LabVIEW 2012 while event structure cannot stop

I am trying LabVIEW 2012.
An example of while-loop with Event structure inside cannot be stopped with the boolean stop button. Any thing wrong?
Please see the attached VI.
Thanks.
Solved!
Go to Solution.
Attachments:
Close VI prompt.vi ‏9 KB

Yep, something is wrong. You need to add a event case to detect a value change on the stop button.
The thing is now your event structure keeps waiting for one of the event that it handles, and ight now it only handles the "panel close" event, the "timeout" event is handled too but since you haven't connected anything to the timeout terminal (top left corner of the event structure) the timeout is -1. So when you run the VI the while loop is stuck in the first iteration and waits for a panel close, the stop button will only be taken into account after the even structure catches an event ; I think this is because LabVIEW will execute code linked to the stop terminal of the while loop only after all the rest of the code in it has finished executing.
Hope this helps
When my feet touch the ground each morning the devil thinks "bloody hell... He's up again!"

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Do you really want the event handling to stop after detecting the first event? If so then as Christian says the event structure will cause the front panel to lock. What you can do is dynamically register and unregister the events. You right click on the event structure and enable "Show Dynamic Event Terminals" Then you can programatically register and unregister events.
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=====================
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event structure test.vi ‏13 KB

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Hello,
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Hello,
I have a bit different problem.
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terminate event_diagram.jpg ‏200 KB
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How to stop a while loop of event structure from a main vi

Hello;
sorry for my english
I have to stop a subvi from my main vi, the subvi contains a while loop and an event structure so I need to stop this loop while directly from my main vi I have tried global variable but it did not work
any help please or example !!!
Solved!
Go to Solution.
Attachments:
stop a while loop and event structure from main vi.png ‏16 KB

IYED wrote:
Hello;
sorry for my english
I have to stop a subvi from my main vi, the subvi contains a while loop and an event structure so I need to stop this loop while directly from my main vi I have tried global variable but it did not work
any help please or example !!!
If this is an example of how your code looks, I'd clean it up before the developer who has to work on it next hits you over the head with his LabVIEW Style Book.
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While loop with stop button within event structure locks up front panel.

I am not sure if this is a bug with my program or a bug within LabVIEW. If you believe that this is a bug with my program then I will post my program to be looked at.
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Once inside the while loop, however, none of the button are responsive within the front panel. The VI continues to run, and only 60% of my CPU is being consumed, but none of the button or scroll bars work. The only way for me to terminate the program is with the "Abort" button next to the "Run" button. If I remove the event structure so that the while loop in question runs as soon as the program starts, the front panel remains responsive. I've inserted probes within the while loop and verified that it is not running prior to the "Activate" button being asserted, and it is running after the assertion of the "Activate" button with the expected polling frequency set by the "wait till next ms multiple" vi.
Can anyone help? Do I need to post my code?
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It is typically not a good idea to stall an event structure by placing loops inside event cases. What good is an event structure if it is not free to repond to events?
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Event controll: How to stop a running while loop inside a event structure

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Message Edited by MichaGue_01 on 04-23-2010 04:37 AM
Solved!
Go to Solution.
Attachments:
Event_Controll.vi ‏27 KB

Hello,
Try not to use while loops inside a Event structure.
My approach is using two While loops (one will have only the Event structure).
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Event_Controll[1]_modified.vi ‏18 KB

Stopping an event structure inside a while loop.

I am relatively new to LabView, and especially the event structure. I have been looking at previous posts regarding the event structure and people having trouble stopping it. In my VI, I have two event cases in addition to the timeout. I am using this VI for stepper motor control. I have 2 buttons (for each case), one for movement to the left, the other to the right. It runs like it is supposed to, but when I try to stop it I have to press both buttons before it stops. As if the loop has to execute everything inside before stopping.
In my VI, how can I make the execution stop when I press the stop button? I tried many setups of the stop button and boolean logic (which I believe was correct) but am now stuck.
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Solved!
Go to Solution.
Attachments:
motor control2.vi ‏24 KB

OK, here's my simplified version. All you need is two event cases.
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We don't need a timeout event
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Message Edited by altenbach on 06-23-2008 05:09 PM
LabVIEW Champion . Do more with less code and in less time .
Attachments:
RightLeft.png ‏13 KB
motor_control2MOD.vi ‏15 KB

LabVIEW 2012 while event structure cannot stop

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