Abstract: An operating device for an overhead closure which comprises a motor, operatively connected to the closure for opening and closing the closure, and at least one sensor unit mountable either the closure or a support surface bordering the closure. The sensor unit is operable to detect the presence of an obstacle obstructing a travel path of the closure and to generate a signal in response thereto. A control system is in communication with the sensor and with the motor. The control system includes a control unit which receives the signal and provides a sensing feature which stops and/or opens the closure in response to the signal. The control unit deactivates the sensing feature at a selected point prior to an end limit position of the closure. The selected point is determined by the control unit based on a calculated delay characteristic.