It is possible to save data to a text file on the cRIO,
and to read it back. Team 1425 has done this in the past.
Having a robot ability to update tunable parameters without firing
up WindRiver workbench is a great time saver.
This works wonders when you need to calibrate some component that is
likely to get adjusted during normal maintenance and repair during
competition.
I'm currently trying to get the team I'm working with in MN (3765)
to recreate this.
The neat thing about creating ascii based files is that you can use external tools to view them.
Last night I was showing the team how you can use the robot's built in FTP server to look at the file system on the cRIO. We looked at the system install files and noted the changes and deletions that happen when code is deployed and undeployed from workbench. We also used the ftp server to create a team data directory on the robot as a location to create our persistent data files.
On a PC that is connected to your team's robot, you can use ftp to browse the robot's file system by opening a web browser and using the URL:
ftp://10.XX.YY.2/
10.XX.YY.2 being the standard FIRST defined IP address for your robot.
Note that the protocol part of the URL is ftp - not http like you see during
regular web browsing.
This will give you a file listing of the root of the robot file system, and you can browse down into the various sub-directories.
The web browser is a good place to start since it gives a read-only view of the file system. You want to be sure that you don't modify any of the existing files there, without fully understanding the consequences.