Importance

Loading Importance Indicators...

Abstract

A remote unit contains function circuits to be controlled in response to control data from a central location and function circuits to generate information for transfer to the central location. The control data is transferred between the remote unit and the central location as frequency-shift-keyed signals. In the remote unit, a programmed microcomputer contains three blocks of instructions for enabling the microcomputer to perform background operations, to respond to the initial receipt of a message, and to thereafter transmit and decode the message. Further, in response to the decoding block of instructions, that are provided on a fixed time basis, the microcomputer is able to transmit frequency-shift-keyed signals without the need for a separate frequency-shift-keyed transmitter. Table of Contents Cross References to Related Patent Applications Background of the Invention Summary Brief Description of the Drawings Description of an Illustrative Embodiment A. General Description B. Specific Description 1. Multifunction Telephone Structure a. Voice Signal Path and Telephone Receiver and Transmitter 52 b. Power Supply 57 and Local Power Option 60 c. Phase Loop Receiver and Transmit Driver 54 d. Audio Amplifier 61 and Speaker 62 e. Hook Switch Circuit f. Tone Ringer 63 and Transducer 64 2. Common Equipment a. Control Circuit 47 b. Line Card 41 3. Operation a. Microport Control Unit 40 to Line Card 41 b. Line Card 41 to Multifunction Telephone 16A c. Multifunction Telephone d. Multifunction Telephone 16A to Line Card 41 4. Detailed Operation of the Multifunction Telephone a. Background State b. External Event State c. Timer Interrupt State C. Summary of the Description

Loading the Abstract Image...

First Claim