Display signal from oscilloscope on Waveform Chart has problem

[yangyi]

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@GerdW wrote:

Hi Yangyi,

unfortunately I'm still using LV2017 so you need to downconvert your VI… (Edit->Save for previous)

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[GerdW]

Hi yangyi,

I removed the myRIO stuff from your VI and use again the signal generation function:

I set all charts/graphs to autoscale their X scale…

[yangyi]

Hi GerdW,

I tried autoscale the X scale of chart but it did not work.

The output of signal generation function is in Waveform(DBL) but the output of read oscilloscope VI is in 1D array of waveform(DBL), I am not sure whether yours can simulate the data read from scope?

Yangyi

[GerdW]

Hi yangyi,

as can be seen in the image I also create an array of waveforms (with just one element)…

[yangyi]

Hi GerdW

Sorry, but is the element the 'interleave 1D arrays'? I tried this in my VI but it had some connection errors.

Thanks 

Yangyi

[GerdW]

Hi yangyi,

no, I build an array of waveforms from a single waveform - using BuildArray…

[yangyi]

Hi GerdW,

Thanks, but if I put all of them inside a while loop, the chart could not show expected waveform?

[GerdW]

Hi yangyi,

in your test.vi the graph and chart show the expected waveforms/plots (IMHO).

Maybe your expectation is wrong?

What exactly do you expect?

Do you know the difference(s) between a chart and a graph?

[yangyi]

Hi GerdW,

My expectation is the chart can display dynamic waveform in same shape as graph displaying. But the chart display looks more density? Is it because it reads too fast?

By the way I tried to remove the loop as yours but chart display nothing? I attach the picture and vi without loop.

In my simple understanding, graph can display an array of data in one time but charts can be rolling in new data point to the end of buff?

Thanks,

Yangyi

[GerdW]

Hi yangyi,

when I run your VI all graphs/charts show the same data:

In my simple understanding, graph can display an array of data in one time but charts can be rolling in new data point to the end of buff?

A chart has its own history buffer, whereas a graph only displays the data present in the wire to its terminal. That's why charts allow for "rolling" displays on their own…