What It Is
The E3FABP21OMI is a diffuse reflective photoelectric sensor from Omron's E3FA series, delivering a 500 mm sensing range with a visible red LED. It's a PNP output, light-ON / dark-ON selectable unit, switching in 500 µs. Power supply is 10–30 VDC, output load rated 100 mA. The M12 4-pin connector makes it a quick swap on a line — no hard-wiring.
Where It Lives
Housing is 16.6 mm wide, 45 mm long — the standard E3FA footprint. If your panel already has M12 pigtails cut for this series, it drops right in. IP67 and IP69K protection means it can take washdown cycles; fine for food or beverage lines. Operating temperature -25 to 55 °C covers most indoor factory floors.
How It Compares to the 300 mm Sibling
The closest functional peer is the E3FADP22OMI — also diffuse, PNP, same housing and connector. The difference is reach: the E3FABP21OMI covers 500 mm compared to 300 mm on the E3FADP22OMI. Both share the 100 mm minimum sensing distance, so if your old bin had the 300 mm part but the application needs more headroom, this is a non-wiring upgrade. The retro-reflective E3FARP21F2OMS goes to 4 m but uses a reflector; that's a different install pass.