The 4-channel push button interface has 4 independent channels which – depending on parameterization – can be used as inputs or alternatively as outputs (only channels 1 or 2). The push button interface can therefore be used to poll its inputs for the switching state of up to 4 potential-free push buttons/switches with a common reference potential and send the corresponding telegrams to the instabus. These may be telegrams for switching or dimming, shutter/blind control or value transmitter applications (dimming value transmitter, light-scene extension, temperature or brightness value transmitter).