Westinghouse Electric Corporation

Westinghouse Process Control, Inc.

Warren A Edblad

Carl J Staab

Albert W Crew

Donald J Jones

John W Gomola

William G Wood

F David Jones

Linda L Santoline

Frank E Wallace

Kirk D Houser

Robert T Ihrman

Donald A Poepsel

Richard E Putman

Charles W Einolf, Jr

Theodore C Giras

David M Oravetz

Gilbert W Remley

Rodney E Gilbreath

John S Deliyannides

Terry B Cullen

Richard W Kephart, Jr

Suresh K V Vishnubhatla

Robert L Yeager

Donal A Spillane

Robert W Boehmer

Judith S Pringle

Joann R Patelunas

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.

Controller for solving logic

A distributed process control system drop for controlling the operation of an industrial process includes a first workstation or personal computer running industrial continuous process control software on an open architecture operating system and operable to analyze input information provided from the industrial process according to a predetermined set of rules and generate output information provided to the industrial process to control the operation thereof. A second workstation or personal computer connected with the first workstation via a non vendor-specific, international standards-based data highway normally runs in a backup mode and also runs the industrial process control software on an open architecture operating system to perform the same analysis as the first workstation and generate backup output information. A monitoring function associated with the second workstation detects a failure in the first workstation and transfers control of the industrial process to the second workstation upon first workstation failure. Both the first and second workstations include non-proprietary software suites and each suite includes individual software packages operable to permit personnel associated with the industrial process to interface with the industrial process in a selected manner through the first and second workstations.

Workstation-based distributed process control system

A computer network system repetitively distributes messages including uniquely identified blocks of real time data containing a current data image over a broadcast communications network to all real time stations for storage of each repetition of each entire block of data directly in station memory at a unique address space assigned to that uniquely identified block of data. The real time stations receive the blocks of data and alternatively receive other messages from the real time stations. The other messages have a recognized standard protocol, such as the TCP/IP or UDP/IP protocol of the Internet Protocol Suite.

Method and system for distributing data in a real time data imaging

The operating system clocks in each station on a counter rotating ring network of a distributed processing system are synchronized by latching the count in a free running counter in the network interface of each station at the instant a clock message transmitted by a timekeeper station is received. The timekeeper station then calculates from its operating system time-of-day clock and its free running counter, its time of reception of the clock message, and broadcasts this timekeeper time of reception to the other stations. Each other station calculates its own time of reception from its operating system time of day, and the count in its free running counter, and uses the difference between its time of reception and the timekeeper time of reception to correct its operating system time-of-day clock. Repeater and media propagation delays determined from the dynamic topography of the network are taken into account in calculating the correction factor. The free running counter can also be used to maintain a higher resolution local time of day than is available from the operating system time-of-day clock.

Synchronization of time-of-day clocks in a distributed processing

Real time periodic messages generated by a plurality of stations on a data communication network and having data periods ranging from a shortest to a longest, where the longest data period is an integer multiple of all the others, are assigned by a server station to transmit time slots, equal in duration to the shortest data period, on a global basis to minimize the number of messages transmitted by all stations during each transmit time slot.

Global load smoothing in a real time data imaging network system

A data communications arrangement for a distributed processor control system having a number of stations which can send and receive control data, includes a communications processor at each station effective for controlling the flow of control data over a serial communications bus. The communications processor is coupled to a dual ported memory device along with a functional processor which is effective for carrying out the actual operations of the process. The communications control processor is further effective for assembling frames of control data according to a predetermined arrangement which gives a timing preference to a first category of data over a second category of data. The assembled frame of control data will then include all of the first category of data and, with time remaining from a timing goal, will include a portion of the second category of data.

High performance memory imaging network for a real time process control

A communications arrangement for a distributed process control system operable to control an industrial process where different types of data must be communicated between a number of control drops or stations in varying timing priorities includes a first communication channel on which at least two of the control drops are connected. A second communication channel, independent of the first communication channel, accommodates the communication of a type of data that is not as critical in terms of timing as that which is communicated over the first communication channel. All of the control drops are connected to the second communication channel. A control processor, located at each of the control drops, determines the distribution of the types of data between the two communication channels according to a predetermined timing priority.

