NI 6703/6704 Calibration
Procedure for Traditional NI-DAQ
Introduction
This document contains instructions for calibrating the NI 6703/6704 for
PCI/PXI/CompactPCI using Traditional NI-DAQ. Use this calibration
procedure with the
ni6704Cal.dll
file, which contains specific functions
required for calibrating the NI 6703/6704.
The NI 6703/6704 should be calibrated at a regular interval as defined by
the measurement accuracy requirements of your application. National
Instruments recommends that you perform a complete calibration at least
once every year. You can shorten this interval to 90 days or six months.
Note
Refer to
ni.com/support/calibrat/mancal.htm
for a copy of the
ni6704Cal.dll
file.
Calibration Options: External Versus Internal
NI 6703/6704 products have two calibration options, an internal or
self-calibration, and an external calibration.
Internal Calibration
The NI 6703/6704 is continuously applying corrections to the output levels
based on previous calibration results. Both the NI 6703 and the NI 6704
have 16 voltage outputs and two voltage calibration channels. The NI 6704
also has 16 current outputs and two current calibration channels. All the
output and calibration channels are scanned and refreshed together. The
outputs of the calibration channels for the NI 6703/6704 are continuously
compared to the onboard reference, and the offset and gain of the 16-bit
digital-to-analog converter (DAC) are adjusted to minimize the error of the
calibration channels. Because the NI 6703 and NI 6704 have excellent
channel-to-channel matching of offset and gain errors, minimizing the error
on the calibration channels also minimizes the error for all of the voltage
and current outputs.
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