Patent · US Expired

Subscriber monitoring unit for electronic telephone exchanges

US4035592A · kind A · utility

2Cited by
9References
4Claims
0Family size

Assignee

Inventor

Key dates

Filing dateJul 27, 1976
Grant dateJul 12, 1977
Priority date—
Expiry dateJul 27, 1996

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04Q3/54591
  • WIPO fieldTelecommunications
  • WIPO sectorElectrical engineering

Abstract

The monitoring peripheral equipment is intended to inform the exchange's central unit about the state and nature of the subscriber's receiver and it comprises: a circuit sensing the positions of the relays of the line equipment, a memory unit, an internal logic with a scanner thereof, a liaison circuit logic and a line equipment monitoring device, whereby the lifting of a subscriber's receiver is detected, the information is sent to the internal logic as regards the location, state and processing to be performed, said central unit calls back said liaison circuit logic and the internal logic sets the subscriber's telephone in the connected position.

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