Transparent multiplexer communication transmission system

Claim 2

A multiplexing apparatus for coupling a plurality of data terminal devices to a plurality of lines of a common interface for transmissions and reception of data over a communications channel, said multiplexing apparatus comprising: channel control means, said control means including a plurality of bistable switching means, each connected to be coupled to a different one of said plurality of terminal devices, each of said plurality of bistable switching means being conditioned for switching to a predetermined state upon sensing both a request to send data signal and a data terminal ready signal indicating readiness to maintain connection to said communications channel for processing data from said different one of said plurality of terminal devices; free running scanning means coupled to each of said plurality of bistable switching means, said scanning means being operative to generate signals to scan each of said bistable means for device requests, each of said plurality of bistable means switching to said predetermined state in response to signals from said scanning means when conditioned by said send data and data terminal ready signals, and sensing means being coupled to said plurality of bistable means and being operative in response to any one of said bistable means being switched to said predetermined state to inhibit further scanning by said scanning means; and, signal transfer means coupled to said terminal devices and to said bistable switching means, said transfer means being conditioned by said plurality of bistable switching means to selectively couple to said lines of said interface only a device coupled to said bistable switching means in said predetermined state for said transmission and reception of data without requiring detection of special control information by said multiplexing apparatus.

Claim 3

The apparatus of claim 1 wherein said scanning means includes a free running clocking means and input power source means for receiving input power signals, said clocking means being coupled to said source means and being arranged to be switched at a rate corresponding to the frequency of said input power signals.

Claim 4

Apparatus of claim 2 wherein said multiplexing apparatus further includes mode control means coupled to said clocking means, said mode control means including logic gating means for receiving a control signal, said logic gating means being operative in response to said control signal to inHibit said clocking means from enabling the operation of said scanning means.

Claim 5

The apparatus of claim 3 wherein said mode control means further includes first manual switching means coupled to said logic gating means, said manual switching means being operative when switched to a predetermined state to generate said control signal.

Claim 6

The apparatus according to claim 3 wherein said mode control means further includes pulse generating means coupled to said logic gating means and operative to generate a timing signal, said clocking means being conditioned by said control signal to advance said scanning means a step at a time in response to each occurrence of said timing signal.

Claim 7

The apparatus of claim 5 wherein said pulse generating means includes manual switching means coupled to said logic means, said manual switching means being operative when switched to generate said timing signal.

Claim 8

The apparatus of claim 1 wherein said scanning means includes counting means and decoding means coupled to said counting means, said decoding means being arranged to decode predetermined counts from signals generated by said counting means for conditioning each of said channel bistable means to be switched only during nonoverlapping time intervals defined in accordance with said predetermined counts.

Claim 9

The apparatus of claim 7 wherein said counting means is a binary counter and said predetermined counts correspond to alternate counts of said counter.

Claim 10

The apparatus of claim 1 wherein said multiplexing means further includes data receiving means coupled to at least a predetermined one of said plurality of lines of said interface and individually of each of said terminal devices for transferring information received from said predetermined one of said interface lines to each of said terminal devices and wherein said plurality of devices each includes address control means for sensing when said information includes a predetermined address code assigned to one of said plurality of devices for initiating a data transfer operation, said address control means being operative in response to said address code to generate said request signal to switch a corresponding one of said bistable means to said predetermined state.

Claim 11

The apparatus of claim 1 further including control means coupled to said common interface and individually to each of said plurality of devices, said control means including: a plurality of gating means, corresponding in number to said plurality of devices and each being coupled to a different one of said plurality of terminal devices, each of said gating means being connected to receive a signal from a predetermined one of said plurality of lines of said common interface indicating when said interface is connected to said communications channel and each of said gating means being coupled to predetermined ones of said plurality of bistable means, each said gating means being conditioned by said predetermined ones of said plurality of bistable means to apply said signal only to the device which is to transmit data to said interface.

Claim 12

The apparatus of claim 1 wherein each of said bistable devices are coupled to said associated terminal devices and each are arranged to be switched from said predetermined state to a reset state by the terminal device associated therewith inhibiting generating said data terminal ready signal signalling readiness to disconnect said connection to said communications channel at the completion of processing data.

Claim 13

A communication system comprising: a communication interface including a plurality of data and control interface lines operatively coupled to transmit and receive information signals over a communications channel; a plurality of terminal devices, each device being connected to a plurality of lines corresponding in number and kind to said data and control lines for transmission and reception of binary information signals to and from said interface lines; and, multiplexing mEans being operatively coupled to each said plurality of lines of said plurality of terminal devices and to said plurality of interface lines of said communications interface, said multiplexing apparatus including: channel select means operatively coupled to each of said plurality of terminal devices, said select means including a plurality of bistable means, each of said bistable means being coupled to first and second control lines of each said plurality of lines from a different one of said plurality of terminal devices; free running counting means coupled to said channel select means, said counting means being operative to generate signals for selecting different ones of said plurality of bistable means in sequence, each of said bistable means selected being operative to switch to a predetermined state in response to signals being applied to both said first and second control lines by a terminal device associated therewith, said counting means including means responsive to any one of said bistable means being switched to said predetermined state to inhibit generating of said signals; and, data transfer means coupled to a data line of each said said plurality of lines terminal devices and to said channel select means, said data transfer means including output means coupled to a corresponding one of said data lines of said plurality of lines of said communications interface, said data transfer means being operative in response to one of said plurality of bistable means being switched to said predetermined state to enable the transmission of information signals from the device coupled to said one of said bistable means to said communications channel without requiring detection of special characters by said multiplexing means.

