Digital information transfer system having integrity check

Claim 2

In a digital information transfer system including a plurality of addressed, energizable utilization device control means, a plurality of utilization device selection means, digital message generating means for producing a unique digital address upon actuation of each selection means, digital message processing and handling means and decoding means responsive to receipt of a digital address for enabling one of the control means, the improvement of means for assuring the system is highly secure comprising: a. address complement generating means responsive to the energization of one of the control means for generating the digital complement of the energized control means address; b. address complement decoding means for producing one of a plurality of outputs when an address complement is received, said address complement generating and decoding means being interconnected by said digital message processing and handling means; and c. a plurality of systems security indicating means, each of said indicating means being responsive to simultaneous energization of first and second inputs to indicate system security, each of said first inputs adapted to be individually connected to and energized by one of the utilization device selection means and each of said second inputs being connected to and energized by the one decoding means output energized by receipt of said decoding means of the digital complement of the selected control means, the first and second inputs of a single indicating means, thereby being simultaneously energized when the selected and enabled control means are identical, the first and second inputs of different said indicating means being energized when the selected and enabled control means are different, said security means thereby assuring that an operative system exists between the control and selection means.

Claim 3

A digital information transfer system as recited in claim 1 wherein the unique digital address contains first and second address characters, said address complement generating means producing the complement for each character of the enabled control means address and said address complement decoding means having first and second character decoders, said first character decoder providing an enabling input to said second character decoder and said second character decoder energizing one of said indicating means second inputs.

Claim 4

A digital information transfer system as recited in claim 2 wherein the control means are divided into groups, the first address character designating a group and the second character designating a control means in that group, said first cHaracter decoder enabling said second character decoder whenever any control means in the selected group is energized.

Claim 5

In a supervisory control system including a master station and a plurality of digitally addressed remote stations, each of said remote stations having digitally addressed, two-condition actuators adapted to be enabled by a first signal and energized by a second concurrent signal to control a utilization device and each remote station being connected to the master station by communication means, means for controlling a specific utilization device from the master station comprising: a. point selector means at said master station corresponding to each controllable utilization device; b. digital address generating means responsive to actuation of one of said point selector means for generating the remote station and actuator addresses; c. master station digital message handling means connected to said digital address generating means for transmitting onto and receiving from communication means; d. remote station digital message handling means for receiving from and transmitting onto the communication means; e. remote station address decoder means responsive to receipt of a digital address to enable one specific actuator with the first energizing signal; f. actuator address complement generating means having a plurality of inputs connected to each actuator to be responsive to the enabling thereof for generating the digital complements of the enabled actuator and remote station addresses for transmission through said master and remote station digital message handling means and said communications means; g. master station decoder means energized by the digital complements having a plurality of outputs, one of said outputs being energized in response to each digital complement; h. a plurality of security indicating means, each indicating means being energized by one point selector means and the master station decoder means output energized by the complement of the generated address; and i. second energizing signal generating means connected to all of said indicating means to be enabled upon simultaneous energization by a point selector means and by the master station decoder means and thereby permit actuation of the utilization device.

Claim 6

In a supervisory control system including a master station and a plurality of digitally addressed remote stations, each of said remote stations having digitally addressed, two-condition actuators adapted to be enabled by a first signal and energized by a second concurrent signal to control a utilization device and each remote station being connected to the master station by communication means, means for controlling a specific utilization device from the master station comprising: a. point selector means at said master station corresponding to each controllable utilization device; b. digital address generating means responsive to actuation of one of said point selector means for generating the remote station and actuator addresses; c. master station digital message handling means connected to said digital address generating means for transmitting onto and receiving from communication means; d. remote station digital message handling means for receiving from and transmitting onto the communication means; e. remote station address decoder means responsive to receipt of a digital address to enable one specific actuator with the first energizing signal; f. actuator address complement generating means having a plurality of inputs connected to each actuator to be responsive to the enabling thereof for generating the digital complements of the enabled actuator and remote station addresses for transmission through said master and remote station digital message handling means and said communications means; g. master station decoder means energized by the digital complements having a plurality of outputs, one of said outputs being energized in response to each digital complement; h. a plurality of security indicating means, each indicating means being energized by one point selector means and the master station decoder means output energized by the complement of the generated address; and i. second energizing signal generating means connected to all of said indicating means to be enabled upon simultaneous energization by a point selector means and by the master station decoder means and thereby permit actuation of the utilization device.

Claim 7

A supervisory control system as recited in claim 4 wherein said point selector means comprises a latch means having an output connected to said digital address generating means and to said security indicating means and switching means for selectively grounding an input of said latch means to thereby cause selection of a utilization device control actuator.

Claim 8

A supervisory control system as recited in claim 5 wherein said digital address generating means comprises a remote station address encoder and a plurality of control actuator address encoders, each control actuator address encoder being associated with all point selector means for a given remote station and having an output individually connected to an input of said remote station address encoder thereby grounding the latch input causes the control actuator address and a remote station address to be generated to thereby uniquely define a specific utilization device control actuator.

Claim 9

A supervisory control system as recited in claim 6 wherein said master station digital message handling means includes common busses connected between circuitry in said master station, a parallel-serial converter coupled to said common busses and a transceiver connected to said parallel-serial converter and said communications means and wherein said remote station digital message handling means includes a transceiver connected to said communication means, a parallel-serial converter connected to said transceiver and remote station common busses connected to said parallel-serial converter, all of said common busses, said parallel-serial converters, said transceiver and said communication means being operative to handle and process the dIgital message and its complement.

Claim 10

A supervisory control system as recited in claim 7 wherein the two-condition actuators include first and second serially connected switching means and a latch adapted for energization by the first signal and connected to said remote point address complement encoder for causing the energization thereof.

Claim 11

A supervisory control system as recited in claim 7 wherein said actuator address complement generating means includes a remote station address digital complement encoder and an actuator address digital complement encoder, said remote station address digital complement encoder being energized by said remote station address decoder and said point address complement encoder being energized by energization of said actuator latch.

Claim 12

A supervisory control system as recited in claim 9 wherein said master station decoder means includes a remote station address digital complement decoder and a plurality of actuator address digital complement encoders, receipt of said remote station address digital complement at said master station enabling one of said actuator address digital complement decoders.

Claim 13

A supervisory control system as recited in claim 10 wherein said security indicating means are constituted by a plurality of comparator circuits, each of said comparator circuits being individually connected to one of said point selector latch means and one of said actuator address digital complement decoder outputs.

Claim 14

A supervisory control system as recited in claim 11 wherein said second energizing signal generating means includes command encoder means connected to all of said comparator outputs to be enabled when one of said comparator outputs is energized, said command encoder additionally including actuation selection means and means for generating a command code onto said common busses for transmission to the remote station and means responsive to said command message for decoding said message and energizing all of said two-condition actuators with the second energizing signal whereby only one of said actuators is energized by both said second and first energizing signals.

Claim 15

A supervisory control system as recited in claim 5 wherein said actuators and said point selector means are grouped according to remote station and wherein a plurality of said actuators may have the same actuator address, each of said remote stations having a unique address so that the combination of said remote station address and said actuator address define a specific actuator, each of said groups having a single actuator address complement generating means responsive to the energization of said latch means for generating the actuator address digital complement and simultaneously energizing one input to a remote station address complement encoder to generate the appropriate remote station address digital complement.

Claim 16

A supervisory control system as recited in claim 13 additionally including means for monitoring the two-condition actuator for responding to a fault therein to thereby prohibit system operation.