The electromotor actuator ST/K 1.1 is a proportional actuator for controlling radiator valves via ABB i-bus®. The actuator is mounted on thermostat valve bases (common valve adapters VA10, VA78 included in delivery). It is controlled via a continuous EIB/KNX room temperature controller. The actual valve position is displayed by 5 LEDs. The electromotor actuator ST/K 1.1 also has two binary inputs that can be used, for example, to connect a presence contact and/or window contact. The status of these inputs can be sent to the EIB/KNX.