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Export to excel from express VI table is not working


Hi Zaqf,


nly a part of the graph is visible , rest of the graph vanishes after stopping.

You are mixing the terms "chart", "graph" and "plot" - and it not clear what you are trying to say here!

Why don't you show an image of your frontpanel when that problem occurs?


How would I get a waveform chart with discrete output ?

What do you understand by "discrete output"?

Best regards,
CLAD expired, using LV2011SP1 + LV2017 (+LV2019 sometimes) on Win7+cRIO
Kudos are welcome Smiley Wink

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Message 61 of 64

@Zaqf wrote:

Discontinous as in after stopping the pgm , only a part of the graph is visible , rest of the graph vanishes after stopping.  I think a waveform graph would solve the issue ? How would I get a waveform chart with discrete output ?

Thank you

Sounds a lot like you're hitting the History Length limit. You can modify this via the Properties for the Chart, or you can store the data you want in a Shift Register (as has already been described) and use a Graph.


Note that either of these imply increasing memory usage as the graph/chart dataset grows. To avoid infinite expansion of your in-memory dataset (and eventual Out-of-memory errors) you can do things like outputting data to file during acquisition, and decimating appropriately over time what is displayed.

Message 62 of 64

Sounds right . I'm not aware how to edit the properties of the chart or to save in the shift register and proceed with graph. 


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Message 63 of 64

There is a lot you should learn about "Basic LabVIEW", including how to plot two channels on one Chart, how to use Index Array to get out both Index 0 and Index 1 without fuss, and how to simplify your VIs and test them part-by-part to figure out where you are making your mistakes.


I took your Exp1 routine, which generates data using a DAQ routine taking 1 sample, N Channels, and doing other things inside the same loop (such as saving to disk and plotting the data).  I deleted the DAQ code, replaced it with generating two random numbers at 100 Hz and output it as an Array, split the Array into Channel 0 and 1, and plotted them on your Charts (I set the Charts to Autoscale Y, but otherwise left them alone).


The problem you have been seeing is not present in this simple VI.  This implies that you are introducing the problem either in your DAQ code or in the File I/O routines in your code.  Try taking this working "Data Generation and Plotting" routine and adding your "Save to Disk" code, see if it has hiccups at 1038 samples (which might imply that your file I/O is taking too much time and your DAQ Task is timing out).


Bob Schor

Message 64 of 64