The 3RG7640-0AB00 is a SIMATIC PXO210 M18S diffuse photoelectric sensor from Siemens — energetic (direct reflection) optics in a straight M18×52 barrel, rated for 500 mm sensing range on a light-on PNP output. Supply is 10-30 VDC, switching up to 150 mA, and it terminates in a 2 m PUR cable (3×0.34 mm²). The IP67 rating means it handles washdown and dusty conveyor environments without a secondary enclosure.
The 500 mm diffuse range is the maximum for a standard white target (90% reflectance); real-world range on dark or matte surfaces will be shorter — factor 30-50% reduction for black targets. The PNP light-on output is sourcing (positive switch), so it mates directly with most PLC inputs that expect a +24 V signal when the target is present. The 2 m PUR cable is oil- and abrasion-resistant, suitable for drag chains or flexing applications, but the 3×0.34 mm² cross-section limits the cable run to about 30 m at 24 V before voltage drop becomes a concern.
Signal Integrity Note
In a plant with VFDs or welding gear nearby, the unshielded cable can pick up common-mode noise. If the signal is jittery, check the shield first — this sensor doesn't come with a shielded cable, so you'll want to run it in a separate metallic conduit or add a ferrite clamp near the sensor head. The IP67 housing is metal, so grounding the barrel through the mounting bracket helps shunt EMI to earth.