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Unbundled class value different to actual class value

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Hope someone can help with what looks like an obscure issue. I have a class called 'mcp2210', and one of the private data values is called "Handle".  When I create the class, the "Handle" value is created and stored with the class. Everything looks fine up to this point. However, when I then try to access the "Handle" value, the unbundled value is different to the stored value. Putting probes on the class wire and the unbundled value, I can clearly see that the class wire holds the correct "Handle" value, but the unbundled value always reads as 256d.

 

Some other points of info:

1. Before I run this test VI, I can edit the block diagram. However, after I run the test VI just once, the cursor changes to the 'hand' symbol, and I can't edit it anymore.

2. On one occasion, for no obvious reason, the test VI ran fine, i.e. the unbundled value was correct. The it reverted back to the non-working state.

3. This code is part of a library which has been running fine for 12 months. However, I had to do a rebuild of the library to fix something else unrelated to this issue, and the fix got a bit complicated, requiring lots of mass compiles to get right. This issue has only surfaced in the new library.  

4. LabVIEW version is 2016 32-bit.

 

Unbundled class value issue.png

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Solution
Accepted by topic author DMurrayIRL

Impossible to debug a picture.

One thing ti try is clearing out your class mutation history.

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Could you have more than 1 data field called "Handle" with one of them defined as U8 datatype? I don't know how many times things like that have driven me mad for days only to find out I was writing and reading different data fields with the same name (but different places in the hierarchy of classes).

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Hi, just to understand , is this VI reentrant or not? 

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Clearing the class mutation history seems to have fixed the issue. Thanks for the help!

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In order of my thoughts before I read any of the other responses:

1. Do you have multiple items in your class called "Handle"?

2. Clear the mutation history.

3. Clear the object cache (Tools->Advanced->Clear Compiled Object Cache) and then recompile.


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