duty cycle measurement hardware.

[Bouwser]

I need to measure the duty cycle of a 10 - 300 Hz PWM, with a minimum on time of 275 us and a minimum off time of 100 us and duty cycle resolution of .125%. I plan to use labWindows CVI. What hardware would be capable for these measurements?  I've already spent about 45 minutes searching NI's website for this information, so please don't chastise me if this question has been answered already.

thanks,

Brent

[JÞB]

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Why is this required wrote:

I need to measure the duty cycle of a 10 - 300 Hz PWM, with a minimum on time of 275 us and a minimum off time of 100 us and duty cycle resolution of .125%. I plan to use labWindows CVI. What hardware would be capable for these measurements?  I've already spent about 45 minutes searching NI's website for this information, so please don't chastise me if this question has been answered already.

thanks,

Brent

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1/(1/300Hz*.00125)=240000hz so a minimum 250 Khz counter-timer is needed to meet your spec.

 Google Search shows several available from Keithley, MCC and others in PCI, PC/104, USB, and other formats.  You haven't stated the voltage of the signal or the desired PC conectivity but the link should get you started

[Seth_B.]

Depending on what form factor you want (PCI, USB, etc.) and the number of signals you need to measure, a PCI 6220 would meet your needs. The counters operate up to 20 MHz and should easily be capable of the measurement you describe.

Regards,