The Siemens 3RG7401-0CH00 is a SIMATIC PXO320 K20 retro-reflective photoelectric sensor with an integrated polarisation filter. It detects objects across a 0.1 to 2.5 m range, outputting a PNP signal at 100 mA. The sensor operates on 10–30 V DC and includes a 2 m PUR cable with 4×0.14 mm² conductors. The light/dark-on switching behaviour is programmable, and the IP67 rating handles washdown and dusty environments.
The 0.1–2.5 m sensing range is the effective detection distance for a standard 100 mm reflector; shorter ranges improve immunity to background interference. The polarisation filter rejects false triggers from shiny or reflective targets — critical on packaging lines or conveyor transfers where glossy film or metal surfaces are present. PNP output with 100 mA sink drives most PLC inputs directly; verify the load current if driving a relay or valve coil. The 2 m PUR cable is oil- and abrasion-resistant, rated for flexing in cable carriers. IP67 means the housing is dust-tight and protected against temporary immersion — suitable for washdown zones but not continuous submersion.