Counter/Timer
Two-edge separation and arm vs. read
Solved!
That worked!
I set the Implicit Timing VI to Finite Samples and a buffer size of 2. (It wouldn't let me set it to 1.)
I do get a warning later on that I prematurely stopped my finite acquisition, but I can live with that.
Thanks for the suggestion!
Here's an answer from NI, confirming Kevin's solution...
They mentioned that whether the Counter Tas is armed by the DAQmx Start is dependent on the sampling timing type. In this case, for On-Demand mode the counter task is not armed until you call the DAQmx Read function while Implicit or Sample Clock timing allows the counter task to be armed with the DAQmx Start so this is why the workaround that they suggested on the forum works.
...
So we already filed a bug for this behavior since that is not a known good workaround for single sample measurement. Just in case that you are interested, the CAR number is 1486552.
