Chapter 3
Adjustment
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National Instruments Corporation
3-17
actualData
should be a pointer to the terminated un-attenuated output
(
lowFrequencyAmplitudeTerminated
). Call the function
ni54xx_CalAdjust
using the following parameters:
•
sessionHandle
—The handle of the calibration session for the
device
•
measurementMode
—
NI54XX_SET_A9_TERMINATED
•
actualData
—
&lowFrequencyAmplitudeTerminated
•
measuredData
—
attenuatedAmplitudesTerminated
13. Call
ni54xx_CalAdjust
for A9TA. The
measuredData
should be a pointer to the terminated un-attenuated output
(
lowFrequencyAmplitudeTerminated
) and the
actualData
should be a pointer to the unterminated un-attenuated output
(
lowFrequencyAmplitude
). Call the function
ni54xx_CalAdjust
using the following parameters:
•
sessionHandle
—The handle of the calibration session for the
device
•
measurementMode
—
NI54XX_SET_A9TA
•
actualData
—
&lowFrequencyAmplitude
•
measuredData
—
&lowFrequencyAmplitudeTerminated
Determining the Value of the On-Board
High-Precision Voltage Reference
This calibration constant stores the actual value of the on-board
high-precision voltage reference. The value of this reference relative
to device output can be routed to the on-board analog-to-digital converter
(the calibration ADC). If you measure the value of the device output,
you can subtract the ADC value from this result to obtain the internal
reference. Offsets for the calibration ADC are accounted for internally,
so you only need to measure the ADC value and the device output value.