ADLINK USB-1210 - Manual (Page 50)

40 Operation & Calibration
FPGA. Loading calibration constants entails loading the values of
TrimDACs firmware stored in the onboard EEPROM.
Dedicated space for storing calibration constants is provided in the
EEPROM. In addition to the bank of factory calibration constants,
there is one user-utilization bank, allowing loading of the Trim-
DACs firmware values either from the original factory calibration or
a subsequently-performed calibration.
The default calibration constants are loaded from the user-utiliza-
tion bank and are the same as those in the factory calibration bank
if no auto-calibration is performed.
Since measurement and output errors may vary depending on
time and temperature, it is recommended that you calibrate the
USB-1210 module in your existing testing environment, as follows.
3.2.2 Auto-Calibration
USB-1210 auto-calibration utility measures and corrects almost all
calibration errors with no external signal connections, reference
voltage, or measurement devices. The USB-1210 provides
onboard calibration reference to ensure the accuracy of auto-cali-
bration. The reference voltage is measured in the production line
by a digital potentiometer and compensated in the software. The
calibration constant is stored after this measurement.
3.2.3 Saving Calibration Constants
Factory-calibrated constants are permanently stored in a bank of
the onboard EEPROM and cannot be modified. When the device
is recalibrated, the software stores the new constants in a
user-configurable section of the EEPROM. To restore original fac-
tory calibration settings, the software can copy the factory-cali-
brated constants to the user-configurable section of the EEPROM.
When auto-calibration is complete, the new calibration constants
can be saved to the user-configurable banks in the EEPROM.
NOTE: NOTE:
The USB-1210 should be warmed up for at least 15 minutes
before initiating auto-calibration