Contemporary approaches towards digital controllability facilitate the effective management of intelligent networks in building automation. The KNX eTR 101 is a heating controller for the KNX building bus system. The switch-sized control unit can be placed freely on site in almost any given room. Featuring a purist appearance that has been reduced to the essentials, the unit matches many current furnishing styles. The real-glass surface design is not only durable, it also lends the unit an elegant appeal. The controller offers a high level of user comfort, as it automatically ensures the desired room temperature and enables individual readjustment via touch surfaces. The simple user interface allows use in both private and commercial areas, as well as in hotels, where users want to adjust the room temperature quickly and intuitively. The “Plus” and “Minus” for setting the unit are supplemented by a temperature value display that appears during operation. The KNX eTR 101 allows single-stage and two-stage systems to be controlled easily. It measures the temperature on site and controls the heating and, if necessary, the cooling via integrated PI controllers. All settings such as connected systems and target temperatures for the operating modes of Comfort, Stand-by, Eco and Building Protection (according to KNX HVAC standard) are made in the KNX application of the room temperature controller.