01-09-2017 11:58 AM
I am performing an analog acquisition with a NI USB-216. It is started using an Daqmx StartTrigger.vi, set for digital edge, on PFI2 (I am externally triggering the acquisition). This part works fine. As the AI acquisition occurs I need to control one digital I/O line several milliseconds after the acquisition starts. The timing need to be precise. I wish to use the start of the analog acquisition for the start of a millisecond timer (T0), then after several milliseconds set a Digital line high. I can't seem to find a proper working way that would allow me to do this. I tried using StartTrigger.vi setting it for digital edge on PFI2. That didn't work, Also tried using ExportSignal.vi to export setting input as "StartTrigger" and directing it out to PFI15 which is hardwired to another port line which I try to read but could'nt get that to work either. Seems I would need to run that in a loop to keep reading the port and I didn't want to do that. Any help would be appreciated.
Solved! Go to Solution.
01-10-2017 08:40 AM
You could define a single pulse generation task on one of your counters, using the same Start Trigger from PFI2. Then your digital output will be timed very precisely by your daq hardware.
-Kevin P
01-10-2017 09:12 AM
I've read about doing it that way, was thinking there was a simplier way to do it. But, this is acceptable and should work fine. Thanks...