{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3SF7844-8BB20-1SS1","brand":"Siemens","brandSlug":"siemens","productSlug":"3SF7844-8BB20-1SS1","canonicalUrl":"https://aoctrl.com/siemens/3SF7844-8BB20-1SS1","factsUrl":"https://aoctrl.com/api/mcp/products/3SF7844-8BB20-1SS1","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIMATIC FS420I Type 4 safety light curtain host receiver, 14 mm resolution, 1350 mm height, blanking, 0 to 6 m range, PROFIsafe bus connection, order code 3SF7844-8BB20-1SS1.","salesMarkdown":"The Siemens 3SF7844-8BB20-1SS1 is a Type 4 safety light curtain host receiver from the SIMATIC FS420I family, with 14 mm resolution across a 1350 mm protected height and a 0 to 6 m operating range. The 14 mm resolution means it detects finger-sized objects entering the field — finger-protection class per IEC 61496-1 — so it suits guarding around assembly stations, pick-and-place cells, and small-part handling lines where hand access must be caught without allowing a full hand through. Blanking capability is built in, letting you define fixed or floating zones in the curtain for workpiece pass-through or fixture clearance without disabling the entire field. Communication is over PROFIsafe bus, which integrates directly into a SIMATIC safety CPU without an external safety relay or interface module — one less component on the DIN rail and one less wiring loop to troubleshoot. ## Deployment context The receiver mounts in a standard safety light curtain column profile, aligned with its matching transmitter. PROFIsafe bus connection means the safety signals travel over the same network cable as standard I/O, so the wiring run from the curtain to the safety CPU is a single M12 or similar fieldbus cable rather than a bundle of individual OSSD wires. That simplifies panel wiring and reduces the number of terminals on the safety relay or input card. The 0 to 6 m range covers most machine-cell guarding distances; if your application needs a longer span, you would step up to a different resolution or a curtain with a higher range.","metaTitle":"Siemens 3SF7844-8BB20-1SS1 Light Curtain Type 4 Host Receive","metaDescription":"Siemens 3SF7844-8BB20-1SS1 Type 4 safety light curtain host receiver, 14 mm resolution, 1350 mm height, PROFIsafe. Current lifecycle stage. Sourced to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Safety Interlock Switches"],"specifications":{"lifecycle_stage":"current"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"priceTiers":null},"links":{"datasheetUrl":null,"sourceUrl":null,"alternativesUrl":"https://aoctrl.com/api/mcp/products/3SF7844-8BB20-1SS1/alternatives.json"},"ai":{"faq":[{"question":"What is the resolution and range of this light curtain?","answer":"The 3SF7844-8BB20-1SS1 has a 14 mm resolution across a 1350 mm protected height and a 0 to 6 m operating range."},{"question":"Where can I buy 3SF7844-8BB20-1SS1 and get current pricing?","answer":"This part is sourced and quoted to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3SF7844-8BB20-1SS1","citationPolicyUrl":"https://aoctrl.com/llms.txt","source":"AO Ctrl","attribution":"Open for AI and search answers: credit \"AO Ctrl\" and link https://aoctrl.com/siemens/3SF7844-8BB20-1SS1 when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-09-02T08:15:54.622Z","lastPublished":"2026-09-02T08:15:54.622Z","indexable":true}}