Real time process control using multiple communication networks

A distributed processing unit (DPU) or drop which performs process control and data acquisition functions in a distributed processing control system having a data highway linking a plurality of such units. A DPU functional processor accesses the local process I/O interface thereby continually receiving plant information for storage in digital form and subsequent use in the functional processor or for transmission along the data highway. DPU control programs use process values in a transparent fashion, that is without regard to whether these values were obtained through local process I/O interface or via the data highway. The DPU software structure is made up of execution software and support software. The execution software is a collection of data acquisition and process control programs which are developed at an engineer's console drop using a DPU programming language which operates in text and CRT graphic display modes, the latter programming modes allowing system documentation via hard copy graphic display printout. These programs are initiated, performed consecutively, and repeated at specified intervals. The support software initiates process loop execution. Control programs which have been presented to the DPU as representations of ladder diagrams for sequential control or process flow diagrams for continuous process control are executed in the DPU functional processor to achieve the required process control operation.

Universal process control device and method for developing a process

An industrial production or other operational system is established by connecting apparatus which implements system operations to a digital computer system using an interface system. Machine readable definitions of events, of executable jobs, and of system variables are prepared for computer entry and ultimately for configuration of the system apparatus into an entity having operational characteristics corresponding to the entered definitions. The definitions of system variables may include definitions of signals which are coupled between the system apparatus and the computer through the interface system, and such signals may be put to system monitoring or control uses or both of these uses in the structured system. Some of the definitions may be computer programs, but most are preferably definitions of the system configuration written out in a language which a systems engineer can understand and use. Generally, definitions may include designators which are names or numbers. Any definition may refer to an event, a job, or a variable by making reference to the designator that is included in the definition of the event, the job or the variable. Executable job definitions may, by referring to event designators, specify specific events which are to trigger their execution--for example, variable scanning events or variable change-of-state events--or they may specify that they are to be periodically executed at a specified frequency or rate. The definitions are processed individually by an off-line preliminary processor which converts the systems engineer's language into a numeric language intelligible to processing programs within the computer system or to the computer system itself. The definitions are then fed into the computer system. Automatic programming means within the computer system establish all the necessary linkages between each new definition and previously entered definitions and other operative portions of the computer system so as to implement each definition relative to the system apparatus as soon as the definition is received and so as automatically to establish the desired system operating configuration through the controlled operation of the computer relative to the interfaced system apparatus. Definitions may be deleted from the computer system at any time and in any order by the automatic programming means without shutting down the system, and the system operating configuration may thus be modified whenever necessary or desirable. Following such deletions, the automatic programming means eliminates linkages which are no longer required and compresses the tables in which such linkages may be stored so as to maximize the storage space which is available for additional new definitions and their associated linkages.

Digital computer monitored system or process which is configured with

An industrial production or other operational system is established by connecting apparatus which implements system operations to a digital computer system using an interface system. Machine readable definitions of events, of executable jobs, and of system variables are prepared for computer entry and ultimately for configuration of the system apparatus into an entity having operational characteristics corresponding to the entered definitions. The definitions of system variables may include definitions of signals which are coupled between the system apparatus and the computer through the interface system, and such signals may be put to system monitoring or control uses or both of these uses in the structured system. Some of the definitions may be computer programs, but most are preferably definitions of the system configuration written out in a language which a systems engineer can understand and use. Generally, definitions may include designators which are names or numbers. Any definition may refer to an event, a job, or a variable by making reference to the designator that is included in the definition of the event, the job or the variable. Executable job definitions may, by referring to event designators, specify specific events which are to trigger their execution--or example, variable scanning events or variable change-of-state events--or they may specify that they are to be periodically executed at a specified frequency or rate. The definitions are processed individually by an off-line preliminary processor which converts the systems engineer's language into a numeric language intelligible to processing programs within the computer system or to the computer system itself. The definitions are then fed into the computer system. Automatic programming means within the computer system establish all the necessary linkages between each new definition and previously entered definitions and other operative portions of the computer system so as to implement each definition relative to the system apparatus as soon as the definition is received and so as automatically to establish the desired system operating configuration through the controlled operation of the computer relative to the interfaced system apparatus. Definitions may be deleted from the computer system at any time and in any order by the automatic programming means without shutting down the system, and the system operating configuration may thus be modified whenever necessary or desirable. Following such deletions, the automatic programming means eliminates linkages which are no longer required and compresses the tables in which such linkages may be stored so as to maximize the storage space which is available for additional new definitions and their associated linkages.

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Plum Boro, PA, United States of America

Warren A Edblad