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:
May. 14, 2002
Filed:
Dec. 04, 1998
Yuichiro Morita, Hitachi, JP;
Kotaro Shimamura, Hitachinaka, JP;
Yoshitaka Takahashi, Hitachi, JP;
Takashi Hotta, Hitachi, JP;
Kazuhiro Imaie, Hitachi, JP;
Shigeta Ueda, Hitachi, JP;
Akira Bando, Hitachi, JP;
Mitsuyasu Kido, Hitachinaka, JP;
Takeshi Takehara, Hitachi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In a synchronization system adopted in a synchronous-multisystem control apparatus including a plurality of systems operating synchronously with each other at a fixed control period, the synchronous-multisystem control apparatus can be operated in a single-system mode in the event of failures occurring simultaneously in some of the systems. The synchronous-multisystem control apparatus employs a plurality of control circuits each provided for one of the systems. Any particular one of the control circuits includes: a period-signal generating circuit for generating a period signal indicating a start point of a control period; a synchronization-reference selecting circuit for outputting a synchronization-reference signal by referring to period signals generated by the systems; and a control-period correcting circuit for correcting a control period of the particular system by forming a judgment on a synchronization shift of the period signal generated by the particular system from the synchronization-reference signal and keeping the control period as it is in case the synchronization-reference signal is not generated.