Data communications systems employing redundant series transmission loops

Claim 2

In a communication system having message frames circulated through a plurality of remote stations each having a message frame processing means comprising a plurality of parallel transmission trunk means connected between the several stations and each of said parallel transmission trunk means adapted to simultaneously transmit corresponding message frames from one remote station to the next remote station, each of said remote stations having a trunk selection means operably connecting one of said trunk means to the message processing means at the same remote station and including means to selectively transmit the message frame from one of said trunk means to the frame processing means for processing one of the simultaneously received message frames, and means for retransmitting of the processed message frame on the plurality of the trunk means to the next succeeding remote station.

Claim 3

In the communication system of claim 1 wherein said trunk selection means includes priority logic means selecting a given trunk means, and means responsive to failure of the transmission of the message frame over the selected trunk means to automatically transmit the message on an adjacent trunk means to the message processing means.

Claim 4

In the communication system of claim 1 including monitoring means to continuously monitor receipt of a message frame over the individual trunk means and to transmit an identifying message frame in response to failure to receive a message frame over all the incoming trunk means.

Claim 5

The communication system of claim 1 wherein said communication system includes "available" frames circulated through the system for receiving data from a remote station and being retransmitted as a filled frame, and trunk status sensing means coupled to said incoming trunk means and responsive to the failure of a trunk means to develop a message frame to automatically receive and fill an "available" message frame with identifying data and retransmit said filled "available" frame.

Claim 6

The communication system of claim 1 wherein each remote station includes a frame generating means, fault detection means to separately monitor each of the incoming trunk means to the remote station and means responsive to failure of all incoming trunk means to actuate said frame generating means.

Claim 7

The system of claim 5 having means to fill a received message frame to identify a fault condition in any one of the trunk means including a trunk means previously transmitting message frames to the processing unit and the redundant trunk means.

Claim 8

In the communication system of claim 1 having a digital message frame circulated through said plurality of remote stations in series, a pair of message receivers, detection units connected to the output of the receivers and establishing binary logic signals related to the receiving of the message bits, said trunk selection means including a binary logic means having an output connected to said message processing means and a binary input decoder connected to said detection units to selectively connect one of said receivers to said output.

Claim 9

In the communication system of claim 7 wherein the transmission means includes a plurality of transmitters having inputs connected in common to the message processing means and outputs connected one each to one of said trunk means.

Claim 10

A data communication loop system wherein plurality of remote stations are coupled to a central loop controller station through a serial transmission path means, each of said remote stations being adapted to receive a multiple bit digital message frame and having message frame processing means operable to process and retransmit said frame to a succeeding station, each of said remote stations further including a plurality of load devices divided into functional groups and with each group being defined as a point module, comprising a plurality of individual and separate transmission trunk means connected to each remote station and from each remote station to establish parallel transmission from and to each station, each of said remote stations including selection means to simultaneously receive message frames on such plurality of trunk means and to selectively transmit the message frame from one of said trunk means to the frame processing means, and having detection means responsive to failure to receive a message frame over a trunk means to transmit the message frame from a different trunk means to said frame processing means, each of said remote stations further including transmission means connected to the frame processing means to retransmit the processed message frame over all of the plurality of trunk means to the next adjacent downstream remote station.

Claim 11

A data communication loop system wherein plurality of remote stations are coupled to a central loop controller station through a serial transmission path means, each of said remote stations being adapted to receive a multiple bit digital message frame and having message frame processing means operable to process and retransmit said frame to a succeeding station, each of said remote stations further including a plurality of load devices divided into functional groups and with each group being defined as a point module, comprising a plurality of individual and separate transmission trunk means connected to each remote station and from each remote station to establish parallel transmission from and to each station, each of said remote stations including selection means to simultaneously receive message frames on such plurality of trunk means and to selectively transmit the message frame from one of said trunk means to the frame processing means, and having detection means responsive to failure to receive a message frame over a trunk means to transmit the message frame from a different trunk means to said frame processing means, each of said remote stations further including transmission means connected to the frame processing means to retransmit the processed message frame over all of the plurality of trunk means to the next adjacent downstream remote station.

Claim 12

The data communication loop system of claim 9 wherein said data communication system including available frames circulated through the loop system for receiving data from a remote station and being retransmitted as a filled frame to the controller, and having trunk status sensing means coupled to said incoming trunk means and operable to said failure of a trunk means to develop a message frame for automatically transmitting identifying information to said loop controller.

Claim 13

The data communication loop system of claim 9 including means to separately identify each of the incoming trunk means at a remote station and to individually identify a fault condition in any one of the trunk means including a trunk previously transmitting message frames to the processing unit and to the redundant trunk means.

