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LV2009 .lvclass conversion to previous version

Hi all,

I created one code using the LVOOP feature in LabVIEW 2009. When I try to convert the same to 8.5 using the .lvproj file, LabVIEW crashes giving some "Memory Manager.cpp" error. I am sure that LabVIEW 8.5 supports LVOOP programming, and if all is right, the conversion shouldn't be a problem.

However, after I open the folder after LabVIEW 2009 has been crashed, I can see the VIs converted to 8.5(all broken since classes are not loaded) but I don't see the class (*.lvclass) converted to 8.5 version.

 

The conversion isn't happening from LV2009 to LV8.5 successfully.

 

Anyone aware of this problem?

 

Thanks.

Message Edited by Fragger Fox on 02-02-2010 11:44 AM
-FraggerFox!
Certified LabVIEW Architect, Certified TestStand Developer
"What you think today is what you live tomorrow"
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Can you post your code?
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Well, I took this code just to test my level to give the CLD examination. One of my friends gave this question which was asked to him by some company to me. I coded this one in LV2009 and when I try to convert it to LV8.5, it would pop up memory manager error. I don't want to get this code converted, I just want to know why the error comes up while conversion.

 

Also, one strange thing in this code.........

I know this is a very bad programming practice but I just tried using two event structures on the same button, but in different states of a state machine. Just lock the front panel in any one of the value change ("E" button) and the front panel would be locked, even if the program doesn't go to that specific case having the event structure.

Check the code, you would see this......

-FraggerFox!
Certified LabVIEW Architect, Certified TestStand Developer
"What you think today is what you live tomorrow"
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I belive the recently release service pack has a fix for back-saving.

 

Ben

Retired Senior Automation Systems Architect with Data Science Automation LabVIEW Champion Knight of NI and Prepper LinkedIn Profile YouTube Channel
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@Ben,

Any opinions about the event structures in two different cases(states) ?

-FraggerFox!
Certified LabVIEW Architect, Certified TestStand Developer
"What you think today is what you live tomorrow"
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Hope you had already read about the Caveats & Recommendations about using Event Structures.

- Partha ( CLD until Oct 2024 🙂 )
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@partha:

The thing is everyone here would be knowing about how to use the event structures. I know, that multiple event structures should not be used, but I have done this delibarately to see what happens. It seems that the event structure tends to execute even if it doesn't enter its state (in case structure), which ideally, according to state machine theory, shouldn't happen....

-FraggerFox!
Certified LabVIEW Architect, Certified TestStand Developer
"What you think today is what you live tomorrow"
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The event structure isn't executing, but it is capturing any events assigned to it and will execute those event cases once the order of execution return to it.  Of course if that event structure is buried in a case that will never execute, then the event structure will never execute.

 

There is nothing wrong with this and nothing that violates state machine theory.  In reality, you need this behavior to happen for event structures to work properly.  If you do something like hit a button and while that event case executes and perhaps takes a little bit of time, and you hit another button, don't you want that event to be captured and the appropriate event case to execute as soon as the order of execution allows that to happen again, i.e. the first iteration of the while loop and its event completes?  Otherwise, if the event structure isn't sitting there waiting for an event, the event would never be captured.  You'd hit the 2nd button and then wonder why your code doesn't seem to be acting on it.  Make sure you read Caveats and Recommendations when Using Events in LabVIEW.

 

Careful attention to things like locking the front panel until event completes, how long an event case should execute, multiple events, multiple event structures, dynamic event handling, not losing events when an event structure gets buried in case structures, are all important to think about to make sure your application executes the way you think it should and your users expect so that you have a quick responding, robust application and you don't run into pitfalls like a locked up front panel or events that execute when they shouldn't because the application is no longer in a desired state by the time the event actually gets to being handled.

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