The Siemens 3SF7844-8BB17-0SS1 is a Type 4 safety light curtain receiver from the SIMATIC FS420I family, designed for finger-protection applications with 14 mm resolution over a 1200 mm protected height. The 14 mm detection gap means it catches fingers reaching into the hazard zone (finger-protection class per IEC 61496-1), making it suitable for guarding press brakes, assembly stations, and robotic cells where hand access must be detected before a dangerous motion completes. Communication is via PROFIsafe bus connection, integrating directly into a SIMATIC safety PLC without a separate safety relay or interface module. The operating range spans 0 to 6 m, and blanking capability allows fixed or floating object suppression for workpiece pass-through without disabling the safety function.
Integration Notes
Mounts as the receiver half of a through-beam pair; the emitter (order code 3SF7844-8AA17-0SS1) is ordered separately. The PROFIsafe connection uses a standard M12 bus connector — verify the device-specific GSDML file is loaded into your TIA Portal project before commissioning. The 14 mm resolution and Type 4 architecture (SIL 3 / PL e per IEC 62061 / ISO 13849-1) mean this curtain is rated for the highest risk-reduction category in point-of-operation guarding. Blanking is configured via the FS420I parameterization tool, not hard-wired.