Any attachment to input node makes timed loop unexecutable

[plashley]

I'm having trouble setting up a Timed Loop in LabView 8.0.1 Professional.  When I attach anything to the Input Node, the loop becomes unexecutable.  ("This node is not executable because an unexpected error occured during code generation.")

I can also easily reproduce the problem using the 'Offset for the Timed Loop' example.  When I first open the example, it is runnable.  If I double-click on either Input Node to get the Configure Timed Loop dialog, then click on OK without making any changes, the example becomes unexecutable.

[JLS]

Wow,

I haven't seen this problem, and I tried what you noted regarding the shipping example in both 8.0 and 8.0.1 - I could not reproduce the behavior.  Try repairing the LabVIEW installation from Add/Remove Programs, and if that doesn't work, try a full unintall and reinstall.  I realize this will take time, and can be inconvenient.  If there is any other strange behavior (such as with other express VIs) please note those here as well since perhaps it will give clues to the underlying problem.  Please post the results of your repair and/or un/reinstall process, as well as any additional information you may encounter while exploring this.

Best Regards,

JLS

[plashley]

No joy.  The uninstall/reinstall didn't fix the problem.

Is there any way to get more detailed messages about what it thinks is wrong?

I doubt that it matters; but we're running under Windows XP on a new Gateway GT5032 (Athlon 64 X2 4200+, 1Gb RAM)

Also, when I ran the Mass Compile, there were some 'Insane object' messages.

[ceger]

I'm having the same problem.  I'd like to be able to vary the period of a timed loop using a front-panel control, but no joy.  The only way I can set any loop parameters is by using the "Configure Input Node" dialog.

However, the example "Optimizing timed loop rate.vi" has wired timed loop parameters, and works just fine.  Also, I'm able to modify this vi to add my own loop parameter controls...no problem.

I don't use timed loops very often, and given the above behavior, I can't help but believe that I'm overlooking some setting or loop property that's causing this problem.

Any ideas?

[ceger]

plashley...try a "Ctrl+b".  Quite by accident, I found that this seems to get rid of the error condition.  The following steps can be used to demonstrate this bug/feature:

1) Open a blank vi.

2) Add a timed while loop.

3) Right-click the period terminal and select "Create->Control".  The run button is now broken, indicating an error.

4) Type "Ctrl+b".  The error clears.

5) Right-click on the loop's input node and select "Configure Input Node".  Don't change any values in the dialog...just select "OK".

6) The run button is broken again....  Type "Ctrl+b" and voila...it's fixed again.

Apparently, the wiring of the input node is just a little flaky.  If anybody has further insight into this problem, please explain.  Even though there's a workaround, I'm not entirely comfortable with this "fix".  Also, I'm curious about whether others see different behavior when performing the above steps.  Thanks.

[JLS]

Wow, that is another interesting case, but I can't reproduce it either.  I followed the steps you outlined without a problem in both 8.0 and 8.0.1.  More specifically, the VI doesn't break when I create a control for the period input, nor when I open the input node's config dialog.  plashley, do you also see this behavior, where ctrl+b "fixes" the VI?  I really wish I could reproduce this so that I can make R&D aware of the problem with a concrete example.  ceger, can you put your system specs and LabVIEW version here so that perhaps we can find a correlation between your machines?

Thank you, and I look forward to your updates!

Best Regards,

JLS

Message Edited by JLS on 04-26-2006 01:22 PM

[plashley]

Yes, the Ctrl-B seems to fix the error condition.

[ceger]

Thanks for the reply JLS.  I'm running a Dell Dimension 8400 w/ a 3GHz P4, 1GB RAM, Windows XP, Labview Pro 8.0.  However, a co-worker is running the same machine and LV version, yet he doesn't see the same error.  If, however, I go through the steps outlined above and save the vi in its "broken" state, then have my co-worker open the vi on his machine, he sees it as broken.  I'm attaching a vi in the "broken" state.  It consists of simply a timed loop with a control wired to its period input.

[JLS]

Hello,

Indeed it is broken on my machine until I use ctrl+b... I have filed a corrective action request to R&D (CAR # 3WQD14SQ for future reference) so this can be addressed for a future version.  Thank you very much for raising this problem!

Best Regards,

JLS