigger connections The Model 8503 DIN to BNC Trigger Cable has a micro DIN connector at one end and two BNC connectors at the other end
409. ons Before removing or installing the switching module in the mainframe make sure the Model 2701 is turned off and disconnected from line power Before making or breaking connections to the switching module make sure power is removed from all external circuitry Donotconnect signals that will exceed the maximum specifications of the Model 7700 Specifications are provided in Appendix A If both the front panel terminals and the switching module terminals are connected at the same time the test lead insulation must be rated to the highest voltage that is connected For example if 1000V is connected to the front panel input the test lead insulation for the switching module must also be rated for 1000V Dangerous arcs of an explosive nature in a high energy circuit can cause severe personal injury or death If the multimeter is connected to a high energy circuit when set to a current range low resistance range or any other low impedance range the circuit is virtually shorted Dangerous arcing can result even when the multimeter is set to a voltage range if the minimum voltage spacing is reduced in the external connections For details to safely make high energy measurements see High energy circuit safety precautions in Section 3 As described in the International Electrotechnical Commission IEC Stan dard IEC 664 the Model 2701 is Installation Category I and must not be connected to mains Figure B 2 shows how to access
410. ope n input lead The hardware detector uses a comparator circuit to monitor the voltage on the Input Hi terminal Open circuit voltage on the Input Hi terminal is either 6 6V or 12 8V depending on the selected measurement range see resistance specifications in Appendix A When an input lead Hi or Lo is open as shown in Figure 3 12B voltage rises to the open circuit level which trips the OVRFLW message 10M Q and 100MQ ranges For the two highest ohms ranges open input lead detection is implemented in software Open circuit voltage for the 10MQ and 100MQ ranges is 7V For the 10MQ range the OVRFLW message trips when the open circuit voltage rises to approximately 3 5V For the 1OOMQrange the OVRFLW message trips when the open circuit voltage rises to approximately 6 5 V Open sense lead detection 100 through 1MQ ranges For the 4 function the sense leads must be connected to the DUT As shown in Figure 3 10B the sense leads connect the voltmeter of the Model 2701 to the DUT In general if a test lead for the voltmeter is open the reading on the Model 2701 will randomly drift due to the high impedance circuitry of the voltmeter If this were allowed to happen for the function erroneous ohms readings would be displayed To prevent erroneous ohms readings caused by an open sense lead the Model 2701 implements software to detect an open sense lead As shown in Figure 3 12A with all test leads properly connected
411. operation NOTE _ fusing switching module inputs make sure the front panel INPUTS switch is set to the REAR position in If using the front panel inputs the switch must be in the FRONT position out 1 Select the desired measurement function and an appropriate range setting 2 Apply the signal to be relayed to a switching channel input or to the front panel inputs NOTE For the Model 7700 switching module channels 21 and 22 are available for DCI and ACI Channels 1 through 20 are available for all other functions Model 2701 User s Manual Rel Math Ratio Channel Average dB 5 3 3 If using a switching module use the or key to select close the input channel If using the front panel inputs FRONT inputs selected it does not matter if a switching channel is closed 4 Press the REL key to set the rel value The display will zero and the REL annunciator will turn on 5 Apply the signal to be measured Pressing REL a second time disables rel You can input a rel value manually using the mX b function Set M for 1 and B for any value you want The mX b function is covered in this section see Math page 5 7 Scanning When a simple scan is configured the present rel setting will apply to all channels in the scan When an advanced scan is configured each channel can have its own unique rel setting Details to configure and run a scan are provided in Section 7 For an advanced scan the following general pr
412. opic summarizes the following basic instrument operations and provides simple exercises to perform them Basic DMM measurements front panel inputs Closing and opening channels system channel operation Simple scanning Trigger and return readings remote programming NOTE For remote operations you can use the internal web page of the Model 2701 to send commands queries and take readings See Internal web page in Section 10 for details Also supplied TestPoint Runtime start up software can be used to control the Model 2701 See Section 4 in the Model 2701 Instrument Networking Instruction Manual for details WARNING For the exercises it is not necessary to connect an input signal DUT to the instrument front panel inputs or switching module inputs However if you decide to use an input signal it is recommended that you keep it at a nonhazardous level 42V while learning to use the instrument NOTE When using the front panel input terminals the INPUT switch must be in the F out position The INPUT switch is located on the right side of the front panel near the input terminals When using a switching module the switch must be in the R in position Model 2701 User s Manual Getting Started 1 29 Basic DMM measurements front panel inputs NOTE See Section 3 for details on basic DMM operation The Model 2701 is shipped from the factory to power up to factory defaults The instru me
413. or SLOW turns on NOTE The Model 2701 uses internal references to calculate an accurate and stable reading When the NPLC setting is changed each reference must be updated to the new NPLC setting before a reading is generated Therefore frequent NPLC setting changes can result in slower measurement speed Bandwidth Bandwidth specifies the lowest frequency of interest for AC measurements The RATE setting determines the bandwidth setting SLOW 3Hz to 300kHz e MEDium 30Hz to 300kHz FAST 300Hz to 300kHz When the Slow bandwidth 3Hz to 300kHz is chosen the signal goes through an analog RMS converter The output of the RMS converter goes to a fast 1kHz sampling A D and the RMS value is calculated from 1200 digitized samples 1 25 When the Medium bandwidth 30Hz to 300kHz is chosen the same circuit is used However only 120 samples 120ms are needed for an accurate calculation because the analog RMS converter has turned most of the signal to DC In the Fast bandwidth 300Hz to 300kHz the output of the analog RMS converter nearly pure DC at these frequencies is simply measured at 1 PLC 16 6ms For remote programming the integration rate can be set from 0 002 PLC to 50 or 60 PLC Table 4 4 lists the front panel bandwidth settings for the AC measurement functions For remote programming the FAST MED and SLOW annunciators are only lit when conditions in the table are met In other cases the annunciators are
414. or keys 4 and gt are used to display menu items and options and set parameter values With the desired item option or setting displayed press the ENTER key to select it You can cancel a pending selection and exit the menu structure by pressing the EXIT key Press the SHIFT key and then the CARD key to display the CARD menu The Card menu tree is shown in Figure 2 11 The items and options of the menu are explained as follows NOTE Identifying installed modules If you simply want to identify installed modules or pseudocards select CONFIG or VIEW and use the and key to check each slot When finished press EXIT Model 2701 User s Manual Close Open Switching Module Channels 2 31 Figure 2 11 CARD menu tree SLOT1 77XX SLOT2 77XX SLOT1 77XX SLO T2 77XX Scrolls Scrolls Channels Channels CARD CONFIG This menu item is used to configure switching modules The channels of the Model 7700 switching module and other similar type modules do not need to be configured SLOTX 77XX Use to configure the switching module in Slot X where X 1 or 2 If configuration is not necessary the instrument will exit from the menu when ENTER is pressed 77XX Model number of installed switching module NOTE For switching modules that require configuration refer to packing list that was shipped with each module CARD VIEW This menu item is used to view all analog input channels that are presently close
415. or scan opera tion and includes a simple scanning programming example Also summarizes vari ous aspects of remote scan operation Scanning examples Provides a couple of typical scan operation examples front panel and remote programming 7 2 Scanning Model 2701 User s Manual Scanning fundamentals The Model 2701 can scan the channels of up to two installed Keithley switching modules Each scan channel can have its own unique setup Aspects of operation that can be uniquely set for each channel include function range rate AC bandwidth rel filter digits math Q offset compensation TEMP transducers limits channel average channel ratio and volts dB NOTE Readings for scanned channels are automatically stored in the buffer With buffer auto clear enabled which is the default the buffer clears when the scan is started When disabled scan readings are appended to the buffer The TRACe CLEar AUTO b command is used to enable disable buffer auto clear Section 6 A pseudocard can be installed in an empty slot With the 7700 pseudocard installed the instrument will operate as if a Model 7700 switching module is installed in the slot This allows the user to configure a scan and exercise its operation before the switching module is installed in the Model 2701 Use the following commands to install 7700 pseudocards in empty slots SYSTem PCARd1 C7700 Install 7700 pseudocard in slot 1 SYSTem PCARd2 C7700 Install
416. ord SYSTem PASSword ENABle ON Enable password NOTE The password can also be enabled or disabled from the Model 2701 s internal web page see Internal web page page 10 16 Disable protected commands This places the Model 2701 in the password protected mode In this mode the only commands that can be sent are the ones listed in Note 2 at the bottom of Table 10 1 Example using DEFAULT as the password SYSTem PASSword CDISable DEFAULT NOTE Ifthe password is disabled sending the CDISable command automatically enables the password and then places the Model 2701 in the password protected mode Model 2701 User s Manual Remote Operations 10 5 Enable protected commands This takes the Model 2701 out of the password protected mode Example using DEFAULT as the password SYSTem PASSword CENable DEFAULT e Query the password protection state enabled or disabled Example SYSTem PASSword CENable STATe Change the password The password is case sensitive and can include non ASCII characters from 1 to 255 Make sure to enclose the password in quotes Example to change password to INTEGRA SYSTem PASSword NEW INTEGRA NOTE The password can be changed from the Model 2701 5 internal web page see Internal web page page 10 16 NOTES 1 Sending a password protected command causes error 203 command protected 2 Using an incorrect password in a password command causes error 221 settings co
417. ors 5 2 Rel Math Ratio Channel Average dB Model 2701 User s Manual Relative The rel relative function can be used to null offsets or subtract a baseline reading from present and future readings When rel is enabled the instrument uses the present reading as a relative value Subsequent readings will be the difference between the actual input value and the rel value You can define a rel value for each function Once a rel value is established for a measurement function the value is the same for all ranges For example if 50V is set as a rel value on the 100V range the rel is also 50V on the 1000V 10V 1V and 100mV ranges Therefore when you perform a zero correction by enabling REL the displayed offset becomes the reference value Subtracting the offset from the actual input zeroes the display as follows Actual Input Reference Displayed Reading A rel value can be as large as the highest range Selecting a range that cannot accommodate the rel value does not cause an overflow condition but it also does not increase the maximum allowable input for that range For example on the 10V range the Model 2701 still overflows for a 12V input NOTE The various instrument operations including Relative are performed on the input signal in a sequential manner See Signal processing sequence page D 2 for details It includes flowcharts showing where in the processing sequence that the Rel operation is performed Basic
418. ot auto scan configuration will disable and an interrupted scan will not be resumed Error 517 occurs cannot resume scan to indicate that the scan has been disabled The instrument assumes the normal power on setup The Model 7706 does not support auto scan Trying to enable auto scan with a Model 7706 card installed will cause error 221 settings conflict Scan operation A basic scan is controlled solely by the STEP and SCAN keys When one of these keys is pressed the STEP or SCAN operation will be performed For the manual external trigger scan the TRIG key or triggers received from another instrument starts the STEP or SCAN operation For the monitor scan a channel monitors readings When a set reading limit is reached STEP or SCAN will start 7 22 Scanning Basic scan Model 2701 User s Manual Perform the following steps to run the presently configured scan 1 2 NOTE 6 Buffer To start the scan press STEP or SCAN The STEP or SCAN annunciator turns on and channels are scanned from the lowest to highest number channel Channels that are turned off will not be scanned Keep in mind that the Timer Delay for STEP occurs between channels while the Timer Delay for SCAN occurs between scans If the timer is off both scans will run at virtually the same speed With reading count set to a finite value the last channel scanned will open and the first channel in the scan list will close Keep in mind that the scan is
419. other Trigger Event Detection Control Source Trigger Count lt n gt IN Finity Output Trigger Trigger Source Immediate Trigger Source External Trigger Source Timer Trigger Source Manual Trigger Source BUS Timer Enabled Delay Auto or M anual Sample Count n Trigger D elay n Trigger D elay AUTO lt b gt Device Action 8 18 Triggering Model 2701 User s Manual Trigger model operation Once the instrument is taken out of idle operation proceeds through the trigger model down to the device action In general the device action includes a measurement and when scanning closes the next channel Control Source As shown in Figure 8 10 a control source is used to hold up operation until the programmed event occurs The control source options are as follows IMMediate Event detection is immediately satisfied allowing operation to continue MANual Event detection is satisfied by pressing the TRIG key The Model 2701 must be in LOCAL mode for it to respond to the TRIG key Press the LOCAL key or send SYSTem LOCal via the Ethernet or RS 232 to remove the instrument from the remote mode TIMer With the timer source enabled selected event detection is immediately satisfied On the initial pass through the loop the Timer Bypass is enabled allow ing operation to bypass the Timer and continue on to the Delay block On
420. ount is greater than the scan list length operation loops back to the beginning of the scan list and continues After a scan sequence as determined by the reading count is completed the scan remains enabled STEP annunciator on but the Model 2701 goes into the idle state If you wish to repeat the scan sequence you will have to first take the Model 2701 out of idle This can be done by pressing the STEP or TRIG key SCAN operation In general when the Model 2701 is triggered a complete scan of all the channels in the scan list is performed When the SCAN key is pressed to enable the scan the first channel in the scan list closes When a trigger occurs one scan of the scan list channels is performed After the last channel is scanned the first channel in the scan list will close Reading count determines how many scans will be performed see Trigger models page 7 4 If programmed for another scan it will start when another trigger occurs After the last scan is completed the scan remains enabled SCAN annunciator on but the Model 2701 goes into the idle state If you wish to repeat the scans you will have to first take the Model 2701 out of idle This can be done by pressing the SCAN or TRIG key 5 When finished press SHIFT and then HALT to disable the scan and press EX TRIG to take the Model 2701 out of the external triggering mode 7 24 Scanning Model 2701 User s Manual Monitor scan analog trigger A channel
421. p do not match the switching module types presently installed in the Model 2701 error 520 Saved setup scancard mismatch occurs when the setup is recalled The scan list will reset to the factory defaults and all channels will open However the saved setup is still retained in memory and can be restored when the matching switching module is later installed Model 2701 User s Manual Getting Started 1 23 Table 1 4 Default settings Setting Factory RST Set Diff Auto channel configuration No off No effect Autozero On On Buffer No effect No effect Auto clear Yes on No effect Channel Average Off Off Closed channels None None Closure count interval No effect No effect Continuity Beeper On On Digits 41 digits 41 digits Range 1kQ 1kQ Rate Fast 0 01 PLC Fast 0 01 PLC Threshold level 10Q 10Q Current AC and DC Bandwidth AC 30 30 Digits AC 51 digits 51 digits Digits DC 61 digits 61 digits Filter On Off Window 0 1 0 1 Count 10 10 Type Moving Repeat v Range Auto Auto Rate DC Slow 5 PLC Slow 5 PLC Rel Off Off Ethernet settings IP address No effect No effect Subnet No effect No effect Gateway No effect No effect MAC No effect No effect Frequency and Period Digits 6 digits 6 digits Range 10V 10V Rate aperture 1 second 1 second Rel Off Off Function DCV Keyclick On On 1 24 Getting Started Table 1 4 continued Model 2701 User s Manual Default settings
