Web services-based communications for use with process control systems

#The invention relates generally to process control systems and, more particularly, the invention relates to the use of web services to facilitate communications between a process control system or plant and a plurality of data consuming applications.

#Process control systems, like those used in chemical, petroleum or other processes, typically include one or more centralized process controllers communicatively coupled to at least one host or operator workstation and to one or more field devices via analog, digital or combined analog/digital buses. The field devices, which may be, for example valves, valve positioners, switches and transmitters (e.g., temperature, pressure and flow rate sensors), perform functions within the process such as opening or closing valves and measuring process parameters. The process controller receives signals indicative of process measurements made by the field devices and/or other information pertaining to the field devices, uses this information to implement a control routine and then generates control signals which are sent over the buses or other communication lines to the field devices to control the operation of the process. Information from the field devices and the controllers may be made available to one or more applications executed by the operator workstation to enable an operator to perform desired functions with respect to the process, such as viewing the current state of the process, modifying the operation of the process, etc.

#Typically, a process control system operates within a business enterprise that may include several process control plants, component and/or service suppliers and customers, all of which may be distributed throughout a large geographic area, or in some cases, throughout the world. The process control plants, suppliers and customers may communicate with each other using a variety of communication media and technologies or platforms such as, for example, the Internet, satellite links, ground-based wireless transmissions, telephone lines, etc. Of course, the Internet has become a preferred communication platform for many business enterprises because the communications infrastructure is established, making the communication infrastructure costs for an enterprise near zero, and the technologies used to communicate information via the Internet are well-understood, stable, secure, etc.

#FIG. 1 is a functional block diagram of an example of a web services-based communication system;

#FIG. 2 is a block diagram that illustrates one manner in which the web services-based communication system shown in FIG. 1 may be adapted for use with a process control system or plant;

#FIG. 3 is a more detailed functional block diagram of the advanced control and condition monitoring web service shown in FIG. 2;

#The web services-based communication system and technique described herein may be used within a process control system or plant to facilitate the communication and viewing of information associated with the process control system or plant. More specifically, the web services-based communication system and technique described herein includes a communications engine that performs message routing, scheduling and configuration functions for a plurality of clients or web-services. Additionally, the web services-based communication system and technique described herein includes a graphical user interface that enables one or more users to configure and/or add web-services to the system and to create a highly personalized profile that causes the communications engine to route selected process control information and other information to be displayed to the user via the graphical user interface in a manner desired by the user. The web services, the communications engine and the graphical user interface may communicate with one another via a network such as, for example, the Internet using an extensible markup language (e.g., XML) or any other similar language that enables applications, services and/or systems to communicate with one another without requiring the development of custom communication interfaces or drivers.

#Generally speaking, the web-services described herein may include data services or sources and data subscribers or consumers. For example, data services or sources may be process control systems or applications, asset management systems or applications, equipment condition monitoring systems or applications, diagnostic systems or applications, or any other system or application that acquires or generates information or data associated with the operation of a process control system or plant. On the other hand, data subscribers or consumers may include user-interactive applications such as, for example, campaign management systems or applications, computerized maintenance management systems or applications, and may also include communication systems or applications such as, for example, paging systems or applications, email systems or applications, file generations systems or applications, etc.

#In any event, each of the data services and data consumers may be an application or system that includes a web services interface. As is well known, a web services interface may use an extensible markup language such as XML in conjunction with a messaging protocol such as, for example, simple object access protocol (SOAP) and a communications transport protocol such as, for example, hypertext transport protocol (HTTP). Because web services are somewhat generic in nature (i.e., the behavior or characteristics of the communications via a web server interface are independent of any underlying application or system), data services and data consumers can be easily connected to (i.e., communicate with) the communications engine without having to create any custom communication interfaces, as typically was the case with prior systems. Additionally, the communications engine may be easily adapted to discover or find (either automatically or at the direction of a user) web services that are available for connection to the communications engine. For example, the communications engine may use a web services discovery tool or service such as, for example, universal discovery description and integration (UDDI), or any other type of web services discovery tool or service to identify available web services.