The Siemens 3RG7640-0HC00 is a SIMATIC PXO210 M18S diffuse photoelectric sensor with energetic straight optics. It switches at 500 mm range, outputs NPN antivalent (light-on and dark-on simultaneously), and handles up to 150 mA load. Supply is 10-30 VDC. The 2-meter PUR cable with 4×0.34 mm² conductors brings power and both outputs out to the controller.
The 500 mm sensing range is the rated detection distance for a standard white test card — expect less on dark or matte targets. NPN antivalent means you get a normally-open and a normally-closed output in one housing; wire the pair to a PLC input and you can detect both presence and absence without a separate inversion circuit. The 150 mA per output is generous for a sensor this size; it can drive a small relay or indicator directly if needed.
M18×52 mm threaded barrel, standard for through-hole or bracket mounting. IP67 means it handles washdown and dust without a secondary enclosure. The 2 m PUR cable is oil-resistant and flexible down to -25 °C — good for cable-track or wet-area runs. Four conductors: brown (V+), blue (V-), black (NO output), white (NC output). Shield is not required for a diffuse sensor at this range, but keep the cable away from VFD or contactor power lines to avoid coupled switching noise.