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.

Date of Patent:
May. 11, 1993

Filed:

Jun. 21, 1991
Applicant:
Inventors:

Takeo Anzai, Tokyo, JP;

Shigeyuki Mitani, Tokyo, JP;

Tomohiro Kuroda, Tokyo, JP;

Assignee:

NEC Corporation, Tokyo, JP;

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04J / ; H04L / ; H04M / ;
U.S. Cl.
CPC ...
370 16 ; 370 13 ; 370 582 ; 379 94 ; 379221 ; 371-82 ; 371 112 ;
Abstract

A terminal adapter portion sends and receives data of a data processing unit such as a data terminal device and information of a control portion through an ISDN line. The control portion responds to an externally supplied switching instruction to send switching instruction information to another line switching equipment or receive the information therefrom, through the ISDN line and to control a switching portion. The switching portion switches the data terminal device to either a personal line or the ISDN line depending upon the switching instruction. With this construction, it is possible to perform line switching control of two mutually opposing line switching equipments from either of them. Further, it comprises a line test portion for testing a line and a switching portion for switching the line test portion to either a personal line which is not connected to the data terminal device or the ISDN line, so that it is possible to easily perform a test of the personal line or the ISDN line without degrading on-line data communication.


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