System and method of automatic detection and prevention of motor runaway

A robotic catheter control system includes a plurality of electric motors. Diagnostic logic automatically detects motor runaway fault conditions based on the current motor position, the target motor position and a predetermined tolerance parameter. Fault conditions include overshoot, movement in the a non-prescribed direction, exceeding a prescribed maximum motor speed and exceeding a prescribed maximum motor acceleration. The diagnostic logic terminates operating power to the electric motor when a fault condition is detected for any one of the motor. An error message is generated to notify the operator of the fault.