Possible to add elapse time to stop displaying chart in labview?

[JiaLuo08]

Isit possible to add in elapsed time function to  stop chart from displaying after 20seconds?

[Bob_Schor]

I am not clear what you mean by your question, but if you want to have a chart stop updating (you said "displaying", but I'm assuming you don't want the chart, itself, to vanish).  All you need to do is to stop writing to its indicator.  There are a variety of techniques (including using Elapsed Time, though that is a function I have yet to use, myself) to do this.  

Write a little demo program where you generate random numbers 10 times a second, and see if you can display only the first 20 seconds, using Elapsed Time to "disconnect" the Chart from the random number generator.  If you are still having trouble, post your code (by attaching your VI, not a picture of it) and we'll help.

Bob Schor

[crossrulz]

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@JiaLuo08 wrote:

Isit possible to add in elapsed time function to  stop chart from displaying after 20seconds?

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Do you have a fixed sample rate for your signal?

If so, you just need to set the history length of the chart to be 20 seconds worth of samples (20 second * F Samples/second).

If not, then you will need to change to an XY graph and keep your own history with shift register.  Any sampled older than 20 seconds should just be removed from the array.

[JiaLuo08]

I've tried adding the elapse time, however have no clue how to link it to the chart. I will be displaying the chart remotely using iPad NI dashboard through NI myRIO, how do I just remotely run the program without having to on my labview and run the program?

[JiaLuo08]

Hi Crossrulz, i'm new to labview and just started exploring the functions in it. The signal comes from a current sensor. How do i set the history wit shift register? I've attached the file.