Using the SCXI-1127 Switch Module in LabVIEW, LABWindows/CVI
Contents
1. Close switch c0 r0 status niSwitch Connect instr cO r0 if status VI SUCCESS Error Initializing Interface exiting return 1 Delay 2 Close switch c1 r2 status niSwitch Connect instr cl r2 if status VI SUCCESS Error Initializing Interface exiting return 1 Delay 2 Close switch c5 r3 status niSwitch Connect instr c5 r3 if status VI SUCCESS Error Initializing Interface exiting return 1 National Instruments pg 35 Using the SCXI 1127 Switch Module Delay 2 Close communication channel status niSwitch close instr return 0 Visual Basic example Example 15 SCXI 1127 Matrix vbp Same as example 14 i Simple Acquisition O x Private Sub Start_Click Dim vi As ViSession Dimi As Vilnt32 Disable Acquire button until acquistion complete Start Enabled False Begin by opening a communication channel to the instrument If CheckError niSwitch init SCXIIL 4 MATRIX VI TRUE VI TRUE vi Then GoTo Error End If Close switch c0 r0 If CheckError niSwitch Connect vi c0 r0 Then GoTo Error End If Close switch c1 r2 If CheckError niSwitch Connect vi c1 r2 Then GoTo Error End If Close switch c5 r3 If CheckError niSwitch Connect vi c5 r3 Then National Instruments pg 36 Using the SCXI 1127 Switch Module GoTo Error End If Close communication cha2. SCXIn m1 m2 m3 SCANNER where n chassis ID and m1 m2 m3 module slot number For example to create a scanner out of three SCXI 1127s in slots 5 6 8 in chassis 2 the instrument descriptor would be SCXI2 5 6 8 SCANNER For just one SCXI 1127 in slot 4 of chassis 1 the instrument descriptor would be SCXI1 4 SCANNER To make all of chassis 1 a scanner a shortcut you can use is SCXI1 SCANNER In this version of NI Switch scans cannot span multiple chassis A unique session must be created for each chassis The scanner configuration uses the scanning function calls These calls require scan lists A scan list is a string that specifies the channel connections for scanning The scan list is comprised of channel names that are separated with special characters These special characters determine the operation the scanner performs on the channels when it executes this scan list For proper scanning operation the Continuous Scan parameter in the niSwitch SetContinuousScan niSwitch Set Continuous Scan vi function must be set to TRUE Also the niSwitch_AbortScan niSwitch Abort Scan vi function must be called to stop the scan Before a scan list can be built you should understand the SCXI channel string nomenclature Single Channel The general form is sc lt chassis ID number gt md lt module slot number gt ch lt channel number gt For example channel 3 on module 4 in chassis 2 would be specified as follows sc2 md4
3. to connect channel 0 to analog bus 0 you call niSwitch Connect Channels niSwitch Connect Channels vi with the channel 1 National Instruments pg 24 Using the SCXI 1127 Switch Module parameter set to ch0 and the channel 2 parameter set to com0 Then call niSwitch Connect Channels niSwitch Connect Channels vi with the channel 1 parameter set to com and the channel 2 parameter to ab0 A list of valid channels for the SCXI 1127 is listed below Analog Bus Channel ab0 abl ab2 ab3 These are the four signals which comprise the SCXI High Voltage Analog Bus on the SCXI 1127 Common Bus Channel com0 This is the internal bus on the scanners On the SCXI 1127 the input channels can be connected to the common bus The common bus can also be connected to the analog bus channels Input Channels cA0 ch63 These are the 64 one wire input channels on the SCXI 1127 Channels cA0 ch31 can be configured as two wire inputs Channels cA0 ch15 can be configured as four wire inputs Cold Junction Sensor cjtemp The cold junction sensor channel on the SCXI 1331 terminal block can be accessed through the SCXI 1127 To read from this channel call niSwitch Connect Channels niSwitch Connect Channels vi with the channel 1 parameter set to cjtemp and the channel 2 parameter to com0 Then call niSwitch Connect Channels niSwitch Connect Channels vi with the channel 1 parameter set to com0 and the channel 2 parameter to ab0 The output of th
4. 15 C and 35 to 50 C ranges National Instruments software can convert a thermistor voltage to the thermistor temperature In LabVIEW you can use the Convert Thermistor Reading virtual instrument VI in the Data Acquisition Signal Conditioning palette Channel configuration Run the Measurement amp Automation Explorer and configure the SCXI 1127 channels you are connected to in 2 wire mode National Instruments pg 38 Using the SCXI 1127 Switch Module Application Software Choose the Thermocouple Example vi application from the Examples folder of the niSwitch CD The DMM is configured for DC Volts measurement this is hard wired in the Initialize and Configure DMM vi Linearization of the fetched readings is done in software using the Switch Convert Thermocouple Buffer vi Accuracy The following Table shows the accuracy estimation at control points DegC of 100 0 and 760 for Thermocouple Type J with a DMM scanning at 10Hz 50Hz and 60Hz rate Thermocouple Accuracy Error 10 Hz 50 Hz 60 Hz 100 0 93 0 61 0 74 0 0 42 0 49 0 59 760 0 42 0 47 0 55 Thermistor SCXI 1331 Thernnistor SCKI 1127 Thermistor Measurement Wiring Diagram National Instruments pg 39 Using the SCXI 1127 Switch Module Channel configuration Run the Measurement amp Automation Explorer and configure the SCXI 1127 channels you are connected to in 2 wire mode Application Software Choose the Thermist
5. NISWITCH VAL NONE Then GoTo Error End If If CheckError niSwitch ConfigureScanList inst scxichan _ NISWITCH VAL BREAK BEFORE MAKE Then GoTo Error End If If CheckError niSwitch SetContinuousScan inst 1 Then GoTo Error End If Begin by opening a communication channel to the DMM If CheckError niDMM zmnit DAQ 1 INSTR VI TRUE VI TRUE vi Then GoTo Error End If Call NIDMM ConfigureMeasurement to set function range and resolution If CheckError rnDMM Configure vi NIDMM VAL DC VOLTS range resolution minFrequency maxFrequency Then GoTo Error End If National Instruments pg 30 Using the SCXI 1127 Switch Module Configure Powerline frequency If CheckError niDMM SetPowerlineFrequency vi NIDMM VAL 60 HERTZ Then GoTo Error End If Call NIDMM Configure Trigger to set STP delay If CheckError niDMM ConfigureTrigger vi NIDMM VAL IMMEDIATE 0 05 Then GoTo Error End If Configure a multipoint acquisition If CheckError niDMM ConfigureMultiPoint vi numOfMeas 1 _ NIDMM VAL IMMEDIATE 0 05 Then GoTo Error End If Initiate switch and DMM If CheckError niSwitch InitiateScan inst Then GoTo Error End If If CheckError niDMM Initiate vi Then GoTo Error End If Fetch 30 measurementswith DMM If CheckError niDMM FetchMultiPoint vi 10000 30 _ measurementArray 1 numPointsRead Then GoTo Error End If Format and display measurements For j 1 To 10 measurements Text measurementsl
