Sensor characteristics and wiring note
The Omron E2E-X18ME2-M1 is an inductive proximity sensor with an 18 mm nominal sensing distance, unshielded — meaning it can be flush-mounted in metal without derating the sensing range. Output is NPN normally closed, 3-wire DC, so a target presence opens the load; good for fail-safe detection on a sinking PLC input. Terminated via an M12 quick-disconnect connector, standard on this class of sensors. Oscillation frequency is standard (no high-speed variant), and the sensor carries no self-diagnosis function — it is a straightforward presence detector. Supply and output are DC 3-wire NPN, typical for Omron and many Japanese-sourced control systems.