High-availability data transmission between two coupled buses - involves two alternative coupling paths monitored and switched as necessary between active and standby operational modes

摘要

The buses (B1,B2) are linked by redundant parallel coupling paths (K1,K2) one of which is active and the other is maintained in standby condition during normal operation, with subscriber addresses (TA3,TA5) reciprocally exchanged. If a check on the active path (K1) finds it withdrawn from the logical token rings (R1,R2) routing tokens in the direction of increasing subscriber addresses (e.g. TA1-TA3-TA4), the system is switched so that the standby path (K2) takes over and its former role passes to the other path (K1). USE/ADVANTAGE - In token-passing networked bus systems. Coupling paths can be placed independently without additional signal lines.