Central station system transmission apparatus
First Claim
1. In a central station system for operation under normal transmission line conditions in which there are no disabling transmission line faults, said system including a central station and at least one remote station, apparatus for transmitting information between the central and remote stations comprising:
- first and second signal conductors connected in parallel between the central and remote stations;
first and second central station transmitter means for respectively applying first and second signals to said first and second conductors when information is to be transmitted from the central station to the remote station, each of said first and second signals being representative of the information to be transmitted, said first and second signals being respectively characterized by first and opposite second polarities with respect to a reference potential;
first and second remote station receiver means for respectively detecting signals of said first and second polarities respectively applied to said first and second conductors and for producing an output signal representative of either of said signals;
first and second remote station transmitter means for respectively applying third and fourth signals to said first and second conductors when information is to be transmitted from the remote station to the central station, each of said third and fourth signals being representative of the information to be transmitted, said third and fourth signals being respectively characterized by said second and first polarities; and
first and second central station receiver means for respectively detecting signals of said second and first polarities respectively applied to said first and second conductors and for producing an output signal representative of either of said signals.
4 Assignments
0 Petitions
Accused Products
Abstract
Apparatus for transmitting signal information between central and remote stations in a central station system such as a central station alarm system. The transmission apparatus can continue to transmit information despite the occurrence of any of several types of fault conditions in the transmission line. Apparatus can be provided for detecting various transmission line fault conditions, indicating the nature of those fault conditions, and modifying the transmission apparatus to compensate for those fault conditions.
64 Citations
39 Claims
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1. In a central station system for operation under normal transmission line conditions in which there are no disabling transmission line faults, said system including a central station and at least one remote station, apparatus for transmitting information between the central and remote stations comprising:
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first and second signal conductors connected in parallel between the central and remote stations; first and second central station transmitter means for respectively applying first and second signals to said first and second conductors when information is to be transmitted from the central station to the remote station, each of said first and second signals being representative of the information to be transmitted, said first and second signals being respectively characterized by first and opposite second polarities with respect to a reference potential; first and second remote station receiver means for respectively detecting signals of said first and second polarities respectively applied to said first and second conductors and for producing an output signal representative of either of said signals; first and second remote station transmitter means for respectively applying third and fourth signals to said first and second conductors when information is to be transmitted from the remote station to the central station, each of said third and fourth signals being representative of the information to be transmitted, said third and fourth signals being respectively characterized by said second and first polarities; and first and second central station receiver means for respectively detecting signals of said second and first polarities respectively applied to said first and second conductors and for producing an output signal representative of either of said signals. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. In a central station system including a central station and at least one remote station, apparatus for transmitting information from the remote station to the central station comprising:
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a reference potential source associated with the central station; first and second potential sources associated with the central station respectively characterized by positive and negative polarities with respect to said reference potential; first, second, and third conductors connected in parallel between the central and remote stations, said conductors being respectively connected to said first, second, and reference potential sources at the central station; transmitter means associated with the remote station for selectively connecting said first and second conductors to said third conductor to cause substantially equal and opposite currents to flow in said first and second conductors when information is to be transmitted from the remote station to the central station, the currents in each of said conductors being representative of the information to be transmitted, and receiver means associated with the central station for detecting the currents flowing in either of said first and second conductors to produce an output signal representative of the information transmitted from the remote station. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25)
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26. In a central station system including a central station and at least one remote station, apparatus for transmitting information between the central and remote stations comprising:
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a reference potential source associated with the central station; first and second potential sources associated with the central station and respectively characterized by first and opposite second polarities with respect to said reference potential; first, second, and third conductors connected in parallel between the central and remote stations, said third conductor being connected to said reference potential source at the central station; first and second central station transmitter means respectively connected between said first and second potential sources and said first and second conductors for applying complementary signals respectively characterized by said first and second polarities to said first and second conductors when information is to be transmitted from the central station to the remote station, each of said complementary signals representing the information to be transmitted; first and second remote station receiver means respectively connected between said first and second conductors and said third conductor, said first remote station receiver means including first diode means for permitting current to flow through said receiver means only when signals of said first polarity are applied to said first conductor and said second remote station receiver means including second diode means for permitting current to flow through said receiver means only when signals of said second polarity are applied to said second conductor, said first and second remote station receiver means further including means for detecting the currents flowing therethrough to produce an output signal representative of the information transmitted from the central station; first and second central station receiver means for respectively connecting said second and first potential sources to said first and second conductors and for detecting the currents flowing in said first and second conductors when information is to be transmitted from the remote station to the central station to produce an output signal representative of the information transmitted from the remote station; and first and second remote station transmitter means for selectively connecting said first and second conductors, respectively, to said third conductor to apply complementary signals to said first and second conductors when data is to be transmitted from the remote station to the central station, each of said complementary signals being representative of the information to be transmitted. - View Dependent Claims (27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39)
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Specification