The Siemens 3SF7844-8BD08-1SS1 is a Type 4 safety light curtain host receiver from the SIMATIC FS420I family, with 30 mm resolution and a 600 mm protected height. It handles blanking and reaches 0 to 18 m, connecting via Profisafe bus. That 30 mm resolution means it catches fingers reaching into the hazard zone — finger-protection class per IEC 61446-1 — so it's suited for guarding robot cells, assembly stations, and manual workstations where hand access is the risk.
Deployment Context
As a Type 4 host receiver with Profisafe bus connection, this light curtain integrates directly into a SIMATIC safety controller via the FS420I interface — no separate safety relay needed for the communication path. The 0 to 18 m range covers long reach across a conveyor or gantry cell. Blanking allows fixed obstructions (brackets, machine frames) within the field without disabling the curtain, which avoids nuisance trips on a production line.