The Autonica BF4R is a standard-type photoelectric sensor with a red LED emitter at 660 nm. It uses an NPN open-collector output and offers a selectable Light ON or Dark ON mode via an ON/OFF button. Operated from 12–24 V DC (±10%, ripple up to 10%), it draws up to 45 mA and delivers fast response times of up to 0.5 ms (Frequency 1) and 0.7 ms (Frequency 2), with an OFF Delay timer of 40 ms. Sensitivity is adjustable manually, and mutual interference is managed by a built-in differential frequency mode. It tolerates ambient illumination up to 11,000 lx in sunlight and 3,000 lx under incandescent lighting, with operating temperature from -10 to 50°C and storage from -20 to 70°C, and humidity of 35–85% RH (storage 35–85% RH). Self-diagnosis indicates unstable sensing when the target remains in an unstable level for 300 ms and also flags a short-circuit in the control output. Load voltage up to 30 V DC and load current up to 50 mA, with residual voltage up to 1 V at 50 mA. The housing is made of heat-resistant ABS with a polycarbonate cover, and the cable is Ø4 mm, 4-wire, 2 m long with AWG22 conductors. Accessories include a fixing bracket, bolts, and nuts.