National Instruments NI 5421 User Manual Download

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CALIBRATION PROCEDURE

NI 5421/5441

Contents

Conventions ............................................................................................ 2
Introduction ............................................................................................. 3
Software and Documentation Requirements........................................... 3

Software ........................................................................................... 3
Documentation................................................................................. 5

Self-Calibration Procedures .................................................................... 5

MAX ................................................................................................ 5
FGEN Soft Front Panel.................................................................... 6
NI-FGEN ......................................................................................... 6

External Calibration Options .................................................................. 7

Complete Calibration ....................................................................... 8
Optional Calibration ........................................................................ 9

External Calibration Requirements ......................................................... 11

Test Equipment ................................................................................ 11
Test Conditions ................................................................................ 11

External Calibration Procedures ............................................................. 12

Writing Your Calibration Procedure................................................ 12

Calibration Procedures in LabVIEW........................................ 12
Calibration Procedures in LabWindows/CVI........................... 12
Calibration Procedures in C...................................................... 12

Verifying NI 5421/5441 Specifications ........................................... 13

Verifying the Oscillator Frequency Accuracy.......................... 15
Verifying the DC Gain and Offset Accuracy ........................... 18

Verifying the Main Analog Path Gain............................... 18
Verifying the Main Analog Path Offset ............................ 23
Verifying the Gain of the Direct Path ............................... 26

Adjusting the NI 5421/5441 ............................................................ 29

Initializing the External Calibration Session ............................ 32

Summary of Contents for NI 5421

Page 1: ...11 Test Conditions 11 External Calibration Procedures 12 Writing Your Calibration Procedure 12 Calibration Procedures in LabVIEW 12 Calibration Procedures in LabWindows CVI 12 Calibration Procedures...

Page 2: ...con denotes a note which alerts you to important information This icon denotes a caution which advises you of precautions to take to avoid injury data loss or a system crash When this symbol is marked...

Page 3: ...and external calibration Software Calibrating the NI 5421 requires installing NI FGEN version 2 0 or later on the calibration system Calibrating the NI 5441 requires installing NI FGEN version 2 3 or...

Page 4: ...tions on calling the appropriate calibration functions Table 1 Calibration File Locations File Name and Location Description IVI Bin niFgen_32 dll The NI FGEN library which provides the functionality...

Page 5: ...documentation refer to ni com manuals Self Calibration Procedures The NI 5421 5441 is capable of performing self calibration which adjusts the gain and offset of the main and direct analog paths Self...

Page 6: ...programmatically using NI FGEN complete the following steps 1 Call niFgen_init niFgen Initialize VI to open an NI FGEN session using the following parameters resourceName The name of the device that y...

Page 7: ...fall within the calibration test limits the device is guaranteed to meet or exceed its published specifications for a full calibration interval two years For this reason you must verify against the c...

Page 8: ...alibration procedure you verify that the output error falls within the calibration test limits Figure 1 shows the programming flow for complete calibration Figure 1 Complete Calibration Programming Fl...

Page 9: ...etting the calibration interval without actually performing an adjustment Refer to the Adjusting the NI 5421 5441 section for more information If all of the output errors determined during the first v...

Page 10: ...Published Specifications Update Calibration Dates and Temperatures Without Adjusting Results Within Published Specs Adjustment Optional Adjust Anyway Adjust Cal Dates and Temperatures Updated Verify D...

Page 11: ...midity below 80 Maintain a temperature between 18 C and 28 C Observe the 15 minute warm up time Table 2 Equipment Required for Calibrating the NI 5421 5441 Instrument Applicable Specification Minimum...

Page 12: ...rogram review the programming flows in Figures 1 and 2 Calibration Procedures in LabVIEW To write calibration procedures in LabVIEW you must use the VIs included in the niFgen llb file After installat...

Page 13: ...l the NI 5421 5441 The steps in the verification procedures describe the code that you use to generate the appropriate signals as well as the NI FGEN function calls that you make to verify specificati...

Page 14: ...Calibration Procedure 14 ni com Figure 3 NI PXI 5421 5441 and NI PCI 5421 Front Panel Connectors PFI 0 PFI 1 ACCESS ACTIVE CLK IN CH 0 DIGITAL DATA CONTROL CH 0 PFl 0 DIGITAL DATA CONTROL NI PCI 5421...

Page 15: ...name under Devices and Interfaces in MAX IDQuery VI_TRUE resetDevice VI_TRUE vi A pointer to a ViSession The variable passed by reference through this parameter receives the value that identifies the...

Page 16: ...t the digital filter state niFgen property node Output Attributes Digital Filter Enabled using the following parameters vi The session handle returned from niFgen_init channelName 0 attributeID NIFGEN...

