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Waveform Min Max.vi sample rate

Hello All,

 

I'm looking for some help - So I'm currently outputting multiple virtual waveforms with noise then averaging them (these will in time be real sinusoidal waveforms when I get the rest of the modules I need with a varying frequency over time), I then want to get the minimum and maximum of the average of each cycle, but when I'm using the Waveform Min Max.vi it seems to be sampling at 10Hz as standard and I'm unsure how to change this. 

 

I've tried using shift register to save the Min Max, then reset it every x seconds to match the frequency, but this doesnt work very well and I was wondering if there is an easier way.

 

Any help would be really appreciated - thanks!

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Message 1 of 5
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The min and max is independent of any timing and the respective time points are output based on the timing of the original waveform. If your dt changes, it is no longer a waveform.

 

Please attach a simplified version of you code so we can see what you are doing.

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So here's a really simplified version.  So when I run this, it gives the min max of the wave as its running at 10Hz perfectly as I want it, when I change the frequency, it then takes the min max from only part of the wave. 

 

So (since I've offset it) with an amplitude of 1, the min,max is 0,2 and this is shown in the min max when it's running at 10Hz, but when I change it to say 5Hz, it will only take the Min Max from whatever 1/2 of the pulse it's checking.

 

I just want it to take the min max at a rate equal to the frequency so I can see the min max of each pulse.

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Message 3 of 5
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Hi girl,

 


@robotgirl wrote:

So here's a really simplified version. 


All we got is an image of a block diagram containing some expressVIs.

You know we cannot edit/debug/run images with LabVIEW?

 


@robotgirl wrote:

So (since I've offset it) with an amplitude of 1, the min,max is 0,2 and this is shown in the min max when it's running at 10Hz, but when I change it to say 5Hz, it will only take the Min Max from whatever 1/2 of the pulse it's checking.

 

I just want it to take the min max at a rate equal to the frequency so I can see the min max of each pulse.


From your description and that image I guess you need to OBEY NYQUIST AND SHANNON!

Best regards,
GerdW


using LV2016/2019/2021 on Win10/11+cRIO, TestStand2016/2019
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Message 4 of 5
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You have dynamic data, not even waveforms (notice the coercion dot)?

 

As has been said, express VIs and dynamic data are too opaque to tell what you are doing. You need to attach your VI.

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Message 5 of 5
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