With a modern servo using torque (current) control, the drive current output is directly proportional to the voltage input, With this method, if the motor is commanded to stationary position, and if the encoder indicates that it is in co-incidence, there is no need to output any command voltage, hence no current will flow, all outputs are essentially off.
Unless something attempts to move the servo.
The 50% on 50% off technique was used primarily in velocity drives in order to hold the servo at zero position as the control was weakest around the zero point.
That is why on older systems you could hear the servo's 'singing' at rest, modern servo's are much quieter both at rest and in motion.
Al.
CNC, Mechatronics Integration and Custom Machine Design
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E.