High reliability industrial controller using tandem independent programmable gate-arrays
AssigneeRockwell Automation Technologies, Inc.
InventorDavid A. Vasko
Life of this patent
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Abstract
A highly reliable industrial controller uses low complexity field programmable gate-arrays (FPGA) in lieu of standard microprocessors where each FPGA is programmed so as to provide for a different internal implementation of the control program as a set of interconnected logical gates. Variations in the outputs of the FPGAs caused by hardware failure may be corrected by choosing the most common output, a default output or a default value. Errors may be detected though conventional hardware error detection methods or by a direct comparison of the outputs which under normal conditions should match each other.
Claims21
A high reliability industrial controller for control of an industrial process according to a control program comprising:
- (a) at least a first and second programmable gate-array having logic gates interconnected according to programmable memory cells, the programmable gate having gate-array inputs received by the interconnected logic gates to provide, for each gate-array input, a set of corresponding gate-array outputs that are Boolean functions of the inputs;
- (b) input circuitry accepting electrical inputs from the industrial process and routing the inputs to the gate-array inputs of the programmable gate-arrays;
- (c) comparison circuitry receiving gate-array outputs from the programmable gate-arrays to produce controller outputs for each given gate-array input by a comparison of the set of corresponding outputs of the given gate-arrays input;
- and
- (d) output circuitry receiving the controller outputs and connecting them to the industrial process;
- wherein further the programmable memory cells of the programmable gate-arrays are programmed so that different programmable gate-arrays independently execute the control program using different interconnections between logic gates.
A high reliability industrial controller for control of an industrial process according to a control program comprising:
- (a) at least a first and second programmable gate-array having logic gates interconnected according to programmable memory cells, the programmable gate having gate-array inputs received by the interconnected logic gates to provide for each gate-array input a set of corresponding gate-array outputs that are Boolean functions of the gate-array input;
- (b) input circuitry accepting electrical inputs from the industrial process and routing the inputs to the gate-array inputs of both the first and second programmable gate-arrays;
- (c) diagnostic circuitry monitoring the operation of the programmable gate-arrays to produce an error signal upon failure of operation of at least one programmable gate-arrays;
- (d) output modification circuitry receiving gate-array outputs from the programmable gate-arrays and receiving the error signal from the diagnostic circuitry to produce controller outputs based on at least one of the set of corresponding outputs of the first and second programmable gate-arrays and the error signal;
- (e) output circuitry receiving the controller outputs and connecting them to the industrial process;
- wherein further the programmable memory cells of the first and second programmable gate-arrays are programmed to each independently execute the control program using different interconnections between logic gates.
Dependencies are inferred from the claim text.