Brushless DC Motor Controller - Reverse Direction

I have seen some forum discussion in which this happened.. but can I have an explanations of basics of how this Brushless motor controller actually works and is it possible that it can run the other way

Hmm. Brush less DC motors are actually AC motor's in nature. depending on the design, they usually have a Delta type stator. An optical position index array so that the drive and monitor it's position between fields. some have PM in the rotors, some don't. the controllers can actually fix lock the shaft if it wishes, due to the quaddr sensor array, it can act very smoothly move the shaft in any direction with in a degree of stability.. they use these motors for long service life and synchronization with other moving parts of machines. The one's with the PM do get weak over the years due to the heat on the rotor breaking down the PM. when this happens, slipping starts to take place and timing is out of whack. what we do is increase the current in the fields to make up for it, which just adds to the problem because more heat them builds up. This last for a few months this way. then we finally get around to pulling the motor and sent it out for rebuild.. These motors are not cheap, we 10 Hp Brush less motors that cost 12K each.