What would you like to calibrate on this device? The input thresholds are roughly the same as TTL, so they cannot be adjusted and you must provide the reference voltage for the outputs, so you would have to calibrate that device yourself. As far as the timebase source goes, you cannot calibrate it, but you could measure its accuracy and make adjustments yourself. There are verification instructions for the 6601/02 here which could serve as a starting point, but you'll have to use RTSI lines instead of the PFI lines for measurements to bypass the optocouplers.
I hope this helps!
gus....