422. pended to the old group of readings However the relative timestamps for the new readings will be referenced to 0 sec When recalling stored readings from the front panel both absolute and delta timestamps are provided For remote operation the absolute or delta timestamp is returned with each buffer reading The TRACe TSTamp FORMat command selects the relative timestamp type Table 6 1 Real time clock timestamp With the real time clock selected each stored reading is timestamped with the time and date For the time the seconds reading has 0 01 sec resolution Configuring timestamp Setting time and date For the real time clock the time and date is set at the factory However you can check and correct the time and date as follows Perform the following steps to set the time 1 Press SHIFT and then SETUP 2 Usethe and keys to display SET TIME and press ENTER The displayed clock will be running in the hour minute second AM PM format 3 Use the edit keys 4 gt a and to set the hour minute and AM PM seconds cannot be set and press ENTER Model 2701 User s Manual Buffer 6 5 Perform the following steps to set the date 1 Press SHIFT and then SETUP 2 Use the and keys to display SET DATE and press ENTER to display the date in the month day year format 3 Use the edit keys 4 gt a and to set the date month day year and press ENTER Selecting timestamp Perform the following steps
423. per connections are made instrument chassis is connected to power line ground through the ground wire in the power cord Failure to use a grounded outlet may result in personal injury or death due to electric shock 4 Turn on the instrument by pressing the front panel power switch to the on 1 position 1 16 Getting Started Model 2701 User s Manual Figure 1 3 Power module Model 2701 WARNING NO INTERNAL OPERATOR SERVICABLE PARTS SERVICE BY QUALIFIED PERSONNEL ONLY Link Act__100bT CComme A eume DIGITAL I O TRIGGER ETHERNET RS232 EXT TRIG LINK 10 100 BaseT KEITHLEY SLOT COVER CONTINUED PROTECTION AGAINST FIRE HAZARD REPLACE FUSE WITH SAME TYPE AND RATING Spring Window Fuse Holder Assembly Line frequency The Model 2701 will operate at line frequencies from 45Hz to 66Hz and 360Hz to 440Hz There are no user settings for line frequency It is automatically sensed at power up The following command can be used to read the line frequency SYSTem LFRequency Query power line frequency Setting line voltage and replacing fuse A rear panel fuse located next to the AC receptacle protects the power line input of the instrument If the line voltage setting needs to be changed or the line fuse needs to be replaced perform the following steps WARNING Make sure the instrument is disconnected from the AC line and other equipment before changing the line voltage setting o
424. ple 9 14 Application sorting resistors 9 14 ss iioii feeit RPM pe b d edi iE 9 14 Digital outputs ene eene e REEL Sei Pe ERE Pe e egets 9 17 10 Remote Operations sss 10 1 Operation enhancements sssssssssssssssee eee nnne nnne 10 2 PSeudoCards nadie 10 2 inaudita ede Sl eed genie ea lee due 10 2 dB calc lations 2 5 3 2 ruit i rii tO erben eie p 10 2 Document Number 2701 900 01 Rev F August 2011 V Table of Contents Model 2701 Ethernet Based DMM Data Acquisition System Separate function setups 10 3 DGV input divider cimeira uinen tede rite dietro Dip dee 10 3 Multiple channel 10 3 System comrmiands noir reete rette qe be de ce vt dapi te er a ka 10 3 Interfaea oi o t Fe Eri i rii bet 10 3 oin costae ele P ease Gite a At etl Pe pee nva 10 4 Battery me iio eibi M C D CERTE 10 5 Miscellaneous system commands 10 6 Ethernet set p eec decre re tenet edet dne eee 10 7 Ethernet standards 10 7 Typical Ethernet systems essen 10 7 Ethernet connections cccececcceceeeeeeceeeeteseeceeeeeeseeceeeeeneneeeeeeeneneees 10 10 Ethern
425. query is fully capable of returning meaningless old data When appropriate If for some reason the user wanted the last completed reading even after changing ranges or other measurement settings which would invalidate the old reading The CALC DATA LATest query is similar to the DATA LAT query but applies to readings that have math applied to them e g M X4 B scaling Examples One shot reading DC volts no trigger fastest rate RST SENSe FUNCtion VOLTage DC SENSe VOLTage DC RANGe 10 Use fixed range for fastest readings SENSe VOLTage DC NPLC 0 002 Use lowest NPLC setting for fastest readings DISPlay ENABle OFF Turn off display to increase speed SYSTem AZERO STATe OFF Disable autozero to increase speed but may cause drift over time SENSe VOLTage DC AVERage STATe OFF Turn off filter for speed READ Enter reading One shot reading DC volts bus trigger auto ranging RST TRIGger SOURce BUS SENSe FUNCtion VOLTage DC SENSe VOLTage DC RANGe AUTO ON INITiate TRG Triggers reading SENSe DATA FRESh Enter reading 3 62 Basic DMM Operation Model 2701 User s Manual One shot reading external trigger auto delay enabled RST TRIGger SOURce EXTernal TRIGger DELay AUTO ON Note Auto trigger delay only takes effect with trigger source set for BUS or EXTernal SENSe FUNCtion VOLTage DC SENSe VOLTage DC RANGe AUTO ON
426. r if a storage is in process If no storage is in process changing the timestamp will not clear the buffer SYSTem TSTamp TYPE and TRACe TSTamp TYPE Both of these commands query the timestamp type However SYSTem TSTamp TYPE queries the timestamp that will be used for the next storage operation while TRACe TSTamp TYPE queries the timestamp for readings that are presently stored in the buffer TRACe CLEar Clear the buffer TRACe CLEar AUTO ONI OFF Control on off buffer auto clear TRACe CLEar Used to clear the buffer Buffer readings are not lost cleared when the Model 2701 is turned off When TRAC CLE is sent while displaying stored readings the message BUF CLEARED is briefly displayed and the instrument returns to the normal measurement state TRACe CLEar AUTO With auto clear enabled the buffer will automatically clear when the storage process starts When disabled readings will append to old readings in the buffer until the buffer becomes full 450 000 readings or the storage process is stopped Disabling auto clear automatically sets the buffer size to 450 000 TRACe FREE Query status of storage memory Returns two values separated by commas The first value indicates in bytes memory available for storage while the second value indicates the number of bytes being used for stored readings Model 2701 User s Manual Buffer 6 11 f TRACe POINts lt NRf amp gt Set buffer size 2 to 450000 TRACe POINt
427. r replacing the line fuse 1 Place the tip of a flat blade screwdriver into the power module by the fuse holder assembly Figure 1 3 Gently push in and up Release pressure on the assembly and its internal spring will push it out of the power module Model 2701 User s Manual Getting Started 1 17 2 Remove the fuse and replace it with the type listed in Table 1 2 CAUTION For continued protection against fire or instrument damage only replace fuse with the type and rating listed If the instrument repeat edly blows fuses locate and correct the cause of the trouble before replacing the fuse 3 Ifconfiguring the instrument for a different line voltage remove the line voltage selector from the assembly and rotate it to the proper position When the selector is installed into the fuse holder assembly the correct line voltage appears sideways in the window 4 Install the fuse holder assembly into the power module by pushing it in until it locks in place Table 1 2 Fuse ratings Line voltage Fuse rating Keithley P N 100 120V 0 630A 250V 5 x 20 mm slow blow FU 106 630 220 240V 0 315A 250V 5 x 20 mm slow blow FU 106 315 Power up sequence NOTE lfa problem develops while the instrument is under warranty return it to Keithley Instruments Inc for repair A short description of any displayed error messages are provided in Appendix C NOTE The entire power up cycle takes approximately
428. r settings click Update Settings in order to save the informaiton see Figure 10 9 NOTE Ifyou change the Ethernet settings and they conflict with the PC you will lose the connection to the Model 2701 Ethernet settings for the Model 2701 can be fixed from the front panel Interactive control panel The control panel allows the user to control the Model 2701 You can send commands and queries Readings responses to queries and error messages are displayed in the control panel Details on using the control panel are provided in Figure 10 10 10 18 Remote Operations Model 2701 User s Manual Figure 10 9 Model 2701 Configuration internal web page KEITHLEY A GREATER MEASURE OF CONFIDENCE Instrument Information Firmware Version D01 Calibration Date 2010 06 16 Display Version A02 Calibration Count 1 Serial Number 1241389 Calibration Due Date 2011 06 16 Installed Cards Slot 1 Card Slot 2 Card Card Type NONE Card Type NONE Firmware Revision N A Firmware Revision N A Serial Number N A Serial Number N A Calibration Date N A Calibration Date N A Calibration Count N A Calibration Count N A Network Settings Instrument Settings IP Address 10 90 6453 Date 201007719 Subnet Mask 255 255 255 0 Milano 15 48 05 Gateway 10 80 64 1 Enable Password Yes 9 Ne MAC Address 00 60 14 00 7B 4C Enter New Password IP Mode DHCP Mode 9 Static ip Re Enter Password Update Settings Model 2701 U
429. r the Model 7700 switching module is provided in Appendix B For all other switching modules connection informa tion is provided in their respective packing lists NOTE For maximum system performance it is recommended that all measurement cables be limited to less than 3 meters Pseudocards Using remote programming you can assign a pseudocard to an empty switching module slot With a pseudocard installed the Model 2701 will operate as if the switching module is installed in the Model 2701 This feature allows you to configure your system without having the actual switching module installed in the unit There is a pseudocard for every Keithley Model 77xx series switching module For details see Pseudocards page 2 6 Identifying installed switching modules On power up the model numbers of installed switching modules are displayed briefly If a Model 7700 7701 7702 7703 7705 7708 7709 7710 7711 or 7712 switching module is removed while the Model 2701 is on the instrument will operate as if the module is installed That is the Model 2701 will operate as if the pseudocard is installed NOTE Ifa Model 7706 or 7707 is removed while power is on error 523 Card hard ware error will occur and the module will be removed from the system In gen eral it is not recommended to install or remove switching modules with the power on The CARD menu and remote query commands can be used to identify modules installed in the main
430. rameter values for the various commands used to program enable registers The actual commands are covered later in this section A command to program an event enable register is sent with a parameter value that determines 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 11 2 indicate the binary parameter value For example if you wish to sets bits B4 B3 and B1 the binary value would be 11010 where B4 1 B3z1 B1 1 and all other bits are 0 When you use one of the other formats convert the binary number to its decimal hexadecimal or octal equivalent Binary 11010 Decimal 26 Hexadecimal 1A Octal 32 Note that Figure 11 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 164 842 26 Figure 11 2 16 bit status register A Bits 0 through 7 Decimal Weights B Bits 8 through 15 Decimal 16384 8192 4096 2048 1024 512 256 Weights 214 213 212 211 219 29 28 By SCPI standard definition B15 is not used The bit is always 0 11 6 Status Structure Model 2701 User s Manual The lt NDN gt non decimal numeric parameter type is used to send non decimal values These values
431. ration SE 611 Questionable temperature SE 700 Invalid function in scanlist EE 800 RS 232 Framing error detected EE 802 RS 232 Overrun detected EE 803 RS 232 Break detected EE 805 Invalid system communication EE 808 ASCII only with RS 232 EE 900 Internal system error EE EE error event SE status event SYS system error event C 7 NOTE SCPI confirmed messages are described in Volume 2 Command Reference of the Standard Commands for Programmable Instruments Refer to the SYSTem ERRor command C 8 Status and Error Messages Model 2701 User s Manual signal Processing Sequence and Data Flow D 2 Signal Processing Sequence and Data Flow Model 2701 User s Manual Sienal processing sequence Basic signal processing The signal is applied to the multimeter input via front panel input terminals or a switching module When a channel is closed or scanned the signal connected to that channel or channel pair for 4 wire measurements is connected to the input Figure D 1 is a flowchart that shows the basic processing sequence of an input signal With all the various features filter rel math ratio channel average buffer etc of the Model 2701 disabled the input signal is conditioned and measured A D conversion process The reading is then displayed on the Model 2701 Based on the selected measurement function and range signal conditioning transforms the input signal into a DC voltage that is applied to the A
432. ration enabled a closed channel assumes the scan list setup With this feature you can inspect the channel setups of the scan or manually scan channels When a scan channel is disabled not in scan list it cannot be closed with auto channel configuration enabled As with normal operation when you use lt gt or CLOSE to close a channel or channel pair any other closed channels are first opened Perform the following steps to enable or disable auto channel configuration 1 2 4 Press SHIFT and then SETUP Use the or key to display the auto configuration CH AUTOCFO setting N no or Y yes Press the key to place the cursor on the present setting N or Y and press the aor key to change the setting Press ENTER to return to the normal measurement state NOTES Auto channel configuration cannot be enabled if there is a non scan channel presently closed For example assume the scan list consists of channels 105 through 110 and channel 101 a non scan channel is presently closed When you attempt to enable auto channel configuration from the front panel the message NOT IN SCAN is briefly displayed For remote operation error 221 settings conflict occurs With auto channel configuration enabled the 4 and keys will not properly step through a non sequential scan list Therefore auto channel configuration should not be used for a non sequential scan list For information on non sequential sca
433. rce Caution Maximum 300V peak or RMS 8 x 10 V Hz 3 46 Basic DMM Operation Model 2701 User s Manual Frequency and period measurement procedure NOTE Make sure the INPUTS switch is in the correct position To use front panel inputs it must be in the F out position For switching modules it must be in the R in position 1 Ifa switching channel is presently closed displayed press OPEN to open it 2 Perform one of the following steps to select the function e Press FREQ to perform frequency measurements e Press SHIFT and then FREQ to perform period measurements 3 Use the RANGE and keys to select a measurement range consistent with the expected AC voltage Details on range are provided in Section 4 4 Apply the AC voltage s to be measured CAUTION Do not apply more than the maximum input levels indicated in Figure 3 17 and Figure 3 18 or instrument damage may occur 5 Ifusing a switching module perform the following steps to close the desired channel a Press the CLOSE key b Use 4 gt and to key in the channel number and press ENTER The previously closed channel if there is one will open and the specified channel will close NOTE While in the normal measurement state you can use the 4 and keys to close channels In general each key press will open the presently closed channel and then close the next higher or lower channel 6 Observe the displayed reading If the OVERFLOW
434. re a numeric parameter n can also use the DEFault MINimum and MAXimum parameters for the query form These query forms are used to determine the RST default value and the upper and lower limits for the fundamental command Examples are TRIGger TIMer DEFault Queries the RST default value TRIGger TIMer MINimum Queries the lowest allowable value TRIGger TIMer MAXimum Queries the largest allowable value Case sensitivity Common commands and SCPI commands are not case sensitive You can use upper or lower case and any case combination Examples RST rst DATA data SYSTem PRESet system preset Long form and short form versions A SCPI command word can be sent in its long form or short form version The command subsystem tables in Section 15 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 10 24 Remote Operations Model 2701 User s Manual Short form rules Use the following rules to determine the short form version of any SCPI command If the length of the command word is four letters or less no short form version exists Example auto auto These rules apply
435. re only interested in bit BO of the status byte it is recommended that your program routine mask out the other bits which may also be set For example STB may return decimal 17 The binary bit pattern for decimal 17 is as follows B7 B6 B5 B4 B3 B2 BI BO 0 0 0 1 O 0 0 STB returns decimal 17 B4 and BO set If in your program you logically AND the above returned binary value with 00000001 you will mask out bits B1 through B7 B7 B6 B5 B4 B3 B2 BI BO 0 0 0 1 O 0 0 STB returns decimal 17 BO and set 0 0 0 0 0 0 O0 Mask to read BO decimal 1 0 0 0 0 0 0 0 1 Result of logic AND operation decimal 1 As shown in the above result for the AND operation when BO is set your program routine will generate a 1 to indicate that RAV is set If BO is not set 0 the AND operation will result in 0 to indicate that RAV is not set Example 3 Read BHF bit of measurement event register The buffer half full bit BHF is read in the same manner that the RAV bit was read in Example 2 The difference being that the BHF bit is enabled not the RAV bit The following example performs 500 measurements and stores them in the buffer NOTE Details on using the buffer is provided in Section 6 Model 2701 User s Manual Status Structure 11 21 While measuring and storing readings the status byte is continuously read to detect when the BHF bit sets This example also shows how to use OPC operation complete
