Abstract: A method and arrangement for combined data- and power distribution between nodes (MA, SL, SLN) in distributed data processing systems having a common communication bus (1, CANH/CANL) in which the communication bus includes at least one wire or differentiated dual wires transmitting digital information serially in form of dominant data bits at a first signal level (U1/U3 V/D2) and recessive data bits at a second lower signal level (U2, VD1) in a sequential order dependent on the content of the data being transmitted. Nodes (SL) having a low power consumption obtain power supply through dominant bits being transmitted on the bus (1), which dominant bits charge a capacitance (15) in the low effect nodes (SL). Nodes (MA) having a higher power consumption obtain power supply from a voltage source (V1) separated from the bus.

Abstract: A safety device for diagnostic terminals (3) in distributed computer networks (8) containing at least two nodes and a common communication bus (10a, 10b) for the computer network, preferably implemented in vehicles. The diagnostic terminal enables connection of an external diagnostic equipment (1) to different nodes (20a, 20b, 20c) within the computer network. By a signal evaluation circuit (12) arranged in the computer network a detection of the signal state at the contact pin or pins (3a, 3b) in the diagnostic terminal can be made, which contact pins connect the diagnostic equipment to the communication bus. A predetermined signal state will indicate an authorized connection of a diagnostic equipment (1), and only after an authorized connection will a direct connection to the communication bus (10a, 10b) be established via a relay function (13, 14a, 14b).