[Vikesrock]

Chassis grounded means that the device's enclosure is connected to it's electrical ground.

To isolate the cRIO from the robot chassis means that no conducting material (ie metal) can touch both the cRIO and the robot chassis. There are a few ways this can be accomplished.

If you are already set on using metal plates to mount your electronics to then the easiest way to accomplish isolation is to use nylon bolts, nuts and washers to mount the cRIO. Place nylon washers between the bottom of the cRIO and the metal plate to isolate the cRIO chassis itself. The nylon bolts are necessary to prevent the fastener from being a conductor between the robot chassis and cRIO chassis.

Another method would be to mount the cRIO to a non-conductive material such as lexan.