436. require 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 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 0 through 7 Model 2701 User s Manual Reading registers Status Structure 11 7 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 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 example 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 data format for the returned v
437. res 10 1 through 10 4 The simplest system connects a Model 2701 directly to a PC equipped with a NIC Network Interface Card as shown in Figure 10 1 The Ethernet cable can be up to 100 meters in length Figure 10 1 Direct 2701 connection to PC PC with NIC installed Ethernet cross over cable RJ 45 male male SE F Keithley 270 Up to 100 meters 10 8 Remote Operations Model 2701 User s Manual Adding a hub as shown in Figure 10 2 expands the system into a small LAN Local Area Network The hub allows additional Ethernet instruments to be connected to the PC Figure 10 2 Small LAN system using a hub PC with NIC installed RJ 45 Outlet Ethernet Cables 3 RJ 45 male male a To other Ethernet resources Keithley 2701 L Up to 100 meters gt Adding a second NIC in the PC as shown in Figure 10 3 expands the network system and provides improved performance because there is no corporate LAN data traffic on the instrument LAN It also provides additional security between two groups of users Finally Figure 10 4 shows a simplified diagram of a network system using a router or servers Model 2701 User s Manual Remote Operations 10 9 Figure 10 3 Isolated LAN system using two NICs Network Interface Cards PC with two NICs installed RJ 45 Outlet To other Ethernet resources Increased security using dual NICs Ethernet C
438. ressing 2 will exit VIEW and select the 2 function NOTE When a command is received while the display is scrolling the instrument exits from the CARD menu and the command is executed Switching module queries remote operation For remote operation there are commands to identify installed switching modules and channels that are closed There are also commands to acquire general information about the installed modules OPT For remote operation the OPT command can be used to determine which switching modules or pseudocards are installed in the Model 2701 For example assume a Model 7700 is installed in slot 1 and the other slot is empty The following message is the response message for the command 7700 NONE ROUTe CLOSe ROUTe MULTiple CLOSe ROUTe MULTiple CLOSe S TATe lt clist gt These query commands are used to determine closed switching module channels ROUT CLOS is used to return a list of closed measurement channels including the paired channel for 4 wire measurements It will not return non measurement channels For details see Table 2 1 and related reference information ROUT MULT CLOS 1s used to return all closed channels measurement and non measurement For details see Table 2 2 and related reference information ROUT MULT CLOS STAT is used to return the state open or closed of each specified channel A 0 is returned for an open channel and a 1 is returned for a clos
439. rference The following paragraphs discuss the most important of these effects and ways to minimize them NOTE For comprehensive information on low level measurements see the Low Level Measurements handbook which is available from Keithley Thermoelectric potentials Thermoelectric potentials thermal EMFs are small electric potentials generated by differences in temperature at the junction of dissimilar metals The following paragraphs discuss how such thermals are generated and ways to minimize their effects Thermoelectric coefficients As shown in Table E 1 the magnitude of thermal EMFs generated depends on the particular materials involved Best results are obtained with clean copper to copper connections as indicated in the table Table E 1 Material thermoelectric coefficients Material Copper Copper Copper Silver Copper Gold Copper Cadmium Tin Copper Lead Tin Copper Kovar Copper Silicon Copper Copper Oxide Thermoelectric potential 0 20 V C 0 31 V C 0 3u V C 0 3u V C 1 3y V C 40u V C 400p V C 10000 V C Model 2701 User s Manual Measurement Considerations E 3 Thermoelectric generation Figure E 1 shows a representation of how thermal EMFs are generated The test leads are made of the A material while the source under test is the B material The temperatures between the junctions are shown as T and T To determine the thermal EMF generated the following relationship may be u
440. ription parameter Ref SCPI SYSTem PRESet Return to SYST PRES defaults Sec 14 v POSetup lt name gt Select power on setup RST PRESet SAVO Sec 1 SAV1 SAV2 SAV3 or SAV4 POSetup Query power on setup FRS Witch Query INPUTS switch 0 rear front Sec 1 BEEPer Path to control beeper Sec 14 STATe lt b gt Enable or disable beeper ON STATe Query state of beeper v KCLick lt b gt Turn the keyclick on off ON Sec 1 KCLick Query the keyclick status KEY lt NRf gt Simulate key press 1 to 31 see Figure 14 2 Sec 14 v KEY Query the last pressed key AZERo Path to set up autozero Sec 3 STATe lt b gt Enable or disable autozero ON STATe Query autozero LSYNC Path to control line synchronization Sec 3 STATe lt b gt Enable or disable line sync OFF STATe Query state of line sync LFRequency Query power line frequency Sec 1 FRESistance Path to select 4 wire ohms mode Sec 3 TYPEx name Select 4 wire ohms mode NORMal or CSIDe for 7701 installed in slot x x 1or2 TYPEx Query selected 4 wire ohms mode PCARdX lt name gt Set up an empty slot X 1 or 2 asa Sec 2 pseudocard C7700 C7701 C7702 C7703 C7705 C7706 C7707 C7708 C7709 C7710 C7711 C7712 CARDX Path to query switching module in specified slot X slot number for module SNUMber Request serial number SWRevision Request firmware revision VMAX Request maximum allowable voltage
441. rmal pitch beep and the message IN indicates that the resistor is within the 196 tolerance limit Figure 9 7 This 1 resistor belongs in Bin 1 A raspy beep and the 1 message indicates that the resistor is gt 1 tolerance but lt 5 tolerance This 5 resistor belongs in Bin 2 For resistors gt 5 no beep will sound Place these resistors in Bin 3 Remote Operation For remote operation make sure both Limit 1 and Limit 2 are enabled The following table evaluates the three possible pass fail combinations for this example Limit 1 result Limit 2 result Resistor tolerance Bin assignment Pass Pass 196 1 Fail Pass 5 2 Fail Fail gt 5 3 Keep in mind that a fail condition must be reset before testing the next resistor Fail can be reset manually or automatically see Table 9 2 CLEar command Model 2701 User s Manual Limits and Digital I O 9 17 Digital outputs With the digital outputs of the Model 2701 enabled the digital outputs will respond as follows for each resistor reading Resistor Affected LO limit 2 LO limit 1 HI limit 1 HI limit 2 tolerance bin outputs Pass Pass Pass Pass 1 1 None Pass Fail Pass Pass 5 2 1 and 5 Pass Pass Fail Pass 596 2 2 and 5 Fail Fail Pass Pass gt 5 3 1 3 and 5 Pass Pass Fail Fail gt 5 3 2 4 and 5 Affected outputs are pulled or pulsed high or low when a limit test fails 9 18 Limits and Digital I
442. rocal 1 X math function 5 10 Configuration 5 10 Reference junctions 3 34 External 3 35 Internal 3 35 Simulated 3 34 Registers Bit descriptions 11 11 Clearing 11 4 Condition 11 17 Event 11 18 Event enable 11 18 Measurement event 11 14 Operation event 11 13 Questionable event 11 16 Service request enable 11 9 Standard event 11 11 Status byte and SRQ see Status byte and service request SRQ Status byte register 11 8 Status register sets 11 2 11 10 Relative 5 2 Basic operation 5 2 commands 5 4 Pressing REL using rel commands 5 6 Programming examples 5 6 Remote programming 5 4 Scanning 5 3 Setting rel values 5 6 Relative Math Ratio Channel Average and dB 5 1 Relay closure count 2 34 Reading relay closure count 2 35 Setting count update interval 2 35 Remote operations 10 1 Enhancements 10 2 Remote programing Limits and digital output 9 12 Remote programming Autozero and LSYNC 3 6 Basic measurements 3 51 Buffer 6 8 dB 5 20 Default and user setups 1 26 Digits 4 6 Display 1 19 Filter 4 20 Information 1 27 Math 5 12 Multiple channel control commands 2 20 Range 4 4 Rate and bandwidth 4 11 Ratio and channel average 5 18 Rel 5 4 Scanning 7 26 System channel control commands 2 12 Trigger and return readings 1 38 Triggering 8 16 Resistance measurements 342 and 244 3 20 4 wire common side CSID ohms 3 32 Connections 3 20 Cable leakage 3 23 Front panel inputs 3 20 Model 7700 switching module 3 22 Shielding 3 22
443. rror EE 427 1k 4 w zero error EE 428 10 2 w zero error EE 429 10k 4 w zero error EE 430 10k 4 w ocomp Ion full scale EE 438 Date of calibration not set EE 439 Next date of calibration not set EE 450 100m vac dac error EE 451 1 vac dac error EE 452 10 vac dac error EE 453 100 vac dac error EE 454 100m vac zero error EE 455 100m vac full scale error EE C 5 C 6 Status and Error Messages Table C 1 continued Status and error messages Model 2701 User s Manual Number Description Event 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 1 vac zero error 1 vac full scale error 1 vac noise error 10 vac zero error 10 vac full scale error 10 vac noise error 100 vac zero error 100 vac full scale error 750 vac zero error 750 vac full scale error 750 vac noise error Post filter offset error 1 aac zero error 1 aac full scale error 3 aac zero error 3 aac full scale error 1V 10Hz amplitude error Frequency gain error 1K Ohm loff Ocomp FS error 10K Ohm loff Ocomp FS error Temperature Cold Cal error Analog output zero error Analog output pos gain error Analog output neg gain error 1k 4 w dckt Ioff zero error 1k 4 w dckt Ion zero error 1k 4 w dckt Ioff full scale error 1k 4 w dckt Ion full sca
444. s can instead be used For example FUNC VOLT AC FUNC VOLT AC Scan configuration When using the lt clist gt command to configure a scan channel the scan channel must first be set to the appropriate function before sending other commands to configure it For example to set scan channel 101 to use offset compensated ohms the following command sequence would be sent FUNC FRES 101 Set scan channel 101 to X4 function FRES OCOM ON 9101 Enable offset compensated ohms for scan channel 101 If scan channel 101 was not first set for the 04 function the following errors will occur for the following operations e Error 221 Settings conflict will occur when trying to enable offset compensated ohms for that channel e Error 700 Invalid function in scanlist will occur when trying to query the state of offset compensated ohms for that channel FRES OCOM ON 9101 Details on scanning are provided in Section 7 FRESistance OCOMpensated b lt clist gt The instrument does not have to be on the function to enable offset compensated ohms When lt is selected offset compensated ohms will be enabled When using the lt clist gt parameter to configure a scan channel for offset compensated ohms that channel must already be set for M If set for another function a settings conflict 221 will occur TEMPerature TCouple RJUNction RSELect name lt clist gt To use the EX
445. s With manual delay selected the user can set the delay period from 0 seconds to 99 hours 99 minutes 99 999 seconds However if you set a delay shorter than the corresponding auto delay period measurement uncertainty increases noisy and or unsettled readings may result NOTE Keep in mind that if the timer control source is selected the Delay period is only in effect for the first pass through the loop Ratio Chan Average Delay With ratio or channel average enabled a delay is typically used to keep the channel relays from cycling too fast The default delay period is 0 5 seconds but can be set from 0 to 999999 999 seconds using remote programming see Section 5 for details Ratio and channel average are covered in Section 5 NOTE The Ratio Chan Average Delay is in addition to the Timer or Delay Auto or Manual That is it occurs after the Timer interval or Delay period elapses Device action The channel measurement process is performed at this block If repeat filter is enabled the filter process is also performed 7 10 Scanning Model 2701 User s Manual Reading count NOTE For both STEP and SCAN the reading count specifies the number of readings to store in the buffer STEP operation The reading count specifies the number of channels to scan This can be equal to less than or greater than the number of channels in the scan list The last scanned channel remains closed If you start the scan again it will start
446. s in the scan When an advanced scan is configured each channel can have its own unique math setup Details to configure and run a scan are provided in Section 7 For remote programming the lt clist gt parameter is used to configure channels for a scan 5 12 Rel Math Ratio Channel Average dB Model 2701 User s Manual Remote programming math Math commands NOTE When measurements are performed the readings are fed to other enabled processing operations including Math Appendix D explains Data flow remote operation page D 7 and the commands used to return Math results The commands to perform math calculations are listed in Table 5 2 Details on these commands follow the table NOTE Queries are not included in Table 5 2 All the math commands are provided in Table 15 5 Table 5 2 Math commands Commands Description Def CALCulate 1 FORMat lt name gt lt clist gt Select calculation lt name gt NONE PERC MXB PERCent or RECiprocal CALCulate 1 KMATh MMFactor lt NRf gt Set mX b m factor lt NRf gt 1 lt clist gt 4294967295 to 4294967295 CALCulate 1 KMATh MBFactor lt NRf gt Set mX b b factor lt NRf gt 0 lt clist gt 4294967295 to 4294967295 CALCulate 1 KMATh MUNits char lt clist gt Set mX b units see Setting mX b x units CALCulate 1 KMATh PERCent lt NRf gt lt clist gt Set reference value for percent lt NRf gt 1 4294967295 to 42949672
447. s Query buffer size TRACe POINts A CTual Query of readings stored in buffer TRACe POINts lt NRf gt With buffer auto clear enabled you can set the buffer to store from 2 to 450 000 readings A buffer size of zero or one is not valid error 222 With buffer auto clear disabled you cannot use this command to set buffer size error 221 because it is fixed at 450 000 NOTE full and 34 buffer full measurement events are not intended to be used with buffer size smaller than four readings TRACe POINts and TRACe POINTs ACTual The POINts command queries the set size of the buffer while POINTs ACTual queries the number of readings presently stored in the buffer g TRACe TSTamp FORMat ABSolute DELta Select timestamp format For front panel operation both timestamp formats absolute and delta can be recalled For remote programming you can only use one timestamp at a time NOTE Changing the timestamp format clears the buffer The timestamp will only be included with a returned buffer reading if it is specified as a data element see FORMat ELEMents h TRACeFEED SENSe CALCulate NONE Select source of readings TRACe FEED CONTrol NEXTI ALWays NEVer Select buffer control TRACe FEED The SENSe parameter selects readings before any enabled mX b Percent or Reciprocal math calculation For the CAL Culate parameter the result of the calculation is stored in the buffer The NONE parameter disables storage i
448. s a 0 open or 1 closed for every channel specified in the clist It is valid for both measurement and non measurement channels For example assume channel 125 is closed and you use this command to query channels 101 104 and 125 clist 9 101 104 125 The response message returns 0 0 1 to indicate that channels 101 and 104 are open and channel 125 is closed Remote programming example multiple channel operation The following example assumes a Model 7700 installed in slot 1 This command sequence connects channel 101 to channel 111 through channel 123 Note that these two closed channels will be internally isolated from the DMM since the backplane isolation channels 124 and 125 will be open NOTE The following example can be run from the KE2700 Instrument Driver using the example named CloseChannels in Table G 1 of Appendix G ROUT OPEN ALL Open all channels ROUT MULT CLOS 101 111 123 Close channels 101 111 and 123 When finished with multiple channel operation it is a good safe practice to open all channels ROUT OPEN ALL 2 22 Close Open Switching Module Channels Model 2701 User s Manual Multiple channel operation anomalies Anomaly 1 When you use multiple channel operation to open the system channel the channel will open but the system channel number will still be displayed on the Model 2701 For details see Anomaly 1 example wrong channel displayed
449. s detected the instrument may be subjected to one or more delays before performing the measurement After a reading is taken and stored in the buffer the Model 2701 opens the closed channel and then closes the next channel in the scan list Operation keeps looping around to measure all channels in the scan list After the last channel in the scan list is measured the Model 2701 outputs a trigger pulse If programmed to again scan the channels in the scan list the Model 2701 will wait at the control source for another trigger event After all the scan list channels are again measured the Model 2701 will output another trigger pulse After all programmed scans are completed the instrument returns to the idle state with the first channel in the scan list closed The individual components of the trigger models are explained as follows Idle When a scan is enabled STEP or SCAN annunciator on operation goes into the idle state and immediately drops down to the control source Note that after the last channel in the scan is measured operation returns to the idle state where measurements are halted and the first channel in the list is closed Control sources For front panel operation there are three control sources to manage the scan Immediate Timer and External Trigger Operation is held up at the selected control source until the appropriate trigger event is detected STEP operation When the trigger event is detected a channe
