Patent ID: 6983023

Claim:
A bus system for performing data transfer between a bus master and a plurality of bus slaves that are connected to said bus system, comprising: a main line adapted to perform data transfer between said bus master and said bus slaves; and sub coupling lines disposed in non-contact relationship, in proximity and in parallel to said main line led from said bus master to form directional couplers, together with said main line, wherein each of said sub coupling lines is connected, at in least one end, to a bus slave and when a bus slave is connected to only the at least one end, the other end of said sub coupling line is matching-terminated by a termination resistor, and wherein one end of said main line to which said bus master is not connected is terminated such that total reflection takes place at said one end of said main line and a forward wave on said main line and a reflection wave from a terminated end are used to perform bi-directional data transfer between said bus slave connected to said at least one end of said sub coupling line and said bus master.