User's Manual

Chapter 2 Function Reference — Calibrate_E_Series
NI-DAQ FRM for PC Compatibles 2-62
© National Instruments Corporation
Calibration Constant Loading by NI-DAQ
NI-DAQ automatically loads calibration constants into calDACs whenever you call functions
that depend on them (
AI, AO, DAQ, SCAN, and WFM functions). The following conditions apply:
12-bit E Series Devices 16-bit E Series Devices
• The same set of constants is
correct for both polarities of
analog input.
• One set of constants is valid for
unipolar, and another set is valid
for bipolar configuration of the
analog output channels. When you
change the polarity of an analog
output channel, NI-DAQ reloads
the calibration constants for that
channel.
• Calibration constants required by the 16-bit
E Series devices for unipolar analog input
channels are different from those for bipolar
analog input channels. If you are acquiring
data from one channel, or if all of the channels
you are acquiring data from are configured for
the same polarity, NI-DAQ selects the
appropriate set of calibration constants for
you. If you are scanning several channels, and
you mix channels configured for unipolar and
bipolar mode in your scan list, NI-DAQ loads
the calibration constants appropriate for the
polarity that analog input channel 0 is
configured for.
• Analog output channels on the
AT-MIO-16XE-50 can be configured only for
bipolar operation. Therefore, NI-DAQ always
uses the same constants for the analog output
channels.