A reflective photo eye has two parts: a sensor on one side of the gate opening and a reflector on the other. The sensor sends a beam to the reflector and receives it back.
If something blocks the beam while the gate is open, the gate should stay open. If the gate is closing, it should stop and reverse. Here’s how to mount the photo eye, connect it, line up the reflector, and test the gate.
1. Choose where the beam will go
For a beam across the driveway, place the sensor and reflector where they can see each other and where a vehicle will break the beam before the gate reaches it. Mount both parts on solid posts, columns, or walls. A loose post or vibrating surface can cause alignment problems later.
Check the gate operator manual for the correct beam height and location. A photo eye protecting the area behind an opening gate needs a different location and a different input on the operator board.
2. Mount and wire the sensor
Mount the photo eye in the position required by its manual. Use its bracket and weather cover, and route the cable through the intended opening in the housing.
Turn off power to the gate operator, including battery power, before wiring.
For most of these photo eyes, the connections break down into two pairs:
- Two wires for power run to the voltage source specified in the photo eye manual.
- Two wires for the safety signal run to the photo eye input and common terminal on the gate operator board. This is how the photo eye tells the board that the beam has been blocked.
Some photo eyes come with a cable attached. Others have terminals inside the housing and need you to supply the wire. A model may have an extra lead or terminal because it offers both normally open (N.O.) and normally closed (N.C.) outputs; you use the contact called for by your gate operator and leave the unused one insulated.
The same basic four connections can be used with a monitored or non-monitored setup. What matters is which safety input, contact, and any required resistor or board setting the manuals specify. A driveway closing beam connects to the operator’s CLOSE photo eye input, not its regular OPEN command input.
LiftMaster note: A LiftMaster photo eye such as the LMRRUL uses two wires for its sensor connection. Follow its model-specific diagram rather than this four-connection layout.
3. Mount the reflector
Place the reflector directly across from the sensor at the same height. Attach it loosely so you can adjust its position after you turn on the photo eye.
Make sure the distance between the two parts is within the photo eye’s rated range. Nothing should block the beam when the driveway is clear.
4. Line up the beam
Restore power and look at the photo eye’s indicator light. Move the reflector and adjust the sensor until the indicator shows a good connection. The light colors and adjustment points differ by model, so check the photo eye manual for what its indicator means.
Tighten the sensor and reflector, then check the light again. Finally, pass an object through the beam. The indicator should change when the beam is blocked and return to normal when you clear it.
5. Test the gate
The indicator tells you the photo eye sees the reflector. Now make sure the gate responds. Keep people clear of the moving gate and use an object to block the beam from a safe position.
- Open the gate, block the beam, and give a close command. The gate should stay open.
- Clear the beam and start closing the gate. Block the beam again. The gate should stop and reverse.
- Clear the beam and confirm the gate works normally again.
If the indicator does not show a clear beam, check power, clean the sensor and reflector, and adjust their alignment. If the indicator changes when you block the beam but the gate does not respond, check the two signal connections and the operator’s photo eye settings. Do not put the gate back into normal use until the test works.
A secure mounting spot, a clear beam, and a successful gate test are what make the installation complete. If you need a photo eye or replacement reflector visit our photoeye collection.