Application stops when Client disconnects

[Chris.F]

Hey 🙂

I have to upgrade some older LabView applications here and I am having some trouble 😉
There are three independend applications running on the same computer and the same measurement hardware. All of them are available via a Web-Site, so everybody can do measurements.
So, that they don't mess with each other they are protected against multiple Hardware access. That woks fine I think.

To remote-control the applications we are using the Web-Server and the LabView Browser Plugin. If now someone gains control of an Application (and get it granted) he can do his measurements. So far, so good. But now, if he closes the Windows (and disconnects from the Server) without returning control to the Server the Applications seems to stops somewhere. It just doesn't react anymore (but although can still be viewed via the Server. So the Server seems to be up).

My Problem now is how to debug this Problem! If i run the VIs in LabView the Webserver is not running. So i can't provoke this problem.
If i run the Stand-Alone Application I can't debug. It's a mess!

All other Applications do not cause this problem even though they are using the same hardware and run in the same enviorment.

Does anybody have any Ideas? Or a solution for me?

I am currently using LabView 6.1 on Windows XP SP2. The Browser-Plugin is called "National Instruments LabVIEW Netscape Plug-in for Windows 1.0".
Updating to a newer LabView Version is not planned at the moment.

Thank you! 🙂

[TCPlomp]

Check out your event handling, maybe this app is using some Application.Close event in a different manner?

Ton

[Chris.F]

Hey TonP,
thanks for your quick answer so far.

The application does not call any other apps as far as i know. It directly accesses the GPIB-Hardware, writes to files etc. But I will check this more detailed!

What do you mean with:

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@TonP wrote:
Close event in a different manner?

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I am not new with programming at all but I am still gaining experience with LabView.

[TCPlomp]

No,

I meant the 'Application.Close' Event.
If think you need to check any differences between the applications and I assume the event structure is the first to question.

Ton

[Chris.F]

The Application should not close itself. It is supposed to wait until it is activated again.

I am not shure what you mean by Event Structure. Sorry


Message Edited by Chris.F on 07-30-2008 04:23 PM

[Chris.F]

So, it seems I solved the Problem:

The VI changes the Visible-Property of many ( > 20 ) Front-Panel Elements. This should be no Problem but: The VI did it every time it goes through the main cycle and that happens about 2 times a secound. Additionaly the VI did all changes nearly parallel.

So, if a property was changed in the moment the Client disconnected from the Server the VI simpy freezes. Seems to be a bug for me 😉

Now, the property is only changed when the visibility really has to change and it works fine.

I think there will still be some conditons that could freeze the VI but if this happens one or two times a year... Thats ok.

Thanks for your help TonP!