Hmm, that VI isn't even displaying the reading just trying to fetch it. So how are you seeing large numbers? Are they on the instrument panel then? Why not record the readings in code? (i.e. wire the results to the while loop with a shift register and display the array or plot)
A comments about this VI.
- Fetch Measurement.VI cleary states that if no valid measurement exists then it returns Not a Number 9.91E+37 and throws error -230. Is that what you get? Then there's something wrong with how you configure the measurement.
- You should read the error in the While loop.
- An estimate of the Frequency to be measured is always a good idea, especially if your signal has some noise. It gives the instrument a starting range and helps prevent it from looking at much faster signals.
- Does Abort disable the Auto triggering? I'm not sure but if it does you need to re-enable on every loop.
- You might try changing the trigger conditions. What is the input voltage? Perhaps you are in the signal noise?
- You have a timeout of 70s. A 0Hz signal will take Inf time to acquire, not to mention be purely DC. A frequecy counter is not going to like that sort of signal very much. So what is your true frequency, what does the signal look like on a scope. (What does scope say about frequency?) If you are trying to measure 0.01Hz try giving the meter a few minutes to acquire the frequency.
It strikes me that maybe you are just trying to setup the code and though the meter should easily read 0Hz. If that's the case, then perhaps you need to rethink your development test case. Use a frequency generator or oscillator chip with a nice 1V signal at 1kHz and develop the code using that. Better yet make your test case as similar to your measurement case as possible. Then move to the real signal and apply filter and fine tune the triggering.
