Hi all, I have searched the forum but have not found what I needed, unfortunately I do not have time to read everything posted. Basically I have a main VI that updates about every 200ms or so. This VI measures temperatures, controls an analog out and measures analog in voltages. I need to measure the frequency of two pulsed flowmeter signals, 0-10V square pulses, the frequency regularly goes all the way to zero (at this point I am guessing my max frequency would be about 100Hz). Using NI 9217, 9201 and 9263 modules on an 8 slot USB cDAQ.I think this means I do not have access to any counters.The 9201 also measures two additional voltages that do not need to be sampled fast at all. A few questions: - I assume I need to use two loops here, the main VI and one, that should run faster, to measure frequency (or pulses)? - I found a VI that counts pulses (attached), modified it a bit to give me an average pulse count/min but I do not know how to make it work in my VI, this counter wants a 1D array of Waveform as its input, what I actually have is a Waveform out When taking the Y waveform component and feeding that into the Counter VI the values are wacko and depend on how fast the main VI updates. - If the main VI updates every 200ms should the DAQ read VI be in the faster loop? - I have tried to use the various waveform, pulse, period measurement VI's but these all give an error at a frequency of 0 or 1 Hz - I have used the timing and transition measurement VI for this and wired the error out to a case structure and made the 'error out = true' case empty, this seems to be working but I'd think there must be a better way than that. In addition, I need to average that signal over a timespan of a few minutes. I hope the above made some sense. I'd be happy to try and clarify. A hint in the right direction would be appreciated. Thanks much Arne

I just got back from holiday festivities. Thanks very much for your efforts. I will try and incorporate this into my VI.

Multifunction DAQ

Solved!

I found this to be very helpful - thank you Sean!

BR;
Shaun

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