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:
Nov. 10, 1998
Filed:
Aug. 20, 1996
Applicant:
Inventor:
Makoto Kogure, Hitachinaka, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04B / ;
U.S. Cl.
CPC ...
375257 ; 34031001 ; 340660 ; 340664 ; 361 58 ;
Abstract
In a field bus system for performing communication between at least one field device and at least one higher-rank apparatus which are connected on a field bus transmission line constituted by a pair of transmission lines, an intrinsically safe barrier disposed between a hazardous area and a safe area on the transmission line in order to limit energy to be used in the hazardous area, the intrinsically safe barrier comprising impedance converting circuits provided in the barrier for reducing impedance in a frequency band of communication data.