TDMS not closed, data useless?

[NilsNylon]

Good morning,

I had a problem with my long time messurment. The programm crashed and it did´nt close the tdms file. There is sadly no way, i can repeat the messurment. Is there a way to recover the file? 

The storage was formated in FAT32, that is the reason why the programm crashed at 4 Gb filesize.

 

Thanks for your help.

[hooovahh]

So what I suspect here is that you were using the TDMS write over and over again but the buffer never caused a flush to disk, and you never explicitly called the flush function.  Then the program crashed and no file was written to disk.  If your file did at one time flush to disk then you'd have some data to look at.  If you have a file but it has an error on open, then you might be able to still pull out chunks of the file and recover some of the data.

I tend to have a logging module (actor) that will periodically flush to disk, then check for fragmentation, and close, defrag, and reopen the file if it gets fragmented.  This is in parallel to the test running so data will pile into a queue while this is happening.  This helps make TDMS a bit more robust, because as you found if you have the whole file in memory and then the system crashes, or there is a power outage, then the file is lost.  Flushing to disk periodically help keep at least some of the data.

[drjdpowell]

I would first try copying your 4Gb file to a file system that can handle larger files, then try opening it.