The Siemens 3RG7404-7CH00 is a SIMATIC PXO350 K20 diffuse sensor with background suppression, sized 31x20x12 mm. It runs on DC 10-30V, detects objects 25-100 mm away, and outputs PNP with light/dark-on programming selectable. Rated for 100 mA continuous, it terminates in an M8 4-pole connector and carries IP67 ingress protection.
Compared to a standard diffuse sensor without background suppression, the 3RG7404-7CH00's background suppression eliminates false triggering from reflective surfaces behind the target — critical on conveyors or pick-and-place stations where the belt or backplate would otherwise cause nuisance trips. The 25-100 mm sensing window is fixed but adjustable via the teach-in; the PNP output and M8 connector match the common 4-pin format used on most Siemens IO-Link and digital input modules.