| 摘要 |
In a local area network with a plurality of subscriber stations accessing two optical waveguides which are operated in opposite directions, are separated at one point and form a loop bus, the access authorisation is forwarded in decentralised polling from station to station by through-connection of station-individual address counters, the access authorisation, if there is no response from one station within a predefined time period, being passed on to the next station and a subscriber station transmitting a useful telegram which is to be output only if access authorisation is granted when its address is displayed by its address counter; the address of the sender contained in each useful telegram transmitted is compared in each subscriber station with the address which has just been output by the station-individual address counter, the counter reading being corrected accordingly if said addresses do not match.
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