[BUG] XControl facade VI ends on first iteration

[Olivier Jourdan]

Hi,

Lately I came across a weird behavior on XControl. I think I've find out the issue but want to you to confirm the behavior.

As far as I understand XControl execution theory, it's impossible to have facade VI executing only one iteration loop (just TimeOut case called). However I can obtain this on certain condition. This should not be a problem if data (display state and Data) was not reseted to default value. Ui refresh code called with these inconsistent data give some really weird behavior (NB: data are not lost, next call give the consistent data...)

Here you can find the step to reproduce the issue :

1. Create an XControl
2. Add a slider on facade.vi FP
3. Add beep.vi in a "0" case, outside the while loop, link selector to while loop "i"
4. Add "Slide:Value change" event case
5. Add "Slide:Mouse Enter" event case
6. Drag the Xcontrol in a new VI FP

Issue appears after step 5.

You'll find an example of this behavior in attachment.

I've reproduced the issue in LV2009-SP1 and LV2010. Can you confirm me that you have the same behavior on your side ?

Work around is easy, but I think this deserves a bug fix from NI.

Regards,

Olivier

XCTimeOutIssue-2009.zip

[jgcode]

Can you confirm me that you have the same behavior on your side ?

Hi Oliver

I ran your code in LabVIEW 2009.SP1 and can confirm the behaviour (it beeps).

Interesting! - It seems either Event is fine, but if both are (statically) registered then the issue occurs.

Cheers

-JG

[Olivier Jourdan]

Thank you for testing the code. I'll wait for other test/comment and then report the issue to NI

Thanks,

Olivier

[asbo]

So if I understand correctly, the XControl should only ever beep once?

[Olivier Jourdan]

Hi asbo

The XControl should beep many times. The beep occurs when "the bug" occurs. On my PC, the quicker you move the slider the more often the beep occurs.

2 or 3 go-backs only to have the beep.

I really don't know how events are managed in an XControl. The fact that the "bug" occurs when lots of value change are fired let me think there is probably a link wit this other bug found by JG --> http://lavag.org/top...dpost__p__79794

However, I've came across this issue in a different case: In a code implementing an XControl for long time without problem, I've added a value change event on the Xcontrol. The simple fact to add this event case cause the XControl refresh with "default values". Next event on it refresh it with the correct values. This is a bit different from the example I've posted but fix is the same --> do not refresh when i =0.

Regards

Edited December 8, 2010 by Olivier Jourdan

[asbo]

The XControl should beep many times. The beep occurs when "the bug" occurs. On my PC, the quicker you move the slider the more often the beep occurs.

2 or 3 go-backs only to have the beep.

Ah ha! Probably didn't help that I built the test case wrong I'm reproducing this behavior in both LV2009 and LV2010, but one thing that I noticed that I don't think has been mentioned yet - if you grab the slider with the mouse, and then move off the slider to anywhere to drag back and forth, no beeping! But, I have no idea what that means

[Olivier Jourdan]

Bug reported to NI.

[Olivier Jourdan]

Bug reported to NI.

CAR# 279707