Communication-capable position switch with AS-i
The Siemens 3SF3120-6CV00-0BA1 is a communication-capable position switch with an integrated AS-i adapter, designed for direct connection to an AS-i bus network via the insulation displacement method. The mechanical active principle uses a rounded plunger actuator (10 mm diameter) with positive opening operation — the normally-closed contacts are forced open by the actuator, meeting the requirements of EN 50041 design B for safety-related limit switching in industrial environments. The screw fixing method secures the switch to a standard mounting surface; the 40 mm width matches the EN 50041 footprint for direct replacement of existing block-style limit switches.
Contact configuration and switching function
The switch provides 2 normally-closed (NC) auxiliary contacts and zero normally-open (NO) contacts. The positive opening function per IEC 60947-5-1 ensures that when the plunger is depressed, the NC contacts are mechanically forced open — even if the contacts are welded — making this switch suitable for safety circuits where a fail-safe open state is required. The slow-action (overtravel) contact mechanism provides positive opening over the full plunger travel, not just at the snap point. The metal enclosure and painted coating provide corrosion resistance in humid or mildly aggressive atmospheres.