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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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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?


LabVIEW Champion. It all comes together in GCentral GCentral
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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!


LabVIEW Champion. It all comes together in GCentral GCentral
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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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@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.


LabVIEW Champion. It all comes together in GCentral GCentral
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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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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. 😉


LabVIEW Champion. It all comes together in GCentral GCentral
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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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