The SICK VL18L-4P324 is a cylindrical photoelectric retro-reflective sensor from the V18 series, delivering a 35 m sensing distance using a red laser light source. That 35 m range means it can reliably detect a reflector across a wide conveyor gap or through a warehouse aisle, with the laser giving a tight beam for precise alignment. The PNP output switches at 0.63 ms, fast enough for counting or positioning on a moderate-speed line.
The 35 m sensing distance is the headline figure, but the minimum sensing distance of 100 mm matters too — it means the sensor needs at least that gap between the lens and the reflector to operate reliably, so you cannot mount it flush against a target. The red laser (visible red) aids setup alignment, but the beam is class 1 or 2 depending on variant; verify local laser safety rules for the installation.
Integration notes
The 18 mm diameter cylindrical body fits standard 18 mm mounting brackets and through-hole panel mounts. Termination is via an M12 4-pin connector — no pigtail, so order a mating cordset separately. The sensor operates on 10–30 VDC and draws 20 mA, well within the capacity of a standard 24 VDC control supply. Switching is selectable Light / Dark ON, giving flexibility for normally-open or normally-closed logic in the safety or control circuit.