Safety light curtain receiver, Type 4, 30 mm resolution, PROFIsafe
The Siemens 3SF7844-8BD11-0SS1 is a Type 4 safety light curtain receiver in the SIMATIC FS420I family, with 30 mm resolution, 750 mm protected height, and a sensing range of 0 to 18 m. It connects via PROFIsafe bus, making it a drop-in receiver for a safety-rated light curtain guarding a hazard zone up to that height and range. Type 4 per IEC 61496 means it is rated for the highest level of safety integrity — suitable for guarding robots, presses, or automated cells where a failure could cause serious injury. The 30 mm resolution catches fingers (finger protection) reaching into the guarded area.
Integration notes
Mounts as the receiver half of a Type 4 safety light curtain system. PROFIsafe bus connection integrates directly into a SIMATIC safety PLC or F-CPU, eliminating the need for a separate safety relay for the bus interface. The 750 mm protected height covers a typical conveyor infeed or machine access point; pair with the matching emitter for the full 0-18 m range.