[Mr. Lim]

I second both James' and Al's suggestions, and have some tips to offer to help troubleshoot:

1) Al's suggestion: If it IS a cRIO reboot, you'll lose comm for about 1 minute, then it will come back. The time duration of your comm loss is a good indicator here. If you are running any Banebot 775s on your robot this is likely your problem, and you can check by taking a meter, disconnecting the motor from the speed controller, and measuring resistance between the positive terminal on the motor and the case of the motor. You will want to rotate the motor slightly as your measure. If at any point you see <100k ohm resistance, you have a defective motor which is causing the voltage to dip on your entire electrical bus. There are a few fixes for this that have been posted on CD. Try searching for "case short".

2) James' suggestion: As soon as you lose comm, have two people immediately check the status lights on robot. One person for the cRIO, the other for the radio. Both have telltale blinking-light sequences which are indicative that they've been reset recently. If only the radio looks like it's been reset, then James' suggestion is your best bet. Generally with radio-only resets, comm is re-established faster than 1 minute.