A drive system for driving a belt is presented. The system comprises a frame, a driving shaft connected to a motor, a controller, a driven shaft, two pulleys connected to the driven and driving shafts, and a belt. The frame supports the driving and driven shafts to mount the belt on the pulleys. A signal element is mounted on and drives with the belt. At least two detection elements are mounted on the frame so that when the signal element passes the detection elements, a signal is generated as the belt moves. The detector elements are connected to a controller which controls the motor so that when the system starts, the belt moves until the signal element generates a signal in a first detector element to fix a zero point of the belt movement. The signal of the second detector element checks the zero point during normal drive operation.