National Instruments 6738, Calibration Procedure

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12 | ni.com | NI 6738/6739 Calibration Procedure
• idleState :
DAQmx_Val_Low
• initialDelay :
0.0
• freq :
5000000.0
• dutyCycle :
0.5
4. Call
DAQmxCfgImplicitTiming
with the following parameters:
• taskHandle :
taskHandle
• sampleMode :
DAQmx_Val_ContSamps
• sampsPerChan :
10000
5. Call
DAQmxStartTask
with the following parameter:
• taskHandle :
taskHandle
The DAQ device generates a 5 MHz square wave.
6. Configure the external counter to measure frequency and use a 1 M Ω impedance.
7. Take a measurement of the square wave using the external counter.
8. Compare the value read by your counter to the test limits shown on the device table in the
Test Limits section. If the value falls between these limits, the device passes the test.
9. Call
DAQmxStopTask
with the following parameter:
• taskHandle :
taskHandle
10. Call
DAQmxClearTask
with the following parameter:
•
taskHandle
:
taskHandle
11. Disconnect the external counter from your device.
Note
If the counter verification procedure determines that the device is outside of
the limits, refer to the Worldwide Support and Services section for assistance in
returning the device to NI.
Adjustment
The following procedure adjusts the analog output of your NI 6738/6739.
At the end of each calibration procedure, these new constants are stored in the external
calibration area of the EEPROM. These values are password-protected, which prevents the
accidental access or modification of any calibration constants adjusted by the metrology
laboratory. The default password is
NI
.
Complete the following steps to perform device analog adjustment with a DMM.
Note
If your DMM has a self-calibration routine, self-calibrate the device before
performing AO adjustment.