6. ch3 To create a path between two channels use gt a dash followed by a gt sign between the two channel names For example to scan the channel specified above using the com0 bus the syntax would be sc2 md4 ch3 gt com0 Note that a semicolon is used to indicate that the SCXI 1127 should wait for a trigger before proceeding to the next entry in the scan list Multiple Sequential Channels To scan multiple channels in a scan list concatenate these paths together For example to scan channel 3 4 and 5 on module 12 in chassis 1 over the com0 bus the syntax would be scl md12 ch3 gt com0 sc1 md12 ch4 gt com0 sc1 md12 ch5 gt com0 This example will select channel 3 wait for a trigger then select channel 4 then wait for a trigger and then select channel 5 A simpler way to group channels in a scan list is by using the colon The colon is used to delineate between a start channel and an end channel For example you can use the colon in the example above This could be rewritten as scl md12 ch3 5 gt com0 This command scans and triggers exactly like the example above There is no limitation on the order of the channel sequence on the SCXI 1127 To scan the channels in the opposite order enter the scan list as scl md12 ch5 3 com0 In fact the SCXI 1127 can scan channels in any order National Instruments pg 23 Using the SCXI 1127 Switch Module Multiple Random Channels For example to scan chann
7. 0 Set the Continuous Scan parameter in the niSwitch_SetContinuousScan niSwitch Set Continuous Scan vi function to TRUE Configure the DMM for continuous scanning Initiate switching Initiate DMM scanning Fetch data from the DMM in a loop and de multiplex When done with acquisition Abort and Close DMM Abort and Close Switch void main void 1 ViStatus error VI SUCCESS ViSession vi VI NULL ViSession instr VI NULL ViString resourceName DAQ 2 INSTR ViString scxichan scl md4 ch0 2 gt com0 ViBoolean idQuery VI TRUE ViBoolean reset VI TRUE ViReal64 powerlineFreq NIDMM VAL 60 HERTZ Vilnt32 function NIDMM VAL DC VOLTS ViReal64 range 2 00 ViReal64 resolution NIDMM VAL 3 5 DIGITS ViReal64 minFrequency 20 00 ViReal64 maxFrequency 25000 00 Vilnt32 startTrigSource NIDMM VAL EXTERNAL Vilnt32 startTrigSlope NIDMM VAL POS Vilnt32 numOfMeas 30 ViReal64 measurements 30 Vilnt32 timeLimit 30000 Vilnt32 numPointsRead ViReal64 delay 0 5 ViReal64 period Vilnt32 numpts i National Instruments pg 27 Using the SCXI 1127 Switch Module NI SWITCH configurations P checkErr niSwitch init SCXI1 4 SCANNER VI TRUE VI TRUE amp instr checkErr niSwitch ConfigureScanList instr scxichan NISWITCH VAL BREAK BEFORE MAKB checkErr niSwitch ConfigureScanTrigger instr 0 0 NISWITCH VAL REARCONNECTOR MOD
8. 0000 numOfMeas measurements amp numPointsRead if status lt VI SUCCESS Error Read measurements exiting return 1 for j 0 j lt 4 j printf measurement Vod 9of n i measurements 1 printf n Open switch channel status niSwitch SingleSwitchControl instr channel NISWITCH VAL SWITCH OPEN if status lt VI SUCCESS Error Open switch 0 exiting return 1 j j Close communication channel status niSwitch close instr status niDMM close vi return 0 National Instruments pg 13 Using the SCXI 1127 Switch Module Example 6 SCXI 1127 Path prj Close a path between CH1 and CH7 of an SCXI 1127 configured in Independent Mode Also create a path between channels CH1 and CH10 of the same SCXI 1127 For the second path you need to close switches CH1 BC01 and CH10 int main void ViSession instr Communication Channel ViStatus status For checking errors Vilnt32 1 Begin by opening a communication channel to the SCXI 1127 module in slot4 status niSwitch_init SCXI1 4 INDEP VI TRUE VI TRUE amp instr if status lt VI SUCCESS Error Initializing Interface exiting return 1 j Close switch 1 status niSwitch SingleSwitchControl instr ch1 NISWITCH VAL SWITCH CLOSE if status lt VI SUCCESS Error Close switch 1 exiting return 1 j Close switch 77 status niSwitch Si
9. CXI 1127 National Instruments pg 5 Using the SCXI 1127 Switch Module For independent switch control the program structure should be the following Open a session and Configure the SCXI 1127 module in independent mode by calling niSwitch Init SCXI1 4 INDEP VI TRUE VI TRUE Close Open individual switches by using Low Level Control Functions like niSwitch SingeSwitchControl or niSwitch Control a Single Switch vi in LabVIEW Close the session using niSwitch Close session LABVIEW examples Example 1 SCXI 1127 INDEP vi Measure DC Volt from a sensor connected to switch CH1 of an SCXI 1127 configured in Independent Mode using a DMM for the ADC conversion In order to be able to connect CH1 of SCXI 1127 to the HVABO of the DMM you need to close the following switches CH1 and ABO The following LabVIEW example shows how to implement these operations in software National Instruments pg 6 Using the SCXI 1127 Switch Module S scxii27 INDEP vi Diagram loj x Fie Edit Operate Project windows Help oO amp fi 4pt Application Font nstrument Descriptor Ls ndHalize error in no error Example 2 SCXI 1127_INDEPScan vi Measure DC Volt from sensors connected to switches CHO CH1 CH2 CH3 CH4 of an SCXI 1127 configured in Independent Mode using a DMM for the ADC conversion In order to be able to connect channels CHO CH4 of SCXI 1127 to the HVABO of the DMM you need t
10. CXI 1357HV backplane or outside the SCXI chassis by using the SCXI 1332 and Row Extension Cables connecting each row of one SCXI 1127 to the corresponding row on the second SCXI 1127 In order to expand or add columns you need to connect rows together and the SCXI 1357HV backplane does that for you You can expand the 8x4 matrix into 16x8 By setting up four SCXI 1127 modules and connecting the four rows of modulel with the four rows of the module2 the four rows of module3 with the four rows of module4 via either the SCXI 1357HV backplane or using the SCXI 1332 and Row Extension Cables the four columns of modulel with the four columns of module3 the four columns of the module2 with the four columns of module4 using the Column Extension Cables National Instruments pg 3 Using the SCXI 1127 Switch Module 4 8x1 Matrix configuration If you want to have 4 8x1 matrices for 1 SCXI 1127 Module you will need to use the SCXI 1331 terminal bloc Each bank of 8 switches represents an 8x1 matrix Bank1 for example contains switches ch0 chl ch7 In independent mode if you are connecting a differential signal to chO ch0 and ch0 and then close switch ch0 this signal will be routed to OUTO OUTO and OUTO If you are also closing switch ch5 the same signal is retrievable from both ch5 ch5 and ch5 and OUTO Software Components e LabVIEW LabWindows CVI Visual Basic or Visual C is installed i
