Robot moves when disconnected from laptop

I have two of your motor drivers installed on my robot, which are controlled by my Linux laptop and some programming. I was wondering why, if I didn't have the wires connected from the motor controllers to my laptop, that the robot would move suddenly on its own.

There is no reason for this to happen.
Make sure you configure the controller in RS232 mode. Otherwise, it may mistake noise on the wires as a RC pulse command, although not very likely.

It is configured in RS232 mode. Would it be possible to get a table of commands that you use to tell the motor controllers what to do?

The full list of commands is in the manual. Please retrieve from www.roboteq.com