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DAQ Assistant, Statistics and graph representation

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Hi,

I am currently using a DAQ assistant to collect voltage from 2 channels, then substract one to the other, and look for the mean value of this result.

Capture.PNG

When I add a graph indicator after the soustraction, I obtain a representation over time refreshed regularly of the result, moving from right to left.

When I add a graph indicator after the Statistics -> mean VI, I just obtain a point at the center, evolving up and down showing the mean value, but not from right to left, plotting a line between all the mean values produced over time.

In other words, I would like to have the mean plotted over time the same way I have the soustraction plotted at the beginning.

I looked for a lot of solutions, with waveform analysing and extraction on this forum, and I could not reach my goal. It seems to me really simple, but still I can not achieve to do that.

Thanks for your help !

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Solution
Accepted by topic author Magea

Hi Magea,

 

still I can not achieve to do that

The DAQ Assistent gives you a waveform with more than one sample per channel. After the statistics you get a mean value: just one sample.

This ONE sample is plotted in your graph - just as it should.

 

When you want to have a plot over "time" you could use a chart instead of a graph!

 

When you want to understand your own VI I recommend to get rid of all those ExpressVIs and all those DDT wires…

Best regards,
GerdW


using LV2016/2019/2021 on Win10/11+cRIO, TestStand2016/2019
Message 2 of 8
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Hi GerdW,

I understand what you mean.

About the "try not to use DAQ assistant etc etc", let's say that I have no time to go deeper in my knowledge of Labview and learn how to make that properly 😕

What do you mean by "chart" exactly ? In Labview I mean. I do not get which VI or strategy you advise me to use.

Best regards

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Hi Magea,

 

a chart is something different than a graph - as is written in the LabVIEW help

Best regards,
GerdW


using LV2016/2019/2021 on Win10/11+cRIO, TestStand2016/2019
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I can not find any example of chart on the computer I am using, and no reference in the search palette ...

Am I bad or may I not have it in my soft ? Its Labview 2001 Service Pack 1

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Hi Magea,

 

when using LabVIEW2011SP1 you can open the example finder to find examples for graphs and charts.

In the search tree you will find it under "creation of User Interfaces" (or similar, I'm using the German LabVIEW version)…

Best regards,
GerdW


using LV2016/2019/2021 on Win10/11+cRIO, TestStand2016/2019
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This is not my computer, so I do not know what have been done before, but I have 0 examples ... ahah

I found a way : instead of looking for it from palette,  I went in the "replace" command from the front pannel.

It works fine ! 

Thank you. 

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The chart is certainly available on your controls palette when you are viewing the front panel. Of you are searching for it when you are on the block diagram, you really need to take some of those free tutorials.
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