Patent · US Expired

Data distribution system for private automatic branch exchange

US4286118A · kind A · utility

43Cited by
17References
7Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJul 2, 1979
Grant dateAug 25, 1981
Priority date
Expiry dateJul 2, 1999

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04Q3/625
  • WIPO fieldTelecommunications
  • WIPO sectorElectrical engineering

Abstract

A data distribution system for a private branch telephone exchange for providing information to a plurality of PBX stations. Two embodiments (serial and parallel) including addressable stations are shown. Memory devices driving a plurality of displays at each station are updated in response to command signals from a controller preceded by the station address. Each station may communicate with the controller and transmit keyed-in signals or information reflecting station availability. A novel multiplexed LCD, switching matrix bypass upon controller failure circuit, and bus protection circuit upon remote power supply failure are also shown.

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