NI 9218 Calibration Procedure
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© National Instruments
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13
5.
Use the DAQmx Channel Property node to configure the following properties:
a.
AI.Coupling: AC
b.
AI.Excit.Src: Internal
c.
AI.Excit.VoltageorCurrent: Current
d.
AI.Excit.Val: 0.002
6.
Configure the AI voltage task timing according to Table 16.
a.
Set the calibrator to Operate mode (OPR).
b.
Commit the task using DAQmx Control Task Function/VI.
Note
Wait 6 seconds for the AC coupling filter on the NI 9218 to settle before
acquiring samples.
c.
Start the task.
d.
Calculate and record the AC magnitude for each channel on the NI 9218.
NI recommends using the Extract Single Tone Information VI to calculate the
magnitude.
Note
The output of the Extract Single Tone Information is in Vpk. To convert to
RMS, use the following equation:
Vrms
= (
Vpk
) ÷ (
√
2)
e.
Disable the calibrator.
f.
Stop and clear the task.
7.
Compare the AC magnitude to the limits in Table 14.
8.
Repeat steps 2 through 7 for each test point in Table 14.
9.
Disable the output of the calibrator and disconnect it from the NI 9218.
Table 16.
NI 9218 Timing Configuration
Sample Mode
Samples Per Channel
Rate (kHz)
Finite Samples
512 k
51.2