What it is and what it does
The Omron E3SCT66OMS is an E3S-C series through-beam photoelectric sensor rated for a 700 mm sensing distance, with an M12 connector and dual NPN/PNP output. It operates on 10–30 VDC and switches up to 100 mA load current, with a 1 ms response time and selectable Light-ON or Dark-ON mode. The IP67 housing handles washdown and dusty conditions, so it's a straight fit for packaging lines or conveyor chutes.
How it relates to the cable-terminated E3S-C versions
The E3SCT66OMS shares the same 23 x 20 x 57 mm footprint as the cable versions E3SCT615MOMS and E3SCT612MOMS but swaps the 5 m or 2 m pigtail for an M12 4-pin connector. The big trade-off: this M12 variant tops out at 700 mm through-beam range, while the cable variants reach 30 m. If your panel was wired for a cable version, the M12 connector means a different entry into the conduit or a field-wireable M12 pigtail. The mechanical hole pattern and mounting bracket are identical.
Mounting and installation notes
Dimensions: 23 mm wide, 20 mm tall, 57 mm deep – same as every other E3S-C through-beam head, so existing brackets and hole patterns carry over. IP67 integrity requires the mating connector to be torqued to the sensor housing – finger-tight won't cut it in a washdown zone.