National Instruments 446 Series Скачать руководство пользователя страница 11 | Manualshive

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National Instruments 446 Series Скачать руководство пользователя страница 11

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National Instruments Corporation

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NI 446X Calibration Procedure

Self-Calibration

Call self-calibration before completing the first verification. This function
measures the onboard reference voltage of the device and adjusts the
self-calibration constants to account for any errors caused by short-term
fluctuations in the operating environment. When you self-calibrate a
device, no external signal connections are necessary.

NI 446

X

Verification Procedure

Verification determines how well the NI 446

X

device is meeting

specifications. By completing this procedure, you can see how the device
has drifted over time, which helps you determine the appropriate
calibration interval for your application.

Verifying Analog Input Performance

This section verifies the analog input (AI) performance of all NI 446

X

devices. Refer to the

NI 446X Specifications

for the number of channels,

gain settings, and performance specifications.

NI-DAQmx Function Call

LabVIEW Block Diagram

Call

DAQmxSelfCal

with the following

parameters:

deviceName

:

dev1

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Содержание 446 Series

Страница 1: ...your application NI recommends that you perform a complete calibration at least once every year Based on your measurement accuracy needs you can shorten this interval to 90 days or six months Self cal...

Страница 2: ...word or value that you must supply monospace Monospace text denotes text or characters that you should enter from the keyboard sections of code programming examples and syntax examples This font is al...

Страница 3: ...stants it invalidates the original calibration certificate If an external calibration is done with traceable instruments a new calibration certificate can be issued Software and Documentation Requirem...

Страница 4: ...rt All Programs National Instruments NI DAQmx Base Documentation C Function Reference Manual DAQ Getting Started Guide for NI DAQ 8 1 or later This guide describes how to install your NI DAQmx for Win...

Страница 5: ...different ways Refer to the standard of that language for information about how to write the character into a string You can write user defined information into or read from the EEPROM using the follo...

Страница 6: ...ion stored in the EEPROM Whether the device supports self calibration Date and time of the last self calibration Temperature during the last self calibration Recommended interval for external calibrat...

Страница 7: ...uInt32PointerReturnValue hour uInt32PointerReturnValue minute uInt32PointerReturnValue Call DAQmxGetSelfCalLastTemp with the following parameters deviceName dev1 data float64PointerReturnValue Call D...

Страница 8: ...etExtCalLastTemp with the following parameters deviceName dev1 data float64PointerReturnValue Call DAQmxGetCalDevTemp with the following parameters deviceName dev1 data float64PointerReturnValue LabVI...

Страница 9: ...e optimum relative humidity Maintain the temperature between 18 and 28 C or refer to the device specifications for the optimum temperature range Allow a warm up time of at least 15 minutes to ensure t...

Страница 10: ...rocedures are explained in the following sections Note You must compare the verification limits provided in this procedure with the most recent specifications Refer to the latest NI 446X device specif...

Страница 11: ...e necessary NI 446X Verification Procedure Verification determines how well the NI 446X device is meeting specifications By completing this procedure you can see how the device has drifted over time w...

Страница 12: ...p 3 in LabVIEW You use the object myTaskHandle in all subsequent NI DAQmx function calls 3 Create an AI voltage channel through NI DAQmx using the following function NI DAQmx Function Call LabVIEW Blo...

Страница 13: ...lowing parameters taskHandle myTaskHandle channel dev1 ai0 data 20 0 Call DAQmxSetAICoupling with the following parameters taskHandle myTaskHandle channel dev1 ai0 data DAQmx_Val_DC NI DAQmx Function...

Страница 14: ...lowing parameters taskHandle myTaskHandle numSampsPerChan 1 timeout 10 0 fillMode DAQmx_Val_GroupByChannel arraySizeInSamps 102400 reserved NULL readArray float64ArrayReturnValue sampsPerChanRead int3...

Страница 15: ...nnel and channel Verifying AI Gain Accuracy Complete the following steps to verify AI gain accuracy 1 Connect the output of the calibrator to the analog input channel 0 of the device 2 Output 9 0 VDC...

Страница 16: ...with the following parameters taskHandle myTaskHandle physicalChannel dev1 ai0 nameToAssignToChannel terminalConfig DAQmx_Val_PseudoDiff minVal 10 0 maxVal 10 0 units DAQmx_Val_Volts CustomScaleName N...

Страница 17: ...llowing function NI DAQmx Function Call LabVIEW Block Diagram Call DAQmxCfgSampClkTiming with the following parameters taskHandle myTaskHandle source NULL rate 204800 0 activeEdge DAQmx_Val_Rising sam...

Страница 18: ...e limits V in Table 3 NI DAQmx Function Call LabVIEW Block Diagram Call DAQmxReadAnalogF64 with the following parameters taskHandle myTaskHandle numSampsPerChan 1 timeout 10 0 fillMode DAQmx_Val_Group...

Страница 19: ...owing steps to verify AO DC offset 1 Connect the analog output channel 0 of the device to the input of the multimeter 2 Create an array of double float of size 1024 Initialize all the values in the ar...

Страница 20: ...all LabVIEW Block Diagram Call DAQmxCreateAOVoltageChan with the following parameters taskHandle myTaskHandle physicalChannel dev1 ao0 nameToAssignToChannel minVal 10 0 maxVal 10 0 units DAQmx_Val_Vol...

