PSENcode safety switches offer a complete, co‑ordinated solution that's economical and safe. The safety switch and actuator work together in such a way that the enable condition from the safety device is only triggered if the actuating element is within the switch's response range and the code number on the actuator matches that of the switch. Connecting several PSENcode switches in series, up to Category 4. Two versions of this key lock principle are available: one for use with any actuator or one with an actuator that is uniquely assigned to the PSEncode.