Patent · US Expired

Portable testing device for monitoring communication line activity

US4665521A · kind A · utility

6Cited by
8References
5Claims
0Family size

Assignee

Inventor

Key dates

Filing dateJan 25, 1985
Grant dateMay 12, 1987
Priority date
Expiry dateJan 25, 2005

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY04S40/00
  • WIPO fieldDigital communication
  • WIPO sectorElectrical engineering

Abstract

This invention relates to a portable testing device which is used in a system having a host terminal, a plurality of secondary terminals, and a communication line interconnecting the host and secondary terminals for in-house communication. The transmission line includes a transmit line pair, a receive line pair, and a ground line. The testing device is operated in one of three modes which are selected via a switch on the device. The three modes of operation are: PA0 (1) Monitoring the transmit lines from the host and secondary terminals; PA0 (2) Performing "turn-around" functions with the host or secondary terminals; and PA0 (3) Performing "turn-around and load testing" with the host or secondary terminals.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.