The Omron E3F3-D31 2M is a threaded cylindrical diffuse-reflective photoelectric sensor rated for a 100 mm sensing distance on a 100 × 100 mm white mat paper target, with an infrared LED emitter at 860 nm. The 100 mm range is the working envelope where the receiver detects returned light from the target itself — no reflector is required, which simplifies mounting on conveyors, small-parts feeders, and box-presence checks where the opposite side of the machine is inaccessible. Response time is 1.0 ms maximum and hysteresis is 20% max. of sensing distance — at 100 mm that hysteresis band is up to 20 mm, so the sensor is sized for part-presence and rough-counting duty rather than precision edge detection; downstream filtering should be set wider than 20 ms to ride through the hysteresis transition cleanly.
Output stage, supply envelope, and wiring
The control output is an open-collector transistor stage rated 100 mA max. with 1 V max. residual voltage at 100 mA, protected against output short-circuit and DC supply reverse polarity. That makes the sensor drop-in compatible with a standard 24 VDC PLC sourcing-input card; the 100 mA ceiling covers most relay coils and small solenoids directly without an interposing relay. Power supply voltage is 12 to 24 VDC ±10% with 25 mA max. current consumption, ripple (p-p) 10% max. — the same rail that powers a 24 VDC control cabinet, with headroom to absorb the 10% switch-mode ripple. The unit ships pre-wired with a 2 m lead, so field termination is to a gland or junction box, not an M12 connector on this code.
Form factor and panel-side fit
Body dimensions are 6.5 x 2.2 x 2.4 cm in the threaded cylindrical housing, which keeps the through-hole and mounting-nut footprint compatible with the M18-style threaded-barrel format common on packaging, materials-handling, and small-assembly lines. The pre-wired 2 m lead terminates inside the local junction box rather than at an M12 quick-disconnect, which is the right choice where the sensor is mounted once and not cycled.
Lifecycle and sourcing posture
The part's lifecycle stage is recorded as current, meaning it is still on the manufacturer's active catalogue. For contract-manufacturing and tendered-framework buyers who need traceable paperwork, sourcing through independent distribution per RFQ keeps the BOM line defensible against audit challenge; pricing and lot availability are confirmed at quote time rather than read off a live shelf counter.