Event structure with sub-VI

hi,
I designed a event-driven state machine UI that uses pop-up sub-VI for user date configuration and COM port config. Calling the sub-VIs works fine, but by closing them and sending back the modified data to the main state machine, the event handling routine stalls. With highlighting, I could verify that after returning from the sub-VI, the timeout event is being carried out as the only one (used because there is some background code to be processed repeatedly).
There are more buttons on the front panel then handled events in a certain state (the other buttons are used in other states), but the unused buttons are neither disabled nor hidden. Could that cause the problem? Or does the OK button of the closing sub-VI (or the changing data out of it) affect the main state machine event handler?
Thanks for your reply
Pac

Hi, Pac.  Looking at your original VI, I would make a couple of general comments:
1) I don't suggest using an event structure in a timed loop.  The timed loop is to ensure determinism in the code that is running. This doesn't really fit well with handling user interaction.  As suggested in other posts, I would have a separate loop that is watching for user interaction with an event structure.
2) Having different event structures in each frame of a case structure is asking for trouble.  The link Jarrod posted should be very helpful, but it is just a subset of the thorough documentation on using event structures (note: I may be a bit biased as I am one of the authors of the documentation .  I would browse this whole chapter (http://zone.ni.com/reference/en-XX/help/371361A-01/TOC20.htm) and pay specific attention to the "Caveats and Recommendations" section which should help save you a lot of frustration.
J
Jason King
LabVIEW R&D
National Instruments

Similar Messages

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    Solved!
    Go to Solution.

    natasftw wrote:
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  • Is it better to have one Event Structure with more (10 or 15) cases or several with fewer?

    I have several buttons and events on the GUI of my app to monitor. Would it be better to use one Event Structure with several cases (10 or 15) or have a couple and split the cases evenly? None of the cases have much processing to handle, so there is not a time lag issue. I am just worried about overloading the structure. One of the tech support guys mentioned that the event structures are not that hard to get confused.
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    Attachments:
    Slider event control.vi ‏19 KB

    phillman wrote:
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  • Event structure in Sub VI

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    Solved!
    Go to Solution.
    Attachments:
    Webcam-Control-Projekt-mit-Reference-Design-2013_original.zip ‏286 KB

    Hello Michael,
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    Main_sub_VI.zip ‏18 KB

  • How to use a event structure with a state machine

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    Solved!
    Go to Solution.

    I'm not sure exactly what you are asking, but it sounds like you want to script a bunch of tests and if the user says stop, to immediately stop the current test and abandon the others?  I'm going to assume that you know how to clear the array so that it will abandon the others, so I'm guessing that you are having trouble abandoning the current test?  If this is indeed the case, then the problem is that you are not able to propagate the message from the main VI FP which is the GUI to the sub vi which is the test, where the test may or may not have a GUI (FP visible) of it's own.  Threading was the first thing to come to mind, but this may not be necessary using events.
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    Attachments:
    mainvi.vi ‏17 KB
    subvi.vi ‏33 KB

  • Using Event Structures with Array of Clusters

    Using LabVIEW 8.5
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    Message Edited by bhatiak on 08-04-2008 03:55 PM
    Attachments:
    Array of Clusters4.llb ‏274 KB

    My old tic tac toe example shows how to determine which square of a 2D array has been clicked.
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    Message Edited by Heinen on 02-19-2009 06:16 AM
    Message Edited by Heinen on 02-19-2009 06:20 AM
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    Solved!
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    Hello,
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    Attachments:
    terminate event_diagram.jpg ‏200 KB
    terminate event_front_1.jpg ‏63 KB
    terminate event_front_2.jpg ‏63 KB

  • Can I use Ctlref in a event structure with a mouse up event?

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    Solved!
    Go to Solution.

    Bad luck for you. Mouse down on panel does not have the control refnum as it is not operating on a control. Mouse down on a control does have it and since you can configure mouse down events on several controls in the same event case, it provides also a control refnum so that you can still operate on the control in question.
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  • Event structure: have one event trigger another event

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    Solved!
    Go to Solution.
    Attachments:
    test.vi ‏9 KB

    Tim's reply is the answer you are looking for.
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  • Daqmx "Done" event not triggering event structure

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    BoomTubeMain.vi ‏175 KB

    natasftw,
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  • Event structure buffering?

    Hi all,
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  • How to handle event structures for two buttons and two counters.

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    Attachments:
    events missing.png ‏69 KB

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    Hello.
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