A quick warning that we found. If your system is writing to disk at the time that you power off, it may corrupt the file that you are writing or, even worse, the file allocation table. You could possibly lose all of the data on the hard drive if the FAT gets corrupted.
We have built our program so we can stop all code (including data logging) before turning off the PXI. This eliminates the "write to disk" problem.
Under normal circumstances, the chancces of actually damaging the FAT are pretty small (but it has happened here).
Rob