Information display system for actively redundant computerized process control
AssigneeThe Dow Chemical Company
InventorsDana W. Pressnall, Jeffery T. Polishak, Bradley K. Felix, Michael J. Durisin, Joseph Ellison
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Abstract
In an actively redundant computer system, in which two or more computers simultaneously control a process, live data values representing the actual state of preselected variables are simultaneously displayed along with an alphanumeric representation of a source code statement based on those variables.
Claims29
A computerized process control display system for conveying information to an operator about the state of a process under control, comprising:
- first and second independently and concurrently operating redundant process control computers each having interface means for connection to a common point within the process under control and for concurrently monitoring a common parameter associated with said common point;
- first and second process control programs running respectively on said first and second process control computers, the programs each having means for controlling the behavior of at least a portion of the process under control, said process control programs being capable of representation as a series of source statements wherein said source statements include at least one token to represent said common parameter;
- a display computer coupled to said first and second process control computers for displaying at least a portion of said series of source statements comprising said process control programs;
- said display computer further having data access and display means for obtaining and simultaneously displaying the common parameter value adjacent its token in said source statement from both first and second process control computers, whereby the operator is provided a means to simultaneously visually compare the common parameter values from said first and second process control computers.
A computerized process control display method for conveying information to an operator about the state of a process under control of a plurality of concurrently operating redundant process control computers, comprising the steps of:
- using a plurality of textually represented program statements to represent at least a portion of a process control strategy being used to control said process;
- said program statements comprising a plurality of tokens representing control parameters associated with the process under control;
- automatically obtaining data substantially simultaneously from each of said concurrently operating process control computers and using said data to assign to said tokens an actual state for at least a portion of said control parameter tokens.
A computerized process control display system for conveying information to an operator about the state of a process under control, comprising the steps of:
- using at least one textually represented program statement to represent at least a portion of a process control strategy being used to control said process;
- said program statement comprising a plurality of tokens including at least one L-value token and at least one R-value token each having a Boolean portion;
- automatically obtaining data from said process being controlled and using said data to assign to said R-value tokens an actual Boolean state for each of said tokens;
- displaying said textually represented program statement using a first visually distinguishable display attribute to depict tokens which are currently TRUE and using a second visually distinguishable display attribute to depict tokens which are currently FALSE, whereby information about the state of the process control strategy is conveyed to the operator.
A computerized process control display system for conveying information to an operator about the state of a process under control, comprising the steps of:
- using a plurality of textually represented program statements to represent at least a portion of a process control strategy being used to control said process;
- said program statements comprising a plurality of tokens representing control parameters associated with the process under control;
- automatically obtaining data from said process being controlled and using said data to assign to said tokens an actual state for each of said tokens;
- establishing a main display window and a watch window associated with said main display window for display of textually represented information;
- selecting a first subset of said plurality of textually represented program statements and displaying said first subset in said watch window;
- without changing the first subset selected, selecting a second subset of said plurality of textually represented program statements and displaying said second subset in said main window;
- wherein the steps of displaying said first subset in said watch window and displaying said second subset in said main window are performed independently such that the selection of said first subset is unchanged by a change in selection of said second subset, whereby information about the state of the first and second subsets are independently and simultaneously conveyed to the operator.
Dependencies are inferred from the claim text.