The Sensor KNX T-L-Pr-UP Touch CH for the KNX building system detects brightness and the presence of persons in the room and measures the temperature. Via the bus, the indoor sensor can receive an external temperature measurement and processes it together with its own data to generate an overall temperature (mixed value). The KNX T-L-Pr-UP Touch CH has a settable brightness limit. The limit output and other communication objects can be connected with an AND and OR logic gate. Two integrated touch buttons (bus buttons) and two red LEDs can be freely assigned bus commands. The device is supplemented with a frame of the switch series used in the building, and thus fits seamlessly into the interior fittings.