Sensor selection notes
The XS112B3PAL2 is a 12 mm threaded barrel inductive proximity sensor from the OsiSense XS family. It detects ferrous targets at 4 mm when flush-mounted in metal — no derating from the flush install. Output is PNP normally open, switching at 2500 Hz, so it handles fast part presence or counting without missed edges. Runs on 12 to 24 VDC and sinks up to 200 mA per cycle. The 3-wire PVC cable (2 m) keeps wiring simple: brown to +V, blue to common, black to the PLC input.
The XS1M18MA250A is an 18 mm barrel sensor with a 5 mm sensing range, but it uses a 2-wire AC/DC output (5 to 300 mA AC, 5 to 200 mA DC). That means it won't drop into a 3-wire PNP DC circuit without rewiring. The 18 mm hole also requires a different mounting drill pattern. For a 12 mm PNP DC line, the XS112B3PAL2 is the correct fit.
Body is nickel-plated brass, sensing face is PPS (polyphenylene sulfide). Enclosure is IP65/67, so it stands up to washdown overspray and airborne dust in packaging, food processing, or machine-tool environments. Approvals: UL, CSA, CE. The UPC printed on the box is 78590191482 (12-digit: 389119036378).