The Siemens 3SF5816-2DB20 is an AS-Interface emergency stop station in a metal enclosure rated IP67, meaning it withstands washdown environments and dust ingress on the plant floor. It carries an EMERGENCY STOP function with a pull-to-unlatch mechanism — the operator must physically pull the actuator to reset, preventing accidental restart after a stop command. The slave is configured as an A/B slave with 4 inputs and 3 outputs, which gives it flexibility on both standard and extended addressing AS-i networks. The housing mounts vertically and accepts a 22 mm mounting diameter for the actuator — a standard panel cutout size.
The enclosure measures 85 mm wide by 280 mm high by 65 mm deep. That 65 mm depth is the projection from the mounting surface — check clearance behind the panel if the AS-i cable duct or backplane components sit tight. The metal housing and metal front ring provide mechanical robustness for high-vibration areas like conveyor transfer points or press stations. Six command points with eight switching elements and three lampholders with integrated LED mean this station can combine the emergency stop with illuminated pushbuttons and indicator functions in one enclosure — reducing wiring points compared to separate components.