Claim 14

The data communication loop system of claim 9 wherein said controller generates "available" message frames to be filled by any one of said remote stations, each of said remote stations include a trunk terminating and connection means for interconnecting of the plurality of trunk means to a single trunk message frame processing means, said connection means including individual input coaxial cables and individual output coaxial cables connected respectively to the said trunk means, a pair of receivers connected respectively to said input cables, a first loop failure detection unit connected to the output of the first receiver and establishing a logic output signal related to the presence and failure of a message signal, a second failure detection unit connected and to the output of the second receiver and establish a logic output signal in accordance with the presence and failure of a message frame at said second receiver, a multiplexing means having an input binary decoder connected to said failure detection units, said multiplexing means having a pair of data input means connected respectively to said first and second receivers and having a single data output line connected to the message frame processing means, said remote station including a contact status sensing module including a plurality of status sensing inputs connected respectively one each to the failure detection units, said contact status sensing unit module being operable to establish an interrupt condition for receiving of an "available" message frame and filling of said frame with the status of the corresponding trunk means and then retransmitting of said "available" frame as a filled message frame to the loop system, a dual input logic gate means having a pair of inputs connected respectively to the failure detection units and responsive to failure of both trunk means to generate an output logic signal, each of said remote stations including a fault frame generator operable to and in response to a logic input signal to continuously generate in time-spaced sequence similar filled message frames uniquely identifying the remote station and thereby locating the dual failure between a pair of adjacent stations, the output of said logic gate means being connected to the frame processing means to actuate said fault location identifying frame generator within the remote station to thereby continuously generate dual fault location identifying frames for transmission downstream of the loop to the central station.

Claim 15

The data communication loop system of claim 9 wherein a pair of said trunk means are provided to each of said remote stations, each station includes a dual trunk termination and connection means for interconnecting of the dual trunk means to a single trunk message frame processing means, a by-pass control switch, said dual connection means including a pair of input coaxial cables and a pair of output coaxial cables connected respectively to the said pair of trunk means to the opposite sides of said by-pass control switch, a pair of receivers connected respectively to said input cables, a loop failure detection unit connected to the output of the first receiver and establishing a logic output signal related to the presence and failure of a message signal, a second failure detection unit connected to the second receiver and establishing a logic output signal in accordance with the presence and failure of a message frame at said receiver, a multiplexing means having an input binary decoder connected to said failure detection units, and said multiplexing means having a pair of data input means connected respectively to said first and second receivers and having a single data output line connected to the message frame processing means in accordance with the decoder.

Claim 16

The loop system of claim 13 wherein each of said remote stations includes a contact status sensing module including a plurality of status sensing inputs connected respectively one each to the failure detection units, said contact status sensing unit module being operable to establish an interrupt condition for receiving of an "available" message frame and filling of said frame with the address of the remote station and then retransmitting of said "available" frame as a filled message frame to the loop system, said controller sending a message frame to interrogate the status of the contact status sensing module and thereby obtaining an indication of which loop segment failed.

Claim 17

The system of claim 13 wherein each station includes an input logic gate means having a pair of inputs connected respectively to the failure detection units and responsive to failure of both trunk means to generate an output logic signal, each of said remote stations including a fault frame generator operable to and in response to a logic input signal to continuously generate time-spaced sequence similar filled message frames uniquely identifying the remote station and thereby locating the dual failure between a pair of adjacent stations, the output of said logic gate means being connected to the frame processing unit to actuate said fault location identifying frame generator within the remote station to continuously generate dual fault location identifying frames for transmission downstream of the loop to the central controller.

Claim 18

A connection unit for adapting a remote station for connection to other remote stations and to a central loop controller in a plurality of transmission path means, each of said remote stations being adapted to receive a multiple bit digital message frame and operable to process and retransmit said frame to a succeeding station, comprising a plurality of individual transmission trunk termination means to simultaneously receive message frames and a plurality of individual transmission trunk origination means, trunk selection means connected to said trunk termination means and responsive to the simultaneously received and identical incoming message frames to transmit one of said message frames from one of said trunk means to the frame processing means, transmission means connected to the trunk origination means to retransmit the processed message frame over all of the plurality of trunk origination means, each of said stations including means responsive to failure to receive a message frame over a trunk termination means to activate the processing means for selection and transmission of an identifying message frame from a different trunk termination means to said transmission means.

Claim 19

A connection unit for adapting a remote station for connection to other remote stations and to a central loop controller in a plurality of transmission path means, each of said remote stations being adapted to receive a multiple bit digital message frame and operable to process and retransmit said frame to a succeeding station, comprising a plurality of individual transmission trunk termination means to simultaneously receive message frames and a plurality of individual transmission trunk origination means, trunk selection means connected to said trunk termination means and responsive to the simultaneously received and identical incoming message frames to transmit one of said message frames from one of said trunk means to the frame processing means, transmission means connected to the trunk origination means to retransmit the processed message frame over all of the plurality of trunk origination means, each of said stations including means responsive to failure to receive a message frame over a trunk termination means to activate the processing means for selection and transmission of an identifying message frame from a different trunk termination means to said transmission means.