ADLINK PCI-9527 - Manual (Page 51)

Calibration 39
ADLINK Technology Inc. PCI-9527
Copyright 2010 User’s Manual
4 Calibration
This chapter introduces the calibration process to minimize analog
input measurement errors and analog output errors.
4.1 Calibration Constant
The PCI-9527 is factory calibrated before shipment by writing the
associated calibration constants to the onboard EEPROM. Every
time the system boot up, the PCI-9527 driver will load these cali-
bration constants that minimize the error in analog input path and
analog output circuit. ADLINK provides a software API for calibrat-
ing the PCI-9527 whenever users want to calibrate the module.
The onboard EEPROM provides three banks for calibration con-
stant storage in PCI-9527. The bank 0, which is the default bank,
records the factory calibrated constants. Bank 0 is written protec-
tion that prevents any abnormal auto-calibration process occurred
in user’s environment. The banks 1 and 2, which are user-defined
space, provided for user’s self-calibration constants. When user
execute the auto-calibration process, the calibration constants will
be recorded to bank 1 or 2 based on user assignment.
When PCI-9527 boot up, the driver will access the calibration con-
stants and set to hardware automatically. Without user’s assign-
ment, the driver will load constants stored in bank 0. If user wants
to load constants from bank 1 or 2, user can assign the bank 1 or 2
as the boot up bank through software. Once user re-assign the
bank, driver will load the constants when user re-boot the system.
This setting will be recorded to EEPROM and maintains no
change until user modify it.