Through-Beam Sensor Set – Dark-On NPN
Omron EE-SPW-311 is a through-beam photoelectric sensor set (transmitter and receiver) in a rectangular PBT body, prewired with a 2 m cable terminated bare wire. Dark-On switching mode sinks NPN output when the beam is interrupted, powered by a 5-24V DC supply, pulling up to 100 mA load. Senses opaque objects down to 5 mm diameter across a 1 m gap. Response time is 100 msec with a 100 Hz switching frequency – fine for slow-moving parts on a conveyor or presence detection but not for high-speed counting. IP60 rating means dust-tight but no moisture protection; keep inside a dry enclosure or protected panel.
Decision Point: EE-SPW-311 vs EE-SPW-411
EE-SPW-311 and EE-SPW-411 are mechanically identical – same housing, same sensing range, same supply and output. The one difference that decides fit: EE-SPW-311 is Dark-On (output ON when beam blocked), EE-SPW-411 is Light-On (output ON when beam made). If your existing panel wiring expects a Dark-On signal, the 311 drops in without rewiring. If the spec calls for Light-On, you need EE-SPW-411.
Integration Notes
Body dimensions: 27 mm height, 25 mm width, 8 mm depth. Right-angle sensing face – the light beam emits perpendicular to the cable exit. Mount the pair aligned across a 1 m gap; the built-in indicator and light modulation help during alignment. Supply voltage range is 5-24V DC – no polarity protection built in, so wire brown to +V and blue to 0V. NPN output (black wire) sinks to 0V; pull-up resistor needed if interfacing to a PNP input card.