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cursors on the waveform chart


K Waris

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Is there no way that i can have the cursors on the waveform charts? Designed my entire application and the last bit was to be able to add four cursors and found in the properties there was no column for the cursors!! 


Waveform graph is unsuitable for my application. Any ideas please?

 

Best Regards

K Waris

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Use an XY graph and keep the data yourself instead of having the control keep it. The easiest way is to create a fixed size queue, use lossy enqueue to put the data in and then use the queue status primitive to get all the data without dequeueing (note that you have to wire T into the return elements input).

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Waveform graph is unsuitable for my application. Any ideas please?

Simply because you don't understand a feature, doesn't mean it is unsuitable.  I agree with Yair that a different way of displaying it is the right way.  I've never seen a Waveform Chart used in a real application, only in test demos to show quick data.  When you make a real application you realize how limited it really is and must upgrade to the Waveform Graph, or XY Graph to manage the data your self.  It sounds like you have found one of those times where the Waveform Chart is limited.

 

You can do this with relatively little updates to the code, you just need a way to remember the data your self, in a shift register, functional global, or feedback node.

Edited by hooovahh
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Here is an attempt. 

I have begun to use waveform chart to achieve the requirements in my application but failing miserably!!!! 

 

I have found that the actual time it takes for the waveform graph in the attached code( this is just an example, my data acquisition code is very similar to this) to plot 100000 points keep increasing over iterations. I checked it using the stop watch. Failing to plot the actual time is taking the biscuit too!!

 

Please advise what I am doing wrong please. 

 

Best Regards

K Waris

graph limits.vi

Read-Write.vi

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I have found that the actual time it takes for the waveform graph in the attached code( this is just an example, my data acquisition code is very similar to this) to plot 100000 points keep increasing over iterations. I checked it using the stop watch.

How long did you have to run it to see the time to plot increase?  I added a feed back node to keep track of how long it takes to clear the graph and I saw 10950ms or less.  After running it for about 5 minutes it was around the same.

 

One issue is there is no synchronization between the producer and the consumer loops.  You have some loop getting 100 new data points every 1ms.  And you have a consumer loop that runs every 10ms getting 100 points at a time.  But because your producer runs faster, and overwrites the previous data in the global, the new 100 points your read will not be a continuation of the previous 100 points.  I modified your global so that when you do a write you append to the data in the global, and after it reaches the desired size it resets.

 

I tried modifying the VIs and posting them but my LabVIEW has decided it doesn't like your VIs anymore for some reason...it feels like Friday.

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