No clue how the enable works.  They didn't give me any real detailed information, just enough to supposedly get it running, and a baseline of tuning the motors.  It's a system from www.lowcostcncretrofits.com  http://www.lowcostcncretrofits.com/servo%20controllers.html  20 amp 3 axis controller and supposedly 1500 oz/in Pacific Scientific servo's.  My controller is a little diffrent from the one in the picture, it doesn't have the LED's on the front, but it does have a port for breaking out the 25 pin cable on the back.  I'll check the step and direction and see if I get anything. 

Michael