The 3SF7844-8BB06-0SS1 is a Type 4 safety light curtain receiver in the SIMATIC FS420I family, designed as the receive-side half of a finger-protection light barrier for hazardous machine zones. Its 14 mm resolution means it detects objects as small as a finger reaching into the guarded area — that's finger-protection class per IEC 61496-1, the standard governing electro-sensitive protective equipment. The 450 mm protected height and 0 to 6 m operating range define the physical coverage envelope: a single pair covers a 450 mm tall by 6 m wide access opening. PROFIsafe bus connection means it integrates directly into a Siemens safety PLC network without a separate safety relay module — the safety status travels over the PROFIBUS/PROFINET profile, not hardwired OSSD outputs.
Deployment context — where this receiver fits on the line
This receiver mounts opposite its paired emitter across a hazard zone — typically a press, robot cell, conveyor infeed, or palletizer access point. The 14 mm resolution catches fingers, so it suits applications where an operator can reach into the danger area but the machine must stop before contact. Blanking capability (up to the listed blanking height) lets fixed obstructions like tooling or part fixtures sit inside the curtain without triggering a false stop — the receiver ignores the blocked beams in the programmed blanked zone. PROFIsafe integration means the safety PLC handles the mute, blanking, and restart interlock logic in software, reducing the cabinet wiring count.