11. LabVIEW example shows how to implement these operations in software ib SCXI 1127_SCANNER vi File Edit Operate Project Windows Help fi 3pt Application Font Instrument Descriptor DAG 2 INSTR UN Powerline Frequency 4 60 Hz Auto Zero SiAuto Zero Off Function E DC Volts Reset DMM eit YES Resolution 4 5 Digits NO Range 25 00 0 01 7f Reset Mux 0 Acquired Data NO a ts 2 53 2553 257 3 STP Delay sec 20 0100 E Scan List 0 Module X Scan List Chassis Descriptor 5CX11 4 SCANNER ob lsclImddlchB com Trigger Input Rear Connector of Module 4 ob lsciImddlchB com ob lsciImd4lch com lx SCXI 1127 SCANNER vi Di National Instruments pg 26 Using the SCXI 1127 Switch Module LabWindows CVI example Example 11 Scanning SCXI 1127 prj Measure DC Volt from sensors connected to channels CHO CH1 and CH2 of an SCXI 1127 configured in Scanner Mode This example is using a PCI 4060 DMM as controller for the SCXI 1127 which is located in slot4 of an SCXI 1000 chassis In order to be able to scan channels CH0 2 of SCXI 1127 you need to Initialize the Scanner with instrument Descriptor SCXI1 4 SCANNER Set the SCXI 1127 trigger input to Rear Connector of Module 4 meaning that the DMM will control acquisition through pulses sent to the SCXI 1127 module in slot4 Set the scan list to scl md4 ch0 2 gt com
12. OfMeas Text measurements Text measurements Text amp _ Format measurementArray 1 0 000000 amp _ vbCrLf Next i If CheckError niSwitch_close vi Then GoTo Error End If If CheckError niDMM close vil Then GoTo Error End If Error Enable acquire button Start Enabled True End Sub National Instruments pg 17 Using the SCXI 1127 Switch Module Example 8 SCXI 1127 ReadChannels vbp Same as example 5 i Simple Acquisition B x Start 0 001855 0 002377 0 002004 0 002094 0 001621 0 002094 0 001911 0 002056 0 002053 0 002097 0 002023 0 002481 0 002328 0 002120 0 001960 0 002377 Private Sub Start_Click Dim vil As ViSession Dim vi As ViSession Dim i As Vilnt32 Dim j As Vilnt32 Dim range As ViReal64 Dim resolution As ViReal64 Dim numelements As ViInt32 Dim measurementArray As ViReal64 ReDim measurementArray 1 To 4 Dim numPointsRead As ViInt32 Dim channel As String Dim numOfMeas As Vilnt32 Dim minFrequency As ViReal64 Dim maxFrequency As ViReal64 measurements1 Text measurements2 Text measurements3 Text measurements4 Text range 10 resolution 1 numOfMeas 4 minFrequency 20 maxFrequency 25000 Disable Acquire button until acquistion complete Start Enabled False National Instruments pg 18 Using the SCXI 1127 Switch Module Begin by opening a communication channel to t
13. Powerline frequency ia status niDMM SetPowerlineFrequency vi NIDMM VAL 60 HERTZ if status VI SUCCESS Error Configure Powerline frequency exiting return 1 Call NIDMM Configure to set function range and resolution status niDMM Configure vi function range resolution minFrequency maxFrequency if status lt VI SUCCESS Error ConfigureMeasurement exiting return 1 Close switch ab0 status niSwitch SingleSwitchControl instr abO NISWITCH VAL SWITCH CLOSE if status lt VI SUCCESS Error Close switch ab0 exiting return 1 for i 031 lt 4 i Configure a multipoint acquisition status iDMM ConfigureMultiPoint vi numOfMeas 1 NIDMM VAL IMMEDIATE 0 0 if status lt VI SUCCESS Error Configure a multipoint exiting return 1 National Instruments pg 12 Using the SCXI 1127 Switch Module switch 1 case 0 channel ch0 break case 1 channel ch1 break case 2 channel ch2 break case 3 channel ch3 break Close switch channel status niSwitch SingleSwitchControl instr channel NISWITCH VAL SWITCH CLOSE if status lt VI SUCCESS Error Close switch 0 exiting return 1 Read measurements using NIDMM ReadMultiPoint status niDMM ReadMultiPoint vi 1
14. Text amp _ Format measurementArray j 50 000000 amp _ vbCrLf Next j For j 11 To 20 measurements2 Text measurements2 Text amp _ Format measurementArray j 0 000000 amp _ vbCrLf Next j For j 21 To 30 measurements3 Text measurements3 Text amp _ Format measurementArray j 0 000000 amp _ vbCrLf National Instruments pg 31 Using the SCXI 1127 Switch Module Next j Abort and Close DMM and Switch If CheckError rnnDMM Abort vi Then GoTo Error End If If CheckError niDMM close vi Then GoTo Error End If If CheckError niSwitch close inst Then GoTo Error End If Error Enable acquire button Start Enabled True End Sub National Instruments pg 32 Using the SCXI 1127 Switch Module Matrix mode The matrix topology connects any input to any output Simultaneous connections are possible The SCXI 1127 module is a matrix of size 8x4 8 columns and 4 rows The matrix topology connects multiple instruments to multiple points on a DUT Device Under Test or multiple instruments to multiple DUT s The general form for instrument descriptor is SCXIn m MATRIX wheren chassis ID m module slot number For example to create a matrix out of a SCXI 1127 that you have in slot 12 in chassis 1 the instrument descriptor would be SCXIL 12 MATRIX In this version a unique session must be created for each matrix module The matrix configuration uses the route
15. ULEA NISWITCH VAL NONE checkErr niSwitch SetContinuousScan instr 1 checkErr niDMM init resourceName idQuery reset amp vi Call NIDMM Configure to set function range and res i checkErr niDMM Configure vi function range resolution minFrequency maxFrequency Set Powerline frequency checkErr niDMM SetPowerlineFrequency vi powerlineFreq Call NIDMM Configure Trigger to set STP delay r checkErr niDMM ConfigureTrigger vi NIDMM VAL IMMEDIATE delay Configure a multipoint acquisition checkErr niDMM ConfigureMultiPoint vi numOfMeas 1 NIDMM VAL IMMEDIATE 0 05 Get period measurement checkErr niDMM GetMeasurementPeriod vi amp period Initiate switch and DMM checkErr niSwitch_InitiateScan instr checkErr niDMM Initiate vi Fetch 30 measurementswith DMM checkErr niDMM FetchMultiPoint vi timeLimit 30 measurements amp numpts for i 0 1 lt 30 1 printf measurement Vod 9of n i measurements 1 printf n Abort and Close DMM and Switch j checkErr niDMM_ Abort vi checkErr niDMM close vi National Instruments pg 28 Using the SCXI 1127 Sw
16. Using the SCXI 1127 Switch Module Using the SCXI 1127 Switch Module in LabVIEW LABWindows CVI and Visual Basic Marius Ghercioiu Table of content yy Tei eru o PPE 2 HARDWARE COMPONENTS 5i eias eS YVIN EE dau V ER NE REM AS S OR RR INESSE LAUR TR UR E Nu PRAE EORR OMNI Ne VEA d 3 Matriz configuratii oos tos hodie oe D re A d bestia eed Qu S Pune NR dd dt bip baked 3 You can expand the 8x4 matrix into 8X8 se eeeriesirerri irit er rins ITELE r EAE eee meme 3 You can expand the 8x4 matrix into 8x16 00 cece cece eT N e a 3 You can expand the 8x4 matrix into 16x4 sessssseseseseseseseseresererererereserereserereserereresee 3 You can expand the 8x4 matrix into 16x8 200 ce eee nen rt e EErEE EEE A 3 4 8x1 Matrix configuration ire i P eR Ay el eR ba ee ed teet Awheredeleasak eerte dou 4 SOFTWARE COMPONENTS e esas ke va ues Fo Iun ERA A SERRE EN AS RR RR ORE A E SA EA SR RN ROUEN PUN QE PR NR RETR EN S PAM 4 CONFIGURING AND TESTING YOUR SETUP sscccccesscccccccssccccccccsccccsccccscccsscsscscccossceess 4 WRITING YOUR SOFTWARE so siinecscssse seed sdviesedesdouseasessdedesssSeeVesedeaeedssdeessesassdcceredes 4 Independent mode 55d Go sees vegas odere e E eg uides vegeta OEE E DREES 5 LABVIEW examples ep exi pb eode e gris bv d desc o api ce pe CHR AP ER Ee oed Egg 6 Example 1 SCH 1127 INDEBVQS ndeieetectim iro tertia Go besser repa dere bes operato 6 Example 2 SCXI 1127 INDEPSCaN V iesenii aoim nh nhe ae ne
