With integrated choke and 30 V taken out for supplying another line, e.g. main line via separate choke, connection unit and terminal 6183-101. With diagnosis function for sending of bus current/voltage, operating data, overload, bus reset. Display of bus current used via 7 LEDs. Display LEDs: operation, overload, bus traffic/communication. For generating the system voltage for one bus line. With integrated choke. The bus can be connected via enclosed terminal block.