Abstract: The invention relates to a method for commissioning a bus system and to a corresponding bus system. A test is carried out preferably after installation of the bus system and before it is actually put into operation to check whether the system is functioning properly. The test can comprise several stages which each test different functional aspects of the bus system. The bus system test can be carried out especially from a distributor or gateway (1) which couples several voltage supply lines (2-4), designed to carry information in addition to a supply voltage, with a central voltage supply line (L, N).