Master bus device for a building installation bus and method for providing a voltage supply to the building installation bus

摘要

The method involves providing a supply voltage (U) by a voltage source (20), where the voltage source is connected with one of the communication lines (18) over a controllable switching element (38). A transition of the supply voltage is detected from high-level to low-level at the communication lines by a monitoring unit (28). A switching signal is generated for opening the switching element by the monitoring unit after the detection of the transition. An independent claim is included for a master-bus device for a building installation bus.