ADLINK PXI-2208 - Manual (Page 98)

86 Calibration
5.2 Auto-calibration
Through the DAQ-/DAQe-/PXI-2204/2205/2206/2208 card auto-
calibration feature, the calibration software measures and corrects
almost all calibration errors without any external signal connec-
tions, reference voltage, or measurement devices.
The DAQ-/DAQe-/PXI-2204/2205/2206/2208 card comes with an
onboard calibration reference to ensure the accuracy of auto-cali-
bration. The reference voltage is measured in the production line
through a digital potentiometer and compensated in the software.
The calibration constant is memorized after this measurement. We
do not recommended adjustment of the onboard calibration refer-
ence except when an ultra-precision calibrator is available.
NOTES
• Warm the card up for at least 15 minutes before initiating auto-cal-
ibration.
• Remove the cable before auto-calibrating the card since the DA
outputs are changed during the process.
5.3 Saving Calibration Constants
When auto-calibration is completed, you can save the new calibra-
tion constants to the user-configurable banks in the EEPROM.
The date and the temperature when you ran auto-calibration is
saved with the calibration constants. You can store three sets of
calibration constants according to three different environments
and re-load the calibration constants later.