Omron EE-SX771A — 5 mm through-beam sensor with NPN dark-on output
The Omron EE-SX771A is a through-beam photomicrosensor with a 5 mm sensing slot. It uses an NPN open-collector output configured for dark-on operation — meaning the output transistor sinks current when the light path is interrupted. This is the fail-safe wiring choice for edge detection, part-present sensing, or end-of-travel limits on pick-and-place feeders and small assembly machines. The 5 V supply rail matches classic TTL and 5 V PLC inputs directly; no level translator needed. Mounting is via M3 screws to a chassis bracket, with wire leads for the connection.
Temperature range — indoor and light-industrial only
Rated for -25°C to 55°C ambient. That covers most factory floors, warehouse sorters, and office equipment, but not freezers, ovens, or outdoor cabinets in direct sun. If the application sees sustained heat above 55°C — say a motor drive cabinet or a solar-exposed panel — this sensor is not the pick. The EE-SPW311 shares a similar 5 V supply and NPN dark-on output but adds an IP60 rating and adjustable sensing distance up to 39.37 mm, which may suit a wider range of mounting positions.
Listed as Active with no end-of-life notice. That means no rush to stockpile or find a drop-in replacement for existing designs. For new BOMs, it is a stable line item.