Inventors:
George J. Carrette - Concord MA
James E. Clancy - Chelmsford MA
Gregory H. Fossheim - Hollis NH
Assignee:
Mitech Corporation - Concord MA
International Classification:
G06F 1546, G06F 1518
Abstract:
Digital processing methods and apparatus for monitoring, controlling, and simulating industrial processes operate on data signals representative of process parameter values and generate response values representative of desired or requested process parameter values. A knowledge base stores knowledge of the industrial process in the form of rules, and an inference engine applied the rules to calculate the response values. A time-stamp value is assigned to each data signal, representing the time of receipt of each signal. Currency evaluation elements, responsive to user-selected currency range values and the time-stamp signals, assign an expiration-time value to the data signals and disregard data signals having an expiration-time value outside a corresponding user-selected currency range value.