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property node chart

Hello, I am new to LabVIEW programming. I have a while loop where a chart is updated with values ​​from the RS232. The properties of this chart are defined in an outer loop. How I can do to refresh chart properties without leaving the while loop?. From what I can understand, if not get out of the loop where I am working, the properties are not updated if there was a change in them. If I put the definition of the properties within the while loop, the chart is not updated to the desired speed. My idea was to generate via a button, the refresh chart properties. How I can do?. thank you very much

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Message 1 of 10
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Put the property node inside a case structure in the inner loop and make sure it only goes true whenever a property changes.

 

Can you show us some code? What properties do you need to write?

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Message 2 of 10
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Visual representation of what altenbach told

Refresh.png

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Message 3 of 10
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@nijams wrote:

Visual representation of what altenbach told



Please don't put words in my mouth. I did not suggest at all what you are showing here! Thanks!

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Message 4 of 10
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I think the image below explains a bit what Altenbach described above.


Please correct me if i am wrong.

Plínio Costa
Application Engineering
National Instruments Brazil

Plínio Costa
Senior Techinical Support Engineer
National Instruments Brazil



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Message 5 of 10
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@Plínio wrote:

I think the image below explains a bit what Altenbach described above.


Please correct me if i am wrong.


I never said anything about a "refresh" button. 😮

 

I said "whenever a property changes". To see if the property node needs to update, you can compare it to the previous value using a feedback node. Here's a simple draft.

 

Note that the globally initialized feedback node start out with NaN to ensure that the property is written once at the beginning.

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Message 6 of 10
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NaN is always Not Equal to NaN.

 

Ben

Retired Senior Automation Systems Architect with Data Science Automation LabVIEW Champion Knight of NI and Prepper LinkedIn Profile YouTube Channel
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Message 7 of 10
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I would expect that the control is never NaN, thus resulting in an unconditional TRUE on first run.

In general, simply initialize with a highly unlikely value (-Inf, -1, 0, pi, etc.) as appropriate for the situation.

 

If you want, you can replace the comparison with "equal" and flip the two cases. Same difference. 😉

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Message 8 of 10
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Altenbach, the ideia of a refresh button was wrote by DAScharf


@DAScharf wrote:

Hello, I am new to LabVIEW programming. I have a while loop where a chart is updated with values ​​from the RS232. The properties of this chart are defined in an outer loop. How I can do to refresh chart properties without leaving the while loop?. From what I can understand, if not get out of the loop where I am working, the properties are not updated if there was a change in them. If I put the definition of the properties within the while loop, the chart is not updated to the desired speed. My idea was to generate via a button, the refresh chart properties. How I can do?. thank you very much


Plínio Costa
Application Engineering
National Instruments Brazil

Plínio Costa
Senior Techinical Support Engineer
National Instruments Brazil



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Message 9 of 10
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"Please don't put words in my mouth. I did not suggest at all what you are showing here! Thanks!"

 

  Altenbach, Sorry for my misunderstanding

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Message 10 of 10
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