Patent ID: 8170039

Claim:
A method of transferring data in an automation system having a plurality of communication stations being communicatively connected via communication lines in a hierarchically arranged topology having a plurality of hierarchy levels of communication stations connected via respective entry points, wherein each entry point forms a ring of connected communication stations for the respective level via the entry point, the method comprising: assigning to each communication station a unique identifier comprising an alias, wherein the alias uniquely identifies each communication station and the hierarchy level of each communication station by using a nested notation based on hierarchy levels; designating a first and a second port in each communication station exclusively for transmitting data within each communication station's own hierarchy level along a hierarchically equal line; designating a third or more ports in each communication station exclusively for transmitting data into a subordinate hierarchy level; designating in a telegram to be sent from a sending communication station to a destination communication station a destination alias to identify the destination communication station; forwarding the telegram from the sending communication station to the proper hierarchy level based on the nested notion, wherein telegrams destined for a communication station's own hierarchy level are transmitted along the hierarchically equal line via the first and second port and wherein telegrams destined for a subordinate hierarchy level are transmitted via the third or more ports into the subordinate hierarchy level; upon entry to each hierarchy level via a respective entry point, duplicating the telegram received from the sending communication station for redundant sending, assigning a sequence number to provide a unique identification for the telegram, sequentially logging the sequence number into a position within a vector having a limited number of positions, wherein the vector is arranged such that logging occurs in a circular fashion, and forwarding the telegram in the ring in both directions; when the telegram has reached again the entry point in the ring which has already been passed thereby assuring that the telegram has been received at least once at all communication stations encompassed by the ring, eliminating the telegram at the entry point by recognizing whether the sequence number is a duplicate by evaluating only a section of positions in the vector rather than the entire vector, wherein the section of positions to be evaluated is displaced across the vector; and receiving the telegram at the destination communication station.