17. alse Begin by opening a communication channel to the DMM If CheckError niIDMM_init DAQ 1 INSTR VI TRUE VI TRUE vil Then GoTo Error End If Open a communication channel to the SCXI 1127 in slot4 If CheckError niSwitch_init SCX11 4 INDEP VI TRUE VI TRUE vi Then GoTo Error End If Set Powerline frequency If CheckError niDMM SetPowerlineFrequency vil NIDMM VAL 60 HERTZ Then GoTo Error End If Call NIDMM Configure to set function range and resolution If CheckError niDMM Configure vil NIDMM VAL DC VOLTS range _ resolution minFrequency maxFrequency Then GoTo Error End If Configure a multipoint acquisition If CheckError niDMM ConfigureMultiPoint vil numOfMeas 1 _ NIDMM VAL IMMEDIATE 0 Then GoTo Error End If Close switch 717 If CheckError niSwitch SingleSwitchControl vi ch17 _ NISWITCH VAL SWITCH CLOSE Then GoTo Error End If Close switch bc01 If CheckError niSwitch SingleSwitchControl vi bc02 _ NISWITCH VAL SWITCH CLOSE Then GoTo Error National Instruments pg 16 Using the SCXI 1127 Switch Module End If Close switch ab0 If CheckError niSwitch SingleSwitchControl vi ab0 _ NISWITCH VAL SWITCH CLOSE Then GoTo Error End If Read measurements using NIDMM ReadMultiPoint If CheckErrorrmDMM fReadMultiPoint vil 10000 numOfMeas _ measurementArray 1 numPointsRead Then GoTo Error End If Format and display measurements For i 1 To CInt num
18. e CJS sensor will now be present on analog bus 0 Input Mode Configuration In the scanner mode the input channels can be configured on a per channel basis This configuration is done through the Measurement and Automation Explorer LabVIEW example Example 10 SCXI 1127 Scanner vi Measure DC Volt from sensors connected to channels CH1 CH2 CH3 CH4 CH5 CH6 and CH7 of an SCXI 1127 configured in Scanner Mode using a DMM for the ADC conversion The SCXI 1127 is located in slot4 of an SCXI 1000 chassis In order to be able to scan channels CH1 7 of SCXI 1127 you need to Initialize the Scanner with instrument Descriptor SCXII 4 SCANNER Set the SCXI 1127 trigger input to Rear Connector of Module 4 meaning that the DMM will control acquisition through pulses sent to the SCXI 1127 module in slot4 Set the scan list to ob0 scl md4 ch1 gt com0 ob0 scl md4 ch2 gt com0 ob0 sc1 md4 ch3 gt com0 ob0 sc1l md4 ch4 gt com0 0b0 scl md4 ch5 gt com0 o0b0 sc1 md4 ch6 gt com0 0b0 scl md4 ch7 gt com0 Set the Continuous Scan parameter in the niSwitch SetContinuousScan niSwitch Set Continuous Scan vi function to TRUE Configure the DMM for continuous scanning Initiate switching Initiate DMM scanning Fetch data from the DMM in a loop and de multiplex When done with acquisition Abort and Close DMM National Instruments pg 25 Using the SCXI 1127 Switch Module Abort and Close Switch The following
19. ed You selected as switching hardware the SCXI 1127 module At this point you are ready to connect the system test the configuration write the software verify the system and run your tests This application note describes a systematic approach to the implementation of an automatic test system using the SCXI 1127 and the NI 4060 DMM hardware from National Instruments This application note comes with the several files The LabVIEW files are DMM amp Switch Examples lIb SCXI 1127_INDEP vi SCXI 1127 INDEPPath vi SCXI 1127 INDEPScan vi SCXI 1127 SCANNER vi SCXI 1127 MATRIX vi The following LabWindows CVI files are SCXI 1127 path prj SCXI 1127 path c SCXI 1127 ReadChannel prj SCXI 1127 ReadChannel c SCXI 1127 ReadChannels prj SCXI 1127 ReadChannels c Scanning SCXI 1127 prj Scanning SCXI 1127 c SCXI 1127 MATRIX prj SCXI 1127 MATRIX c The following visual basic files are SCXI 1127 path frm SCXI 1127 path vbp SCXI 1127 path vbw SCXI 1127 ReadChannel frm SCXI 1127 ReadChannel vbp SCXI 1127 ReadChannel vbw SCXI 1127 ReadChannels frm SCXI 1127 ReadChannels vbp SCXI 1127 ReadChannels vbw Scanning SCXI 1127 frm Scanning SCXI 1127 vbp Scanning SCXI 1127 vbw SCXI 1127 MATRIX frm SCXI 1127 MATRIX vbp SCXI 1127 MATRIX vbw National Instruments pg 2 Using the SCXI 1127 Switch Module Hardware Components PCI 4060 plug in board or PXI 4060 SCXI 1000 4 slot or SCXI 1001 12 slot chassis SCXI 1127 module in s
20. el 8 on module 2 then channel 4 on module 4 and channel 12 on module 3 in chassis 1 over the com0 bus the syntax would be scl md2 ch8 gt com0 scl md4 ch4 gt com0 scl md3 ch12 gt com0 This example will select channel 8 module 2 wait for a trigger then select channel 4 module 4 then wait for a trigger and then select channel 12 module 3 Cold Junction Sensor Channel The SCXI 1331 contains a cold junction temperature sensor This sensor connects to a special channel on the SCXI 1127 dedicated to measuring the ambient temperature of the terminal block This channel is used when measuring thermocouples This channel is always scanned as a two wire channel You can include the CJS channel at any position in the list with any number of repetitions For example to scan the cold junction sensor and channels 3 8 and 5 on module 12 in chassis over the com0 bus the syntax would be scl md12 cjtemp gt com0 scl md12 ch3 gt com0 scl md12 ch8 gt com0 scl md12 ch5 gt com0 Analog Bus Configuration for Scanning The Analog Bus Channels are automatically connected to the High Voltage Analog Backplane on the modules you include in the scanner instrument descriptor at the time you initiate the scan In a multi module scan this connects the output of the SCXI 1127 to the High Voltage Analog Backplane In some instances it may be desirable to scan a module without the output connected to the analog backplane For example you might want
21. en GoTo Error End If Close switch 77 If CheckError niSwitch SingleSwitchControl vi ch7 _ NISWITCH VAL SWITCH CLOSE Then GoTo Error End If Close switch bc01 If CheckError niSwitch SingleSwitchControl vi bcO1 _ NISWITCH VAL SWITCH CLOSE Then GoTo Error End If National Instruments pg 21 Using the SCXI 1127 Switch Module Open switch 10 If CheckError niSwitch SingleSwitchControl vi ch10 _ NISWITCH VAL SWITCH OPEN Then GoTo Error End If If CheckError niSwitch close vi Then GoTo Error End If Error Enable acquire button Start Enabled True End Sub Simple error checking function Tf an error occurred get the error description and display in a message box Return true if an error occurred and false if one did not Private Function CheckError errorCode As ViStatus As ViBoolean If errorCode lt VI SUCCESS Then Dim errorMessage As String 256 Call niSwitch error message VI NULL errorCode errorMessage Call MsgBox errorMessage vbCritical niSwitch Error CheckError VI TRUE Exit Function End If CheckError VI FALSE End Function National Instruments pg 22 Using the SCXI 1127 Switch Module Scanner mode The scanner topology sequentially connects N inputs to one output of the SCXI 1127 module We exclude the possibility of simultaneous connections in scanner mode The SCXI 1331 terminal block should be used The general form for the instrument descriptor is
