Distributed control with universal program
First Claim
1. In a distributed control system for an industrial process unit having at least three subprocesses, each subprocess being subjected to both unit control and subprocess control, the unit control being dependent on a plurality of unit operating parameters and the subprocess control being dependent on a plurality of subprocess operating parameters, the control system having at least three process control computers corresponding in number to the number of said subprocesses, each process control computer having input ports for receiving operating input signals of operating parameters of an associated subprocess, a preprogrammed set of operating function instructions which are executed based upon the operating input signals and, which generate in response to the operating input signals in accordance with the programmed instructions, operating control signals outputted through output ports to control said associated subprocess, input ports for receiving safety input signals commensurate with the operational safety of said associated subprocess, a preprogrammed set of safety function instructions which are executed based upon the safety input signals and which generate in response thereto safety shutdown signals outputted through output ports for shutting down said associated subprocess when an unsafe operating condition is approached, input ports for receiving backup input signals commensurate with the operational safety of another subprocess, a preprogammed set of backup function instructions which are executed based upon the backup input signals and which generate in response thereto backup shutdown signals outputted through output ports to shut down said other subprocess when an unsafe operating condition is approached, whereby each of the plurality of process control computers serves as a redundant backup of the operational safety of another of the plurality of process control computers for each of the plurality of subprocesses, a method of unit and subprocess control comprising the steps of:
- (a) storing an identical set of preprogrammed subprocess operating, safety and backup function instructions in each of said process control computers, said set including all preprogrammed instructions for accomplishing said subprocess control;
(b) storing identical set of preprogrammed unit operating, safety and backup control function instructions in each of said process control computers for accomplishing said unit control;
(c) interconnecting each of said process computers with,(1) at least two other of said computers for generating operating, safety, or backup control signals for at least two subprocesses, and(2) at least two of said subprocesses for receiving input signals and sending output signals through said input and output ports to control said at least two subprocesses;
(d) interconnecting at least two of said computers to a source of input data including said unit operating parameters;
(e) repeatedly executing said subprocess and unit sets of instructions in each of the process control computers whether or not input signals are received from or output signals are received by another process computer, a subprocess, or said source of input data;
(f) controlling the unit and each subprocess utilizing only the signals transmitted between said interconnected computers, subprocesses, and source of input data recited in step (e) above.
1 Assignment
0 Petitions
Accused Products
Abstract
A distributed control system controlling a plurality of subprocesses wherein each of the process control computers (44, 46, 48) executes a preprogrammed set of instructions (50-62) identical to the preprogrammed set of instructions (50-62) in the other process control computers (44, 46, 48) in the distributed control system. Inputs from field devices (76, 78, 80) are connected between each subprocess and the process control computer (44, 46, 48) providing control therefor as well as between each subprocess and the process control computer (44, 46, 48) providing redundant safety backup of the operational safety. One or more of the process control computer (44, 46, 48) in the distributed control system executes some preprogrammed set of instructions (50-62) as part of the preprogrammed set of instructions for which there are no inputs from field devices (76, 78, 80) or output control signals to field devices (76, 78, 80).
83 Citations
1 Claim
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1. In a distributed control system for an industrial process unit having at least three subprocesses, each subprocess being subjected to both unit control and subprocess control, the unit control being dependent on a plurality of unit operating parameters and the subprocess control being dependent on a plurality of subprocess operating parameters, the control system having at least three process control computers corresponding in number to the number of said subprocesses, each process control computer having input ports for receiving operating input signals of operating parameters of an associated subprocess, a preprogrammed set of operating function instructions which are executed based upon the operating input signals and, which generate in response to the operating input signals in accordance with the programmed instructions, operating control signals outputted through output ports to control said associated subprocess, input ports for receiving safety input signals commensurate with the operational safety of said associated subprocess, a preprogrammed set of safety function instructions which are executed based upon the safety input signals and which generate in response thereto safety shutdown signals outputted through output ports for shutting down said associated subprocess when an unsafe operating condition is approached, input ports for receiving backup input signals commensurate with the operational safety of another subprocess, a preprogammed set of backup function instructions which are executed based upon the backup input signals and which generate in response thereto backup shutdown signals outputted through output ports to shut down said other subprocess when an unsafe operating condition is approached, whereby each of the plurality of process control computers serves as a redundant backup of the operational safety of another of the plurality of process control computers for each of the plurality of subprocesses, a method of unit and subprocess control comprising the steps of:
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(a) storing an identical set of preprogrammed subprocess operating, safety and backup function instructions in each of said process control computers, said set including all preprogrammed instructions for accomplishing said subprocess control; (b) storing identical set of preprogrammed unit operating, safety and backup control function instructions in each of said process control computers for accomplishing said unit control; (c) interconnecting each of said process computers with, (1) at least two other of said computers for generating operating, safety, or backup control signals for at least two subprocesses, and (2) at least two of said subprocesses for receiving input signals and sending output signals through said input and output ports to control said at least two subprocesses; (d) interconnecting at least two of said computers to a source of input data including said unit operating parameters; (e) repeatedly executing said subprocess and unit sets of instructions in each of the process control computers whether or not input signals are received from or output signals are received by another process computer, a subprocess, or said source of input data; (f) controlling the unit and each subprocess utilizing only the signals transmitted between said interconnected computers, subprocesses, and source of input data recited in step (e) above.
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Specification
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- Resources
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Current AssigneeCombustion Engineering Incorporated (ABB Limited)
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Original AssigneeCombustion Engineering Incorporated (ABB Limited)
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InventorsSchuss, Jack A.
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Primary Examiner(s)Smith, Jerry
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Assistant Examiner(s)Lastova, John R.
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Application NumberUS06/682,383Time in Patent Office904 DaysField of Search364/130-134, 364/184, 364/186, 364/187, 364/200 MS, 364/900 MS, 371/9US Class Current700/4CPC Class CodesG05B 15/02 electricG05B 9/03 with multiple-channel loop,...G06F 11/16 Error detection or correcti...
