I have an old industrial PC that still uses the PCI-DAC6703. I have a few channels that have drifted and it appears that the internal calibration ref voltage has drifted also because calibrating with instacal does not solve the issue. As such, I've had to use offsets to overcome the decreasing voltage output.
I know that this is a legacy card, do you still calibrate or work on these? If so, how do I arrange this?