公开(公告)号：DE3169347D1

公开(公告)日：1985-04-25

申请号：DE3169347

申请日：1981-05-25

Applicant: IBM

Inventor： SZE DANIEL TSI WING

IPC: G06F11/10 ,  H03M13/00 ,  H04L1/00

Abstract: A synchronous data transmission system between remote stations is shown wherein data is transmitted parallel by bit serial by group over a plurality of parallel lines extending between sending and receiving stations. A parity line is also included in the transmission system for checking errors and a clock line is included by synchronization of the parallel data being transmitted. Information is transmitted from one station to another with alternating even and odd parity for succeeding groups of parallel data. The information is checked at the receiving station for even-even or odd-odd parity in succeeding groups of data. Longitudinal redundancy checking (LRC) is also added to the checking at a receiving station.

公开(公告)号：DE3166666D1

公开(公告)日：1984-11-22

申请号：DE3166666

申请日：1981-03-10

Applicant: IBM

Inventor： DAVIS JONATHAN BUTLER ,  LANIER CHARLES STERLING ,  SZE DANIEL TSI WING

IPC: H04L5/22 ,  G06F13/00 ,  H04L7/00 ,  H04L12/42 ,  H04L12/437 ,  H04L11/16 ,  H04Q5/02 ,  H04J6/00 ,  G06F15/16

Abstract: In a loop-structured communication system interconnecting a plurality of data processors (8 ...13) without central controller, stations (2 ...7) are provided comprising modems (20) 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.

公开(公告)号：DE3164650D1

公开(公告)日：1984-08-16

申请号：DE3164650

申请日：1981-03-10

Applicant: IBM

Inventor： DAVIS MICHAEL IAN ,  SZE DANIEL TSI WING

IPC: H04L5/22 ,  G06F13/00 ,  G06F15/173 ,  G06F15/16