ADLINK PCI-9524 - Manual (Page 89)

Calibration 73
ADLINK Technology Inc. PCI-9524
Copyright 2008 User’s Manual
5 Calibration
This chapter introduces the calibration process to minimize AD
measurement errors and DA output errors.
5.1 Loading Calibration Constants
The PCI-9524 is factory calibrated before shipment by writing the
associated calibration constants of TrimDACs firmware to the on-
board EEPROM. TrimDACs firmware is the algorithm in the
FPGA. Loading calibration constants is the process of loading the
values of TrimDACs firmware stored in the on-board EEPROM.
ADKLINK provides a software utility for reading the calibration
constants 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 are three more user-utilization banks. That means
users can load TrimDAC firmware values either from the original
factory calibration or from a calibration that is subsequently per-
formed.
Because errors in measurements and outputs will vary with time
and temperature, it is recommended to re-calibrate when the card
is installed in the user's environment. The auto-calibration function
used to minimize errors will be introduced in the next sub-section.