Time synchronized data transmission system
First Claim
1. An apparatus for coupling a telephone data set to a telephone transmission line connected to a telephone instrument so as to enable the communication of data without ringing said telephone instrument, comprising:
- first means, coupled to said telephone transmission line and said telephone instrument and normally connecting said telephone instrument to said telephone transmission line, for disconnecting said telephone instrument from said telephone transmission line during a predetermined time interval; and
second means, coupled to said telephone transmission line and said data set, for detecting a first electrical signal, such as a ringing signal indicative of a call from a caller, transmitted on said telephone transmission line, without answering the call and for generating a second electrical signal when said first electrical signal on said telephone transmission line has terminated, indicating that the caller has hung up;
said data set being coupled to said second means and said telephone transmission line and being adapted to communicate data in response to the generation of said second electrical signal after said first electrical signal has terminated when said caller has hung up.
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Accused Products
Abstract
A time synchronized data transmission system which allows a computer to access a remote data set via a non-dedicated telephone line is disclosed. The system is coupled to a telephone instrument, a data set and the telephone transmission line. The system disconnects the telephone instrument from the transmission line during predetermined time intervals. During these time intervals, a computer can communicate with the data set via the telephone line without ringing the telephone instrument. In the event the user wishes to use the telephone instrument during the predetermined time intervals when the telephone instrument is disconnected, a subscriber priority circuit allows the user to recouple the instrument to the line by merely lifting the telephone handset.
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Citations
9 Claims
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1. An apparatus for coupling a telephone data set to a telephone transmission line connected to a telephone instrument so as to enable the communication of data without ringing said telephone instrument, comprising:
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first means, coupled to said telephone transmission line and said telephone instrument and normally connecting said telephone instrument to said telephone transmission line, for disconnecting said telephone instrument from said telephone transmission line during a predetermined time interval; and second means, coupled to said telephone transmission line and said data set, for detecting a first electrical signal, such as a ringing signal indicative of a call from a caller, transmitted on said telephone transmission line, without answering the call and for generating a second electrical signal when said first electrical signal on said telephone transmission line has terminated, indicating that the caller has hung up; said data set being coupled to said second means and said telephone transmission line and being adapted to communicate data in response to the generation of said second electrical signal after said first electrical signal has terminated when said caller has hung up. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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Specification