The KNX IO 510.1 secure (2O) is a compact switching actuator with 2 bi-stable relay outputs. The actuator provides the function for universal outputs including scene control, timer, staircase lightning and to control heating valves (PWM for thermoelectric valve drives). Two push buttons and three LEDs allow a local operation and a visualization of the device state. In addition to the output channels the device includes 16 independent functions for logic or timer control. The device supports KNX Data Security, but may also used without it.