Master unit communication system and method for operation thereof

The This invention relates to a communication system having a Master-slave structure, comprising a plurality of subscriber 3, over a first communication path 21 and a second communication path 22 are connected to each other, wherein the first communication path 21 and the second communication path 22 working in opposite directions and 3 participants each have a first first with the communication path associated receiving unit 31 for receiving information signals on the first communication path 21, a first with the first Communication path associated sending unit 32 for sending information signals on the first communication path 21, a second with the second Communication path connected receiving unit 33 for receiving Information signals on the second communication path 22 and a second connected to the second communication path 34 for transmitting unit Sending information signals on the second communication path 22, an input and an output processing unit having 35 for processing information signals and an activatable Coupling means 37, said the activated coupling device 37 in normal operation the input of the processing unit 35 with the first receiving unit 31, the output of the processing unit 35 with the first transmitting unit 32 and the second receiving unit 33 connects to the second transmission unit 34, the operation of the error first transmitting unit 32 and / or ...