What it is and where it fits
EE-SX771R is an Omron EE-SX77 series through-beam photoelectric sensor set (transmitter + receiver in one L-slot body). It detects opaque objects as small as 2 mm x 0.8 mm at a fixed 5 mm gap — designed for tight presence or edge detection in packaging, assembly, or part-present stations. Output is PNP, dark-on (conducts when the beam is blocked), switching at 0.17 msec with a 3 kHz frequency, so it tracks fast-moving small parts without missed counts. Supply voltage spans 5-24V DC, making it drop-in compatible with most PLC DI cards and industrial logic levels.
Mounting and wiring notes
Housing is an L-slot style 13 mm deep, 18 mm wide, 21 mm tall — designed to mount directly on a bracket or actuator fork. Prewired with a 2 m bare-end cable; no connector to purchase separately. Body is PBT with an IP64 seal: dust-tight against fine debris but not rated for pressurized washdowns. The wide supply range (5-24V DC) means you can run it from the same 24V bus as PLC I/O without a regulator. Dark-on logic suits applications where the sensor is normally blocked at rest and unblocked during action — wire accordingly. PNP output sources current up to 50 mA, enough to drive a small PLC input directly.
How it compares to E3T-ST14
Both are PNP through-beam sensors with 2 m cables, but they fill different gaps. E3T-ST14 (Omron E3T series) reaches 1 m with red LED, runs on 12-24V DC only, and responds in 1 msec with an IP67 body. EE-SX771R covers only 5 mm — it's for fork-light or close-proximity detection rather than long-range. The faster 0.17 msec response and wider supply range (5-24V) matter when the sensor is counting fast cycles or running on a mixed-voltage bus. They are not drop-in interchangeable: panel designed for the E3T-ST14's 1 m gap will not work with a 5 mm sensor, and the supply voltage minimum differs (5V vs 12V).