Time independent data transmission system
First Claim
1. An apparatus coupling a telephone data set and a telephone instrument to a telephone transmission line so as to enable the communication of data between the data set and a remote location without interfering with normal use of the telephone instrument, comprising:
- first means, coupled to said telephone transmission line, said telephone instrument and said data set and normally connecting said data set to said telephone transmission line, for disconnectingg said data set from said telephone transmission line and connecting said telephone instrument to said telephone transmission line in response to any of selected ones of a plurality of first electrical signals transmitted on said telephone transmission line, said first signals each being indicative of a call from a caller on said telephone transmission line, said first means preventing disconnection of said data set in response to a selected one of said first signals;
second means, coupled to said telephone transmission line and said data set, for detecting any of said first electrical signals transmitted on said telephone transmission line without answering the call and for generating a second electrical signal when any of the first electrical signals on said telephone transmission line has terminated, indicating that the caller has hung up;
said data set being adapted to communicate data via said first means in response to the generation of said second electrical signal after said selected one of said first electrical signals has terminated.
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Accused Products
Abstract
A time independent data transmission system which allows a computer to access a remote data set at any time via a non-dedicated telephone line is disclosed. The system is coupled to a telephone instrument, a data set and the telephone transmission line and normally connects the data set to the telephone transmission line. The telephone instrument is normally disconnected. In a preferred embodiment, a counting circuit senses the number of ring bursts in a ringing signal from a caller and a central computer is programmed to transmit a ringing signal having only one ring burst. When only one ring burst is sensed, the data set remains connected to the telephone transmission line and the data set begins to communicate with the central computer when the ringing signal terminates. If more than one ring burst occurs, a non-computer call is being sensed and the data set is disconnected and the telephone connected to the telephone transmission line so that normal telephone usage is allowed. Communication between the computer and the data set via the telephone line occurs without ringing the telephone instrument and without otherwise interfering with normal telephone usage. In the event the user wishes to use the telephone instrument at any time, including the time when communication between the computer and data set is taking place, a subscriber priority circuit allows the user to recouple the instrument to the line by merely lifting the telephone handset and to decouple the instrument by replacing the handset.
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Citations
11 Claims
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1. An apparatus coupling a telephone data set and a telephone instrument to a telephone transmission line so as to enable the communication of data between the data set and a remote location without interfering with normal use of the telephone instrument, comprising:
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first means, coupled to said telephone transmission line, said telephone instrument and said data set and normally connecting said data set to said telephone transmission line, for disconnectingg said data set from said telephone transmission line and connecting said telephone instrument to said telephone transmission line in response to any of selected ones of a plurality of first electrical signals transmitted on said telephone transmission line, said first signals each being indicative of a call from a caller on said telephone transmission line, said first means preventing disconnection of said data set in response to a selected one of said first signals; second means, coupled to said telephone transmission line and said data set, for detecting any of said first electrical signals transmitted on said telephone transmission line without answering the call and for generating a second electrical signal when any of the first electrical signals on said telephone transmission line has terminated, indicating that the caller has hung up; said data set being adapted to communicate data via said first means in response to the generation of said second electrical signal after said selected one of said first electrical signals has terminated. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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Specification