Type 4 receiver with PROFIsafe and muting
The Siemens 3SF7844-8MD24-0SS1 is a Type 4 safety light curtain receiver from the SIMATIC FS420I series, designed for point-of-operation guarding where a 30 mm resolution is required. With a 1650 mm protected height and a sensing range of 0 to 18 m, it covers large access openings on assembly lines, packaging machines, or robotic cells. The integrated PROFIsafe bus connection drops the safety signals directly onto the PROFINET network without a separate safety relay or interface module — the receiver talks safety frames to an F-CPU. Muting is built in, meaning the curtain can be temporarily overridden during material feed cycles without removing the guarding function entirely — a standard requirement on conveyor transfer stations. The 30 mm resolution catches fingers reaching into the hazard zone (finger-protection class per IEC 61496-1/2), so it qualifies for applications where operator access to the danger point is possible.
Deployment context — PROFIsafe integration
The receiver is the PROFIsafe node in the light-curtain pair. It connects via the standard M12 bus connector to the PROFINET network, and the safety frames are processed by an F-CPU (e.g., SIMATIC S7-1500F or ET 200SP F). The transmitter (not this order code) is the companion sender — ensure both are ordered as a matched pair for the same 30 mm resolution and 1650 mm height. Muting sensors are wired to the receiver's auxiliary inputs; the muting logic is configured in the safety program. The 0 to 18 m range covers long spans across conveyor belts or gantry openings without needing additional deflection mirrors.