450. s selected Simulated reference junction An example of a simulated reference junction is an ice bath Figure 3 14A and B The copper wire to thermocouple wire connections are immersed but electrically isolated in the ice bath and the user enters the 0 C simulated reference temperature into the Model 2701 The simulated reference temperature for the Model 2701 can be set from 0 to 65 C The Model 2701 measures the input voltage and factors in the simulated reference temperature to calculate the temperature reading at the thermocouple NOTE The most accurate temperature measurements are achieved by using a simulated reference junction using an ice point reference Model 2701 User s Manual Basic DMM Operation 3 35 Internal reference junction Internal implies that a temperature transducer s is used to measure the cold junction CJC For the Model 7700 switching module the cold junction is the screw terminals with voltage temperature sensors strategically placed to measure the temperature of the cold junction The Model 2701 measures the temperature of the cold junction screw terminals measures the input voltage and then calculates the temperature reading at the thermocouple External reference junction For switching modules that do not have built in sensors to measure temperature each module can use a thermistor or 4 wire RTD to acquire the reference temperature Connect a thermistor to channel 1 or connect a 4 wire RTD
451. s two multiplexers by using multiple channel operation to close the 2 pole 4 pole relay The Model 7700 is configured as two independent multiplexers by closing channel 23 As shown in Figure 2 8 the closed position of channel 23 isolates Multiplexer A channels 1 through 10 from Multiplexer B channels 11 through 20 For the dual multiplexer configuration only Multiplexer A channels can be internally connected to the DMM of the Model 2701 For the Model 7700 closing channel 25 allows channels 1 through 10 to be measured by the DMM When using the dual multiplexer configuration the sense backplane isolation relay must be kept open to isolate Multiplexer B channels from the sense terminals of the DMM For the Model 7700 channel 24 must be kept open Figure 2 8 Model 2701 User s Manual Figure 2 8 Close Open Switching Module Channels 2 25 Dual multiplexer configuration Model 7700 Multiplexer A 1x10 M ultiplexer B 1x10 HI a 1 LO o_o Channels 2 9 ii Ch10 Ch 25 E Input LO oo o o LO To Ch 23 2 Closed Model 2701 DMM i h l Ch 24 S is Ch 11 ense 00 o o o LO Channels 12 19 e For the dual multiplexer configuration HI Ch 23 must be closed and Ch 24 must Ch20 remain open o oo 2 26 Close Open Switching Module Channels Model 2701 User s Manual Dual multiplexer application This application demonstrates how to use the Model 7700 as a dual multiplexer to bias
452. same temperature Keeping the two junctions close together is one way to minimize such thermal problems Also keep all junctions away from air currents in some cases it may be necessary to thermally insulate sensitive junctions to minimize temperature variations When a Cu Cu connection is made sufficient pressure must be applied to ensure the connection is gas tight to prevent future oxidation In some cases connecting the two thermal junctions together with good thermal contact to a common heat sink may be required Unfortunately most good electrical insulators are poor conductors of heat In cases where such low thermal conductivity may be a problem special insulators that combine high electrical insulating properties with high thermal conductivity may be used Some examples of these materials include hard anodized aluminum sapphire and diamond Nulling residual thermal offsets Even if all reasonable precautions are taken some residual thermal offsets may still be present These offsets can be minimized by using the Model 2701 Relative feature to null them out To do so place the instrument on the 3mV range and short the end of the connecting cable nearest the measured source first disconnect the cable from the source to avoid shorting out the source After allowing the reading to settle press the front panel REL button to null the offset Select the appropriate range and make your measurement as usual Model 2701 User s Manual Meas
453. se to connect the input at channel 101 to the DMM You now have two input channels 101 and 201 connected to DMM Input at the same time inviting all sorts of problems The above problem can be avoided by opening channels 201 and or 225 before closing channel 101 and 125 as demonstrated by the following sequence 1 Multiple channel operation Close channels 201 and 225 for connection to DMM 2 Multiple channel operation Open channels 201 and or 225 to disconnect from DMM 3 System channel operation Close system channel 101 to connect to DMM 2 18 Close Open Switching Module Channels Model 2701 User s Manual CLOSE key MULTI menu option The MULTI menu option for the CLOSE key can be used to close any individual channel in the mainframe Figure 2 6 Perform the following steps to close a channel NOTE Channels closed by the MULTI option of the CLOSE key are not displayed Use the VIEW option of the CARD menu to display closed channels see CARD menu page 2 30 1 Press the CLOSE key and then use the key to display the CLOSE MULTT message Press ENTER to display the prompt to close a channel CLOSE MLT XXX Using 4 gt a and key in the three digit channel you want to select Press ENTER to close the channel An invalid channel cannot be closed The error messages associated with system channel operation also apply to multiple channel operation Bow Figure 2 6 Multiple channel operation
454. sed Er T where Generated thermal EMF Qap Thermoelectric coefficient of material A with respect to material B uV C T Temperature of B junction C or K T5 Temperature of A junction C or K In the unlikely event that the two junction temperatures are identical no thermal EMFs will be generated More often the two junction temperatures will differ and considerable thermal EMFs will be generated A typical test setup will probably have several copper to copper junctions As pointed out earlier each junction can have a thermoelectric coefficient as high as 0 20 V C Since the two materials will frequently have a several degree temperature differential it is easy to see how thermal potentials of several microvolts can be generated even if reasonable precautions are taken Figure E 1 Thermal EMF generation 2701 Er Qag T HI O CH1 LO O E 4 Measurement Considerations Model 2701 User s Manual Minimizing thermal EMFs To minimize thermal EMFs use only copper wires lugs and test leads for the entire test setup Also it is imperative that all connecting surfaces are kept clean and free of oxides As noted in Table E 1 copper to copper oxide junctions can result in thermal EMFs as high as ImV C Even when low thermal cables and connections are used thermal EMFs can still be a problem in some cases It is especially important to keep the two materials forming the junction at the
455. sed and Ratio or Ch Avg enabled the reading that is applied to the Ratio or Ch Avg block in the flowchart is used as the Chan A value for the calculation The paired channel then closes and that reading is used as the Chan B value for the calculation Ratio or Ch Avg is then calculated as shown in Figure D 3 As shown the result of Ratio or Ch Avg can then be used by an enabled Math operation NOTE For details on these calculations see Ratio and channel average page 5 15 Model 2701 User s Manual Signal Processing Sequence and Data Flow D 7 Data flow remote operation Remote operation can be used with triggering configured to perform a specified number of measurements and then stop The various read commands SENS DATA FETCh READ MEAS CALC2 DATA TRACe DATA and CALCI DATA return the data array s acquired during the measurement cycle Data flow for this triggering configuration is summarized by the block diagram shown in Figure D 4 Refer to this block diagram for the following discussion Figure D 4 Data flow for remote operation TRAC CLE INIT CONT OFF TRIG COUN 1 SEN Se INIT M easurement Filter Rel and Ratio or Ch Avg CALC1 Math mX B Percent or 1 X CALC3 Limit Tests TRACe Data Store CALC2 Min Sdev Mean Pk Pk SEN S 1 D ATA LAT SEN S 1 DATA FRESh CALC3 LIM 1 FAIL CALC3 LIM 2 FAIL CALC2 IMM CALC2 IMM FETCh CALC2 DATA
456. selects the ACV function The second command configures channel 101 to measure ACV when it is scanned See Section 7 for detailed information on scanning 3 8 Basic DMM Operation Model 2701 User s Manual Voltage measurements DCV and ACV The Model 2701 can make DCV measurements from 0 1u V to 1000V and ACV measurements from 0 1uV to 750V RMS 1000V peak DCV input resistance 100V and 1000V ranges 1OMQ 100mV 1V and 10V ranges gt 10GQ 400pF or 1OMQ ACV input impedance IMQII 100pF DCV input divider Normally the input resistance for the 100mVDC 1VDC and 10VDC ranges is gt 10GQ while the input resistance of the 100VDC and 1000VDC ranges is 10MQ However the input resistance for the three lower DCV ranges can also be set to 10MQ by enabling the input divider With the input resistance lowered a more stable OV reading is achieved with an open input Also some external devices such as a high voltage probe must be terminated to a 10MQ load The input divider cannot be enabled from the front panel For remote programming the following command controls the input divider VOLT IDIVider lt b gt Enable ON or disable OFF the DCV input divider Connections WARNING Even though the Model 2701 can measure up to 1000V peak the maximum input to a switching module is less Exceeding the voltage rating of a switching module may cause damage and create a safety hazard When making connections to an external circuit
457. ser s Manual Remote Operations 10 19 Figure 10 10 Web page control panel INTERACTIVE CONTROL PANEL KEITHLEY INITIATE EXECUTE REMOTE COMMANDS SCPI Command KEITHLEY NOTE After you send a command it is recommended that you add the system error query for instance TRIG COUN 20 SYST ERR to make sure errors did not occur from the sent command For example append SYST ERR to the end of any command to check the status However do not add this command to queries because they will return their own data 10 20 Remote Operations Model 2701 User s Manual Front panel aspects of Ethernet operation This section describes aspects of the front panel that are part of Ethernet operation includ ing messages status indicators and the LOCAL key Error and status messages See Appendix C for a list of error and status messages associated with programming The instrument can be programmed to generate an SRQ and command queries can be per formed to check for specific error conditions Status indicators The REM remote and SRQ service request annunciators show remote operation status Each of these indicators is described below REM This indicator shows when the instrument is in the remote state When the instrument is in remote all front panel keys except for the LOCAL key are locked out When REM is turned off the instrument is in the local state and front panel operation is restored NOTE IfSY
458. sible range for the best resolution 7 To measure other switching channels repeat steps 5 and 6 8 When finished press OPEN if there is a channel closed 3 12 Basic DMM Operation Model 2701 User s Manual AC voltage measurements and crest factor The root mean square RMS value of any periodic voltage or current is equal to the value of the DC voltage or current which delivers the same power to a resistance as the periodic waveform does Crest factor is the ratio of the peak value to the RMS value of a particular waveform The crest factor of various waveforms is different since the peak to RMS ratios are variable For example the crest factor for a pulse waveform is related to the duty cycle as the duty cycle decreases the crest factor increases The RMS calculations and crest factor CF for various waveforms are shown in Figure 3 4 and Figure 3 5 The Model 2701 is an AC coupled RMS meter For an AC waveform with DC content the DC component is removed before the RMS is calculated This affects the crest factor in that the peak value of the waveform is different for a DC coupled waveform and an AC coupled waveform In an AC coupled waveform the peak is measured from the original DC average value not DC zero For example if a voltage pulse is measured on the AC function of the Model 2701 with a peak voltage of Vp and a low voltage of zero volts the AC coupled peak value will be calculated as follows ACpgax Vp 1 duty cyc
459. sion Acquire revision level of PC board BATTery Battery PRESent Is a battery installed 0 no 1 yes STATus Returns OK MEMORY LOST or CHARGING FAILURE Memory is lost when the battery is not installed and upon a reset after a firmware upgrade A charging failure occurs when it is time for a new battery PASSword Password ENABle lt b gt Enable or disable the use of a password ENABlIe Query the state of password usage CDISable password Disables protected commands 2 CENable password Enables protected commands STATe lt b gt Returns 0 if password protected commands are disabled Returns 1 if they are enabled NEW lt password gt Set new password 1 There is no query form for this command N affected by PASS CDIS The following commands and queries are NOT disabled by PASSword CDISable Commands and queries not listed are not ESE OPT SYST BOAR SNUM SYST PASS CDIS ESR SRE SYST BOAR REV SYST PASS CEN IDN SRE SYST ERR SYST PASS CEN STAT OPC STB SYST LFR SYST REM OPC STAT QUE NEXT SYST LOC SYST VER Model 2701 User s Manual Remote Operations 10 7 Ethernet setup Ethernet standards The Model 2701 conforms to these standards TCP IP HTTP EEE 802 3 e SCPI 1996 0 Standard Commands for Programmable Instruments Typical Ethernet systems The four typical Ethernet systems using a Model 2701 are shown in Figu
460. source v SAMPle COUNt lt NRf gt Specify sample count 1 to 450000 1 COUNt Query sample count Notes 1 Defaults for continuous initiation SYSTem PRESet enables continuous initiation RST disables continuous initiation 2 Defaults for count SYSTem PRESet sets the count to INF infinity RST sets the count to 1 Model 2701 User s Manual SCPI Reference Tables 15 27 Table 15 10 UNIT command summary Default Command Description parameter Ref SCPI UNIT TEMPerature lt name gt Select temperature units C CEL F C Sec 3 FAR or TEMPerature Query temperature units v VOLTage Path to configure voltage units Sec 5 DC name Select DCV measurement units V or DB V lt clist gt DB Path to set DB reference voltage REFerence n Specify reference in volts 1e 7 to 1000 1 REFerence Query reference DC lt clist gt AC lt name gt lt clist gt DB REFerence n REFerence AC lt clist gt Query DCV units Select ACV measurement units V or DB V Path to set DB reference voltage Specify reference in volts le 7 to 1000 1 Query DB reference Query ACV units 15 28 SCPI Reference Tables Model 2701 User s Manual Specifications A 2 Specifications Model 2701 User s Manual Model 2701 Ethernet Data Acquisition System Put 2701 specs here Model 2701 User s Manual Specifications A 3 A 4 Specifications Model 2701 User s M
461. st also be rated for 1000V Dangerous arcs of an explosive nature in a high energy circuit can cause severe personal injury or death If the multimeter is connected to a high energy circuit when set to a current range low resistance range or any other low impedance range the circuit is virtually shorted Dangerous arcing can result even when the multimeter is set to a voltage range if the minimum voltage spacing is reduced in the external connections For details to safely make high energy measurements see Section 3 High energy circuit safety precautions As described in the International Electrotechnical Commission IEC Standard IEC 664 the Model 2701 measurement terminals are measurement Category I and must not be connected to mains For the Model 7700 detailed connection and wiring information is provided in Appendix B of this manual Model 7700 Connection Guide Connection and wiring information for other modules are provided with the individual switch cards 2 6 Close Open Switching Module Channels Model 2701 User s Manual Pseudocards Using remote programming you can assign a pseudocard to an empty switching module slot With a pseudocard installed the Model 2701 will operate as if the switching module is installed in the Model 2701 This feature allows you to exercise open close scan operations or configure your system without having the actual switching module installed in the unit There is a pseudocard for every Keith
462. strument will then automatically select the most sensitive current or voltage threshold range FREQuency APERture n lt clist gt PERiod APERture n lt clist gt The rate annunciators indicate the following aperture settings SLOW sec MED 0 1 sec FAST 0 01 sec For all other aperture times the rate annunciators are turned off UNIT TEMPerature lt name gt To set temperature measurement units to C use the C or CEL parameter For F use the F or FAR parameter For Kelvin use the K parameter Trigger and retrieve readings NOTE Detailed information on the processes to trigger and retrieve read ings is provided in Section 8 Section 13 and Appendix D INITiate CONTinuous lt b gt INITiate With continuous initiation disabled INITiate CONTinuous OFF you can use the INITiate command to trigger one or more measurements NOTE Note that sending INITiate while the instrument is performing measurements will cause error 213 init ignored 3 56 Basic DMM Operation Model 2701 User s Manual DATA LATest DATA FRESh These commands do not trigger a reading They simply return the last reading string The reading reflects what is applied to the input While the instrument is performing measurements you can use these commands to return the last reading If the instrument is not performing measurements DATA LATest will keep returning the same reading string DATA FRESh can only be used once