22. functions When a SCXI 1127 is configured as a matrix it creates a 8x4 8 column by 4 row matrix The SCXI 1127 which is configured as a matrix should use the SCXI 1332 terminal block and have the accessory field set appropriately in Measurement and Automation Explorer The columns can be expanded by connecting the rows together through the High Voltage Analog Backplane Both columns and rows can be expanded via the SCXI 1332 terminal block Unlike the scanner topology that uses a channel naming convention the matrix uses a column row naming convention For example to connect the row 0 to column 3 call niSwitch Connect Channels niSwitch Connect Channels vi with the channel parameter set to r0 and the channel 2 parameter set to c3 The row names are r0 r1 r2 r3 The column names are c0 c1 c2 c3 c4 c5 c6 c7 To connect the rows to the analog bus for expansion call the niSwitch Connect Channels niSwitch Connect Channels vi function For example to connect r0 to ab0 call niSwitch Connect Channels niSwitch Connect Channels vi with the channel 1 parameter set to r0 and the channel 2 parameter set to ab0 To connect all of the rows close the rest of the switches in a similar manner connect r to ab1 connect r2 to ab2 connect r3 to ab3 LabVIEW example Example 13 SCXI 1127 Matrix vi Connect multiple instruments to multiple points on the DUT according to the following system diagram National Instruments pg 33 Using
23. he DMM If CheckError niDMM init DAQ 1 INSTR VI TRUE VI TRUE vil Then GoTo Error End If Open a communication channel to the SCXI 1127 in slot4 If CheckError niSwitch_init SCXI1 4 INDEP VI TRUE VI TRUE vi Then GoTo Error End If Configure Powerline frequency If CheckError niDMM SetPowerlineFrequency vil NIDMM VAL 60 HERTZ Then GoTo Error End If Call NIDMM Configure to set function range and resolution If CheckError rmDMM Configure vil NIDMM VAL DC VOLTS range _ resolution minFrequency maxFrequency Then GoTo Error End If Close switch ab0 If CheckError niSwitch SingleSwitchControl vi abO _ NISWITCH VAL SWITCH CLOSE Then GoTo Error End If Fori 1 To4 Configure a multipoint acquisition If CheckError niDMM ConfigureMultiPoint vil numOfMeas 1 _ NIDMM VAL IMMEDIATE 0 Then GoTo Error End If Select Case 1 Case 1 channel ch0 Case 2 channel ch1 Case 3 channel ch2 Case 4 channel ch4 End Select Close switch channel If CheckError niSwitch SingleSwitchControl vi channel NISWITCH VAL SWITCH CLOSE Then National Instruments pg 19 Using the SCXI 1127 Switch Module GoTo Error End If Read measurements using NIDMM ReadMultiPoint If CheckErrorrmnDMM ReadMultiPoint vil 10000 numOfMeas _ measurementArray 1l _ numPointsRead Then GoTo Error End If Format and display measurements Select Case 1 Case 1 Forj 1 To numOfMeas mea
24. ion range and res status niDMM Configure vi function range resolution minFrequency maxFrequency if status lt VI SUCCESS Error Configure exiting return 1 j Configure a multipoint acquisition x status iDMM ConfigureMultiPoint vi numOfMeas 1 NIDMM VAL IMMEDIATE 0 0 if status lt VI SUCCESS Error Configure a multipoint acquisition exiting return 1 j Close switch 17 status niSwitch SingleSwitchControl instr ch17 NISWITCH VAL SWITCH CLOSE if status lt VI SUCCESS Error Close switch 17 exiting return 1 j Close switch ab0 status niSwitch SingleSwitchControl instr abO NISWITCH VAL SWITCH CLOSE if status lt VI SUCCESS Error Close switch ab0 exiting return 1 j National Instruments pg 10 Using the SCXI 1127 Switch Module Close switch BC02 status niSwitch SingleSwitchControl instr bc02 NISWITCH VAL SWITCH CLOSE if status lt VI SUCCESS Error Close switch BC02 exiting return 1 j Read measurements using NIDMM ReadMultiPoint status niDMM ReadMultiPoint vi 10000 numOfMeas measurements amp numPointsRead if status lt VI SUCCESS Error Read measurements exiting return 1 j Close communication channel status niSwitch close instr status niDMM close vi return 0 E
25. itch Module checkErr niSwitch AbortScan instr checkErr niSwitch close instr Error if vi niDMM close vi if error lt VI SUCCESS messageHandler error j Visual Basic example Example 12 Scanning SCXI 1127 vbp Same as example 11 w Simple Acquisition Iof x Start 0 002664 0 002429 0 002250 0 002667 0 002056 0 002772 0 002839 0 002705 0 002697 0 002399 0 002615 0 002559 0 002727 0 002675 0 002433 Private Sub Start Click Dim vi As ViSession Dim inst As ViSession Dim scxichan As String Dim j As Vilnt32 Dim range As ViReal64 Dim resolution As ViReal64 Dim numelements As ViInt32 Dim measurementArray As ViReal64 ReDim measurementArray 1 To 30 Dim numPointsRead As Vilnt32 Dim channel As String Dim numOfMeas As Vilnt32 National Instruments pg 29 Using the SCXI 1127 Switch Module Dim minFrequency As ViReal64 Dim maxFrequency As ViReal64 scxichan scl md4 ch0 2 gt com0 measurements1 Text measurements2 Text measurements3 Text range 10 resolution 1 numOfMeas 30 minFrequency 20 maxFrequency 25000 Disable Acquire button until acquistion complete Start Enabled False NI SWITCH configurations If CheckError niSwitch_init SCXI1 4 SCANNER VI TRUE VI TRUE inst Then GoTo Error End If If CheckError niSwitch ConfigureScanTrigger inst 07 _ NISWITCH VAL REARCONNECTOR MODULEA _
26. lot4 respective slot12 if SCXI 1001 chassis is used SCXI 1331 or SCXI 1332 for matrix configuration connector blocs SCXI 1357 High Voltage Analog Buss HVAB connector plugs into the SCXI 1000 SCXI 1001 chassis the back of SCXI 1127 in slot4 or slot12 for SCXI 1001 e Voltage cable HV8 toBan4 connects the HI LO channel terminals of the DMM with the HVAB e Communications Trigger cable SH9MD 9MD connects the AUX I O connector of the DMM with the AUX IN connector of the HVAB Matrix configuration The SCXI 1127 module is a 32 channel differential high voltage multiplexer matrix device The SCXI 1331 terminal block allows for any configuration of the SCXI 1127 module while the SCXI 1332 terminal block configures the SCX 1127 into an 8x4 matrix 8 columns and 4 rows You can expand the 8x4 matrix into 8x8 By setting up two SCXI 1127 modules and connecting each column of one SCXI 1127 to the corresponding column on the other SCXI 1127 using Column Expansion Cables In order to expand or add rows you need to connect columns together You can expand the 8x4 matrix into 8x16 By setting up three SCXI 1127 modules and connecting each column of modulel to the corresponding column of module2 and to the corresponding column of module3 using Column Expansion Cables You can expand the 8x4 matrix into 16x4 By setting up two SCXI 1127 modules and connecting the four rows of one with the four rows of the other via either the S
