The transponder-coded safety switch CES-C04 from Euchner is available with an AR interface for series connection of up to 20 devices. In addition to the CES-AR-C04 safety switch, all other devices from the manufacturer that have the AR interface can be connected in series. Wiring is carried out either directly in the control cabinet or via M12 plug connectors and Y-distributors. The 'CES-AR' evaluation unit is available for querying the door position of all fused safety devices. This information is forwarded to the evaluation unit via a special data transmission without the need for additional wiring. The safety switch has OSSD outputs and two LED indicators that are clearly visible regardless of the installation position. An integrated LED limit range indicator makes it possible to detect any misalignment of the safety guard in good time. The transponder coding ensures absolute protection against tampering and guarantees PL e/category 4 in accordance with EN ISO 13849.