Hi,
Thanks for contacting National Instruments. Writing to floppy disk from the PXI-RT controller in RT mode is not supported. You may be successful sometimes in doing this, but you may see erratic behavior including corrupted files when you do this. This is because the RTOS doesn't extend its file operating system to the floppy drive. As you may be aware, a PXI-RT controller may be booted using an RT bootdisk. At this point, the floppy becomes part of the boot sequence. Limiting write access to the floppy disk ensures that the bootdisk is not written to and made corrupt, since the OS is installed from the bootdisk.
I would suggest writing files to the hard drive of the PXI controller and then transferring them to the PC using FTP. If you have the Internet Connectivity toolset, you can even do the FTP part programmatically.
Hope this answers your question. Please let me know if you have any additional questions.
Have a nice day!
Anu Saha
Academic Product Marketing Engineer
National Instruments