27. m ple 2 er estet er APER eu Ear ere 33 Example 13 SCXLE 1127 Matrie vi visi rite epe RAV WR EA PEE Ven Ve FR PAS M Vev VA Pe vA PER PEE RPU T LV ERPE RS 33 LabWindows CV exam ple oecicceecgis ise iret tete Reda Ax FOROR EPA yd SERI RR H ARA eT EUIS Dr gs 35 Example 14 SCXI 1127 Matrix prj ee ier einen rir Rin ror Or Rer e enio rea naa drea Fe or ep ero eon e no ur Ri rais 35 Visual Basic example nener iris anani E D ee ue tee dete tee eee UTE 36 Example 15 SCXF 1127 Matrix vbp sssssssssssssssssseeeeeee a r aaa nnn nnn h nnn nnne nete a nnne nna 36 MEASUREMENT AND SWITCHING SYSTEMS cccccccccccscsccccccccsccccccccccscsssscsccsccscscseces 38 The programmable ShertrioTletet c ie eoe Poco edere ee adiesd ead RR DN cod HR au a 38 Thermocouple S versed hen re ete de Re trece Pee ex te red erede dees QU e eed 38 Thermistot x 4 eR E EM C E AER a dn 0g OR da eles ER e te NU Co ada PR CR ER E SUE E eR tes 39 dpa 40 The programmable resistance Tester eife coum end dede Ped bed du a Eg Qu eeu OX DER IE 41 The General Purpose Switching matrix igs ee e tra eR x e ERR aaa M aU o den 42 National Instruments pg 1 Using the SCXI 1127 Switch Module Introduction With the general understanding of switching acquired maybe from previous experience with switching devices you identified the tests to be performed selected the source and measure instruments determined the setup of each test and the switching topology s to be us
28. n your computer e NI Switch 1 1 or higher version instrument driver needs to be installed This installation will install in your computer all necessary drivers needed to run the setup During the installation pay attention to the advanced button which allows you to verify which versions of other drivers like NI DAQ NI IVI NI VISA and CVI RTE are installed in your machine The NI Switch installer will install all these other drivers if necessary The NI Switch CD also contains an Example folder which will not be installed in your computer but it is useful to know about later on when testing the setup e NI DMM 1 1 or higher Configuring and testing your setup e Install NI Switch Shut Down your computer install the hardware reboot e run the Measurement amp Automation Explorer and see that the NI 4060 board is listed under Devices and Interfaces as NI 4060 for PCI Device 1 Test the board e Highlight Devices and Interfaces go to the Edit Menu and choose Insert SCXI 1000 or SCXI 1001 chassis Insert also the SCXI 1127 module in slot4 and make sure that in the Configuring SCXI 1127 Module in Chassis Slot 4 window you have Connected to Devicel NI 4060 for PCI and the field This device will control the chassis is marked Input channels can be configured on a per channel basis To configure the SCXI 1127 channels select the tab on the properties panel that is named Channels Set the proper input mode configuration for the channels y
29. ngleSwitchControl instr ch7 NISWITCH VAL SWITCH CLOSE if status lt VI SUCCESS Error Close switch 77 exiting return 1 j Close switch BCO1 status niSwitch SingleSwitchControl instr bcO1 NISWITCH VAL SWITCH CLOSE if status lt VI SUCCESS Error Close switch BCO1 exiting return 1 j Close switch 710 status niSwitch SingleSwitchControl instr ch10 NISWITCH VAL SWITCH CLOSE National Instruments pg 14 Using the SCXI 1127 Switch Module if status lt VI SUCCESS Error Close switch 10 exiting return 1 Close communication channel status niSwitch close instr return 0 Visual Basic examples Example 7 SCXI 1127 ReadChannel vbp Same as Example 4 i Simple Acquisition B x Start Number fMeas is 0 002149 0 002224 0 002373 0 002265 Private Sub Start_Click Dim vil As ViSession Dim vi As ViSession Dim i As Vilnt32 Dim range As ViReal64 Dim resolution As ViReal64 Dim numelements As ViInt32 Dim measurementArray As ViReal64 ReDim measurementArray 1 To 4 Dim numPointsRead As Vilnt32 Dim minFrequency As ViReal64 Dim maxFrequency As ViReal64 National Instruments pg 15 Using the SCXI 1127 Switch Module n measurements Text range 1072 resolution 1 minFrequency 20 maxFrequency 25000 Disable Acquire button until acquistion complete Start Enabled F
30. nnel If CheckError niSwitch close vi Then GoTo Error End If Error Enable acquire button Start Enabled True End Sub National Instruments pg 37 Using the SCXI 1127 Switch Module Measurement and switching systems The programmable thermometer Multiplex 32 thermocouple inputs Expand to 384 inputs Thermocouple types B E J K R S T N Deg Celsius Fahrenheit Kelvin or mV readings Display and store temperature profiles Record temperature trends Thermocouple CXI 1331 Themocouple SCXI 1127 Thermocouple Measurement Wiring Diagram This figure shows a thermocouple connected to channel 3 of the SCXI 1331 terminal block The thermocouple is connected in two wire configuration Due to the small voltages that thermocouples produce National Instruments recommends that you connect them in a two wire differential configuration versus a one wire configuration The SCXI 1331 contains a cold junction temperature sensor CJS This sensor is a special channel on the SCXI 1127 dedicated to measuring the ambient temperature of the terminal block This channel is always scanned as a two wire channel To include a CJS channel in the scan list is optional You can include a CJS channel at any position in the list with any number of repetitions The SCXI 1331 temperature sensor outputs 0 2 to 0 024 V from 0 to 50 C and has an accuracy of 0 5 C over the 15 to 35 C range and 0 9 C over the 0 to
31. o close the following switches ABO then to emulate a scanning operation repeat for each switch the sequence close switch configureDMM read measurement open switch wait for debounce The following LabVIEW example shows how to implement these operations in software ib SCXI1127 INDEPScan vi iof x File Edi Operate Project Windows Help ia j Instrument Descriptor Switch Name DAQ 2 INSTR ab Switch Close Function pc Volts Channels to Scan Resource Name ISCxH 4 INDEP error in no error National Instruments pg 7 Using the SCXI 1127 Switch Module SCXI1127_INDEPScan vi Diagram File Edit Operate Project Windows Help HS K 13pt Application Font 3o vla 7 IMeasurements Channels to Scan Example 3 SCXI 1127_INDEPPath vi Close a path between CH1 and CH10 of an SCXI 1127 configured in Independent Mode In order to create a path between channels CH1 and CH10 of SCXI 1127 you need to close the following switches CH1 BCO1 and CH10 The following LabVIEW example shows how to implement these operations in software National Instruments pg 8 Using the SCXI 1127 Switch Module lx SCX11127_INDEPPath vi Diagram File Edit Operate Project Windows Help r3 M amp fi 3pt Application Font Switch Action cop LabWindows CVI examples Example 4 SCXI 1127 ReadChannel prj Measure DC Volt from a sensor connected to
32. or Example vi application from the Examples folder of the niSwitch CD The DMM is configured for 2 Wire Resistance measurement this is hard wired in the Initialize and Configure DMM vi Linearization of the fetched readings is done in software using the Convert Thermistor Reading vi Accuracy Measurement of 55 Ohms under the following conditions in2000hms range atatemperature of 28degC 24 hours after calibration is done with an error of 0 0533Ohms RTD SCXI 1331 SCXI 1127 RTD Measurement Wiring Diagram Channel configuration Run the Measurement amp Automation Explorer and configure the SCXI 1127 channels you are connected to in 4 wire mode Don t forget to connect the AB2 AB2 connectors of the Voltage cable HV8 toBan4 to the HI LO mA Ohms channel terminals of the DMM When you configure the DMM to make measurements in 4 Wire Mode excitation will be provided by the DMM to the sensor using this channel Application Software Choose the RTD Example vi application from the Examples folder of the niSwitch CD The DMM is configured for 4 Wire Resistance measurement this is hard wired in the Initialize National Instruments pg 40 Using the SCXI 1127 Switch Module and Configure DMM vi Linearization of the fetched readings is done in software using the Convert RTD Reading vi Note when using the SCXI 1127 and the NI 4060 hardware you can a combine different types of sensors inside the SCXI 1131
