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. 19, 1985
Filed:
Dec. 30, 1981
Norihiko Sugimoto, Katsuta, JP;
Nobuhiro Hamada, Hitachiota, JP;
Ikuro Masuda, Hitachi, JP;
Jinichi Sakurai, Mito, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In a plant control system, a transmission channel includes loop transmission lines arranged in duplex. Equivalently connected to this transmission channel are a plurality of one-loop controller stations, a backup station backing up a disabled one of the plural controller stations and a display station for displaying the status of the controller stations and the backup station. Each of the controller stations, backup station and display station includes a built-in microcomputer. Each of these stations includes also a transmission interface circuit and a self-diagnostic circuit. The transmission interface circuit in each station selects one of the transmission lines for data transmission between its own station and the others. The self-diagnostic circuit in each station detects the presence of failure of normal operation of its own station and disconnects the disabled station from the transmission line, so that the other stations may not be adversely affected by the disabled station.