we are doing counter verification for PXIE-6363 and its kind of confusing for us:
First this procedure is counter out put or counter input ?( calibration procedure Aug2010), if it is counter input how we should monitor the data ? and what is the negative and positive input ?
I think what we did according to calibration procedure document of NI is probably counter output , as the VI generates 5 mega HZ freuency and we monitored with scope ( passed the upper limit).
Another Question is in document is written : " Connect your counter positive input to CTR 0 OUT (pin 2) and your counter negative input to D GND (pin 35)." ? so is any pin assigned for negative input or its just digital ground ?
I hope I could make you understand what I am meaning as I am lost in this procedure.
The step specified in the following document:
is a counter output. You should be measuring the frequency of the timebase with an outside source. There is not way to calibrate this, you can only monitor it. This should be 10 Mhz if you are using the 6363. To answer your other questions, you measure with reference to D GND. Hope this helps!