ADLINK DAQe-2502 - Manual (Page 69)

Calibration 59
5 Calibration
This chapter introduces the calibration process to minimize AD
measurement errors and DA output errors.
5.1 Loading Calibration Constants
The DAQ-/DAQe-/PXI-2502/2501 card is factory-calibrated before
shipment. The associated calibration constants of the TrimDACs
firmware to the onboard EEPROM. TrimDACs are devices con-
taining multiple DACs within a single package. TrimDACs do not
have memory capability. That means the calibration constants do
not retain their values after the system power is turned off. Load-
ing calibration constants is the process of loading the values of
TrimDACs firmware stored in the onboard EEPROM. ADLINK pro-
vides a software utility that automatically reads the calibration con-
stants automatically, if necessary.
There is a dedicated space for storing calibration constants in the
EEPROM. In addition to the default bank of factory calibration con-
stants, there is one user-utilization bank. This bank allows you to
load the TrimDACs firmware values either from the original factory
calibration or from a subsequently-performed calibration.
Because of the fact that measurements and outputs errors may
vary depending on time and temperature, it is recommended that
you calibrate the card when it is integrated in your computing envi-
ronment. The auto-calibration function is presented in the follow-
ing sections.