KNX bus device with actuator function (in combination with a KNX room temperature controller) or controller / actuator (with acquisition of the temperature value by a KNX sensor or by a sensor connected to an analog input). For installations in 2-pipe hydraulic distribution systems with ON / OFF control of an electrothermal actuator on a shut-off valve and a 3-speed fan. The outputs not used for controlling a fan coil unit can be configured as outputs to carry out other functions. Mounting in distribution board on EN 60715 rail (4 modular units, each 18 mm). To be used in KNX installations for home and building automation.