Update control from called VI

[Sparky]

I would like to be able to update a picture control in the main application VI from a sub vi. I need to reference the picture control and send the reference to the VI. I am not sure how to do this. I have been reading on refnum's and refnum controls, but cannot seem to see how to do this. Can anyone help?

Thanks

[TobyD]

QUOTE (Sparky @ Sep 30 2008, 12:13 PM)

I would like to be able to update a picture control in the main application VI from a sub vi. I need to reference the picture control and send the reference to the VI. I am not sure how to do this. I have been reading on refnum's and refnum controls, but cannot seem to see how to do this. Can anyone help?

Thanks

Right click on the picture control and select Create --> Reference. You can then drag that reference onto the Front Panel of your SubVI to create a control to wire your input terminal to.

[PaulL]

Exactly. See the attached file for an example.

Paul

[David Boyd]

QUOTE (Sparky @ Sep 30 2008, 03:13 PM)

I would like to be able to update a picture control in the main application VI from a sub vi. I need to reference the picture control and send the reference to the VI. I am not sure how to do this. I have been reading on refnum's and refnum controls, but cannot seem to see how to do this. Can anyone help?

Thanks

I *must* be missing the point of both your original question and the responses you've received so far. I don't see why you need a reference to the picture control in the subVI to change the contents of the picture on the caller's front panel. Can you not simply pass the subVI the existing picture data and pass the modified picture data back from the subVI, to the indicator on the calling VI FP?

Unless you need to change an attribute of the picture, as opposed to its data, the reference passing just circumvents dataflow. Perhaps if we asked the same question with "numeric indicator" substituting for "picture control", my objection would be more obvious.

Best regards,

Dave

P.S. to Paul: all I found in your zip attachment was an .lvproj file - no VIs. Also, you might want to update your profile to show you're posting LV8.6.