Measuring the frequency of a pulsed input

[RobC]

Hi

I am using the analogue NI USB-6008 DAQ to measure a pulsed signal and would like LabVIEW to measure the frequency of this signal using the Timing and Transition Measurements block. However, I get an error saying that the input waveform is zero (occasionally adding that as a result of this the histogram method cannot be used).

This happens regardless of the input frequency I am applying. I have attached my VI.

Thanks

Rob

[LeeM]

Hello Rob,

I am afraid that the USB 6008 does not have the functionality to measure pulses. It can only do simple edge counting (on the falling edge only). For more complex operations on inputs such as the pulse width measurements you are after, and frequency measurements, the least expensive device i think you will find would be the USB 6210.

You can also perform approximate edge counted frequency measurements in software on the USB 6008 as can be seen at this developer zone page:

http://zone.ni.com/devzone/cda/epd/p/id/513

Hope this helps,

LeeM
NIUK

[Miaa]

Hello there,

So can we use the code in http://zone.ni.com/devzone/cda/epd/p/id/513 to work with USB6210 or what changes do we have to make in it to measure the frequency of an application. The application is changing frequency from 10 Hz to 2500Hz.

I used USB6008 for measuring the frequency of an application. And am not getting good results, recently got USB6210 and was hoping if there is any example for measuring the frequency using USB6210.

Thanks

[Miaa]

Hello there,

Was just reading your thread and was thinking if its possible to use the code in http://zone.ni.com/devzone/cda/epd/p/id/513 to work with USB6210 or what changes do we have to make in it to measure the frequency of an application. The application is changing frequency from 10 Hz to 2500Hz.

I used USB6008 for measuring the frequency of an application. And am not getting good results, recently got USB6210 and was hoping if there is any example for measuring the frequency using USB6210.

Thanks

[Dennis_Knutson]

Help>Find Examples>Hardware Input & Output>DAQmx>Digital Frequency>Meas Dig Frequency-Low Freq 1 Ctr.vi

[Miaa]

thanks Dennis for your prompt reply. Will this example work with USB 6210 ? I am thinking of using USB6210 instead og USB 6008 to measure the frequency of my signal.

Thank you once again.

[Dennis_Knutson]

I know you are trying to use the 6810. You mentioned that in both of your posts above.

Do you see the 'Requirements' box in the example finder? It says right there what hardware can run the example.