Detect frequency of a square wave with LabVIEW6.1

[FMS]

Hello,
I am a "rookie" with using LabVIEW. I am working with LabVIEW6.1 and a DAQ 6024E device. I want to measure the frequency of non-constant square wave (from a flowmeter).
I already tried with "Auto Power Spectrum.vi" and "Power and Frequency Estimate.vi". It does not work -maybe because the wave is square.
Currently I am trying to work by counting rising edges, and after dividing them by time... I am not sure it is working.
Would you have any other ideas?

Thanks a lot for your attention

[Doug_Norman]

Try running the Example Finder - from the menus go to Help>>Find Examples... Search on "frequency". If your signal is TTL, the (DAQ-STC) examples will work for you using counters.

Best Regards,
Doug Norman

[Bill B]

Hello,

Your 6024E board has two general purpose counters which can be used to measure the frequency of a TTL logic level signal. There is an example program titled Measure Period.vi. You can use this example to measure the period of your signal and then take the inverse of that value to determine the frequency. You will connect your signal to pin 3(GPCTR0_GATE) of your 6024 and the ground to pin 36(DGND). Please see the screenshots listed below for assistance.