Page 17: ...niFgen_init 12 Measure the frequency out of the NI 5421 5441 A frequency error of 45 Hz for a 10 MHz signal corresponds to an error of 4 5 ppm This limit accounts for the initial accuracy and the fre...

Page 18: ...t panel connector to the DMM for measuring DC gain and offset accuracy 2 Call niFgen_init niFgen Initialize VI using the following parameters resourceName The name of the device that you want to verif...

Page 19: ...GEN_ATTR_ANALOG_PATH value NIFGEN_VAL_MAIN_ANALOG_PATH 6 Call niFgen_SetAttributeViReal64 to set the output impedance niFgen property node Basic Operation Output Impedance using the following paramete...

Page 20: ...sentation double 11 Call niFgen_CreateArbWaveform niFgen Create Arbitrary Waveform VI using the following parameters vi The session handle returned from niFgen_init wfmSize The size in samples 500 of...

Page 21: ...50000 0 850000 0 001860 0 003900 11 0 600000 0 600000 0 600000 0 001460 0 002900 12 0 415000 0 415000 0 415000 0 001164 0 002160 13 0 300000 0 300000 0 300000 0 000980 0 001700 14 0 205000 0 205000 0...

Page 22: ...returned from niFgen_init 16 Measure the DC voltage out of the NI 5421 5441 This is the Measured Positive Full Scale Value 17 Determine the error for positive full scale using the following forumla E...

Page 23: ...m 0 VDC This array should contain 500 samples with each sample having the value 0 0 representation double 2 Call niFgen_CreateArbWaveform niFgen Create Arbitrary Waveform VI using the following parame...

Page 24: ...425000 0 001988 0 004113 11 0 600000 0 300000 0 300000 0 001550 0 003050 12 0 415000 0 207500 0 207500 0 001226 0 002264 13 0 300000 0 150000 0 150000 0 001025 0 001775 14 0 205000 0 102500 0 102500...

Page 25: ...itiate Generation VI to initiate the waveform generation using the following parameter vi The session handle returned from niFgen_init 7 Measure the positive DC voltage out of the NI 5421 5441 This is...

Page 26: ...f any of the errors are greater than the Calibration Test Limit perform an external adjustment Verifying the Gain of the Direct Path To verify the gain of the NI 5421 5441 Direct path complete the fol...

Page 27: ...using the following parameter vi The session handle returned from niFgen_init 6 Measure the positive DC voltage out of the NI 5421 5441 This is the Measured Positive Full Scale Value Table 6 Values f...

Page 28: ...of the NI 5421 5441 This is the Measured Negative Full Scale Value 11 Call niFgen_AbortGeneration niFgen Abort Generation VI to abort the waveform generation using the following parameter vi The sessi...

Page 29: ...ternal calibration session using the following parameters resourceName The name of the device you want to calibrate This name can be found under Devices and Interfaces in MAX password The password req...

Page 30: ...all the standard NI FGEN functions and attributes with the external calibration session Along with the standard NI FGEN attributes the external calibration session uses a set of calibration constants...

Page 31: ...Ext Cal Session Initialize Analog Output Calibration Adjust Main Path Pre Amp Offset Adjust Main Path Pre Amp Gain Adjust Main Path Post Amp Gain and Offset Adjust Direct Path Gain Adjust Oscillator F...

Page 32: ...to all subsequent NI FGEN functions Adjusting the Analog Output The analog output adjustment procedure has several sub procedures that adjust the following Main path pre amplifier offset Main path pr...

Page 33: ...Fgen_SetAttributeViInt32 to set the offset DAC value niFgen property node Calibration Offset DAC Value using the following parameters vi The session handle returned from niFgen_InitExtCal channelName...

Page 34: ...ANCE value 50 10 Call niFgen_SetAttributeViBoolean to enable the analog output niFgen property node Basic Operation Output Enabled using the following parameters vi The session handle returned from ni...

Page 35: ...ble 7 changing the Analog Filter Enable Pre Amplifier Attenuation and Current Configuration values for each iteration Table 7 Attributes and Values for Main Path Pre Amplifier Offset Iteration Analog...

Page 36: ...The Pre Amplifier Attenuation value for the current iteration from Table 7 7 Take the following voltage measurements at the NI 5421 5441 CH 0 front panel connector into a high impedance load a Call n...

Page 37: ...vi The session handle returned from niFgen_InitExtCal h Wait 500 ms for the output to settle i Use the DMM to measure the voltage output by the device This measurement is measurement 1 which is used...

Page 38: ...measuredOutputs An array containing three elements the three output voltages measurement 0 measurement 1 measurement 2 that you measured in the order that you measured them Adjusting the Main Path Pre...

