The Model 302210 Gate Safety Edge Transmitter is for adding obstacle sensing for motorized gates or barrier arms. Using a safety edge transmitter is more economical and discrete than the traditional coiled cord connection method. The transmitter mounts directly on the gate or barrier arm and wires to a standard exterior safety edge sensor (a Miller gate edge sensor is recommended). If an obstacle is encountered, the sensor will present a closed circuit across the connecting wires and the 302210 will transmit a message to the receiver signaling entrapment to the gate operator. The operator then stops or reverses the movement of the gate.