AS-Interface F-adapter for emergency-stop circuits
The Siemens 3SF5402-1AA05 is an AS-Interface F-adapter designed to connect an EMERGENCY-OFF mushroom-type actuator (SIRIUS 3SB3 series) onto an AS-i safety network. It provides 2 digital inputs for the dual-channel safety signal, wired via the AS-i insulation displacement method — no screw terminals, just pierce the flat cable. This is the gateway between a panel-mounted E-stop pushbutton and the AS-i safety monitor upstream. Rated IP20, so it lives inside an enclosure — not on the machine frame. The 52 mm depth and 30 mm width fit a standard front-panel cutout for the 3SB3 actuator; mounting is front-panel, not DIN rail.
Safety integration and connection detail
The adapter carries a safety-related designation (Safety-Related = 2), meaning it is intended for use in safety circuits up to SIL 3 / PL e when paired with an appropriate AS-i safety monitor. The two digital inputs map to the dual-channel E-stop contact block — one channel per input, monitored for discrepancy by the safety logic. Connection is via AS-i insulation displacement — strip the flat cable, press the adapter down, the piercing contacts bite through. No tool needed beyond the cable prep. The adapter itself has no digital outputs; it is purely an input node for the safety signal.