The USAutomatic 550010 Photo Eye Send & Receive 12/24 VDC Has Been Discontinued and Replaced By USAutomatic Part 550011.
The photo eye is a secondary safety device. It produces a beam between the 2 units. When the beam is broken it will keep the gate from closing. It requires wires to be connected to both units (20 gauge) for operation. Typically a swing gate needs two sets of photo eyes for the best area protection.
One set of photo eyes pointing across the drive on the outside of the hinge post (A). The second set mounted across the drive at the point where the gate is fully opened (B). The photo eye must be installed where the gate does not break the beam.
The primary unit (Receiver) should be installed close to the control box. It requires 4 wires to be installed from the unit to the control box.
The second unit (Transmitter) should be installed on the opposite side of the drive. It requires 2 wires to be installed from the unit to the control box.
The two units must face each other to establish the beam (maximum distance 50 feet).