463. surement methods For 100Qto 1MQranges the Model 2701 uses the constant current method to measure resistance The Model 2701 sources a constant current T to the resistance and measures the voltage V Resistance R is then calculated and displayed using the known current and measured voltage R V D For the 10M and 100M CO ranges the ratiometric method is used to measure resistance 4 wire common side CSID ohms measurements Explains the CSID ohms mode which is used with the 7701 module to perform 4 wire common side ohms measurements Connections NOTE When using the front panel inputs the INPUTS switch must be in the F out position For switching modules it must be in the R in position Front panel inputs Connections for resistance measurements are shown in Figure 3 8 For 2 wire resistance measurements 2 connect the test leads to INPUT HI and LO as shown in Figure 3 8A For 4 wire resistance connect the test leads to INPUT HI INPUT LO SENSE and SENSE LO as shown in Figure 3 8B Model 2701 User s Manual Basic DMM Operation 3 21 Figure 3 8 42 and 421 connections for front panel inputs Model 2701 Shielded Optional Shield aa WIRE T Cable LO INPUTS SI Resistance e Under Test O Note Source current flows from the L 1 INPUT HI to INPUT LO terminals A 2 Connections Model 2701 ERAS Shielded
464. system performance it is recommended that all measurement cables be limited to less than 3 meters DC voltage DC current and resistance e Select 6 2 digits 10 PLC filter ON up to 100 readings fixed range Use REL on DC voltage and 2 wire resistance measurements Use 4 wire resistance measurements for best accuracy AC voltage and AC current e Select 6 2 digits 10 PLC filter ON up to 100 readings fixed range Temperature e Select 6 2 digits 10 PLC filter ON up to 100 readings Optimizing measurement speed The configurations listed below assume that the multimeter has had factory setups restored DC voltage DC current and resistance e Select 3 digits 0 002 PLC filter OFF fixed range AC voltage and AC current Select 3 digits 0 002 PLC filter OFF fixed range Temperature Select 3 digits 0 002 PLC filter OFF For all functions turn off the display autozero and set the trigger delay to zero Use the SAMPle COUNt and READ bus commands B Model 7700 Connection Guide B 2 Model 7700 Connection Guide Model 2701 User s Manual Card configuration schematic Figure B 1 shows a simplified schematic diagram of the Model 7700 module As shown the Model 7700 has channels that are grouped into two banks of ten channels twenty channels total Backplane isolation is provided for each bank Each bank also includes separate cold junction reference points The first bank conta
465. t Power On STB SRE SRE Master Summary Status MSS MSB Measurement Summary Bit EAV Error Available QSB Questionable Summary Bit MAV Message Available ESB Event Summary Bit MSS Master Summary Status OSB Operation Summary Bit Note RQS bit is in serial poll byte MSS bit is in STB response Operation Operation Operation Condition Event Event Enable Register Register Register Always Zero Measurement Measurement Measurement Condition Event Event Enable Register Register Register Reading Overflow Low Limit 1 Event High Limit 1 Event Low Limit 2 Event High Limit 2 Event Reading Available Buffer Notify Buffer Available Buffer Half Full Buffer Full Buffer Overflow Hardware Limit Event Buffer Quarter Full Measuring Waiting for Trigger Filter Settled Idle State Buffer Three Quarter Full BTF Master Limit Always Zero Always Zero 11 4 Status Structure Model 2701 User s Manual Clearing registers and queues When the Model 2701 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 event enable registers and the Error Queue are listed in Table 11 1 In addition to these commands any enable register can be reset by sending the
466. t Query range v AUTO lt b gt lt clist gt Enable or disable auto range ON v AUTO lt clist gt Query state of auto range v DIGits n lt clist gt Specify measurement resolution 4 to 7 7 Sec 4 DIGits lt clist gt Query resolution REFerence n lt clist gt Specify reference 3 1 to 3 1 0 Sec 5 v STATe lt b gt lt clist gt Enable or disable reference OFF v STATe lt clist gt Query state of reference v ACQuire lt clist gt Use input signal as reference REFerence lt clist gt Query reference value v AVERage Path to configure and control filter Sec 4 TCONtrol lt name gt Select filter type MOVing or REPeat Note 3 TCONtrol Query filter type WINDow lt NRf gt Set filter window in of range 0 1 0 to 10 WINDow Query filter window COUNt n lt clist gt Specify filter count 1 to 100 10 COUNC lt clist gt Query filter count STATe b lt clist gt Enable or disable filter Note 4 STATe lt clist gt Query state of digital filter 15 12 SCPI Reference Tables Model 2701 User s Manual Table 15 5 continued SENSe command summary Default Command Description parameter Ref SCPI SENSe 1 CURRent AC Path to configure AC current Sec 3 v APERture lt n gt lt clist gt Set integration rate in seconds Note 2 Sec 4 3 333333e 5 to 1 APERture lt clist gt Q
467. t a conflict error 221 will occur For example VOLTage AC DIGits 4 5 9 101 is only valid if scan channel 101 is set for the ACV function Setting digits Even though the parameters for the DIGits command are expressed as integers 4 to 7 you can specify resolution using a real number For example to select 3 digit resolution let n 3 5 Internally the instrument rounds the entered parameter value to the nearest integer As implied by the commands in Table 4 3 each mainframe input function can have its own unique digits setting Digits programming examples NOTE The following examples be run from the KE2700 Instrument Driver using the example named Digits in Table G 1 of Appendix G Example 1 The following commands set digits for and ACI VOLT DIG 5 5 CURR AC DIG 4 Set DCV to 5 2 digits Set ACI to 3 2 digits Example 2 The following command sequence configures channels 101 through 110 of the Model 7700 to select 42 digits when they are scanned FUNC RES 101 110 RES DIG 4 5 101 110 Select function Set scan channels to 4l2 digits 4 8 Range Digits Rate Bandwidth and Filter Model 2701 User s Manual Rate and bandwidth Rate Setting the rate sets the integration time measurement speed of the A D converter the period of time the input signal is measured also known as aperture The integration time affects the amount of reading noise as well
468. t DCV for 3 digits all the other functions will also be set to 3 digits Using remote programming each function can have its own unique setup For example can be set to 312 digits ACI can be set to 4 digits and DCI can be set to 5 digits Global settings from the front panel that can be set separately using remote programming include digits rate and filter configuration except on off which can be set separately NOTE Do not confuse function setups with scan channel setups For scan channels separate settings for digits rate and filter configuration can be set from either the front panel or remote programming See Section 7 for details on scan channel setup input divider Using remote programming you can enable the DCV input divider for the 100mV 1V and 10V ranges When enabled the input resistance for these DCV ranges are reduced to 10MQ See Section 3 for details on the DCV input divider Multiple channel operation For normal system channel operation when one measurement channel is closed the previous measurement channel opens With the use of the ROUTe MULTiple commands you gain independent control of all switching module channels including the relays that connect the input signal to the DMM See Section 2 for details System commands Interface SYStem subsystem commands are used to select and configure the interface for remote programming System commands for the Ethernet are provided in Table 10
469. t NRf gt Set filter window in lt NRf gt 0to 10 01 TEMPerature AVERage COUNt n clist Specify filter count n 1 to 100 10 TEMPerature AVERage STATe lt b gt clist Enable or disable the filter Note 3 Channel list parameter lt clist gt SCH where S Mainframe slot number 1 or 2 CH Switching module channel number must be 2 digits Examples 101 Slot 1 Channel 1 101 203 Slot 1 Channel 1 and Slot 2 Channel 3 101 110 Slot 1 Channels 1 through 10 Notes 1 The lt clist gt parameter is used to configure one or more channels for a scan Each channel in the lt clist gt must be set to the function specified by the filter command If not a conflict error 221 will occur For example VOLTage AVERage STATe ON 99101 is only valid if scan channel 101 is set for the DCV function REPeat is the RST default and MOVing is the SYSTem PRESet default From the front panel the factory default is MOVing OFF is the RST default and ON is the SYSTem PRESet default EDC is optional for the commands to set DCV and DCI filter Filter window Parameter value 0 for the WINDow commands sets the filter window to NONE 4 22 Range Digits Rate Bandwidth and Filter Filter programming examples Model 2701 User s Manual Example 1 The following command sequence configures filtering for the DCI function NOTE The following example be run from the KE2700 Instr
470. t 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 user documentation 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 perform safe installations and repair products Only properly trained service personnel may perform installation and service procedures Keithley Instruments products are designed for use with electrical signals that are rated Measurement Category and Measurement Category 11 as described in the International Electrotechnical Commission IEC Standard IEC 60664 Most measurement control and data I O signals are Measurement Category and must not be directly connected to mains voltage or to voltage sources with high transient over voltages Measurement Category II connections require protection for high transient over voltages often associated with local AC mains connections Assume all measurement control and data I O connections are for connection to Category sources unless otherwise marked or described in the user documentation Exercise extreme caution when a shock hazar
471. t gt Use input signal as reference REFerence lt clist gt Query reference value AVERage Path to configure and control filter Sec4 TCONtrol lt name gt Select filter type MOVing or REPeat Note 3 TCONtrol Query filter type WINDow lt NRf gt Set filter window in of range 0 1 0 to 10 WINDow Query filter window COUNt n lt clist gt Specify filter count 1 to 100 10 COUNC lt clist gt Query filter count STATe b lt clist gt Enable or disable filter Note 4 STATe lt clist gt Query state of digital filter DETector Path to set bandwidth Sec 4 BANDwidth lt NRf gt Set AC detector bandwidth in Hertz 30 lt clist gt 3 to 3e5 BANDwidth lt clist gt Query bandwidth Model 2701 User s Manual SCPI Reference Tables 15 11 Table 15 5 continued SENSe command summary Default Command Description parameter Ref SCPI SENSe 1 CURRent DC Path to configure DC current Sec3 v APERture n lt clist gt Set integration rate in seconds Note 2 Sec4 3 333333e 5 to 1 APERture lt clist gt Query aperture integration rate NPLCycles n lt clist gt Set integration rate in line cycles 60Hz 5 0 Sec 4 v 0 002 to 60 50Hz 0 002 to 50 NPLCycles lt clist gt Query line cycle integration rate v RANGe Path to set measurement range Sec 4 v UPPer n lt clist gt Select range 0 to 3 1 3 v UPPer lt clist g
472. t kit Mounts two instruments Models 182 428 486 487 2000 2001 2002 2010 2400 2410 2420 2430 2700 2701 6430 6517A 7001 side by side in a standard 19 inch rack Model 4288 4 side by side rack mount kit Mounts Model 2701 and a 5 25 inch instrument Models 220 224 230 263 595 614 617 775A 6512 side by side in a standard 19 inch rack Carrying case Model 1050 padded carrying case A carrying case for the Model 2701 includes handles and shoulder strap Model 2701 features Model 2701 is 66 101 high performance multimeter data acquisition system It can measure voltage DC and AC current DC and AC resistance 2 and 4 wire temperature thermocouple thermistor and 4 wire RTD frequency and period and test continuity The Model 2701 has two slots that will accommodate Keithley Model 7700 series switch ing modules Table 1 1 Each channel of a switching module that is closed or scanned is measured by the Model 2701 For scanning each channel can have its own unique setup i e function range digits etc More information on the measurement capabilities of the Model 2701 is provided in DMM measurement capabilities page 3 2 A connection guide for the Model 7700 is provided in Appendix B Specifications for the Model 2701 and 7700 switching module are provided in Appendix A Additional features of Model 2701 include Setup storage Seven instrument setups five user RST defaults
473. t of slot 1 module channels 1 through 10 ROUT CLOS COUN 101 110 Setting count update interval Relay closure counts are updated in temporary RAM every time a channel is closed regardless of how it was closed by an SCPI command front panel control or during a scan These counts are permanently written to the EEPROM on the card only at a user set time interval which is initially set to 15 minutes at the factory or whenever the counts are queried Valid intervals set in integer number of minutes are between 10 and 1440 minutes 24 hrs The lower the interval the less chance there is of losing relay counts due to power failures However writing to the EEPROM more often may reduce scanning throughput The higher the interval the less scanning throughput is reduced However more relay counts may be lost in the event of a power failure NOTE Ifthe Model 2701 is turned off before the updated count is written to EEPROM the relay counts will be lost It is good practice to add the ROUT CLOS COUN clist command at the end of a program to manually update the count To set the count update interval send this command ROUTe CLOSe COUNt INTerval lt NRf gt where lt NRf gt 10 to 1440 minutes For example to set the interval to 30 minutes send this command ROUT CLOS COUN INT 30 2 36 Close Open Switching Module Channels Model 2701 User s Manual Model 7700 switching module NOTE Connection and wiring procedures for
474. t results are returned as a 4 bit binary number abcd where a High limit 2 b Low limit 2 c High limit 1 d Low limit 1 A 0 indicates that the limit has passed while a 1 indicates that the limit has failed For the binary data formats the limits information must be decoded from the returned value 0 to 15 Convert the value to its binary equivalent for abcd where d is the LSD and is the MSD For example the value 10 converted to its binary equivalent 151010 That means High Limit 2 and High Limit 1 have failed Figure 14 1 ASCII data format Channel Units Number 1 m 1 23456789E 03VDC 11 664SECS 236RDNG 000 0000LIMITS Reading Timestamp Reading Limits Number Code Units VDC DC Volts HZ Frequency VAC AC Volts SECS Period ADC DC Current C Temperature in C AAC Current F Temperature in F OHM 2 Wire Resistance or Continuity K Temperature in K OHM4W 4 Wire Resistance An overflow reading is displayed as 9 9E37 with no limits 14 4 FORMat and Misc SYSTem Commands Model 2701 User s Manual Miscellaneous SYSTem commands SYSTem commands not covered in other sections of the manual are documented here Table 15 7 lists all SYSTem commands and provides references on where to find more information SYSTem PRESet Returns the instrument to states optimized for front panel operation SYSTem PRESet defaults are listed in the SCPI tables in Section 15
475. tching modules Model 7051 X BNC cable male to male 7051 2 is 2 ft long 7051 5 is 5 ft long and 7051 10 is 10 ft long These cable are used with the Model 7711 switching module Model 2701 User s Manual Getting Started 1 5 Model 7712 SMA 1 SMA cable male to male 1 0m 3 3 ft long This cable is used with the Models 7711 and 7712 switching modules Model 7712 SMA N Female SMA to male N type adapter This adapter is used with the Models 7711 and 7712 switching modules S46 SMA X SMA cable male to male S46 SMA 1 is one foot long and S46 SMA 0 5 is one half foot long This cable is used with the Models 7711 and 7712 switching modules Cables and adapters Ethernet RS 232 and trigger link Ethernet cross over cable 3 meters Keithley P N CA 180 3 Models 8501 1 and 8501 2 trigger link cables Connect Model 2701 to other instru ments with Trigger Link connectors e g Model 7002 Switch System Model 8501 1 is one meter long Model 8501 2 is two meters long Model 8502 trigger link adapter Lets you connect any of the two trigger link lines of Model 2701 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 one External Trigger of Model 2701 to instruments that use BNC trigger connectors Model 8503 is one meter long Model 7009 5 shielded RS 232 cable Five foot RS 232 cable wi
476. te The instrument is considered to be in the idle state whenever operation is at the top of the trigger model As shown in Figure 8 10 initiation needs to be satisfied to take the instrument out of idle While in the idle state the instrument cannot perform any measure or step scan operations The following commands will return operation to the top of the trigger model idle at the START point of the trigger model ABORt e RCLO 1 2 or 3 e SYSTem PREset e RST What happens next depends on the state of initiation If continuous initiation is already enabled the instrument will leave the idle state SYSTem PRESet enables continuous initiation Therefore operation will immediately leave the idle state when it is sent The RCL command will do the same if INITiation CONTinuous ON is a user saved default RST disables continuous initiation Therefore the instrument will remain in the idle state Either of the following two initiate commands will take the instrument out of the idle state e INITiate INITiate CONTinuous ON NOTE While in remote pressing the LOCAL key restores continuous front panel operation Model 2701 User s Manual Triggering 8 17 Figure 8 10 Trigger model remote operation RCL N Rf START O SYST PRES RST INIT CIM M INIT CONT ON Initiate eg INIT INIT CONT ON Trigger Signal An