Page 39: ...eturned from niFgen_InitExtCal channelName 0 attributeID NIFGEN_ATTR_ANALOG_FILTER_ENABLED value The Analog Filter Enable value for the current iteration from Table 8 Table 8 Attributes and Values for...

Page 40: ...rom niFgen_InitExtCal channelName 0 attributeID NIFGEN_ATTR_GAIN_DAC_VALUE value 1500 b Call niFgen_WriteBinary16AnalogStaticValue niFgen Write Binary 16 Analog Static Value VI to set the main DAC val...

Page 41: ...d in step 7 7 Call niFgen_CalAdjustMainPathPreAmpGain niFgen Cal Adjust Main Path Pre Amp Gain VI using the following parameters vi The session handle returned from niFgen_InitExtCal channelName 0 con...

Page 42: ...N_ATTR_ANALOG_FILTER_ENABLED value VI_FALSE 3 Call niFgen_SetAttributeViReal64 to set the pre amplifier attenuation niFgen property node Calibration Pre Amplifier Attenuation using the following param...

Page 43: ...for the current iteration from Table 9 Table 9 Attributes and Values for the Main Path Post Amplifier Gain and Offset Iteration Analog Path Post Amp Attenuation Current Configuration 1 NIFGEN_VAL_FIXE...

Page 44: ...ed from niFgen_InitExtCal c Wait 500 ms for the output to settle d Use the DMM to measure the voltage output by the device This measurement is measurement 0 which is used in step 8 e Call niFgen_SetAt...

Page 45: ...ray containing two elements the two output voltages measurement 0 measurement 1 that you measured in order Adjusting the Direct Path Gain 1 Call niFgen_WriteBinary16AnalogStaticValue niFgen Write Bina...

Page 46: ...Call niFgen_SetAttributeViReal64 to set the post amplifier attenuation niFgen property node Calibration Post Amplifier Attenuation using the following parameters vi The session handle returned from ni...

Page 47: ...value using the following parameters vi The session handle returned from niFgen_InitExtCal channelName 0 value 32767 b Call niFgen_SetAttributeViInt32 to set the gain DAC value niFgen property node Ca...

Page 48: ...InitExtCal channelName 0 attributeID NIFGEN_ATTR_GAIN_DAC_VALUE value 1500 l Call niFgen_Commit niFgen Commit VI to commit the attribute values to the device using the following parameter vi The sessi...

Page 49: ...or can be adjusted and then re measuring the resulting frequency This process is repeated until the difference between the desired and measured frequency falls within the desired tolerance 4 5 ppm Thi...

Page 50: ...ll niFgen_SetAttributeViBoolean to set the digital filter state niFgen property node Output Attributes Digital Filter Enabled using the following parameters vi The session handle returned from niFgen_...

Page 51: ...mples 500 of the waveform you created in step 10 wfmData The array of waveform samples that you created in step 10 wfmHandle The variable passed by reference through this parameter receives the value...

Page 52: ...waveform generation using the following parameter vi The session handle returned from niFgen_InitExtCal d Measure the frequency of the generated waveform This value is the measured frequency 16 Call...

Page 53: ...Fgen_SetAttributeViInt32 to set the offset DAC value niFgen property node Calibration Offset DAC Value using the following parameters vi The session handle returned from niFgen_InitExtCal channelName...

Page 54: ...on Output Enabled using the following parameters vi The session handle returned from niFgen_InitExtCal channelName 0 attributeID NIFGEN_ATTR_OUTPUT_ENABLED value VI_TRUE 11 Call niFgen_Commit niFgen C...

Page 55: ...d from niFgen_InitExtCal numberOfReadsToAverage 3 returnCalibratedValue VI_FALSE calADCValue A ViReal64 variable The variable passed by reference through this parameter receives the voltage measured b...

Page 56: ...r the output to settle 27 Call niFgen_ReadCalADC niFgen Read CAL ADC VI to measure the analog output voltage with the onboard calibration ADC using the following parameters vi The session handle retur...

Page 57: ...calibration ADC in the order that you measured them 33 Call niFgen_SetAttributeViBoolean to disable the analog output niFgen property node Basic Operation Output Enabled using the following parameter...

Page 58: ...ments performed on the NI 5421 5441 restore an external calibration change the external calibration password and store small amounts of information in the onboard EEPROM You can retrieve some data usi...

Page 59: ...the complete function reference The utility functions include niFgen_RestoreLastExtCalConstants niFgen_GetSelfCalSupported niFgen_GetSelfCalLastDateAndTime niFgen_GetExtCalLastDateAndTime niFgen_GetS...

Page 60: ...round the world to help address your support needs For telephone support in the United States create your service request at ni com support and follow the calling instructions or dial 512 795 8248 For...

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