33. ou are using e Test SCXI 1000 or SCXI 1001 chassis The chassis has been verified is the message you should get if everything is set correctly Writing your software The SCXI 1127 module implements three basic switching topologies Independent mode Scanner mode Matrix mode Module topology is set in the initialization function or VI by calling National Instruments pg 4 Using the SCXI 1127 Switch Module niSwitch Init SCXI11 4 SCANNER VI TRUE VI TRUE where the SCXI 1127 is in slot4 Note that you can dynamically choose or change the switching topology from inside the programming environment LabVIEW CVI etc by using the other initialization function or LabVIEW VI niSwitch InitWithOptions DAQ 1 INSTR VI TRUE VI TRUE Simulate 0 DriverSetup SCXI 1127 Mux session The option DriverSetup let s you dynamically change switching topology Other setting selections for DriverSetup are SCXI 1127 8x4 Matrix and SCXI 1127 Mux manual AB You need to close the previous session with niSwitch Close session before opening a new session with niSwitch InitWithOptions This is because the SCXI 1127 does not support several topologies in the same time Independent mode This is the basic switching topology because any topology can be built with the SCXI 1127 configured in Independent mode if one is willing to complete the external wiring Independent mode provides the user with individual control
34. over any switch The SCXI 1331 terminal block should be used A unique session must be created for each module The independent configuration uses the low level functions such as niSwitch_SingleSwitchControl niSwitch Control a Single Switch vi The switch names used in these low level functions refer to physical switches on the module Before using the low level functions it is important to understand the switch naming conventions Refer to Figure 2 26 on page 2 30 of the SCXI 1127 User Manual for more information The SCXI 1127 is comprised of switches that are opened or closed based on the configuration of the software These switches and their names are listed below Analog Bus Switches ab0 abl ab2 ab3 These switches connect disconnect the SCXI 1127 internal common bus to from the high voltage analog backplane Channel Switches cA0 ch31 These switches connect disconnect the input signals to from the SCXI 1127 internal common bus Bank Connect Switches bc01 bc02 bc23 The input of the SCXI 1127 consists of four 8 to 1 multiplexers These multiplexers can be connected together by closing the bank connect switches bc0 connects bank 0 to bank 1 bc02 connects bank 0 to bank 2 and bc23 connects bank 2 to bank 3 Cold Junction Sensor cjtemp The cold junction sensor on the SCXI 1331 terminal block can be accessed through the SCXI 1127 Closing this switch will connect the cold junction sensor to the internal common bus on the S
35. surements Text measurements Text amp _ Format measurementArray j 50 000000 amp _ vbCrLf Next j Case 2 For j 1 To numOfMeas measurements2 Text measurements2 Text amp _ Format measurementArray j 0 000000 amp _ vbCrLf Next j Case 3 For j 1 To numOfMeas measurements3 Text measurements3 Text amp _ Format measurementArray j 0 000000 amp _ vbCrLf Next j Case 4 For j 1 To numOfMeas measurements4 Text measurements4 Text amp _ Format measurementArray j 0 000000 amp _ vbCrLf Next j End Select Open switch channel If CheckError niSwitch SingleSwitchControl vi channel _ NISWITCH VAL SWITCH OPEN Then GoTo Error End If Next i If CheckError niSwitch_close vi Then GoTo Error End If If CheckError niDMM close vil Then GoTo Error End If National Instruments pg 20 Using the SCXI 1127 Switch Module Error Enable acquire button Start Enabled True End Sub Example 9 SCXI 1127_Path vbp Same as Example 6 im Simple Acquisition B x Private Sub Start Click Dim vi As ViSession Dimi As Vilnt32 Disable Acquire button until acquisition complete Start Enabled False Begin by opening a communication channel to the SCXI 1127 module in slot4 If CheckError niSwitch init SCXIIL 4 INDEP VI TRUE VI TRUE vi Then GoTo Error End If Close switch 1 If CheckError niSwitch SingleSwitchControl vi ch1 _ NISWITCH VAL SWITCH CLOSE Th
36. switch CH17 of an SCXI 1127 configured in Independent Mode In order to be able to connect CH17 of SCXI 1127 to the HVABO of the DMM you need to close the following switches CH17 BC02 and ABO This example is using a PCI 4060 DMM as controller for the SCXI 1127 int main void ViSession instr Communication Channel ViStatus status For checking errors ViSession vi VI NULL Vilnt32 function NIDMM VAL DC VOLTS ViReal64 resolution NIDMM VAL 3 5 DIGITS ViReal64 minFrequency 20 00 ViReal64 maxFrequency 25000 00 ViReal64 range 10 00 Vilnt32 numOfMeas 4 ViReal64 measurements 4 Vilnt32 numPointsRead Begin by opening a communication channel to the DMM status niIDMM_init DAQ 1 INSTR VI TRUE VI TRUE amp vi if status lt VI SUCCESS Error Initializing Interface exiting return 1 National Instruments pg 9 Using the SCXI 1127 Switch Module j Open a communication channel to the SCXI 1127 in slot4 Mi status niSwitch init SCXII 4 INDEP VI TRUE VI TRUE amp instr if status VI SUCCESS Error Initializing Interface exiting return 1 j Set Powerline frequency xd status niDMM SetPowerlineFrequency vi NIDMM VAL 60 HERTZ if status lt VI SUCCESS Error Set Powerline frequency exiting return 1 Call NIDMM Configure to set funct
37. t eh nnn nennen nennen nnns 7 Example 3 SCXI LI27 INDEPPath i is ande ran D On Ope rode pr REX 8 LabWindows CVI examples ecese reine ira e meme me mense ehe ee e mense emen ee enne 9 Example 4 SCXI 1127 ReadChannel prj sessi h tnn nnne nnne nennen 9 Example 5 SCXI 1127 ReadChannels prj sessi he nnne nennen nnns 11 Example 6 SCXI 1127 Path prj eee peret et eiae eene eiae shave uvisbavaban sbavepivebavebavabacsvivevaces 14 Visual Basic examples ooo Ex A ed ta eerta ee et Ered awe GEI PRU OR ge iud 15 Example 7 SCXI 1127 ReadChanneLvbp ieie E nnnn 15 Example 8 SCXI 1127 ReadChannels vbp sesenta 18 Example XQ SCXLI T127 Path Ubp isi ee vedo eA AP Fave E TR VER EPE EVE ERE s 21 Scanner mode xo Siac lM rores lated sad cuadoceads Sae ade EEA e E REOR De edd a Lae eO Rene soe ee dux 23 LabVIEW exam ple orcos rhet teer eO ee t EA Ix o x Ig Ed eas 25 Example 10 SCXI 1127 Sanner Viscontid tii n hne hh nennen enhn nennt hene n nnne Ee nnne n nna 25 LabWindows CVI xam ples noc ode ate rae eet age ar eeepc eee ri ae e RR RC eoo tees 27 Example 1 1 Scanning SCXLE 1127 prj iet dms ee demo aede va ue Va a eo eM ne va a ama deno ne Pa da veau vaa v SEP va 27 Visual Basic example TTE Rr CREE ARN ei TA e e xe ERE E XN E Re NETS 29 Example 12 Scanning SCXI 1127 vbp ssssssssssssssseeeee eene nennen nennen ennt nnne nnne nennen 29 M Ecina dpesloo Ur 33 LabVIEW exa
