Recovering a corrupted VI

[jamieslaird]

Hello NI,

Recently my application (FPGA and host code) somehow crashed the entire PC and took out my application (host) VI with it.

This had happeded a feww times and the preceding occurence asked me to move the recovery file to a different location too recover. I did that and it did recover. However, the next time no such recovery file existed and hence the VI is now corrupted.

Any ideas how to restore a corrupted VI ?

I have two files which I'd like to included but they are too large: (a) the actual corrupted VI and (b) the recovery file from the previous occurence. Please let me know and i can also send these later.

I desperately hope you can guide me on how to recover one or both of these

Thanks

Jamie

[SteveChandler]

The easiest way is to revert back to the latest version in your SCM repository. Otherwise you are likely out of luck. But maybe someone can pull out their hex editor and work some magic. So stay tuned and don't give up hope. In the meantime go check out subversion or one of the other excellent SCM tools if you are not using version control. If you are then I hope you don't take offense at this - it could serve as a warning to someone out there reading this who is not.

[SteveChandler]

One more thing. If your vi is really too big to post, and I don't think it is, then that could explain the corruption problems. If a vi exceeds a megabyte or two you should start to think about how you can modularize things.

[jamieslaird]

Thanks for your prompt message. Just curious though, what and where is the SCM repository ? I assume its source control something or another.

The VI is about 6.5Mb in size which does seem quite large for a relatively simple application.

I'm using Labview 2010.

thanks

Jamie

[SteveChandler]

The SCM repository is something you set up and is separate from labview. It is any version control software. A popular one in the labview community is subversion and is sometimes called SVN. There is a great windows client called TortoiseSVN. But maybe someone can help fix your vi. I saw a thread here recently where someone fixed a corrupted llb using a hex editor but I am sure that fixing a vi is going to be much more challenging.

[jamieslaird]

Thanks again. Are there any known links for how to hexedit a VI ? Wouldnt NI engineers have some familiarity with this kind of procedure ?

thanks

Jamie

[SteveChandler]

I don't know of a proceedure but maybe someone at NI does.

This reminds me of this thread from a few weeks ago. Someone had a LabVIEW crash resulting in a corrupted llb. Andrey Dimitriev wrote a vi that decorrupted all but the main vi. MikeS81 came in later and said which bytes to alter with a hex editor to fix the whole thing. Mike never did get back and say how he figured it out. Daklu's first secret to success? In any case Florian got lucky. Darin.K suggested using a cloud storage like DropBox to prevent this which is very easy to set up.