Controller for solving logic
AssigneeWestinghouse Process Control, Inc.
InventorsSuresh K. V. Vishnubhatla, Richard W. Kephart, Jr., Warren A. Edblad, Donal A. Spillane
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Abstract
A logic controller includes a memory for storing representations of boolean logic. The boolean logic includes AND and OR boolean logic functions having target values and a plurality of inputs. The processor of the logic controller has input/output circuitry and communications circuitry which provide a plurality of input/output digital logic signals. The processor employs the digital logic signals and solves the boolean logic representations. A firmware routine solves each boolean logic function when the value of any of its inputs is equal to its target value.
Claims24
In a plant process data acquisition and control system receiving plant process inputs and providing plant process outputs, including a logic controller apparatus for solving boolean logic comprising:
- means for storing representations of logic, said logic including a logic function, wherein said logic function has a target value and a plurality of inputs corresponding to said plant process inputs, wherein each of the inputs of said logic function has a value, said logic further including a plurality of logic circuit elements, wherein each of said logic circuit elements includes at least one of an AND boolean circuit element and an OR boolean circuit element;
- means for providing a plurality of digital logic signals;
- means for solving said representations of said logic employing at least some of the digital logic signals;
- and
- means for solving said logic function when the value of at least one of the inputs of said logic function is equal to the target value and providing a corresponding plant process output;
- wherein at least one input of said logic circuit elements is a plurality of inputs including at least one first input which is connected to an output of said logic circuit elements, and at least one second input which is interconnected with an output of said logic circuit elements by an inverter;
- and wherein said means for solving said logic function includes means employing a mask for selectively inverting at least one output of said logic circuit elements which is interconnected with the last said at least one second input.
Dependencies are inferred from the claim text.