38. terminal block b configure your channels in different modes 1 wire 2 wire 4 wire C scan several channels all requesting the same DMM function In a scanning operation you can NOT scan channels requesting different DMM functions For example you can not have the followings a channel string of ob0 sc1 md4 ch26 gt com0 ob0 scl md4 ch27 com0 0b0 scl md4 ch28 gt com0 and have ch26 scanned as DC Volt reading by the DMM have ch27 scanned as 2 Wire Resistance reading by the DMM have ch27 scanned as 4 Wire Resistance reading by the DMM all in the same scan list The NI 4060 can not change its measurement function on the fly during a scan operation The programmable resistance tester Multiplex 8 4 Wire Resistance DUT s Expand to 96 inputs Lowest range 200 Ohms with internal excitation from DMM Display and store resistance values The resistance test method used in this application is the 4 terminal method where two leads supply a known current to the device while two separate leads sense the voltage across the device SOURCE HI NI 40 60 Divi SOURCE HI SENSE HI R DUT 2 4 Wire Resistance SENSE LO Measurement Schematic SOURCELO National Instruments pg 41 Using the SCXI 1127 Switch Module The switching for this test involves sourcing current to eight R DUT s one at a time and Simultaneously reading the voltage across the same R DUT s This requires a combination of 8 1 m
39. the SCXI 1127 Switch Module In order to make these connections you need to Initialize and configure the SCXI 1127 switch for MATRIX topology Connect the first pair of channels cO r0 Make the instrument measurement Disconnect the path between c0 r0 Repeat the sequence Connect make measurement Disconnect for each pair of channels you have in the system Close switching session i SCXI1127 MATRIX vi Be E amp inen bore indowe Help J unnugrnugduuuurut National Instruments pg 34 Using the SCXI 1127 Switch Module LabWindows CVI example Example 14 SCXI 1127 Matrix prj Connect multiple instruments to multiple points on the DUT according to the following system diagram c0 r0 c1 12 c5 r3 In order to make these connections you need to Initialize and configure the SCXI 1127 switch for MATRIX topology Connect the first pair of channels c0 r0 Make the instrument measurement Disconnect the path between c0 r0 Repeat the sequence Connect make measurement Disconnect for each pair of channels you have in the system Close switching session int main void ViSession instr Communication Channel ViStatus status For checking errors Begin by opening a communication channel to the instrument status niSwitch_imit SCXI1 4 MATRIX VI TRUE VI TRUE amp instr if status VI SUCCESS Error Initializing Interface exiting return 1
40. to route the output of the multiplexer to the output terminal of the terminal block instead of routing them to the High Voltage Analog Backplane This can be achieved by calling niSwitch_InitWithOptions niSwitch Initialize With Options vi with the configuration string DriverSetup SCXI 1127 MUX manual AB this will open a session to a scanner but will leave the analog busses open To close the analog bus you must call niSwitch_Connect_Channels niSwitch Connect Channels vi and route the common bus to the analog bus For example to close the ab0 switch call niSwitch Connect Channels niSwitch Connect Channels vi with the channel 1 parameter set to com0 and the channel 2 parameter set to ab0 You can also close ab2 in a similar manner You would call niSwitch Connect Channels niSwitch Connect Channels vi with the channel parameter set to com0 and the channel 2 parameter set to ab2 This is important if you are in a 4 wire configuration If you are using a DMM with the SCXI 1127 it is important to keep in mind that the NI DMM uses both the ab0 and ab2 buses for making measurements The ab2 bus is used as the sense lines for 4 wire resistance measurements and for current measurements Route Functions in Scanner Mode You can also route signals while in scanner mode The route functions allow you to connect disconnect from to one point to from another point n scanner mode you can ONLY have one input channel in your signal path For example
41. ultiplexing for the source leads and 8 1 multiplexing for the sense leads Channel configuration Run the Measurement amp Automation Explorer and configure the SCXI 1127 channels you are connected to in 4 wire mode Use the SCXI 1331 terminal block Application software Choose the General Measurement Example vi application from the Examples folder of the niSwitch CD Configure the DMM for 4 Wire Resistance measurement on the vi panel The General Purpose Switching matrix 8x4 switching matrix 32 crosspoints Expand to 4608 crosspoints Front panel indicates relay status The General Purpose Switching Matrix provides maximum flexibility in signal switching and makes configuring a system easier allowing multiple input columns cO to c7 to connect to multiple rows r0 to r3 through simple paths The front panel displays relay states for visual monitoring and verification during the test Column Row 0 General 8x4 Matrix System Channel configuration Run the Measurement amp Automation Explorer and configure the SCXI 1127 channels you are connected to in 2 wire mode Use the SCXI 1332 terminal block Application Software Choose the Matrix Configuration Example vi application from the Examples folder of the niSwitch CD National Instruments pg 42 Using the SCXI 1127 Switch Module National Instruments pg 43
42. xample 5 SCXI 1127_ReadChannels prj Measure DC Volt from sensors connected to switches CHO CH1 CH2 CH3 CH4 of an SCXI 1127 configured in Independent Mode This example is using a PCI 4060 DMM as controller for the SCXI 1127 In order to be able to connect channels CHO CH4 of SCXI 1127 to the HVABO of the DMM you need to close ABO then to emulate a scanning operation repeat for each switch the sequence close switch configure DMM read measurement open switch int main void ViSession instr Communication Channel ViStatus status For checking errors ViSession vi VI NULL Vilnt32 function NIDMM VAL DC VOLTS ViReal64 resolution NIDMM VAL 3 5 DIGITS ViReal64 minFrequency 20 00 ViReal64 maxFrequency 25000 00 ViReal64 range 10 00 Vilnt32 numOfMeas 4 ViReal64 measurements 4 Vilnt32 numPointsRead 1 j National Instruments pg 11 Using the SCXI 1127 Switch Module ViConstString channel Begin by opening a communication channel to the DMM i status niDMM init DAQ 1T INSTR VI TRUE VI TRUE amp vi if status VI SUCCESS Error Initializing Interface exiting return 1 j Open a communication channel to the SCXI 1127 in slot4 i status niSwitch init SCXII 4 INDEP VI TRUE VI TRUE amp instr if status lt VI SUCCESS Error Initializing Interface exiting return 1 Set
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