What this sensor does on your line
The SICK WTB4S-3P2261 is a miniature photoelectric proximity sensor with background suppression from the W4S-3 family. It detects objects up to 180 mm away using a visible red PinPoint LED, and the background suppression means it ignores surfaces behind the target — no false triggers from a conveyor belt or machine frame behind the detection zone. The 500 µs response time catches fast-moving parts on a packaging or assembly line without missing a beat.
At 12.2 mm wide and 41.8 mm tall, this sensor fits into tight spaces where a standard 18 mm cylindrical sensor won't. The M8 4-pin connector keeps wiring clean — no cable glands to wrestle in a crowded junction box. Rated IP66 and IP67, so it handles washdown on food processing lines or dust in a sawmill without sealing concerns. Operating temperature from -40 °C to 60 °C covers freezer applications and hot factory floors alike.
Output and switching logic
PNP output (sourcing) at 100 mA max — mates directly to sinking PLC inputs common in European-style control cabinets. Switching is selectable Light / Dark ON via the teach-in, so you can set it to fire when an object is present or when the beam is clear. Runs on 10–30 VDC, which is standard for industrial sensor supplies.