The ability of one's automation architecture to readily enable seamless integration rests in no small part on making the necessary engineering tasks easier to do. Rather than custom-coding an interface between two applications, why not drag-and-drop the needed data point from one window to another in the engineering console—and let the underlying architecture take care of the rest?
Perhaps more than any other underlying technology, the use of object-oriented architectures is helping to make this streamlining of integration effort a reality. Object architecture makes it possible to implement the common engineering, information and visualization environment that effectively abstract implementation details from the configuration and day-to-day management of seamlessly integrated production systems.
Aspects and Objects
In short, the concept of object orientation encompasses those software development and systems engineering principles such as instantiation, inheritance and encapsulation that help to make possible managing—and effectively integrating—the enormous number of details involved with the thousands of pieces of equipment and information in a typical process plant.
In its System 800xA control system and object-oriented architecture, ABB refers to the range of plant entities and the data that describe them as Objects and Aspects, respectively. Objects are the many physical and logical entities that exist in the plant (such as pumps and control loops). Aspects are the pieces of information that describe the particular instances of these objects (such as pump speed setpoints and control loop gains). Object-oriented engineering allows object types to be created, then instantiated throughout the control code with different aspects as necessary.
Each object, including associated aspects such as HMI graphics or control logic, can be developed once and deployed everywhere that same object type is used. The utility of this is that if a change needs to be made, it can be made once on the object type and automatically replicated to all the other "instances" of the object type. Object architectures also allow for smaller objects (pressure transmitters) to be aggregated into larger objects (distillation columns) and so on. This makes engineering and integration tasks easier to do, the results easier to maintain, and facilitates the implementation of standards throughout the organization.
The Integrated Environment
In short, the System 800xA Engineering environment allows engineers to engineer. They can spend their time focused on developing automation and integration strategies rather than writing code. The platform creates efficiency and boosts productivity, allows collaboration among on-site and off-site engineering groups, allows the development and re-use of intellectual assets and more readily supports the full system lifecycle.
Essential productivity-enhancing features of the System 800xA Engineering environment include graphical tools for the management of HART, Foundation fieldbus, and Profibus intelligent devices. Microsoft Excel add-ins can be used to automatically import and assign bulk data from external sources. Further, system data can be readily exported to support data validation and modification needs. The system also includes extensive change management features to support the validation requirements of regulated industries. "Detailed difference" reports can pinpoint changes and reduce the time needed for verification procedures.
System 800xA also provides the ability to associate related documentation to equipment and applications. Documents based on Microsoft Word, AutoCAD and many other formats can be enhanced with live process values for easier diagnostic review.
Process Engineering Tool Integration
Opportunities to drive engineering productivity improvement begin early in the project lifecycle, when key asset information is being created in core process design systems. Engineering tools integration improves plant communications, data management and decision support; increases engineering value by streamlining workflow and ensuring data quality and consistency; and allows use of the native engineering environment.
For example, information from Intergraph's SmartPlant Instrumentation® (SPI) solution can be bi-directionally integrated with the System 800xA engineering environment. Automation system structure, functionality and graphics within the System 800xA can be created directly from the Intergraph SPI design, and operational changes such as ranges, units and settings can be continually reflected back to SPI. Engineering firms and owner-operators have documented engineering savings of 40% and operational savings of 20% through the reduction of as-built cycles and automatic design synchronization.
A Platform for State-based Control
An object-oriented information and automation architecture such as System 800xA's is uniquely suited to supporting state-based control (SBC) methodologies and the improvements in engineering and operations productivity they can deliver throughout a plant's lifecycle. SBC has been shown to result in higher asset utilization rates for both people and equipment. Further, it provides an environment for ongoing knowledge capture directly into the system design.
In essence, state-based control is based on the principle that all process facilities operate in recognized, definable "process states" characterized by definable differences in processing conditions. Changes in rates, product grades or other factors influencing process performance dictate changes in automation and control parameters. Influences to be taken into account might include equipment operating conditions such as enabled/disabled alarm or safety interlock status.
Because it represents such a structured view of process conditions, direct management of many abnormal situations is possible with SBC. It can eliminate human errors and optimize processing conditions, even if conditions themselves are less than optimal. Traditional automation strategies, in contrast, rely on operator response and the multitude of sub-optimal outcomes that can—and do—occur. And when a situation arises that does require operator involvement, a SBC implementation often presents a less cluttered view and greater situational visibility to the operator.
Another element of SBC's secret sauce is that it creates a platform across which much of an organization's design methods and elements can be standardized, regardless of whether the processes at hand are continuous, batch or hybrid in nature. Better utilization of engineering resources—whether internal or external to the organization—is a key deliverable. Improvements in operator effectiveness, as measured by reductions in operator errors, increased attention to key performance indicators, and the consistent performance of true value-added activities also can be delivered with SBC.
And while using SBC may seem like a no-brainer, implementing it on a traditional DCS platform was anything but. The result often was an overly complex, monolithic beast that was difficult and costly to maintain. Until, that is, the development of object architectures and state-based control engines such as those in ABB's System 800xA.
Within the System 800xA architecture, objects can be applied from the lowest individual control element level (Control Modules) through increasing levels of complex objects (Equipment Modules and Unit Modules), creating a high degree of reuse and far-reaching corporate standards. State-engine control logic can be embedded directly inside these objects.
All of this makes delivering on the promise of SBC easier and more cost effective than ever before.