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How can I make a waveform graph store the entire wave, not just the current time period and how can I save the actual graph?

I am taking temp readings with a 4 channel DAQ, sending them to a waveform graph and exporting the data to excel, how do I manipulate the graph to take a continuous reading as opposed to losing the previous GUI and how can I save the entire graph?

 

Using LabVIEW 2011 operating on Windows 7 professional. 

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Message 1 of 12
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append your new data to the end of the array that you sent to the previous iteration of the graph.  You can get a picture of the graph by using an invoke node (right click on the graph terminal>>create>>invoke node).

 

You could also use a graph chart -- it will not erase the previous data until you start to over run the chart history length value.

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Message 2 of 12
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I think you have to build an array out of each data acquisition.  Then feed this into an graph.  How much of a time period are looking to view with your graph?  Also what is your acquisition speed?

 

If you aren't looking for a long time/sample size to view, put each data point in a chart.

 

I recommend you take a look at the continuous measurement and logging template.  I assume that you can get it with LV2011.

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Message 3 of 12
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I will have to do some research to attempt building an array out of each data acquisition. And it's actually a Waveform Chart that I am genertating.  The temperature tests we are running typically range about 4-5 hours.  But I will need the cabability of running a 96-hour burn-in test. I do not know what the acquisition speed is. 

 

 

I will take a look at the continuous measurement and logging template.  

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Message 4 of 12
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I cannot find the property for chart history length value.  Can you provide instruction ro finding it. Also, do you know what the max time frame is?  As of now the chart only projects the current 6 mintes of data.

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Message 5 of 12
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I located both the history length default was 1024, though it doesn't say what unit of measurement that was and I also created an invoke node to export the image.  However, the waveform chart does not have an output so I am lost as to how to wire the node.

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Message 6 of 12
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The history length is just number of samples.
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Message 7 of 12
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I opened an X axis scroll bar, but it's greyed out. Regarldless of the history length or number of samples, everything not in the history period is lost.  It seems there has to be a way to generate a continuous reading that generates a longer and longer graph that can be scrolled through.  I just cannot figure out how.

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Message 8 of 12
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That is the nature of the chart -- everything not in the history is lost (it is a FIFO buffer of length=1024 samples by default).

 

The scroll bar is probably grayed out because you're show all of the data.

 

Attached is a program that will add 5 random points to a graph and prompt you for a file location where to save a JPG snapshot of the graph.  It's not particularly good programming style, but it has all of the elements/concepts you're after. 

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Message 9 of 12
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Thank you for the graph, however I cannot open it due to LabVIEW 2011 being incompatible.

 

Is anyonw aware of how to have the program export the image of the graph atthe end of each history period?  A continuous GUI would be preferred but if over several hours of testing, looking at multiple graphs would still be much preferred over thousands of lines of excel data.

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Message 10 of 12
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