Because it performs as a single integrated system, it features both high- and low-level integration of control and safety system components without compromising the performance of either. Further, taken separately, the ABB High Integrity safety instrumented system can be deployed with control systems from other suppliers either in standalone mode or with top-end integration.
The 800xA platform with 800xA High Integrity safety system functionality features common engineering and visualization tools for both process control and safety functions, boosting both engineering efficiency and operator effectiveness. The integrated approach also allows functions such as information management, asset management and production management to be fully leveraged across the entire automation system. The ABB approach even enables certified safety controllers that can run both process control and safety applications simultaneously—a feature that in some high speed applications can both optimize safety and control performance while reducing capital and hardware needs.
Robust Safety with Lower Project Costs
While the safety components of an integrated environment must adhere to the design, testing, validation and certification processes applicable to safety systems, an integrated approach to control and safety functions can cut capital costs by eliminating some redundant aspects of independent safety and control networks. A smaller system footprint, a unified engineering environment and elimination of a custom interface between the control and safety systems also contribute to project savings.
With the ABB System 800xA, users can decide how much separation to maintain between safety and process control. Even if fully segregated systems are chosen, many residual benefits apply. For example, potential sources of common cause failure already have been analyzed and minimized during the design phase by the development team and independently reviewed by the assessor during the certification of the product. This effectively makes the system smarter and safer from the day it's turned on.
Further, integrated testing is performed during the design validation and verification test, which includes network security as part of the test protocol. Version control, compatibility and interoperability testing are included in the release procedure. The result is a set of common best practices resulting in implementation of an integrated safety system that costs less, works better and even extends the capabilities of the process control system.
In the case of ABB's System 800xA, access control and security are built into the system as an off-the-shelf set of features, including user privileges, user action validation and a common audit trail. It also includes such extended capabilities as write protection, SIL access control and authorization, bypass management, and override mechanisms. The result is a robust set of security controls that apply uniformly across all systems.
As safety systems get replaced, or as new projects are developed, there is an opportunity to decide how you want to address safety in your operation—not just today but for years into the future. Integrated safety can deliver significant performance and cost benefits not only during the project phase, but during the entire operating life of the system. And that's the safety system lifecycle phase that we'll discuss in the final article in this series: Once your safety system is running at peak performance, how can you keep performance from degrading over the next 20 years it's likely to be in use?