Industrial Process Control Data Access Server Supporting Multiple Client Data Exchange Protocols

Abstract

A method and process control data server system architecture are disclosed for providing process data to a variety of client applications via a plurality of differing data sharing standards. The system architecture incorporates a ready platform for subsequently added client application data exchange protocols. In an exemplary embodiment, a set of standard interface definitions between client application data exchange protocol-specific plugins and a data access server engine supports incorporating new client application data exchange protocols by means of plugins designed to interface with the data access server engine according to the standard interface definitions.

Description

CROSS REFERENCE TO RELATED APPLICATION[0001]This application claims priority of Todorov et al. U.S. provisional application Ser. No. 60 / 232,731 filed on Sep. 15, 2000, entitled “Remote Multiple Client Protocol Support,” the contents of which are expressly incorporated herein by reference in their entirety including the contents and teachings of any references contained therein.FIELD OF THE INVENTION[0002]The present invention generally relates to the field of computerized process control networks. More particularly, the present invention relates to data access server systems providing access by supervisory level client applications to process control information.BACKGROUND OF THE INVENTION[0003]Significant advances in industrial process control technology have vastly improved all aspects of factory and plant operation. Before the introduction of today's modern industrial process control systems, industrial processes were operated / controlled by humans and rudimentary mechanical contr...

AI Technical Summary

Benefits of technology

[0010]The present invention offers a new degree of extensibility to client application interfaces in a process control system. Enhanced extensibility / flexibility is achieved in a data access server by decoupling data access server engine functionality from the client data exchange protocols used by client applications to request data from a data access server. The present invention achieves such decoupling by abstracting client application data communication protocols in a set of user installable / selectable / replaceable program modules such as, for example plugins. These program modules are installed on the data access server to facilitate presentation of data to the client applications according to a variety of protocols utilized by the client applications. After installation, the program modules provide a protocol-specific interface to client applications and communicate with the data access server engine via standardized universal set of interfaces. Thus, extension of a data access server incorporating the present invention is accomplished by providing and installing a new data exchange protocol module on the data access server. Previously existing software on the data access server, including the data access server engine and the previously installed protocol-specific protocol modules, need not be modified to include the new data exchange protocol module in the data access server system.

[0011]The present invention is directed to an extensible architecture for a data access server. The extensible architecture facilitates extending the set of client application data exchange protocols supported by the data access server—even a substantial period of time after installing the data access server. In particular, the present invention comprises a data access server that includes a set of components that are separately programmed and installable, yet run as an integrated system. The integrated components include a set of client data exchange protocol modules that provide data exchange protocol-specific interfaces between the data access server and client applications. The data access server also includes a data access server engine that executes a set of core functions. The core functions execute (i.e., process and respond to) client application requests for data supplied by a process control system. Communication between the set of client data exchange protocol modules and the data access server engine is carried out according to a standardized set of interfaces. The standardized set of interfaces provides an abstraction layer between the client data exchange protocols and the engine functions that acquire and provide process data to requesting client applications. The abstraction layer insulates the data access server from changes to client data exchange protocols supported by the data access server. Conversely, the DAS engine can be modified / replaced without impact upon the client protocol modules—assuming that the previous abstraction layer / interface is supported by any changes to the DAS engine or the DAS engine's replacement.

[0013]A benefit of the process data server embodying the present invention is extensibility. The process data server supports incorporating additional protocols in support of new client applications, and continues to support existing data sharing / passing protocols associated with legacy clients, after the process data server is deployed on a process control network. A vendor of a process data access server incorporating the present invention can now deploy a reusable, extensible, optimized (e.g., only install needed protocols) process data access server to communicate to the data source.

Problems solved by technology

As a consequence, the complexity and degree of control over a process was limited by the speed with which one or more people could ascertain a present status of various process state variables, compare the current status to a desired operating level, calculate a corrective action (if needed), and implement a change to a control point to affect a change to a state variable.

This relatively static, limiting approach to client application implementation leads to duplication / replication of effort (a distinct version of client application for extracting device data is created for each communication standard that may be used to retrieve that data).

This approach also creates an inability of data access server developers to leverage prior server versions.

Users were slow in migrating from existing client applications to new client applications incorporating more effective protocols developed over the years due to incompatibilities with existing data provider communication protocols.

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