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:
Jul. 06, 1982
Filed:
Mar. 06, 1979
Alan Bloch, New York, NY (US);
Frank A Coviello, Peekskill, NY (US);
Ira Guzik, Fairfield, CT (US);
Candido Puebla, Bridgeport, CT (US);
TIE/Communications, Inc., Shelton, CT (US);
Abstract
Each of the station sets in the system generates a continuous, current-modulated digital data stream carrying information concerning the status of pushbutton-actuated switches associated with a particular service or feature. This data stream is transmitted via a phantom pair over standard four-wire cable to an associated station card in the key service unit, which receives and decodes the data, implements any service requested at the associated station set by closure of a pushbutton-actuated switch in the station set, and generates a continuous voltage-modulated digital data stream carrying instructions for the connection of the station set speakerphone to either the first or second talk path formed by the first and second conductor pairs in the standard four-wire cable, for energization of light-emitting diodes associated with the pushbutton-actuated switches in the station set, and for controlling background music transmission to the associated station set. This data stream is transmitted via the aforementioned phantom pair to the station set, which receives and decodes the data and carries out the instructions contained therein. Each station card and each station set incorporates a stored-program digital microcomputer for decoding the received data and for generating the data to be transmitted. Each station card also includes a series of crosspoints in the form of field-effect transistors, the gate electrodes of which are connected to crosspoint latches controlled by the microcomputer. Each crosspoint has an associated input terminal in a status multiplexer which receives data from the passive port to which the associated crosspoint is connected. Each crosspoint and its associated status multiplexer input terminal constitute an active port. Each station card also includes at least one passive port for hotline connection to an active port of another station card or cards, and may also include a passive port for connection to the active ports of one or more link cards. Other system component circuits are disposed on line cards having a single passive port, an internal conference card having a single passive port, a page card having multiple passive ports, a register card or cards connected to the link card or cards, and a tone generator card.