Patent ID: 8055826

Claim:
A communication system comprising: a multiplicity of slave units, the slave units being coupled to one another via a first communication path and a second communication path, the first communication path and the second communication path operating in opposite directions to one another; and a master unit, the master unit being coupled to the multiplicity of slave units via the first communication path and the second communication path, the master unit comprising a transmit control unit and a receive control unit, wherein the communication system is operable in a read mode with the transmit control unit separately transmitting an information signal with a data field on the first communication path as a first information signal and on the second communication path as a second information signal, the receive control unit superimposing the data field of the first information signal circulated on the first communication path and the data field of the second information signal circulated on the second communication path by oring the data fields bit by bit; wherein the data field comprises a separate data area for each slave unit, such that each slave unit has a respective data area to write data to be transmitted to the master unit when the information signal passes through the slave unit.