LV8.5 cant get reference to image display

[falkpl]

Why cant I get a control of image display type in Labview 8.5 and vision module.  I have done this many times in older versions.  Is this a bug (would be a major problem) or am I missing something?

[yaHeard]

Hello falkpl,

If you right-click on the front panel to bring up the controls palette then navigate to Vision » IMAQ Image.ctl you will be able to have an image data type control for the front panel/block diagram.  You can also create a ImageControl reference to the front panel image display for use with property and invoke nodes.

[falkpl]

This is how it is normally done, but does not work with the IMAQ control.  This worked in 7.1 but in 8.5 the reference to the IMAQ control is not working.  Yes I can create a reference to a imaq control but when I try to make it into a control that is a reference to a imaq control type this will not work.  I cant create a subvi (create  subvi selected on a portion of code) if the reference wire to the imaq image display is used nor can I create a generic reference and set it to be an imaq display.  It is as is 8.5 does not have an imaq display in the control hiearchy.  The only work around is to import a vi I created in 7.1 and copy and paste the control reference into the new vi.  Very bizar behavior.  Can you do this on your 8.5 is it a universal bug?  Is something wrong with my 8.5 I have tried this repeatably on another install.

Paul  

[yaHeard]

Hi Paul,

It looks like it is an issue that is still being looked into for future releases of LabVIEW.  The workaround appears to be casting the reference to a more generic class and then in the subVI casting it back to the more specific ImageControl class.  Here are a few threads that talk about the issue and provide some example code for the workaround.

http://forums.ni.com/ni/board/message?board.id=170&message.id=213405&requireLogin=False
http://forums.ni.com/ni/board/message?board.id=170&thread.id=196345&view=by_date_ascending&page=1

[falkpl]

The workaround I have done is to save a vi with the control refernece in it from vision 7.1 then import it and copy into the vis as needed.  This is a rather big bug for anyone doing vision.  I have many projects with vision so I hope it gets fixed soon.  Thanks for confirming that I havent completly lost it and it was a bug not my own stupidity this time.

Paul

[rpursley8]

Using the example in the other thread, I was able to get it to work.  I dragged the ImageControl reference from the block diagram of the Main.vi to the front panel of the sub.vi and it seems to work.

[ShadowofVT]

I stumbled across this thread, and am having a similar problem trying to pass a reference to a visual indicator in 8.5.  I'm creating a rather complicated program, and it would be a mess to have everything in the same VI.  I've got a visual indicator in the main VI, and editor subVI's are loaded into a subpanel when called.  But I need to get certain information about the image indicator into the subVI's, such as the current ROI of the image.  This is eventually going to be built into an executable, so the above workaround won't work for me.  Is there anything else I could do to access image properties in another suvi?  The only thing I could come up with is creating a notifier between the two VI's that could be loaded with the required information.

[falkpl]

The current workaround works fine in both debun and executables in 8.5.  I control the top level imaq display from the subvis but it is just an anoyance that I have to use a workaround.

Paul