SNAP-AOV-25 to SNAP-AIV


#1

Trying to understand readings expected for wiring a 10V output to a +/-10V input when calibrating on a B3000 Mistic mode. Firmware chips just changed to R81.36.

If I set output to 0 counts, and send ‘calculate and set offset’, then set output to 4095 and send ‘calculate and set gain’, then read the AIV module current counts, a 4095 on the output is 24999 on the input, and 0 on the output is near 0 on the input.

I would have expected the module to read 0 at 0V and 4095 at 10V when I use my AOV-25 to generate 0V and 10V and calibrate offset at 0V and gain at 10V.

Does an offset calculation expect 0V or -10V on the AIV +/-10V input for low scale?


#2

I am writing Python3.4 code to talk to my B3000 on Linux. I am running through the command responses to verify operation, thus the original question.

I see part of the answer in the “Using Offset and Gain Technical Note” which says, “Note that minimum scale on a bipolar module is a negative number. For example, minimum scale on a
SNAP-AIV is –10 V, not 0 V”.

So what I am trying to do is send 0 to 10V from an analog output module to a +/-10V analog input module and verify operation of the various analog commands. Right now working through the engineering units vs counts conversions.