Fit and function
The XUX0ARCTT16T: This is a through-beam photoelectric sensor transmitter — the emitter half of a paired system. It sends an infrared beam up to 40 m to a separate receiver. The rectangular PBT housing (92 mm × 77 mm × 31 mm) is rated IP65/IP67, suitable for washdown or dusty environments. Supply voltage accepts 24-240 V AC or DC, which lets you consolidate one line item across panels with different voltage rails. Switching frequency is 20 Hz with a 25 msec response time — adequate for moderate-speed conveyor or material-handling applications where you are detecting object presence, not counting fast cycles. Maximum load current is 500 mA, so it can drive a small contactor coil or a PLC input directly without an interposing relay.
The tubular XU2M18AP20D is a through-beam transmitter-and-receiver set in a nickel-plated brass M18 housing. Key differences: the XU2 set runs on 12-24 V DC only, its load rating is 100 mA, and it includes both emitter and detector. The XUX0ARCTT16T is a transmitter alone, so if you need a receiver you must order it separately. However, the rectangular unit's universal AC/DC supply and 500 mA load capacity give it broader application reach — especially in panels where 24 V DC is not dedicated. The 40 m range of the XUX0ARCTT16T is shorter than the 70 m of the XU2 set, but sufficient for most indoor conveyor and door sensing. Because the XUX0ARCTT16T is a transmitter only and uses a different form factor, it will not drop into a panel wired for the XU2M18AP20D set without changing the mounting bracket and pairing it with a compatible receiver. For a new design or a transmitter replacement where the existing receiver is from the XU series, this part is a strong fit.
Integration notes
M12 3-pin connector — verify the receiver-side pinout for pairing. The rectangular body mounts via two M4 slots; right-angle face orientation. Supply wiring accepts 24-240 V AC or DC on the same terminals; no voltage selector needed. The selectable light-on/dark-on output is set via a DIP switch inside the housing. Operating temperature spans -13 °F to 131 °F, covering most indoor industrial environments. The PBT housing resists many oils and chemicals common on factory floors.