Claim 14

A communication system comprising: a communication interface including a plurality of data and control interface lines operatively coupled to transmit and receive information signals over a communications channel; a plurality of terminal devices, each device being connected to a plurality of lines corresponding in number and kind to said data and control lines for transmission and reception of binary information signals to and from said interface lines; and, multiplexing mEans being operatively coupled to each said plurality of lines of said plurality of terminal devices and to said plurality of interface lines of said communications interface, said multiplexing apparatus including: channel select means operatively coupled to each of said plurality of terminal devices, said select means including a plurality of bistable means, each of said bistable means being coupled to first and second control lines of each said plurality of lines from a different one of said plurality of terminal devices; free running counting means coupled to said channel select means, said counting means being operative to generate signals for selecting different ones of said plurality of bistable means in sequence, each of said bistable means selected being operative to switch to a predetermined state in response to signals being applied to both said first and second control lines by a terminal device associated therewith, said counting means including means responsive to any one of said bistable means being switched to said predetermined state to inhibit generating of said signals; and, data transfer means coupled to a data line of each said said plurality of lines terminal devices and to said channel select means, said data transfer means including output means coupled to a corresponding one of said data lines of said plurality of lines of said communications interface, said data transfer means being operative in response to one of said plurality of bistable means being switched to said predetermined state to enable the transmission of information signals from the device coupled to said one of said bistable means to said communications channel without requiring detection of special characters by said multiplexing means.

Claim 15

The system of claim 12 wherein said free running counting means includes free running clockwise means and input power source means for receiving input power signals, said clocking means being coupled to said source means and being arranged to be switched at a rate corresponding to the frequency of said input power signals.

Claim 16

The system of claim 13 wherein said multiplexing means further includes mode selection means coupled to said clocking means, said mode selection means including logic gating means for receiving a test signal, said logic gating means being operative in response to said test signal to inhibit said clocking means from enabling the cycling of said counting means.

Claim 17

The system of claim 12 wherein said counting means includes decoding means coupled to each of said plurality of bistable means, said decoding means being operative in response to signals representative of predetermined counts from said counting means to generate said signals for selecting each of said bistable means in sequence only during nonoverlapping time intervals defined in accordance with signals representative of said predetermined counts.

Claim 18

The system of claim 15 wherein said counting means including a binary counter and said predetermined counts correspond to alternate counts of said counter.

Claim 19

The system of claim 12 wherein any one of said bistable devices switched to said predetermined state is conditioned to be switched to a reset state in response to a change of state in a predetermined one of said first and second control lines by the terminal device associated therewith signalling nonreadiness to transmit data.

Claim 20

The system of claim 12 wherein said multiplexing means includes control means coupled to a predetermined one of said control lines of said plurality of interface lines of said communications interface, said control means including a plurality of gating means, each being coupled to a third control line coupled to a different one of said plurality of terminal devices, each of said plurality of gating means being coupled to a different one of said plurality of bistable means and each of said gating means being enabled prior to said transmission by a change of state in said predetermined one of said control Lines to apply said change of state only to said third line coupled to one of said devices when each said different one of said plurality of bistable means is in said predetermined state signalling to said one device that information can be transmitted across said data lines of said plurality of lines of said communications interface.

Claim 21

The system of claim 12 wherein said multiplexing means further includes: data set ready control means coupled to a predetermined control line of said plurality of lines of said communications interface, said data set ready control means including a plurality of logic gating means corresponding in number to said plurality of devices, each of said plurality of gating means being coupled to predetermined ones of said plurality of said bistable means and to another control line of a different one of said plurality of lines of ones of said terminal devices, each of said gating means being responsive to a change of state in said another control line to transmit said change of state only to one of said plurality of devices designated by the states of said predetermined ones of said plurality of bistable means.

Claim 22

The system of claim 12 wherein said multiplexing means includes logic gating means coupled to a predetermined one of each of said first and second control lines of said plurality of lines and to a predetermined one of control interface lines of said plurality of lines of said communications interface, said logic gating means being operative in response to a change of state in said any one of said predetermined one of said first and second control lines to transmit said change of state to said predetermined one of said control interface lines.

Claim 23

The system of claim 20 wherein said logic gating means includes: a plurality of input gating means each being connected to receive one of said predetermined one of said first and second control lines and a bilevel test control signal, and output gating means coupled to said plurality of input gating means, each of said input gating means being conditioned by a predetermined level of said test control signal to inhibit said output gating means for applying said change of state to said predetermined one of said control interface lines.

