The Siemens 3SF7844-6TD08-0SS1 is a Type 4 safety light curtain receiver with 30 mm resolution and a 600 mm protective height, covering a sensing range of 0 to 18 m. It connects via ASISAFE bus to a SIMATIC FS440I cycle control unit, making it a matched component for a safety-rated optical guard on a production line or automated cell.
Type 4 per IEC 61496-1/2 is the highest safety integrity for electro-sensitive protective equipment — it can detect a 30 mm finger-sized object reaching into the hazard zone and will initiate a stop signal. The 600 mm protective height and 0 to 18 m range suit guarding a single machine opening or a conveyor infeed where the transmitter and receiver are mounted opposite each other. The ASISAFE bus interface ties directly into a SIMATIC FS440I safety controller, so this receiver is not a standalone unit — it expects the FS440I cycle control for configuration and diagnostics.
Integration context
Mounts in a standard industrial enclosure or on a machine frame using the supplied brackets. The receiver and its paired transmitter must be aligned within the optical window; the ASISAFE bus cable routes back to the FS440I controller in the panel. No separate safety relay is needed — the FS440I handles the logic and output switching.