How to measure duty cycle of very low frequency digital signal?

[Nishant]

Hiii, All

          I want to measure the duty cycle of the digital signal which hasminimal frequency at a time, i have tried through the express vi Timing and Transition measurments which measures the duty cycle, but it has the limitation that it is giving an error for the signal with the frequency lower than 17hz, so how should i measure the duty cycle of this signal? please suggest me something.

Thanks in advance,

Nishant Desai

[davidpcl]

Just as a possible idea you could maybe compress the signal you've got by removing a certain number of samples so that it appears to be a higher frequency i.e remove every other sample which should double the frequency then divide the resultant duty cycle by 2 but you might lose some detail that way. Other than that there should be a way using the .Vi's in the waveform palette to be able to manipulate your waveform to change its fundamental frequency - I've found one that gives you an example of how to set a waveform properties that might help :-

Create Waveform example.vi in the labview\examples\waveform\Operations.llb

Then just rescale all your results - this vi is for analogue, but there are some equivalent .vis in the Waveform\digital waveform palette.

I don't know if that helps you or not, but good luck with it.