초록 ▼

Primary and back-up closed loop unidirectional transmission lines transmit self-clocking data streams and null data, respectively, in opposite directions to a plurality of loop interface units (LIUs) connected to the primary and back-up lines. To protect against failure of the entire system due to a

Primary and back-up closed loop unidirectional transmission lines transmit self-clocking data streams and null data, respectively, in opposite directions to a plurality of loop interface units (LIUs) connected to the primary and back-up lines. To protect against failure of the entire system due to a break in the primary and/or back-up lines or failure of one of the loop interface units, each loop interface unit can detect a signal loss on the primary or back-up transmission line and wrap signal flow to bypass the detected fault. After wrapping around a detected fault, an LIU then creates a failure on the non-failing line causing an analogous wraparound in the LIU on the other side of the actual failure. After error recovery, there is then a complete loop connecting all non-failing loop interface units, although it is twice as long as before the signal loss was detected. Also disclosed is an alternate embodiment in which a microprocessor and attached external device are interconnected to a similar loop structure.

대표청구항 ▼

A self-healing loop communications system comprising: a primary closed loop unidirectional transmission line for transmitting signals in a first direction; a back-up closed loop unidirectional transmission line for transmitting signals in a second direction opposite to said first direction; first me

A self-healing loop communications system comprising: a primary closed loop unidirectional transmission line for transmitting signals in a first direction; a back-up closed loop unidirectional transmission line for transmitting signals in a second direction opposite to said first direction; first means coupled to said primary and back-up lines for providing on one of said primary and back-up lines a serial data stream in a self-clocking code and further for providing on said other of said primary and back-up lines a stream of self-clocking idle data; and a plurality of loop interface units coupled to said primary and back-up lines, each of said loop interface units including second means connected to said one of said primary and back-up lines for detecting a first fault in said one of said primary and back-up lines, third means connected to said other of said primary and back-up lines and said second means and responsive to said second means for switching between a first state wherein that one of said loop interface units is coupled to said other of said primary and back-up lines and a second state wherein that one of said loop interface units is uncoupled from said other of said primary and back-up lines, and fourth means connected to said one of said primary and back-up lines and said second and third means and responsive to said second means for switching between a third state wherein that one of said loop interface units is coupled to said one of said primary and back-up lines and a fourth state wherein that one of said loop interface units is uncoupled from said one of said primary and back-up lines and said primary and back-up lines are interconnected and transferring said signals on said back-up and primary lines to the other of said back-up and primary lines, said primary and back-up lines thereby cooperating to provide a first new closed loop unidirectional transmission line to bypass said first fault.