Страница 21: ...on Call DAQmxSetAOTermCfg with the following parameters taskHandle myTaskHandle channel dev1 ao0 data DAQmx_Val_PseudoDiff LabVIEW Block Diagram NI DAQmx Function Call LabVIEW Block Diagram Call DAQmx...

Страница 22: ...AQmxCfgSampClkTiming with the following parameters taskHandle myTaskHandle source NULL rate 204800 0 activeEdge DAQmx_Val_Rising SampleMode DAQmx_Val_ContSamps sampsPerChanToAcquire 1024 NI DAQmx Func...

Страница 23: ...Repeat steps 3 through 12 for all remaining gain values used in step 5 Refer to Table 4 for all the device gain values NI DAQmx Function Call LabVIEW Block Diagram Call DAQmxStartTask with the followi...

Страница 24: ...vice AO 0 4 If you use C function calls create a task using the following function If you use LabVIEW skip this step The task is created in step 5 in LabVIEW You use the object myTaskHandle in all sub...

Страница 25: ...mxSetAOIdleOutputBehavior with the following parameters taskHandle myTaskHandle channel dev1 ao0 data DAQmx_Val_HighImpedance Call DAQmxSetAOGain with the following parameters taskHandle myTaskHandle...

Страница 26: ...DAQmx Function Call LabVIEW Block Diagram Call DAQmxSetWriteRegenMode with the following parameters taskHandle myTaskHandle data DAQmx_Val_AllowRegen NI DAQmx Function Call LabVIEW Block Diagram Call...

Страница 27: ...l LabVIEW Block Diagram Call DAQmxWriteAnalogF64 with the following parameters taskHandle myTaskHandle numSampsPerChan 1024 autoStart FALSE timeout 10 0 dataLayout DAQmx_Val_GroupByChannel writeArray...

Страница 28: ...46X devices All analog inputs use a single circuit on each device The NI 4461 analog output channels also use the same timebase frequency circuit Therefore you need to verify only the analog input fre...

Страница 29: ...oltage channel through NI DAQmx using the following function NI DAQmx Function Call LabVIEW Block Diagram Call DAQmxCreateTask with the following parameter taskHandle mytaskHandleReturnValue LabVIEW d...

Страница 30: ...ters taskHandle myTaskHandle channel dev1 ai0 data 0 0 Call DAQmxSetAICoupling with the following parameters taskHandle myTaskHandle channel dev1 ai0 data DAQmx_Val_DC NI DAQmx Function Call LabVIEW B...

Страница 31: ...nction Call LabVIEW Block Diagram Call DAQmxReadAnalogF64 with the following parameters taskHandle myTaskHandle numSampsPerChan 1 timeout 100 0 fillMode DAQmx_Val_GroupByChannel arraySizeInSamps 25600...

Страница 32: ...constants are stored in the external calibration area of the device EEPROM which ensures that you do not accidentally access or modify any calibration constants adjusted by the metrology laboratory wh...

Страница 33: ...calibration or if you do not want to save the new AI calibration constants in the device EEPROM Use the action commit if you want to save the new AI calibration constants in the device EEPROM NI DAQmx...

Страница 34: ...Device Output Voltage Requested High Voltage listed in Table 7 for 40 dB device gain Use this array to output a DC voltage using the device analog output channel 0 5 If you use C function calls create...

Страница 35: ...m Call DAQmxCreateAOVoltageChan with the following parameters taskHandle myTaskHandle physicalChannel dev1 ao0 nameToAssignToChannel minVal 10 0 maxVal 10 0 units DAQmx_Val_Volts customScaleName NULL...

Страница 36: ...etAOTermCfg with the following parameters taskHandle myTaskHandle channel dev1 ao0 data DAQmx_Val_PseudoDiff LabVIEW Block Diagram NI DAQmx Function Call LabVIEW Block Diagram Call DAQmxSetWriteRegenM...

Страница 37: ...ck Diagram Call DAQmxCfgSampClkTiming with the following parameters taskHandle myTaskHandle source NULL rate 204800 0 activeEdge DAQmx_Val_Rising SampleMode DAQmx_Val_ContSamps sampsPerChanToAcquire 1...

Страница 38: ...ion 15 Repeat steps 4 to 14 using the Requested Low Voltage for 40 dB device gain from Table 7 Record the multimeter DC voltage measurement as actualLowVoltage NI DAQmx Function Call LabVIEW Block Dia...

Страница 39: ...vice Replace ao0 with ao1 in the function call parameters physicalChannel and channel NI DAQmx Function Call LabVIEW Block Diagram Call DAQmxAdjustDSAAOCal with the following parameters calHandle myCa...

Страница 40: ...nerator to the analog input 0 of the device 2 Output a sine wave using the function generator The sine wave should have an amplitude of 9 Vp p no offset and a frequency of 1 000 000 Hz 3 Initialize th...

Страница 41: ...ebase calibration or if you do not want to save the new timebase calibration constants in the device EEPROM Use the action commit if you want to save the new timebase calibration constants in the devi...

Страница 42: ...oduct supports calibration you can obtain the calibration certificate for your product at ni com calibration National Instruments corporate headquarters is located at 11500 North Mopac Expressway Aust...

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