The XS1M18MA250A: Shielded flush-mount barrel means sensing is only from the front face — 5 mm at standard target. Two-wire NO: load must complete the circuit; confirm off-state leakage is acceptable for the connected input. AC switching at 25 Hz suits presence detection; for faster counting (up to 2000 Hz), use DC supply.
Mounting: flush into 18 mm hole, torque to option values per datasheet. Connector: 3-pin 7/8-16 male mini; mate with a corresponding female cordset (not included). Sensor body is nickel-plated brass; sensing face is PPS. For best EMC, route sensor cable away from VFD and contactor lines.