http://wpilib.screenstepslive.com/s/...ging-your-crio
Yes. Safe mode is a way to image a "messed up" cRIO.
When the DS doesn't get communications, please switch to the Diagnostics tab and see if the messages and LEDs give any clues. The LEDs show the results of pings. The error messages may indicate something that caused it.
If the cRIO responds to ping, but communications doesn't work, it means the UDP communications between DS and robot are not working. Check firewalls, and if you have a null-modem serial cable, you can see if the cRIO or the FRC_Communications.out file have crashed.
Another tool I sometimes use is to use wireshark to verify that the DS is sending packets to the robot and see whether the robot is sending status back. I know this is a pretty advanced tool, but if you are familiar with it, it gives lots of valuable data.
Greg McKaskle