The Siemens 3SF1244-1QV40-1BA2 is a SIRIUS mechanical safety switch with a 24 V LED indicator, designed for guard-door and position-sensing applications where a positive-opening contact is required per IEC 60947-5-1. The 0.1 mm repeat accuracy means the switch signals position consistently cycle after cycle — critical for safety circuits that must not drift. IP66/IP67 sealing lets it live on a washdown line or outdoors without a secondary enclosure.
Integration Notes
Mounts in any position via screw fixing; the 50 mm wide block housing fits standard machine-frame brackets. The M12 4-pin connector (pin 1 = ASI+, pin 3 = ASI-) carries both power and AS-Interface communication — no separate sensor cable needed. The slow-action, positive-opening contact ensures the NC circuit breaks even if the contacts weld, which is the core requirement for a safety-rated interlock.