Claim 24

The system of claim 21 wherein each of said input gating means is coupled to different ones of said bistable means and includes means for receiving a manually generated control signal, and each of said input gating means being conditioned by said predetermined level of said test control signal to transmit said manually generated control signal to said predetermined one of said first and second control lines in place of the signal applied to said predetermined one of said first and second control lines by the terminal device associated therewith.

Claim 25

A multiplexing system for selectively coupling a plurality of input/output terminal devices to a communications channel through a common communications interface comprising a plurality of lines for bidirectional data transmission said plurality of lines of said interface including a plurality of input and output control and data interface lines and said system comprising: a plurality of sets of input and output data and control lines, a different one of said plurality of input/output terminal devices being coupled to a different one of said plurality of sets of input and output data and control lines; and, multiplexing control apparatus including: scanning means having a plurality of states for selecting different ones of a plurality of channels for interconnecting corresponding ones of said plurality of terminal devices to said plurality of lines of said common interface, said scanning means including counter means connected to be cycled repetitively to generate signals representative of said plurality of states, and channel select means coupled to said counter means and individually to first and second control output lines of each of said plurality of sets of input And output data and control lines, said channel select means including a plurality of bistable storage means corresponding in number to said plurality of channels, each of said a channel as being coupled to said first and second control outlet lines of a different set of said plurality of sets of control lines and each of said a channel as being conditioned by signals from said counter means designating a predetermined one of said channels to be switched to a predetermined state by a corresponding one of said plurality of terminal devices; and, a plurality of gating means, a first one of said gating means being coupled to a data output interface line and to a data output line of each of said plurality of sets of input and output data and control lines, a second one of said gating means being coupled to a first output interface control line and to a first input control line of each of said plurality of sets of input and output data and control lines, and a third one of said gating means being coupled to a second output interface control line and to a second input control line of each of said plurality of sets of input and output data and control lines, each of said first, second and third gating means connected to be conditioned by said channel select means when one of said plurality of a channel as switch to said predetermined state to connect only the set of data and control lines of the terminal device connected to channel designated by said one of said plurality of a channel as connected to corresponding ones of said data and control interface lines enabling the transfer of data signals between said set of lines and said interface lines without requiring detection of characters by said multiplexing control apparatus.

Claim 26

A multiplexing system for selectively coupling a plurality of input/output terminal devices to a communications channel through a common communications interface comprising a plurality of lines for bidirectional data transmission said plurality of lines of said interface including a plurality of input and output control and data interface lines and said system comprising: a plurality of sets of input and output data and control lines, a different one of said plurality of input/output terminal devices being coupled to a different one of said plurality of sets of input and output data and control lines; and, multiplexing control apparatus including: scanning means having a plurality of states for selecting different ones of a plurality of channels for interconnecting corresponding ones of said plurality of terminal devices to said plurality of lines of said common interface, said scanning means including counter means connected to be cycled repetitively to generate signals representative of said plurality of states, and channel select means coupled to said counter means and individually to first and second control output lines of each of said plurality of sets of input And output data and control lines, said channel select means including a plurality of bistable storage means corresponding in number to said plurality of channels, each of said a channel as being coupled to said first and second control outlet lines of a different set of said plurality of sets of control lines and each of said a channel as being conditioned by signals from said counter means designating a predetermined one of said channels to be switched to a predetermined state by a corresponding one of said plurality of terminal devices; and, a plurality of gating means, a first one of said gating means being coupled to a data output interface line and to a data output line of each of said plurality of sets of input and output data and control lines, a second one of said gating means being coupled to a first output interface control line and to a first input control line of each of said plurality of sets of input and output data and control lines, and a third one of said gating means being coupled to a second output interface control line and to a second input control line of each of said plurality of sets of input and output data and control lines, each of said first, second and third gating means connected to be conditioned by said channel select means when one of said plurality of a channel as switch to said predetermined state to connect only the set of data and control lines of the terminal device connected to channel designated by said one of said plurality of a channel as connected to corresponding ones of said data and control interface lines enabling the transfer of data signals between said set of lines and said interface lines without requiring detection of characters by said multiplexing control apparatus.

Claim 27

The system of claim 23 wherein said free running counting means includes free running clocking means and input power source means for receiving input power signals, said clocking means being coupled to said source means and being arranged to be switched at a rate corresponding to the frequency of said input power signals.

Claim 28

The system of claim 24 wherein said counting means includes decoding means coupled to each of said plurality of bistable storage means, said decoding means being operative in response to signals representative of predetermined states from said counting means to generate said signals for selecting each of said bistable storage means in sequence only during nonoverlapping time intervals defined in accordance with said predetermined states.

Claim 29

The system of claim 25 wherein said counting means including a binary counter and said predetermined states correspond to alternate counts of said counter.

Claim 30

The system of claim 24 wherein any one of said bistable storage devices switched to said predetermined state is conditioned to be switched to a reset state in response to a change of state in a predetermined one of said first and second control lines by the terminal device associated therewith signalling nonreadiness to transmit data.