[Andy A.]

It should also be noted that there is a function called dynamic braking, in which the Victor shorts it's output creating a short across the motor windings. This causes drag on the motor that is proportional to the speed in which it is spinning. It only engages when the Victor receives a neutral signal.

It is controlled by a jumper setting, and there is round about method of remotely turning this on and off. It can't hold a motor stopped on it's own, but it will slow down a free spinning motor. Some teams use dynamic braking on the victors that control their main drive motors. It has the effect of eliminating any coasting a robot might otherwise have. Most teams, however, do not use dynamic brakes, feeling that the sudden stops produce more strain on the drive train and victors then is worth it. More common uses are for motors controlling long arms that otherwise 'droop' when no power is applied.

Could you describe what you want a brake for?

Edit- The method that I know of for remotely turning the dynamic brake on and off is to wire the jumper pins to a limit switch, and toggling the switch with a servo (or other mechanism). I don't know exactly how the pins function, so I couldn't say what the result of applying voltage from a digital out might be. Can you simply cause digital out to create a short? If so, that would be a much simpler way of doing it, although possibly illegal.

-Andy A.