The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 06, 1990
Filed:
May. 04, 1987
Susumu Nakayashiki, Yokohama, JP;
Jiro Kashio, Kawasaki, JP;
Takeshi Harakawa, Hadano, JP;
Yoshinori Bekki, Hadano, JP;
Mitsuhiro Yamaga, Kawasaki, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A ring network system in which a plurality of line concentrators each having terminal stations connected thereto through respective branch lines are interconnected through at least one ring transmission lines. Each line concentrator includes configuration control switches capable of disconnecting from the ring transmission line all the branch lines placed under control of the line concentrator while holding the ring transmission line in the state to allow communication. The branch line(s) disconnected from the ring transmission line form(s) a local ring through cooperation with an internal transmission line. The line concentrator detected abnormality of communication or the line concentrator to be set to the rest state can undergo internal diagnosis operation or continue to be in the rest state without disturbing the communication among other line concentrators. At activation of the line concentrators, any of them may be activated arbitrarily and independently from each other by again connecting the branch lines to the ring transmission lines.