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AssigneeInternational Business Machines Corporation
InventorsJonathan B. Davis, Charles S. Lanier, Daniel T. W. Sze, Leonard Weiss
Estimating the term…
In a loop-structured communication system interconnecting a plurality of data processors without central controller, stations comprise modems which can start loop operation and achieve synchronous frame transmission around the loop through all participating stations. In an initialization procedure after system start or after loss of frame synchronization on the loop, modems select a temporary master station. The temporary master will adapt total loop delay to be an integer multiple of the basic frame period, and will transmit available frames. All active modems adapt their timing to the circulating stream of frames until the whole loop and all participating stations are synchronized. Synchronization conditions are continuously monitored in all stations to start resynchronization or initialization procedures if necessary. In a specific arrangement, the location of a loop failure which prevents establishment of synchronization can be determined. All initialization and synchronization operations are handled by the modems without participation by other functional units or by the host processing system of any station.
In a serial loop data communication system including a plurality of stations serially interconnected by way of a communications link, said stations being further characterized with respect to any selected station as preceding stations that are upstream on said link from said selected station or succeeding stations that are downstream from said selected station, said stations operating on a peer-to-peer basis, and each of said stations being designated by a uniquely identifiable address code, said stations transmitting and receiving message frames including synchronization characters for transfer of information in the form of messages from one station to another, said frames being categorized as available or unavailable, each station transmitting only on frames that are marked as available or that have an address code equal to the station address code and each station marking frames transmitted by it as unavailable if the station has inserted information in said frames and each station further marking frames transmitted by it as available if the station has no information to transfer, and each of said stations incorporating a modem for handling link related functions, such as information coding, and modulation, and the like, a loop initialization system for achieving synchronized frame transmission around the loop for all stations upon system start or after loss of frame synchronization on the loop by defining one of said stations as a temporary master station to create available message frames for use in establishing synchronized operation of said system and comprising at each station:
In a serial loop data communication system including a plurality of stations serially interconnected by way of a communications link, said stations transmitting and receiving message frames including synchronization characters for transfer of information in the form of messages from one station to another each frame comprising a plurality of characters and each of said stations incorporating a modem for handling link related functions, such as information coding and modulation and the like, a system for achieving synchronized operation of a station after loss of frame synchronization comprising at each station:
Dependencies are inferred from the claim text.