Create Callback VI for IMAQdx Event -> Broken Wire

[James.M]

My application is using IMAQdx to communicate with a Basler camera. When my camera is triggered with a digital trigger, it sends out an event when exposre finishes. I can use this event to know when to grab an image.

I have a working VI that uses an event structure to handle this event and pull the image. Using an event structure in my main application will not work for my arcitecture, though, so I need to do a callback VI upon event generation.

I have been trying everything to get a callback VI to work, but it seems LabVIEW thinks that the callback VI doesn't match the input to the "Register Event Callback." I have tried everything ranging from making my own VI to match the exact inputs to just using "Create Callback VI" by right-clicking. No matter what I do to the VI, there is a broken wire.

See attached VI's. The callback VI is unnecessary because it is just a blank VI that was generated.

Any help with this would be highly appreciated!

Thank you,

James

[Bob_Schor]

It looks like your code is looking for a TypeDef called CtlRef.  I don't know if this is part of the IMAQdx spec, or something you need to provide, but providing it should get rid of the broken arrow.

[__LC__]

Dear James.

Did you found a solution for this already?

Regards

[approximately_whatever]

I am having the same problem: trying to create an Event Callback with an IMAQdx sessions as the event source. When you click create callback vi, it creates the VI, but the wire is broken. It says "Wire: function conflict" even though it has the correct connector pane, types, everything.

If I try to create an Event Callback with a different event source (This VI ref, for example) it works fine. No broken wire. It just has a problem with IMAQdx. 

Anybody has a solution?

P.S.: I know this a very old thread, but it's still unresolved.

[Bob_Schor]

It would help us (to help you) if you could create a simple demo VI that illustrates the problem and attach the VI so that we could try to duplicate it with our IMAQdx setups.  I'm not certain I've ever tried to create an IMAQdx callback, otherwise I'd look at my own code, but looking at a small picture of someone else's code "that doesn't work" doesn't give me much to go on.

Bob Schor

[approximately_whatever]

As requested, I have created a simple VI as an example. Its LabVIEW 2020 SP1.

As the comment says, try to create the callback VI by right clicking on the menu item. Is should result in a callback VI strict reference with a broken wire (as in the picture in my previous post).

[billko]

It appeared to work for me:

LV 2020.

[approximately_whatever]

Hmm ... that's strange. I have a fresh LabVIEW install with some basic VIPM packages. No customizations.

Could you please upload the example vi with the callback vi, so I can try it on my machine?

[FireFist-Redhawk]

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@approximately_whatever wrote:

As requested, I have created a simple VI as an example. Its LabVIEW 2020 SP1.

As the comment says, try to create the callback VI by right clicking on the menu item. Is should result in a callback VI strict reference with a broken wire (as in the picture in my previous post).

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Replicated in 2020 SP1 and 2017 SP1 (32b). When I hover over the register node's VI Ref terminal, this is what I get in Context Help:

Spoiler

Here's all my IMAQdx version info for comparison:

Spoiler

[billko]

This is what I get in LV 2020: