The Omron E3G-ML79-G is a long distance retroreflective photoelectric sensor with a relay output, designed to work on AC or DC supplies up to 250 V. The relay can switch loads directly, making it a simple drop-in for older control cabinets or for interfacing with a PLC without an extra amplifier. Sensing range is 0.2 to 2 m (retroreflective with reflector; reflector not included). Response time is 30 ms, fast enough for most conveyor, part-positioning, and door applications. The switching output is selectable via a physical slide: Light-ON or Dark-ON. That means one part covers both machine-state logics — no need to carry two variants in the van.
Field-fit note
Plastic housing, 68 x 29 x 85 mm. Operating temperature -25 to 55 °C. The relay output means you can drive a contactor coil or PLC input directly, but watch the load rating — the sensor's relay contacts are rated for the supply voltage, so confirm your load current is within the relay's spec (data sheet required for exact contact rating). If you're replacing a failed sensor on a line and the panel runs on 250 VAC, this one fits without adding a DC supply brick.