18mm tubular through-beam sensor, DC NPN output
The Telemecanique XUB2ANBNL2R is an 18mm threaded tubular photoelectric through-beam detector from the XUB series. It provides a 15 m sensing range between separate emitter and receiver, aimed and aligned frontally. Operating on 12 to 24 VDC with a 3-wire, NPN normally-closed output, it switches a maximum load current of 100 mA. On/off response time is 1 millisecond, with a switching frequency of 500 Hz — fast enough for part counting or web break detection. The housing is PBT with a PMMA lens, rated NEMA 4X/12 and IP67 — suited for washdown and dusty environments. A mounting nut is included. Approvals UL, CSA, and CE cover most industrial and commercial installations.
Field wiring and integration
Connected via a 2-meter PVC cable, three conductors: standard brown/blue/black for V+, V-, and NPN NC output. The NC (normally-closed) configuration means the output transistor is on when the beam is uninterrupted, and switches off when the beam is blocked. Verify the sink current from the input card — 100 mA maximum load means this can drive most PLC digital inputs or small relays directly.
Not a drop-in for the XU2 series
A common cross-reference to check is the XU2M18MB230. That part operates on 24 to 240 VAC/VDC, uses a 2-wire connection, and has a 20 ms response time — too slow and the wrong voltage for a DC NPN system. The XUB2ANBNL2R requires 12-24 VDC and a 3-wire NPN sinking input. No rewiring shortcut exists between the two.