What this laser BGS sensor does
The Omron E3Z-LL61 is a distance-settable photoelectric sensor with background suppression (BGS) using a red laser diode at 655 nm. It throws a tight 0.5 mm spot at 300 mm, so you can pick out a small target against a close background—good for presence checks on conveyors or registration marks. Sensing range on white paper goes 20 to 300 mm; on black paper it drops to 20 to 160 mm, so factor in your target reflectivity. It runs on 12 to 24 VDC (ripple within 10%) and pulls 30 mA max. The output is an open collector rated 100 mA at up to 26.4 VDC, which means it can drive a PLC input or a small relay directly—just mind the pull-up resistor and flyback diode if switching an inductive load.
Wiring and mounting notes
Wiring uses brown (12-24 VDC), blue (common), black (open collector). The laser spot at 300 mm is 0.5 mm diameter.