Patent ID: 8144718

Claim:
A method for transmitting data in a control system comprising a plurality of spatially distributed stations which are connected to one another via a communication medium, the stations comprising at least one control unit for processing state data captured by sensors and for generating control data for operating actuators and comprising a plurality of I/O units connected to said sensors and actuators, the stations being logically arranged in a series which defines a first station, at least one second station and a last station, the method of performing peer-to-peer communication between all stations in said series of stations within a single communication cycle defined from the start of an outgoing data frame from the first station and the receipt by the first station of a returning data frame, comprising the following steps: the first station generates a data frame having a plurality of data fields, with every second station and the last station being clearly assigned at least one data field for filling with transmission data, said transmission data comprising said state data and said control data, the first station sends the data frame as said outgoing data frame to that second station which comes after the first station in the series, the second stations receive the outgoing data frame from the respective previous station in the series, fill a data field assigned to it with transmission data and send the outgoing data frame with the transmission data to the next station in the series, and the last station receives the outgoing data frame from the previous station in the series, fills a data field assigned to it with last transmission data and returns the data frame with all the accumulated transmission data as said returning data frame to the series of stations, wherein the stations read said transmission data from other stations from the data fields in the returning data frame.