477. ted by a flashing menu item or parameter Cursor position is controlled by the and keys With the cursor on a menu item or parameter use the 4 and keys to scroll through the available options e displayed menu item and parameter is selected by pressing ENTER e You can exit from the menu structure by pressing EXIT However any ENTERed selections will apply Thermocouple temperature measurement configuration The steps to configure thermocouple measurements are provided in Table 3 3 After pressing SHIFT and then SENSOR the menu starts at step 1 to select measurement units Each time you press ENTER to make a selection the menu will automatically go to the next selection After pressing ENTER for the last step the instrument will return to the normal measurement state NOTE An INT card is a switching module that has an internal reference junction i e Model 7700 The INT reference junction setting cannot be selected if there is not at least one INT card installed in the unit With no INT cards installed selecting INT will cause the NO INT CARDS message to be displayed briefly With at least one INT card installed the INT reference junction can be selected However if you select it for the front panel inputs or for a switching module that does not have an internal reference junction i e Model 7702 the simulated SIM reference junction will instead be used and the ERR annunciator will turn on Model 2701
478. ter on page 11 20 Bit B9 Buffer Full BF Set bit indicates that the trace buffer is full Bit B10 Buffer Overflow BOF Set bit indicates that the filled buffer has wrapped and written over previously stored readings Bit B11 Hardware Limit Event HL Set bit indicates that a reading has exceeded the hardware limit Bit B12 Buffer Quarter Full BQF Set bit indicates that the trace buffer is one quarter full NOTE Bits B12 14 full and full are not intended to be used with buffer sizes smaller than four readings Bit B13 Buffer Three Quarter Full BTF Set bit indicates that the trace buffer is three quarters full Model 2701 User s Manual Status Structure 11 15 Bit B14 Master Limit ML Set bit indicates that one or more of the other limits have been reached or exceeded Bit BI5 Not used Figure 11 6 Measurement event status Measurement Condition Register ML BTF BQF HL BOF BF BN IRAV HL2 LL2 HL1 LL1 B15 B14 B13 B12 BT1 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 Measurement Event Register a To Measurement Summary Bit MSB of Status Byte Register Measurement Event Enable ML BTF HL BOF BF BHF BAV BN RAV HL2 LL2 HL1 Register B15 B14 B13 B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1
479. th a male DB 9 con nector on one end and a female DB 9 connector on the other end Wired as a straight through cable not null modem Software The following optional software is available from Keithley ExceLINX 1A This is an economical easy to use add in utility for Microsoft Excel 5 and Keithley Integra Series Multimeter S witch systems No programming is required Configure your measurements quickly using pop up menus and eliminate time consuming and error prone programming Acquire data into a spreadsheet on the fly during a scan or transfer data into a spreadsheet after a scan is completed A few mouse clicks are all it takes to configure channels set parameters triggers and scan lists There is no need to launch a separate data logging or data crunching application live data streams automatically into an Excel workbook ready for analysis or charting using all of Excel s powerful built in tools TestPoint application development package This powerful and economical programming environment uses object oriented technology through a drag and drop interface to build a basic system quickly and without in depth programming Optional toolkits database and statistical process control are available to expand ExceLINX 1A capability 1 6 Getting Started Model 2701 User s Manual Rack mount kits Model 4288 1 single fixed rack mount kit Mounts a single Model 2701 in a standard 19 inch rack Model 4288 2 side by side rack moun
480. that the calculation will be applied to all measurement functions 3 disable 1 X again press SHIFT and then MATH The MATH annunciator will turn off NOTE The result of the 1 X calculation may be displayed in exponential notation For example a displayed reading of 2 500E 03 R is equivalent to 2500 R 2 5K R When using Rel the rel ed reading of the input signal is used by the 1 X calculation Model 2701 User s Manual Rel Math Ratio Channel Average dB 5 11 Basic operation NOTE _ fusing switching module inputs make sure the front panel INPUTS switch is set to the REAR position in If using the front panel inputs the switch must be in the FRONT position out 1 Configure and enable the mX b percent or reciprocal 1 X math function as previously explained 2 Select the desired measurement function 3 Apply the signal to be measured to a switching channel input or to the front panel inputs NOTE For the Model 7700 switching module channels 21 and 22 are available for DCI and ACI Channels 1 through 20 are available for all other functions 4 If using a switching module REAR inputs selected use the or key to select close the input channel If using the front panel inputs FRONT inputs selected it does not matter if a switching channel is closed The result of the math calculation will be displayed Scanning When a simple scan is configured the present math calculation will apply to all channel
481. the AMPS and INPUT LO terminals as shown in Figure 3 6 Figure 3 6 DCI and ACI connections using front panel inputs Model 2701 SENSE 5 A HI Oo Current Source Caution Maximum Input DC or RMS 3 16 Basic DMM Operation Model 2701 User s Manual Model 7700 switching module Connections for the Model 7700 switching module are shown in Figure 3 7 Note that only channels 21 and 22 can be used for current measurements Figure 3 7 DCI and ACI connections using Model 7700 switching module Model 7700 gt ns Switching Module Caution Maximum input 60VDC or 30V RMS 3A switched 60W 125VA maximum Amps measurement procedure NOTE Make sure the INPUTS switch is in the correct position To use front panel inputs it has to be in the F out position For switching modules it has to be in the R in position If a switching channel is presently closed displayed press OPEN to open it Select the amps measurement function by pressing DCI or ACI 3 Use the RANGE and keys to select a measurement range consistent with the expected current or press AUTO to select autoranging AUTO annunciator turns on Details on range are provided in Section 4 4 Apply the current s to be measured CAUTION Do not apply more than 3A to the input or the AMPS fuse will blow Model 7700 switching module When performing current measure ments the maximum allowable voltage is 60VDC or 30V RMS Exc
482. the Filter is enabled the FILT annunciator is on The FILT annunciator will flash when the filter is not settled When disabled the FILT annunciator is off The filter can be configured while it is enabled or disabled The filter is configured from the filter configuration menu Figure 4 4 Perform the following steps to configure the filter 1 Select the desired function Press SHIFT and then TYPE The present WINDOW setting will be displayed 3 Use the RANGE key to display the desired window setting 0 01 0 1 1 10 or NONE and press ENTER 4 Usethe lt gt and keys to display the number of readings to filter 1 to 100 and press ENTER 5 Use the or key to display the desired filter type moving or repeating and press ENTER The filter turns on and the instrument returns to the normal measurement state NOTE While the filter is enabled FILT annunciator on changes to the configuration take effect as soon as they are made With filter disabled FILT annunciator off changes to the configuration take place when the filter is enabled While the filtering operation is in progress the FILT annunciator blinks Read ings will continue to be processed i e displayed stored sent over the bus but they could be questionable When the FILT annunciator stops blinking the filter has settled Changing function or range causes the filter to reset The filter then assumes the state enabled or disabled
483. the RST default conditions see Default column of SCPI tables Cancels all pending commands 3 Cancels response to any previously received OPC and OPC commands NOTE OPC or OPC should be used with RST which is a slow responding command Details on OPC and OPC are provided in this section Model 2701 User s Manual Common Commands 12 7 TRG trigger Send bus trigger to Model 2701 Use the TRG command to issue a trigger to Model 2701 Use the TRG command as an event to control operation Model 2701 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 provided in Section 8 Programming example The following command sequence configures Model 2701 to be controlled by bus triggers The last line which sends a bus trigger triggers one measurement Each subsequent bus trigger will also trigger a single measurement NOTE The following example can be run from the KE2700 Instrument Driver using the example named BusTrg in Table G 1 of Appendix G RST Restore RST defaults TRIG SOUR BUS Select BUS control source TRIG COUN INF Set trigger layer count to infinity INIT Take 2701 out of idle TRG Trigger one measurement H 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 qu
484. ting and configuring RS 232 interface 10 30 RS 232 connections seessssssesseseneeeee nnne 10 32 Error MESSAGES tee Liner e ete HERE eor ula a ee ua setae E 10 33 11 Status Structure ooo we eei Ade eua Oita 11 1 OVEGIVIOW PREDR 11 2 Status byte and SRQ sse 11 2 Status register Sets o eat pe eden ei ee e ei dee tune 11 2 QUEUES stricta rores Da iacet a aote tea Uii era 11 2 Clearing registers and queues sssssseeeee e 11 4 Programming and reading registers 11 5 Programming enable 11 5 Reading 11 7 Status byte and service request SRQ 11 8 Status byte register senten nnns 11 8 vi Document Number 2701 900 01 Rev F August 2011 Model 2701 Ethernet Based DMM Data Acquisition System Table of Contents Service request enable register sssssssseese 11 9 Status byte and service request 11 10 Status register Sete eerte eet tra Lo p P o voee eo HAT eeu 11 10 Register bit descriptions essenn e 11 11 Condition registers ssssssssssssssseeeeeee nennen 11 17 Event registers
485. tional information 0 1 i e 100 0 V 3 digits 0 01 i e 10 00 V 3 digits 0 001 i e 1 000 V 3 digits 0 0001 i e 1 0000 V 41 digits 0 00001 i e 1 00000 V 51 digits 0 000001 i e 1 000000 V 61 digits The resolution of the res parameter value and the selected range sets the number of display digits As shown above with the 100V range selected and res 0 1 a 100V reading will be displayed as 100 0 V 3 digits The display will default to 3 digits when using parameter values that attempt to set the display below 31 digits For example 10V reading using res 0 1 for the 10V range is displayed as 10 00 V not 10 0 V A command using parameter values that attempt to set the display above 7 digits is ignored and generates error 221 settings conflict error The res parameter is ignored when a lt clist gt is included in the command string Resolution for the scanlist channel s is determined by the present setting for the specified function and by the present resolution setting for the specified function See the NOTES that follow Table 13 1 for additional information Channel s in the scanlist to be configured When the channel list parameter lt clist gt is included the present instrument settings are not affected Instead the channel s in the lt clist gt for the specified function is configured See the NOTES that follow Table 13 1 for additional information
486. to determine when the measure measure process is finished RST Put 2701 in one shot mode CLS Clears measurement event register STAT PRES Clears measurement event enable register STAT MEAS ENAB 256 Enables BHF bit B8 of the measurement event register ESE 1 Enables OPC bit BO of the standard event register TRAC POIN 500 Sets buffer size to 500 readings TRAC FEED SENS Sets to store raw readings TRIG COUN 500 Sets 2701 to perform 500 measurements TRAC FEED CONT NEXT Enables buffer INIT Starts measurement and storage process OPC Sets OPC bit BO of standard event register after the measure store process is finished While readings are being triggered and stored in the buffer the following command STB can be put into a program loop to continuously read the status byte STB Read status register By masking the status byte with binary 00000001 decimal 1 only BO will be read by STB The AND ed result of the mask and the STB response will be either 0 BHF clear or 1 BHF set In the above command sequence ESE enables the OPC bit After OPC is sent the OPC bit will set when the measure store process is finished After the BHF bit sets you can then continuously read the status byte to determine when the OPC bit sets When OPC sets bit B5 ESB in the status byte sets Since this time you only want to read bit B5 a different mask will be needed B7 B6 B5 B4 B3 B2 BI
487. to channel 1 and its paired channel Position the temperature transducer near the terminals for the channel s being used to measure temperature Be sure to electrically insulate the transducer leads to keep them from making contact with other conductors When you close channel 1 to measure the cold junction temperature that temperature reading will be used to calculate the temperature when you close a thermocouple channel Open thermocouple detection Long lengths of thermocouple wire can have a large amount of capacitance that is seen at the input of the DMM If an intermittent open occurs in the thermocouple circuit the capacitance could cause an erroneous on scale reading The Model 2701 has an open thermocouple detection circuit When enabled a 10 A pulse of current is applied to the thermocouple before the start of each temperature measurement If gt 12kQ is detected open thermocouple the OVRFLW message will be displayed If 12kG is detected the current is turned off and a normal thermocouple temperature measurement is performed NOTE Channel average cannot be used with thermocouple temperature measurements if open thermocouple detection is enabled 3 36 Basic DMM Operation Model 2701 User s Manual Thermistors For thermistors the temperature measurement range is 80 C to 150 C 0 01 C resolution Thermistor types that are supported include the 2 2kQ 5 and 10 types The thermistor is a temperature sensitive
488. to command words that exceed four letters If the fourth letter of the command word is a vowel including y delete it and all the letters after it Example immediate imm If the fourth letter of the command word is a consonant retain it but drop all the letters after it Example format form If the 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 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 Model 2701 User s Manual Remote Operations 10 25 Single command messages The above command structure has three levels The first level is made up of the root command STATus and serves as a path The second level is made up of another path C OPERation and a command PRESet The third path is made up of one
489. to display the desired setting Y enabled N disabled and press ENTER NOTE remote programming the TRACe CLEar and TRACe CLEar AUTO commands are used to clear the buffer Table 6 1 6 4 Buffer Model 2701 User s Manual Timestamps Each stored reading is referenced to either a real time clock timestamp or to a relative timestamp Relative timestamp With relative selected there are two timestamp types for each read ing absolute and delta The absolute timestamp S references each stored reading to zero seconds Therefore the first reading in the buffer has an absolute timestamp of zero sec onds The delta timestamp dS indicates the time in seconds between the displayed reading and the reading before it The resolution for each timestamp is lusec NOTE With auto clear disabled and the relative timestamp selected every stored read ing is referenced to the first reading 0 even if the buffer is stopped and started again For example assume you stored 10 readings in the buffer and one hour later you store 10 more readings The timestamps for all 20 readings are referenced to the first reading Therefore the timestamp for the 11th reading 10 is one hour 3600 seconds When the Model 2701 is turned off the relative timestamp resets to 0 sec when the instrument is turned back on If you have readings stored in the buffer and auto clear is disabled when the unit is turned off subsequent stored readings will be ap
490. to return the same reading string That is the reading must be fresh Sending this command again to retrieve the same reading string will generate error 230 data corrupt or stale or cause a time out In order to again use DATA FRESh a new fresh reading must be triggered FETCh READ FETCh is similar to DATA LATest in that it can be used to return the last reading However it can also be used to return more than one reading When returning more than one reading the readings are automatically stored in the buffer In order to return multiple reading strings continuous initiation must be disabled INIT CONT OFF so that the sample count SAMPle COUNTt which specifies the number of measurements to be performed can be set gt 1 After INITiate is sent to trigger the measurements FETCh will return the reading strings In general READ performs an INIT to trigger measurements and then a FETCh to retrieve the reading strings With continuous initiation disabled INITiate CONTinuous OFF you can use the READ command to trigger and return readings The sample count determines the number of reading strings to be returned With the sample count gt 1 the returned readings are automatically stored in the buffer NOTE When readings are stored in the buffer by the TRACe command or by front panel data store operation INIT and multi sample READ queries are locked out With readings in the buffer that were stored in that ma
