Connect two numeric controls on labview

[sasquatchd]

Hello everyone,

I would like to connect two numeric controls, meaning I need 2 controls on the front panel that will perform the same function. If I change the value of one of them, the other should automatically change as well.

Please note that one of these controls needs to be within a cluster (which I will define beforehand).

I am still very much a beginner in LabVIEW, so if you could send me a VI to show me a small example of an application, that would help me understand what I need to do.

Thank you!

[GerdW]

Hi sasquatchd,

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@sasquatchd wrote:

I would like to connect two numeric controls,

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You cannot connect two controls as both are data surces. (THINK DATAFLOW!)

But you can set one control (using a local variable of that control) with the data of the other control.

And you can use an event structure to (re)act upon value changes of your controls…

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@sasquatchd wrote:

I am still very much a beginner in LabVIEW, so if you could send me a VI to show me a small example of an application, that would help me understand what I need to do.

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As a beginner you should take note of the Training resources offered at the top of the LabVIEW board - and all those example VIs in the example finder!

[sasquatchd]

Can u send me an example who do this work please ? 

[sasquatchd]

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@GerdW  a écrit :

But you can set one control (using a local variable of that control) with the data of the other control.

And you can use an event structure to (re)act upon value changes of your controls…

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do u mean that I can change the value of the two controls by changing only one of them ?

[sasquatchd]

I did this, for what I see it does what I want to do, but I dont know if it will always work 
If u can verify it for me please

[GerdW]

Hi sasquatchd,

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@sasquatchd wrote:

I did this, for what I see it does what I want to do, but I dont know if it will always work 
If u can verify it for me please

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Basically you implemented what I suggested.

(You may delete the TimeOut event case and and a "Stop" button value change event case.)

Why do you fear the VI will not "always work"? Why should it fail after one hour?

[daveTW]

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@GerdW wrote:

Why do you fear the VI will not "always work"? Why should it fail after one hour?

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Not after one hour, but after approx. 49.7 days, when the 2^32 tick counter will overflow... 😁

[sasquatchd]

Hi GerdW,

Haha, 

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Why do you fear the VI will not "always work"? Why should it fail after one hour?

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It's not about duration.

I was wondering if there is some prohibited cases for this VI, that's why i wanted to take your opinion

[pincpanter]

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@sasquatchd  ha scritto:

I was wondering if there is some prohibited cases for this VI, that's why i wanted to take your opinion

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Yes, there is one. If you assign a value to one control via a local variable in another part of your program, the Value change event will not be triggered.

Those events will be executed, other than by direct user interaction, by a Value(signaling) property node assignment :

[stevem181]

You can put multiple controls of the same data type in an Event case.

This prevents the maintenance problem of duplicate code.