High security digital conversion and transmission scheme for a closed loop control system

Claim 2

In a closed loop apparatus including a digital processing unit for regulating a system having M-inputs and N-outputs and responsive to analog signals applied to its inputs for generating analog signals at its outputs, said regulating apparatus including M actuation means responsive to commands generated by the processing unit for applying analog signals to the inputs of the system and N detecting means for measuring the resulting analog output signals of the system for application to the unit, an improved arrangement for coupling the output of the detecting means to the processing unit, which comprises: N first converters each having first normally unconditioned means operable when conditioned for translating an analog signal applied to a first input thereof to a corresponding digital signal at its output, and first guard means responsive to the application of a digital address code thereto for conditioning the first translating means for operation; means for individually applying the outputs of the N detecting means to the first inputs of each of the N first translating means; first means for applying uniquely associated address codes from the processing unit to each of the first guard means to condition the associated first translating means for operation; and means associated with the processing unit and responsive to the conditioning of the first translating means for effecting the operation of the first translating means.

Claim 3

In a closed loop apparatus including a digital processing unit for regulating a system having M-inputs and N-outputs and responsive to analog signals to its inputs for generating analog signals at its outputs, said regulating apparatus including M actuation means responsive to commands generated by the processing unit for applying analog signals to the inputs of the system and N detecting means for measuring the resulting analog output signals of the system for application to the processing unit, an improved arrangement for coupling the outputs of the detecting means to the processing unit and for coupling the commands generated by the processing unit to the actuation means which comprises: N first converters each having first normally unconditioned means operable when conditioned for translating an analog signal applied to a first input thereof to a corresponding digital signal at its output, and first guard means responsive to the application of a digital address code thereto for conditioning the first translating means for operation; N second converters each having second normally unconditioned means operable when conditioned for translating a digital signal applied to a first input thereof to a corresponding analog signal at its output, and a second guard means responsive to the application of a digital address code thereto for conditioning the second translating means for operation; means for individually applying the outputs of the N detecting means to the first inputs of each of the N first translating means; means for individually applying the outputs of the M second converters to the inputs of the M actuation means; first means for Applying uniquely associated address codes from the processing unit to each of the first guard means to condition the associated first translating means for operation; second means for applying uniquely associated address codes from the processing unit to each of the second guard means to condition the associated second translating means for operation; first means associated with the processing unit and rendered effective upon the conditioning of the first translating means for effecting the operation of the first translating means; means associated with the processing unit and rendered effective upon the conditioning of the second translating means for applying digital commands from the processing unit to the first input of the second translating means; and second means associated with the processing unit and rendered effective upon the receipt of the digital commands by the second translating means for effecting the operation of the second translating means.

Claim 4

In a closed loop apparatus including a digital processing unit for regulating a system having M-inputs and N-outputs and responsive to analog signals to its inputs for generating analog signals at its outputs, said regulating apparatus including M actuation means responsive to commands generated by the processing unit for applying analog signals to the inputs of the system and N detecting means for measuring the resulting analog output signals of the system for application to the processing unit, an improved arrangement for coupling the outputs of the detecting means to the processing unit and for coupling the commands generated by the processing unit to the actuation means which comprises: N first converters each having first normally unconditioned means operable when conditioned for translating an analog signal applied to a first input thereof to a corresponding digital signal at its output, and first guard means responsive to the application of a digital address code thereto for conditioning the first translating means for operation; N second converters each having second normally unconditioned means operable when conditioned for translating a digital signal applied to a first input thereof to a corresponding analog signal at its output, and a second guard means responsive to the application of a digital address code thereto for conditioning the second translating means for operation; means for individually applying the outputs of the N detecting means to the first inputs of each of the N first translating means; means for individually applying the outputs of the M second converters to the inputs of the M actuation means; first means for Applying uniquely associated address codes from the processing unit to each of the first guard means to condition the associated first translating means for operation; second means for applying uniquely associated address codes from the processing unit to each of the second guard means to condition the associated second translating means for operation; first means associated with the processing unit and rendered effective upon the conditioning of the first translating means for effecting the operation of the first translating means; means associated with the processing unit and rendered effective upon the conditioning of the second translating means for applying digital commands from the processing unit to the first input of the second translating means; and second means associated with the processing unit and rendered effective upon the receipt of the digital commands by the second translating means for effecting the operation of the second translating means.

Claim 5

Apparatus as defined in claim 2, in which the second operation effecting means comprises, in combination, means responsive to the receipt of the command data at the second translating means for generating a replica of the received command data to the processing unit, and means for comprising a stored version of the command data with the transmitted replica of such data, the occurrence of the coincidence between the stored command data and the replica effecting the operation of the second translating means.

Claim 6

Apparatus as defined in claim 2, in which each first converter comprises means for suppressing portions of the output digital signal which represent analog output signals from the detecting means having a magnitude outside a predetermined useful range.

Claim 7

Apparatus as defined in claim 2, in which the second conditioning means comprises, in combination, a first digital address register responsive to digital address codes; means for comparing the contents of the first register with a stored digital word representative of the address of the associated second converter and for generating a control indication representative of a coincidence therebetween; a second normally closed data register for receiving digital commands to be translated; and means responsive to the occurrence of the control indication for opening the second register.

Claim 8

Apparatus as defined in claim 2, in which the first conditioning means are arranged to apply address codes to the first guard means of all the first converters in sequence, and in which the first operation effecting means associated with each first converter is rendered effective in timed relation to the operation of the first translating means associated with the preceding first converter in the sequence.