491. to the rear panel Trigger Link connector SCAN operation After all channels in the scan list are scanned an output trigger is applied to the rear panel Trigger Link connector Model 2701 User s Manual Scanning 7 11 Scan configuration A scan is configured from the scan configuration menu which is accessed by pressing SHIFT and then CONFIG Figure 7 3 shows the basic flowchart to configure a scan After entering the menu structure you can configure a simple scan an advanced scan or reset the configuration to the default setup for a simple scan Refer to the flowchart in Figure 7 3 for the following discussions on Scan reset Simple scan and Advanced scan NOTE Only a sequential scan can be configured from the front panel For a sequential scan the scan proceeds from the lowest numbered channel to the highest Non sequential backward scanning is only intended to be performed using remote programming Unexpected results may occur if a non sequential scan is run from the front panel For more information see Scanning fundamentals Sequential and non sequential scans page 7 3 Figure 7 3 Scan configuration flowchart Imm Scan Timer NOTE The instrument is always configured to run a scan On power up each available channel uses the power on default setup For example for factory power on default settings and two Model 7700s installed the instrument will scan channels 101 through
492. ts for the Q2 function and then performs a measurement When this command is sent the following commands execute in the order that they are presented ABORt CONFigure lt function gt READ When ABORt is executed the instrument goes into the idle state if continuous initiation is disabled If continuous initiation is enabled the operation re starts at the beginning of the Trigger Model When CONfigure is executed the MEASure parameters lt rang gt lt res gt and lt clist gt are executed and the instrument goes into the one shot measurement mode It is similar to sending the CONFigure command with no lt clist gt parameter See CONFigure for more details When READ is executed its operations will then be performed In general another ABORt is performed then an INITiate and finally a FETCh to acquire the reading See READ for more details Programming examples Programming example 1 The following command measures DCV on channel 101 using the 10V range with 3 digit display resolution MEAS VOLT 10 0 01 8101 Programming example 2 The following command measures DCV on the 100V range MEAS VOLT 100 13 10 SCPI Signal Oriented Commands Model 2701 User s Manual 14 FORMat and Miscellaneous SYSTem Commands e FORMat commands Covers the SCPI commands to configure the format that readings are transmitted Miscellaneous SYSTem commands Covers miscellaneous SYSTem commands 14
493. turned by the read commands SENS DATA FETCh READ MEAS CALC2 DATA TRACe DATA CALCI DATA will include the result code for limit tests if the limits data element is selected See FORMat ELEMents lt item list gt page 14 2 to select the limits element and interpret the code TRACe DATA When the data store is enabled sample buffer data or CALC1 results are stored in the buffer The TRACe DATA command reads the entire contents of the data store The selected feed TRAC FEED SENSe or TRAC FEED CALCI determines which group of readings are stored Signal Processing Sequence and Data Flow Model 2701 User s Manual CALC2 IMM CALC2 IMM CALC2 DATA Statistical information minimum maximum mean standard deviation and peak to peak is available for the readings stored in the buffer data store When the desired calculation is selected using the CALC2 FORMat command and CALC2 is enabled CALC2 STATe ON use the CALC2 IMM or CALC2 IMM command to perform the calculation When CALC2 IMM is used the statistic is calculated and result is returned When CALC2 IMM is used to calculate the statistic the CALC2 DATA com mand is then used to return the result The CALC2 DATA command does not initiate a calculate operation It simply returns the result of the last calculation If you calculate a statistic for an empty buffer the number 9 910000E 37 will be returned when it is read If you perform a calc
494. turned off Scanning When a simple scan is configured the present rate or bandwidth setting will apply to all channels in the scan When an advanced scan is configured each channel can have its own rate or bandwidth setting Details to configure and run a scan are provided in Section 7 For remote programming the lt clist gt parameter is used to configure channels for a scan Model 2701 User s Manual Range Digits Rate Bandwidth and Filter Remote programming rate and bandwidth Rate and bandwidth commands 4 11 The commands to set the integration rate and bandwidth are listed in Table 4 5 Additional information on these commands follows the table NOTE Query commands are not included in Table 4 5 All commands for the SENSe subsystem are provided in Table 15 5 Table 4 5 Rate and bandwidth commands Commands Description Default Integration rate commands SENSe 1 VOLTage DC NPLCycles n lt clist gt Set rate for DCV in PLCs lt gt 0 002 to x2 5 0 VOLTage DC APERture n Set rate for DCV in secs lt NRf gt 3 333e 5 to 1 Note 3 lt clist gt VOLTage AC NPLCycles lt n gt lt clist gt Set rate for ACV in PLCs lt n gt 0 002 to x24 15 0 VOLTage AC APERture n lt clist gt Set rate for ACV in secs lt n gt 3 333e 5 to 1 4 Note 3 CURRent DC NPLCycles lt n gt lt clist gt Set rate for DCI in PLCs lt n gt 0 002 to x 5 0 CURRent D
495. tus bit in the Status Byte Register will set When used with the immediate initiation command INITiate the OPC bit in the Standard Event Status Register will not set until the Model 2701 goes back into the idle state The INIT command operation is not considered finished until the Model 2701 goes back into the idle state See the description for WAI for more information on command execution Programing example The first group of commands program sends the command after the INITiate command and verifies that the OPC bit in the Standard Event Status Register does not set while the instrument continues to make measurements not in idle The second group of commands return the Model 2701 to the idle state and verifies that the OPC bit did set SYST PRES Returns 2701 to default setup INIT CONT OFF Disables continuous initiation ABORt Aborts operation Places 2701 in idle INIT IMM Initiate one trigger cycle OPC Sends the OPC command ESR Reads the Standard Event Status Register 12 4 Common Commands Model 2701 User s Manual The returned value of 0 denotes that the bit bit 0 is not set indicating that the INITiate operation is not complete ABORt Aborts operation Places 2701 in idle ESR Reads the Standard Event Status Register The returned value of 1 denotes that the bit bit 1 is set indicating that the INITiate operation is now complete SYST PRES Returns 2701 to default setup
496. u Structure Description UNITS C E Select temperature measurement units C F or K 2 SENS 4W RTD Select the 4 wire RTD transducer 3 TYPE PT100 D100 F100 Select 4 wire RTD type PT385 PT3916 or USER Model 2701 User s Manual Basic DMM Operation 3 45 Temperature measurement procedure NOTE Make sure the INPUTS switch is in the correct position To use front panel inputs it must be in the F out position For switching modules it must be in the R in position 1 Ifa switching channel is presently closed displayed press OPEN to open it 2 Select the temperature measurement function by pressing TEMP 3 Configure the temperature measurement as previously explained in Temperature measurement configuration page 3 42 Connect the temperature transducer s to be measured 5 Ifusing a switching module perform the following steps to close the desired channel Keep in mind that for 4 wire RTD measurements you will close the primary INPUT channel 1 through 10 The channel that it is paired to will close automatically a Press the CLOSE key b Use gt lt to key in the channel number and press ENTER The previously closed channel s if any will open and the specified channel or channel pair will close NOTE While in the normal measurement state you can use the and keys to close channels In general each key press will open the presently closed channel an
497. ual Reference Brief Description Advance4 None Use Case 4 Two scans using 7708 module 40 channel DCV scan 1V range Configuration saved in User Setup 1 20 channel scan Configuration saved in User Setup 2 e Models 2700 2701 1000 range e Model 2750 10Q range dry circuit ohms enabled Setup 1 or Setup 2 recalled to perform scan Measurement speed rate 0 1 plc e DCV input divider Enabled 10MQ input impedance Filter Disabled no filtering Buffer Store 40 reading strings 20 reading strings Buffer elements include reading only Limits DCV scan Limit 1 all channels 20mV Master Latch enabled Triggering Bus control source Data retrieval SRQ if limit fails Advance5 None Use Case 5 32 channel scan using 7701 module Common side 4 wire ohms measurements CSIDe mode Dry circuit ohms option for Model 2750 Install jumpers to connect Input Hi and Sense Hi directly to DUT common side bus Install jumpers to connect channel 35 to Sense Lo and Input Lo Buffer Store 32 reading strings Buffer elements include reading only e Triggering Immediate control source Data retrieval SRQ when buffer full Model 2701 User s Manual KE2700 Instrument Driver Examples G 15 Table G 2 continued LabVIEW examples Manual Name Reference Brief Description Advance6 Non
498. ual explains hazards that could damage the instrument Such damage may invalidate the warranty Inspection Model 2701 was carefully inspected electrically and mechanically before shipment After unpacking all items from the shipping carton check for any obvious signs of physical damage that may have occurred during transit There may be a protective film over the display lens which can be removed Report any damage to the shipping agent immedi ately Save the original packing carton for possible future shipment The following items are included with every Model 2701 order e Model 2701 with line cord e Safety test leads Model 1751 e Accessories as ordered e Hardware for rack mounting e Certificate of calibration e Model 2701 User s Manual PDF on CD ROM e Model 2701 Instrument Networking Instruction Manual Hard copy and PDF on CD ROM e Model 2701 Getting started foldout Model 2701 User s Manual Getting Started 1 3 e Ethernet cross over cable 3 meters in length Software CD containing the following e TestPoint Runtime Provides basic data logging capabilities This can be modified with the TestPoint application development package optional software e KE2700 IVI Instrument Driver Provided for programmers designed for use with application development environments Optional Software available from Keithley is summarized on page 1 5 NOTE The Model 2701 Service Manual is a separate purchased p
499. ual multiplexers 2 24 Identifying installed 1 7 2 30 Installation 2 4 Model 7700 2 36 Queries 2 32 Viewing closed channels 2 30 System channel Control commands 2 12 Controlling 2 10 Operation 1 31 2 7 SYSTem commands 14 4 Summary 10 6 10 15 10 31 15 20 SYSTem BEEPer STATe lt b gt 14 5 SYSTem KEY lt NRf gt 14 4 SYSTem PRESet 14 4 SYSTem VERSion 14 4 Temperature Best temperature sensor 3 33 Equations F 1 Measurements see Temperature measure ments Temperature measurements 3 33 4 wire RTDs 3 37 Configuration 3 42 Connections 3 38 Procedure 3 45 Thermistors 3 36 Thermocouples 3 33 Terminator 10 30 Test leads and connector adapter 1 4 Tests Continuity see Continuity testing Thermal EMFs 3 15 Minimizing E 4 Thermistors 3 36 Connections 3 40 Equation F 6 Temperature measurement configuration 3 43 Thermocouples 3 33 Color codes 3 40 Connections 3 38 Equation F 2 Open thermocouple detection 3 35 Reference junctions see Reference junc tions Temperature measurement configuration 3 42 Thermoelectric Coefficients E 2 Generation E 3 Potentials E 2 Timestamps 6 4 Configuring 6 4 Real time clock timestamp 6 4 Relative 6 4 Selecting 6 5 Setting time and date 6 4 TRIG LINK 1 14 TRIG LINK pinout 8 8 Trigger level 3 46 Trigger link Connections 8 12 Input 9 5 Input pulse specifications EXT TRIG 8 9 Output pulse specifications VMC 8 10 Trigger model Control source and event detection 8 3 Front panel operation
500. ubsequent storage operation appends the readings to the buffer When the buffer fills with 450 000 readings the storage process stops The 450 000 readings are cleared before the next storage operation starts With buffer auto clear disabled the only two valid buffer size values are 450000 and 000000 Buffer size 000000 clears the buffer Entering any other buffer size value resets the buffer size to 450000 Model 2701 User s Manual Buffer 6 3 NOTE Ifthe buffer is empty when the Model 2701 is turned off buffer auto clear will enable when it is turned back on If the buffer is not empty the instrument will power up to the last auto clear set ting Keep in mind that if the instrument powers up with buffer auto clear off buffer size is fixed at 450000 You will have to enable auto clear to change the buffer size The auto clear setting on or off is not affected by SYSTem PRESet or RST front panel or remote operation However front panel FACTory defaults enables buffer auto clear Enabling disabling buffer auto clear 1 Press SHIFT and then SETUP 2 Use the and keys to display the present state of buffer auto clear BUF AUTOCLR Y yes or no To retain the present state of buffer auto clear press ENTER or EXIT NOTE Ifyou change the state of buffer auto clear the buffer will clear 3 To change the state of buffer auto clear press to place the cursor on the present setting Y or N 4 Use the or key
501. ucture 10 14 Remote Operations Model 2701 User s Manual Figure 10 8 Flowchart to SET Ethernet Press Aor Vito display ETHERNET ON or OFF ETHERNET SET Press A or VW to display ON and press ENTER Press ENTER See Op Note 1 IP ADDR2 168 IP ADDR3 000 IP ADDR4 002 it keys C 5 Prompt for an action Displayed message or setting DHCP ON or OFF Press Aor V to display ON or OFF and press ENTER IP ADDR1 192 it keys Use edi AY gt gt d ge value to chan to change value Press ENTER Press ENTER Press ENTER SUBNETI 255 SU BN ET2 255 SU BNET3 255 SU BN ET4 000 it keys it keys PAY ge value M Me Ay Press ENTER Press ENTER Press ENTER Press ENTER GATEWAY 1 192 GATEWAY 2 168 it keys it keys it keys A to change value ge value e value Press ENTER Press ENTER Press ENTER Press ENTER See Op Note 2 Op Notes 1 If Ethernet was off turning it on will cause the 2701 to re boot To change Ethernet settings return to the beginning of this flowchart and start over 2 After pressing ENTER for the Gateway4 settting the 2701 will re boot 3 Changing Ethernet settings or remote interfaces automatically reboots the M odel 2701 Reboot process takes 28 seconds Model 2701 User s Manual Remote Operations 10 15 Remote programming System comm
502. uery aperture integration rate NPLCycles n lt clist gt Set integration rate in line cycles 60Hz 5 0 Sec 4 v 0 002 to 60 50Hz 0 002 to 50 NPLCycles lt clist gt Query line cycle integration rate v RANGe Path to set measurement range Sec 4 v UPPer n lt clist gt Select range 0 to 3 1 3 UPPer lt clist gt Query range AUTO lt b gt lt clist gt Enable or disable auto range ON AUTO lt clist gt Query state of auto range DIGits n lt clist gt Specify measurement resolution 4 to 7 6 Sec4 DIGits lt clist gt Query resolution REFerence n lt clist gt Specify reference 3 1 to 3 1 0 Sec 5 v STATe lt b gt lt clist gt Enable or disable reference OFF STATe lt clist gt Query state of reference ACQuire lt clist gt Use input signal as reference REFerence lt clist gt Query reference value AVERage Path to configure and control filter Sec4 TCONtrol lt name gt Select filter type MOVing or REPeat Note 3 TCONtrol Query filter type WINDow lt NRf gt Set filter window in of range 0 1 0 to 10 WINDow Query filter window COUNt n lt clist gt Specify filter count 1 to 100 10 COUNC lt clist gt Query filter count STATe b lt clist gt Enable or disable filter Note 4 STATe lt clist gt Query state of digital filter DETector Path to set bandwidth Sec4 BAN
503. uffer control mode NEVer NEXT or NEV ALWays CONTrol Query buffer control mode v FEED Query source of readings for buffer DATA Read all readings in the buffer v DATA SELected start count Specify readings to be returned specify starting point first reading is 0 and number of readings count SYSTem PRESet and RST have no effect on commands in this subsystem The listed defaults are defaults set at the factory 15 26 SCPI Reference Tables Model 2701 User s Manual Table 15 9 Trigger command summary Default Command Description parameter Ref SCPI INITiate Subsystem command path Sec 8 y IMMediate Initiate one trigger cycle CONTinuous b Enable or disable continuous initiation Note 1 CONTinuous Query continuous initiation v ABORt Reset trigger system v TRIGger SEQuence 1 Path to program Trigger Layer v COUNt lt n gt Set measure count 1 to 450000 or INFinity Note 2 Query measure count DELay n Set delay 0 to 999999 999 sec 0 v AUTO lt b gt Enable or disable auto delay ON AUTO Query state of delay DELay Query delay SOURce name Select control source IMMediate TIMer IMM MANual BUS or EXTernal SOURce Query control source TIMer n Set timer interval 0 001 to 999999 999 sec 0 1 TIMer Request the programmed timer interval v SIGNal Loop around control
