NI PXIe-4339 Calibration Procedure
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© National Instruments
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11
These values will be used to adjust the paired channels measurement of the excitation
voltage. Use the following formula to adjust the measurements:
Vadj_chx
= (
Vmeas_chx
-
Oadj_chx
) *
Gadj_chx
10. Set the calibrator voltage output to a
Test Point
value for the appropriate excitation voltage
indicated in Table 8, beginning with the settings in the first row.
For the first test point, set the calibrator to operate mode (OPR) to enable output.
11. Simultaneously acquire a ratiometric (V/V) measurement of the channel being verified and
a voltage measurement of the paired channels excitation with the NI PXIe-4339.
a.
Create a DAQmx task.
b.
Create and configure the AI Bridge (V/V) measurement using the values in Table 6.
c.
Commit the task to turn on and set the excitation voltage using the following
parameters:
Task
: DAQmx control task
task/channels in
: <task_out from the previous step>
action
: Commit
d.
Use the paired channels to simultaneously measure the excitation of the ratiometric
(V/V) channels that are being verified. This is accomplished by configuring the paired
channels for voltage mode and adding them to the task that was configured in step 11b
using the values in Table 7.
Table 6.
V/V Measurement Parameters
Configuration
Value
Channel Name
Dev1/ai0,ai2,ai4,ai6
Task
AI Bridge (V/V)
Task Out
<task_out>
Sample Mode
Finite number of samples
Sample Clock Rate
100
Samples Per Channel
100
Excitation Voltage
Appropriate excitation voltage
value from Tables 8 through 15
Maximum Value
Range Max from Tables 8 through 15
Minimum Value
Range Min from Tables 8 through 15
Units
V/V
