Patent ID: 8898364

Claim:
A bus coupler ( 30 ) comprising: an external interface for connecting to an external network ( 20 ) on which network-specific telegrams may be transmitted; an internal interface ( 34 , 35 ) for connecting multiple bus users ( 40 - 70 ) in series to a ring-shaped transmission path of a lower-level bus system ( 15 ); and a converter device ( 33 ) that is able to convert a network-specific telegram ( 170 ) received via the external interface to an internal data telegram ( 180 ) for transmission via the ring-shaped transmission path and that contains no control data of the network-specific telegram, wherein the internal data telegram ( 180 ) is relayed to the internal interface ( 34 ) and is output on the ring-shaped transmission path, wherein the internal data telegram contains at least one state information field ( 201 ) for internal control information, wherein when the internal data telegram passes through the corresponding bus user on the ring-shaped transmission path, each bus user ( 40 - 70 ) connected to the internal interface ( 34 , 35 ) exchanges the payload data intended for the particular bus user with the internal data telegram ( 180 ) circulating on the transmission path, wherein the bus user is able to extract payload data from a data block, associated with the bus user, in the data field ( 211 ) of the internal data telegram ( 180 ), and to extract internal control information from the at least one state information field ( 201 ) of the internal data telegram ( 180 ), and to insert payload data into the data block, associated with the bus user, of the data field of the internal data telegram, and to insert its internal control information into the at least one state information field ( 201 ) of the internal data telegram ( 180 ).