504. ulation with no statistic selected CALC2 FORM NONE or CALC2 disabled CALC2 STAT OFF the result of the last statistic calculation will be returned when a read operation CALC2 IMM or CALC2 DATA is performed However if there was no calculation previously performed the number 9 910000E 37 will instead be returned Continuous measurement mode With continuous initiation enabled INIT CONT ON the instrument continuously performs and displays measurements Data flow is the same except that only one data array is stored in the sample buffer at a time The single data array is then fed to the other enabled data flow blocks When the next measurement occurs that data array overwrites the previous data array in the sample buffer The new data is then fed to the other data flow blocks When SENS DATA FETCh READ CALC1 DATA is sent the latest data array will be returned NOTE The READ command tries to perform an INIT operation This will cause error 213 Init ignored to occur since the instrument is already initiating measurements NOTE When the instrument is not in the continuous measurement mode the INIT CONT ON command can be sent to enable continuous initiation However if the sample count is gt 1 a setting conflict error 221 will occur Set the sample count to 1 SAMP COUN I and then send INIT CONT ON Model 2701 User s Manual Signal Processing Sequence and Data Flow D 13 Scanning For remote operation scannin
505. umber or one of the following name parameters DEFault MINimum MAXimum When the DEFault parameter is used the instrument is programmed to the RST default value When the MINimum parameter is used the instrument is programmed to the lowest allowable value When the MAXimum parameter is used the instrument is programmed to the largest allowable value Examples ARM TIMer 0 1 Sets timer to 100 msec ARM 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 Channel list Specify one or more channels Example ROUTe SCAN 101 110 Scan list slot 1 channels 1 10 List Specify one or more numbers for a list Example STATus QUEue ENABle 110 222 Enable errors 110 through 222 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 RATio lt b gt The lt b gt indicates a Boolean type parameter is required Therefore to enable channel ratio you must send the com mand with the ON or 1 parameter as follows RATio ON RATIO 1 Model 2701 User s Manual Remote Operations 10 23 Query commands This type of command requests queries the presently programmed status It is identified by the question mark at the end of the fundamental form of the command Most commands have a query form TRIGger TIMer Queries the timer interval Most commands that requi
506. ument Driver using the example named MAFilter in Table 1 of Appendix CURR AVER TCON MOV CURR AVER WIND 0 01 CURR AVER COUN 10 CURR AVER ON Select the moving filter Set filter window to 0 01 Set to filter 10 readings Enable filter Example 2 The following command sequence configures channels 101 through 115 of the Model 7700 to use the repeat filter when they are scanned NOTE The following example can be run from the KE2700 Instrument Driver using the example named RAFilter in Table G 1 of Appendix G FUNC VOLT VO VOI VOI LT AVER TCON REP LT AVER COUN 20 101 115 LT AVER ON 101 115 1 Select DCV function Select the repeating filter Set to filter 20 readings Enable filter 5 Relative Math Ratio Channel Average and dB Relative Explains how to null an offset or establish a baseline value Includes the commands for remote programming e Math Covers the three basic math operations mX b percent and reciprocal 1 X Includes the commands for remote programming Ratio and channel average Explains how to use these calculations to display the ratio or average of two switching channels dB Explains how to use remote programming to configure the instrument to perform DCV dB and ACV dB measurements WARNING When using these functions the display may indicate a non hazardous voltage but hazardous voltage may be present on the input connect
507. ure RJUNction RSELect lt clist gt Query reference junction TEMPerature RJUNction SIMulated lt n gt lt clist gt Set simulated reference temperature 0 to 50 C 32 to 122 F or 273 to 323 K TEMPerature RJUNction SIMulated lt clist gt Query simulated reference temperature When using multiple channel operation ROUT MULT command to connect a switching module channel to the DMM for thermocouple temperature measurements the SIMulated reference junction will be used if the INTernal or EXTernal reference junction is selected With a Model 7700 7706 or 7708 installed the default sensor junction is Internal Otherwise the Simulated 23 C junction is selected Only one USER RTD per scan list Model 2701 User s Manual SCPI Reference Tables 15 19 Table 15 6 STATus command summary Default Command Description parameter Ref SCPI STATus Note 1 Sec 11 v MEASurement Measurement event registers EVENt Read the event register Note 2 ENABle NDN or lt NRf gt Program the enable register Note 3 Read the enable register CONDition Read the condition register OPERation Operation status registers v EVENt Read the event register Note 2 v ENABle lt NDN gt or lt NRf gt Program the enable register Note 3 v ENABle Read the enable register v CONDition Read the condition register v QUEStionable Questionable status registers v EVENt
508. urement Considerations E 5 Source resistance noise Noise present in the source resistance is often the limiting factor in the ultimate resolution and accuracy of Model 2701 measurements The following paragraphs discuss the generation of Johnson noise as well as ways to minimize such noise Johnson noise equation The amount of noise present in a given resistance is defined by the Johnson noise equation as follows JAkTRF where rms value of the noise voltage k Boltzmann s constant 1 38 x 10 23J K T Temperature K R Source resistance ohms F Noise bandwidth Hz At a room temperature of 293K 20 C the above equation simplifies to 10 Egug 1 27 x 10 ARE Since the peak to peak noise is five times the rms value 99 of the time the peak to peak noise can be equated as follows E 635x 107 JRF For example with a source resistance of 10kQ the noise over a 0 5Hz bandwidth at room temperature will be p p 635 107194010 10 0 5 45nV m m Minimizing source resistance noise From the above examples it is obvious that noise can be reduced in several ways 1 lower the temperature 2 reduce the source resistance and 3 narrow the bandwidth Of these three lowering the resistance is the least practical because the signal voltage will be reduced more than the noise For example decreasing the resistance of a current shunt by a factor of 100 will also redu
509. urned data string to a point in time There two timestamps relative and real time clock The following command selects the timestamp SYSTem TSTamp TYPE name Select timestamp type RELative or RTCL The relative timestamp operates as a timer that starts at zero seconds when the instrument is turned on or when the relative timestamp is reset SYSTem TSTamp RELative RESet After 99 999 99 seconds the timer resets back to zero and starts over Model 2701 User s Manual FORMat and Misc SYSTem Commands 14 3 For buffer readings recalled from the front panel the relative timestamp is referenced to the first reading stored in the buffer absolute format which is timestamped at 0 seconds and to the time between each stored reading delta format For remote programming you can only return the absolute or delta timestamp The following command is used to select relative timestamp format for the buffer TRACe TSTamp FORMat Select timestamp format ABSolute or DELTa Reading number The reading counter starts at zero when the Model 2701 is turned on When returning buffer readings using TRACe DATA each reading will be referenced to the first reading which is 0 The following command will reset the counter SYSTem RNUMber RESet Channel number The channel number indicates the switching module channel for the reading Channel number 000 indicates that no channel was closed Limits For the ASCII data format limit tes
510. using res 0 1 for the 10V range is displayed as 10 0 0 V not 10 0 V A command using parameter values that attempt to set the display above 7 digits is ignored and generates error 221 settings conflict error See the NOTES that follow Table 13 1 for additional information lt clist gt Single channel only When included this is the channel to be closed and measured Description The MEASure command combines all of the other signal oriented measurement commands to perform a one shot measurement and acquire the reading If the lt clist gt parameter is included the specified channel will close before performing the measurement When a MEASure command is sent the specified function is selected If specified range and resolution will also set Model 2701 User s Manual NOTE SCPI Signal Oriented Commands 13 9 Depending on the specified resolution the measurement rate is set as follows 6V5 digits NPLC z 1 0 Medium 5V5 digits NPLC 0 1Fast 3 or 4 4101 5 NPLC 0 01 gt Fast If resolution is not specified 6 2 digit resolution and medium speed will be selected when MEAS is sent All other instrument settings related to the selected function are reset to the RST defaults If a function is not specified the command executes as if the present function is specified For example assume the 2 function is presently selected When MEAS is sent the instrument resets to the RST defaul
511. ust be 2 digits 101 203 Slot 1 Channel 1 and Slot 2 Channel 3 101 110 Slot 1 Channels 1 through 10 The lt clist gt parameter is used to configure one or more channels for a scan Each channel in the lt clist gt must be set to the function specified by the rel reference command If not a conflict error 221 will occur For example UNITs VOLTage AC dB 9 101 is only valid if scan channel 101 is set for the ACV function Programming examples dB Example 1 The following command sequence configures the Model 2701 to perform DCV dB measurements A 1V input will be measured as OdB FUNC VOLT UNIT VOLT DB UNIT VOLT DB REF 1 Select DCV function Select DCV dB Set dB reference to 1V Example 2 The following command sequence configures channels 101 and 105 of the Model 7700 to perform ACV dB measurements when they are scanned A 10V input will be measured as OdB FUNC VOLT AC 101 105 UNIT VOLT AC DB 101 105 UNIT VOLT AC DB REF 10 Set 101 and 105 for ACV Set 101 and 105 for dB Set 101 and 105 for 10VAC dB reference 5 22 Rel Math Ratio Channel Average dB Model 2701 User s Manual Buffer Buffer overview Summarizes basic buffer data store capabilities Front panel buffer Explains how to store and recall readings Discusses the various statistics available on buffer data including minimum and maximum values average mean standard deviation
512. ust be rated for 1000V 1 Make sure all power is discharged from the Model 7700 module Access the screw terminals Figure B 2 3 Using a small flat blade screwdriver loosen terminal screws and install wires as desired Figure B 4 shows connections to channels 1 and 2 Route wire along wire path and secure with cable tie as shown Fill in a copy of the connection log Table B 1 and affix it to the module cover o wk Close and lock cover Model 2701 User s Manual Model 7700 Connection Guide B 7 Figure B 4 Wire dressing r ame AANA ae INPUT AAZIZIZIZIZIZ tv 2 WIRE au No Supplementary Insulation EI Iz Fere H LH LH LH L e 19 CH20 H LH LE LH LH LH LH L CH21 CH22 2 CHI CHI2 CHI3 CHi4 CHi6 9 B 8 Model 7700 Connection Guide Model 2701 User s Manual Typical connections The following examples show typical wiring connections for the following types of measurements e Thermocouple connections Figure B 5 e 2 Wire and thermistor connections Figure B 6 e X Wire and RTD connections Figure B 7 e Current connections AC or DC Figure B 8 Voltage connections AC or DC Figure B 9 Figure B 5 Thermocouple
513. verage Two type K thermocouples are used to measure temperature Since the internal cold reference junction of the Model 7700 is being used the thermocouples can be connected directly to the screw terminals of the switching module Operation A simplified model of monitor scan operation is shown in Figure 7 5 while the procedure steps and programming commands are listed in Table 7 3 In Figure 7 5 notice that there are two modes of operation While in the monitor mode the Model 2701 continuously performs temperature measurements Keep in mind that channel average is being used Therefore each temperature reading is the average of two temperature measurements one on channel 101 and one on channel 111 As long as the average temperature reading remains below 30 C the instrument will remain in the monitor mode When the temperature reading reaches 30 C the Model 2701 switches over to the scan mode Figuratively speaking it is as if a finger presses the SCAN key when the monitor detects that the average temperature is at or above 30 C The instrument is configured to scan four channels The monitor TEMP channel reading and three DCV channel readings are stored in the buffer After the fourth channel is measured operation returns to the monitor mode to again measure temperature Note that if the average temperature is still at or above 30 C the finger will again press SCAN to start the scan 7 36 Scanning Figure 7 5 Monitor
514. voltage on Sense Hi is at virtually the same potential as Input Hi and Sense Lo is at virtually OV When a sense lead Hi or Lo opens that terminal will drift to 15mV and it will trip the OVRFLW message Figure 3 12C shows detection for an open Sense Hi lead Model 2701 User s Manual Basic DMM Operation 3 31 Figure 3 12 Open ohms test lead detection A Normal 4 wire ohms measurement 2701 Reading 100Q range 100000 9 set 2701 H W Detection 6 6V OVRFIW 9 2701 Reading 1000 range C O pen sense lead lead detected O pen Sense Lead OVR FLW 2701 Reading 1000 range 3 32 Basic DMM Operation Model 2701 User s Manual 10 100MQ ranges Open sense lead detection for the LOMQand 100M detection is slightly different and is shown in Figure 3 13 Detection is performed at Sense Lo only Sense Hi is not used It does not need to be connected to the DUT When the Sense Lo lead opens the Sense Lo terminal will drift to 15mV and trip the OVRFLOW message Figure 3 13 Open Sense Lo lead detection 10 100MC ranges Sense Hl o Not U segs 2701 Input HI OVRFLW MQ 2701 Reading 10M Q range Open Sense Lo Since Sense Hi is not used for the measurement there is no open Lead test lead detection for Sense Hi The Sense Hi test lead does not need to be connected to the DUT 4 wire common side CSID ohms measurements 7701 module For normal 4
515. wire ohms measurements using a switching module channels are paired to provide the switch paths for input and sense Each tested DUT requires two input channels For example the 7700 module has 20 channels With the function selected channel 1 is paired to channel 11 channel 2 is paired to channel 12 and so on This configuration allows up to 10 DUT to be tested The 7701 module has 32 input channels For normal 4 wire ohms measurements up to 16 DUT can be tested However this module can be configured for common side CSID 4 wire ohms measurements allowing up to 32 DUT to be tested With a 7701 module installed the 4 wire ohms mode can be selected using the following key press sequence 1 Press SHIFT and then press CARD 2 Select CONFIG 3 Select slot that has the 7701 1 SLOTI 7701 4 Select 4W MODE NORM normal or CSID common side Model 2701 User s Manual Basic DMM Operation 3 33 For remote programming the following commands are valid with a 7701 module installed SYSTem FRESistance TYPEx NORMal Select normal 4W mode SYSTem FRESistance TYPEx CSIDe Select common side 4W mode SYSTem FRESistance TYPEx Query 4W mode Where the x in TYPEx is the slot number for the 7701 module NOTE Details on 4 wire common side ohms measurements using the 7701 module are provided in the manual packing list supplied with the module Temperature measurements The Model 2701 ca
516. wire ohms mode lt name gt NORMal or CSIDe x Slot number 1 or 2 Enable disable offset compensated ohms 3 51 Default Ref VOLT a OFF OFF b NORM 3 52 Basic DMM Operation Table 3 7 continued Basic measurement commands Model 2701 User s Manual in secs n 0 01 to 1 0 Commands Description Default Ref TEMP function SENSe 1 Optional root command TEMPerature I TRANsducer lt name gt Select temperature transducer name TC lt clist gt TCouple FRTD or THERmistor TEMPerature TCouple TYPE type Select T C type type J K T E K lt clist gt R S B or N TEMPerature TCouple ODETect lt b gt Enable disable open thermocouple OFF detector lt b gt ON or OFF TEMPerature TCouple RJUNCtion Select reference junction name Note3 c RSELect lt name gt lt clist gt SIMulated INTernal or EXTernal TEMPerature TCouple RJUNCtion Set the simulated reference temperature 23 d SIMulated n lt clist gt n 0 to 65 C 32 to 149 F or 2773 to 338 K TEMPerature THERmistor lt NRf gt Set thermistor type in ohms 5000 lt clist gt lt NRf gt 1950 to 10050 TEMPerature FRTD TYPE lt name gt Select FRTD type lt name gt PT100 PT100 e lt clist gt D100 F100 PT3916 PT385 or USER TEMPerature FRTD RZERo lt NRf gt Specify constant for USER type 100 lt clist gt lt NRf gt 0
517. www keithley com Model 2701 Ethernet Based DMM Data Acquisition System User s Manual 2701 900 01 Rev F August 2011 KEITHLEY Model 2701 Ethernet Based DMM Data Acquisition System User s Manual 2002 2011 Keithley Instruments Inc All rights reserved Cleveland Ohio U S A Document Number 2701 900 01 Rev F August 2011 KEITHLEY Safety Precautions 04 09 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 using the product Refer to the user documentation for complete product specifications If the product is used in a manner not specified the protection provided by the product warranty may be impaired The types of product users are Responsible body is the individual or group responsible for the use and maintenance of equipment for ensuring that the equipment 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 mus

Model 2701 Ethernet-Based DMM / Data Acquisition

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