Patent ID: 8234427

Claim:
A communication system comprising a master unit and a plurality of slave units, wherein the master unit and the slave units each comprise two first terminals connected to a first communication path and two second terminals connected to a second communications path, wherein the first terminals of the master unit and the slave units are connected via the first communication path to form a first ring structure, wherein the second terminals of the master unit and the slave unit are connected via the second communication path to form a second ring structure, wherein the master unit comprises a transmitting unit connected to one first terminal for sending data signals, a receiving unit connected to the other first terminal for receiving data signals, and a master coupling unit configured to short-circuit the two second terminals in a failure mode of the master unit, the failure mode of the master unit being triggered by an occurrence of a link fault in the first communication path, wherein, in a normal mode of the master unit the two second terminals of the master unit connected to the second communication path are closed, so that the two second terminals are unconnected within the master unit and no data transmission takes place on the second communication path, and wherein, in the failure mode of the master unit the two second terminals of the master unit connected to the second communication path are opened and short-circuited by the master coupling unit, so that the two second terminals are directly connected to each other within the master unit in order to push data signals through the second communication path.