Network system with an asynchronous access mechanism

摘要

A network system is described with a number of subscriber stations (A-G) which are connected via a physical medium (10) and in which the authorisation of the individual subscriber stations (A-G) of the network system (1) to access the physical medium (10) is provided by an asynchronous access method in that, in a first operating mode of the network system (1), a token signalling the access authorisation is forwarded by a subscriber station (A-G) with current transmission authorisation to the logically adjacent subscriber station (A-G) according to a token sequence pre-defined for this first operating mode. According to the invention, it is provided that, at the request of at least one subscriber station (E) of the network system (1), the latter is switched to a second operating mode in which the token signalling the access authorisation is forwarded by the subscriber station with current transmission authorisation to the logically adjacent subscriber station in the second operating mode of the subscriber station with current transmission authorisation according to a modified token sequence pre-defined for this second operating mode of the network system. <IMAGE>