real time output update from custom express vi

[ricardosilva]

Hello to all

I have a question. Is it possible to update a express vi output on real time in a vi that uses it?

Inside the vi there is a while loop receiving constantly data, and it is stopped only when a certain button is pressed. I use local variables to update a YT chart outside that loop. The chart updates on real time as I pretend.

When I build the express vi, or even if I use the vi as a subvi, nothing happens, the output only updates when the subvi finishes. I will need to update a input on real time too. 

I have tried with event structures also, they work, but only inside the vi, if I use it again as a subvi the problem persists.

I know that the output of a subvi only updates when it finishes, but I really need it to update on real time to be possible to use it as an express vi, to be implemented on any project.

Thanks for the help 

[AdnanZ]

This should answer your question:

Updating a Control or Indicator of a Top Level VI from a SubVI

If it doesn't, please post a version of your code that highlights the issue and we can help you quicker.

[ricardosilva]

Ok it worked, the STOP button control is working now from the top vi. 

Another question, is it possible to do this to a indicator. When I change the refnum to an indicator I can't connect it to the property node.

I want this subvi to be controlled by the STOP button and it´s output to be updated on real time in the top vi, until the STOP button is pressed.

I don´t know if it is possible to do, but I want this subvi to be easy to use, what I intend to say is that when someone create a control, let´s use the STOP button, I want it to connect directly to the subvi without creating references as I´m doing now. The same happens to the output.

Thanks 

[ricardosilva]

I forgot to mention, I can update the output on the main vi using a global variable, but as I mentioned before it´s not practical to use. The vi I´m building is a data acquisition vi and is intended to use much like the DAQ assistant from NI. So when I want to see the output it would be only necessary to create an indicator, the same happens to the stop button.

Thanks