Omron EE-SX772A — 5 mm through-beam sensor, NPN dark-ON output
The Omron EE-SX772A is a through-beam photoelectric sensor with a 5 mm sensing gap, delivering an NPN open-collector output that switches to ground when the beam is interrupted — dark-ON logic. The housing is chassis-mounted using M3 screws, and the wire lead exits the body for panel wiring.
The 0.197 inch (5 mm) sensing distance is the maximum unobstructed gap between the emitter and receiver. That is a short range — think part-present detection on a small conveyor, edge sensing on a PCB handling fixture, or flag detection inside a pick-and-place head. It will not work across a belt gap or through a window; the emitter and receiver must face each other with nothing in between beyond the 5 mm span.
NPN dark-ON — wiring and load
The output is NPN open-collector, dark-ON: the transistor turns on (pulls low) when the light path is blocked. That means the load — a PLC input, counter, or relay — connects between the collector and the positive supply rail. The 35 mA switching current handles most standard 5 V logic inputs directly; for a larger load, add an interface relay. This is the common sinking-output configuration for Japanese-origin PLC families.
Temperature and environment
Rated for -25°C to 55°C ambient, the EE-SX772A is suited for indoor industrial cabinets, assembly machines, and packaging equipment. It is not specified for freezing storage or hot enclosures above 55°C — keep it out of ovens, dryers, and unheated warehouses in northern climates. No IP rating is listed, so the sensor should be mounted inside a panel or protected from dust and splash.
Mounting and wiring
Chassis mount with M3 screws through the sensor body. No DIN-rail adapter, so plan for a drilled bracket or panel. The wire lead exits the housing; allow strain relief and route away from high-voltage cables. The 5 V supply must be clean — share the same rail as the PLC input card, not a motor-drive auxiliary.
The EE-SX772A is an active product.