The Omron E3T-FT11 is a through-beam photoelectric sensor set — transmitter and receiver in one rectangular PBT body, prewired with 2 m of bare-wire cable. It switches NPN (sinking) output, light-on mode, at 12-24V DC. Rated sensing distance is 500 mm, and the minimum detectable object is 1.3 mm diameter opaque. The set carries IP67 sealing, so it handles washdown and damp environments without a secondary enclosure.
500 mm through-beam range is the gap between the emitter and receiver faces — not the distance to a reflective target. For a conveyor belt or part-present application, the beam path must be clear of obstructions; the 1.3 mm minimum object size means it catches small parts like bottle caps or fasteners. The 1 msec response time is fast enough for most packaging lines but not for high-speed counting above 500 parts per minute. NPN output sinks current to ground when the beam is made (light-on mode). That means the load connects between +24V and the output wire. If your PLC input card is sourcing (PNP), you will need a converter or a different sensor variant. Maximum load current is 50 mA — enough for a PLC input or a small relay, not for a contactor coil directly. IP67 and PBT body mean the sensor can be mounted directly on a machine frame in a wet area — no need for a separate enclosure. The right-angle face orientation lets the beam exit parallel to the mounting surface, which helps in tight spaces. Overall dimensions are 19 mm tall, 12 mm wide, 4 mm deep — that is a slim profile for a DIN-rail or bracket mount.