Process manufacturing companies face ever increasing pressure to get new products to market quickly. Frequently, however, making a new product requires extensive reprogramming. With an open, object-oriented automation platform, plant operators are able to significantly reduce the time and cost involved in making the necessary changes.
Process control engineers are under pressure to adapt mechanical and software systems to changing production volumes and new products and recipes in a shorter and shorter time. It's the only way process manufacturing companies can keep pace with the demands of their market.
Their aging process control systems, however, generally consist of hardware and software components from various manufacturers. On top of that, the changes often have to be made without interrupting operation and sometimes require contributions from engineers in different locations – a challenging situation for everyone involved.
"Object-oriented engineering has proven to be an effective tool for mastering these challenges," says Martin Reichinger, who heads B&R's process automation business unit. This approach allows you to design flexible systems with a low error rate.
In object-oriented software engineering, measurement and control elements such as sensors are each assigned a unique identification number, or tag. "Each data point only has to be defined once and is then available throughout the entire system," explains Reichinger. If the tag of a measurement and control element is changed, the change is automatically applied in all the core components of the process control system – including the alarm, graphics, reporting and trend systems.
Since each function is encapsulated in an object or module, changes to a function only have to be made in one location and are applied everywhere in the system. Not only does this speed up the programming process for new developments, but also for any changes that are made to it down the road.
The B&R APROL automation platform is based on the concept of object-oriented engineering. The Process Automation Library (PAL) contains more than 100 standardized control modules that provide all the most important functions of a process control system, such as version management, security login, audit trail, change control and much more. The library also includes modules for advanced process control, model predictive control, performance monitoring, condition monitoring and asset monitoring. All of these functions are fully programmed, field tested and ready to simply be added in and configured. This saves developers valuable time.
"When it comes to software blocks, quality is just as important to us as functionality," emphasizes Reichinger. New and modified blocks are subjected to strict quality control in the form of unit tests, integration tests and field tests. Only when they have successfully completed all these steps are they ready to be included in an APROL release.
When software is updated at a plant, the integrated DownloadManager ensures that system consistency is maintained even while updating the individual controllers, operator stations and runtime servers.
Users are also able to incorporate their own technological know-how by modifying existing control modules or developing entirely new ones. "A USB flash drive with encrypted data transmission ensures copy protection," says Reichinger. This prevents unauthorized access to the intellectual property these custom modules contain.
Customer-specific blocks are kept in separate user libraries. The libraries also include GUI faceplates, as well as all alarm and trend definitions. "Graphic modules and solution blocks can be created simply via drag-and-drop," adds Reichinger, highlighting the efficiency of library-based engineering.
Larger production plants typically have numerous engineers collaborating on a project. APROL is organized so that the configuration data for all objects is stored on a central engineering server – one of the core components of the automation platform. There's no need to worry about access conflicts, because as soon as one engineer begins editing a certain part of the project, all others are restricted to read access only.
APROL also allows engineers to work on a remote computer instead of the engineering server. Known as offline engineering, this allows parts of the project to be developed in China or India while the project manager coordinates things from Germany. "A well-structured workflow ensures consistency, even when individual tasks are delegated," says Reichinger.
When you get to the heat of commissioning, you can easily have 20 or more engineers on site. "If they're all working in parallel, conflict handling becomes essential," says Reichinger, "and that's another challenge that can be mastered with the APROL engineering server." The integrated change control feature, for example, documents all the changes made to each part of the project. A convenient version management feature makes it possible to revert parts of the project to an earlier version, which speeds up development and commissioning considerably.
In addition to providing highly efficient engineering, APROL is also easy to link with existing process control and SCADA systems. Supervisory-level communication is handled via fieldbus controllers and gateway servers that are also able to serve as OPC UA clients and servers.
"The platform is open to all the major fieldbus technologies," explains Reichinger, "and with integrated FDT/DTM technology and HART modems integrated in AI/AO modules, APROL creates a completely uniform automation system from the field level to the management level."
High availability with standard hardware
Developing software for high-availability systems is notoriously complicated and expensive. "Not with APROL," says Martin Reichinger. With B&R's process control system, the required controller redundancy can be implemented inexpensively, even when added to an existing system.
In addition to the primary process controller, there is a second, inactive controller that stays synchronized and is updated cyclically with process data. If the primary controller fails, the previously inactive controller takes over within milliseconds in a completely bumpless transition.
"What's special about this solution is that it relies exclusively on standard B&R hardware," notes Reichinger. Even the programming and project development are the same as with standard hardware. "That opens up the possibility of cost-effective controller redundancy even in smaller operations."
Author: Carmen Klingler-Deiseroth, freelance journalist
Business Manager - Process Automation, B&R
"Object-oriented engineering is optimal for flexible systems."