Visa Constant Grayed Out?

[pallen]

This might not even be a "bug". But it's unusual behavior I've just started to notice on my current project.

I'm using constants to supply a VISA resource name in my code. This gives me a little drop down box from which I can select COM1, COM3, or LPT1.

For some reason all my drop down boxes keep graying out occasionally. But they restore on a reboot.

The code still works alright, and the port isn't being held open or anything. I'm just wondering what the problem might be.

[crelf]

It sounds like your constants are type-defs that are set to auto update from their ctl source, and the source is being changed (or at least marked as changed) somewhere else...

[pallen]

It sounds like your constants are type-defs that are set to auto update from their ctl source, and the source is being changed (or at least marked as changed) somewhere else...

Hmmm.....Everything is set to COM 3.....or at least it better be.

Thanks though. I'll double check things to make sure nothing has been overlooked.

[Grampa_of_Oliva_n_Eden]

Hmmm.....Everything is set to COM 3.....or at least it better be.

Thanks though. I'll double check things to make sure nothing has been overlooked.

I do not have a diffinative answer but I will share my thought.

Those constants are populated based on what ports LV thinks your PC has. I have noticed that VI's with VISA constants can take quite a while to open the first time.

I suspect.....

MAX is being invoked in the background and a refresh is happening.

Does right-clicking and selecting "allow undefined names" change this behaviour?

Done guessing.

Ben

[pallen]

Does right-clicking and selecting "allow undefined names" change this behaviour?

I'll give that a try.

NI AE's are currently working on another COM problem I'm having with my PXI system.

Maybe it's all related?