LV2011 bug - Error wired to boolen function breaks when saving for previous version

[SteveChandler]

I just downloaded LabVIEW 2011 this morning. I created this VI and saved it for LV2010 to see how it would deal with it. I opened the VI in LabVIEW 2010SP1 and the error wire is broken. There were no warnings about problems saving this VI as an earlier version.

[Gregor Cerne]

Hello Steve,

Connection or error wire directly to logic function is the feature of LabVIEW 2011 and is not supported in older versions. In order to connect error wire to a logic function in older versions you need to unbundle error cluster and then connect status from that error cluster to a logic function.

Best Regards,

Gregor Cerne

[SteveChandler]

Understood. But should LabVIEW2011 do that for me when I backsave?

[Gregor Cerne]

Hello Steve,

Unfortunatelly not, because there is no option to save VI into previous version VI.

But you can post your idea here and our R&D will take a look at your proposal:

http://forums.ni.com/t5/NI-Idea-Exchange/ct-p/ideas

You can see near your post how many kudos you got from other users - more the kudos you have more probable is that your feature will be in the next edition of LabVIEW

Best Regards,

Gregor Černe

[Broken_Arrow]

Things like this are, unfortunately, just a fact of life in a "constant improvement" design scheme. When the Event Structure came out in version 7, I had to avoid it for years because I continually had to make code for 5.1 and 6.i. Similarly, I loaded some code the other day and LV told me it was "too old". There's no stopping Progress!

[smercurio_fc]

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@Gregor Cerne wrote:

Hello Steve,

Unfortunatelly not, because there is no option to save VI into previous version VI.

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Huh?

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 But you can post your idea here and our R&D will take a look at your proposal:

http://forums.ni.com/t5/NI-Idea-Exchange/ct-p/ideas

You can see near your post how many kudos you got from other users - more the kudos you have more probable is that your feature will be in the next edition of LabVIEW

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Oh, trust me, Steve is quite aware of the Idea Exchange: http://forums.ni.com/t5/forums/searchpage/tab/message?filter=location&location=Board%3Alabviewideas#...

[SteveChandler]

So is this a bug? I thought that new features were somehow backsaved. I also thought that if the version you are saving for is incompatible with the code you should at least get a warning.

[Norbert_B]

I would not consider this to be a "bug".

I would call it rather an "incomplete feature" were the extra-mile (backwards compatibility) is not fully implemented. So filing a suggestion is really the best thing to do (i will not file one since it is your idea, but i will kudo it!).

Saving VIs to previous versions does not change the BD itself. The requested functionality would require BD analysis and inserting (per scripting) an unbundle into the error wire. This is a complete new functionality, at least i am not aware that this is happening anywhere else....

As a "part time solution" i would like to see a BD analyzer which warns you about possible issues during downconvert. So in your case an "errorlist entry" like:

Warning: Connecting the error cluster to boolean functions is a new feature to LV 2011. Saving for previous version will lead to a broken VI.

just my 5 cents,

Norbert

[SteveChandler]

Thanks Norbert. It is done.

[fdinoff]

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@Norbert B wrote:

Saving VIs to previous versions does not change the BD itself. The requested functionality would require BD analysis and inserting (per scripting) an unbundle into the error wire. This is a complete new functionality, at least i am not aware that this is happening anywhere else....

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I would consider the behavior inconsistent. The reason I say this is because Saving VIs to previous does change the Block Diagram with the merge error change in 2010. If you back save a merge error it gets replaced with a build array and the old Merge Error VI and the VI is not broken.