The highly complex, dynamic and multi-faceted operational nature of tank farms and petroleum product terminals, combined with the environmental and price sensitivity of the products being handled, requires a special breed of automation systems.
A good terminal automation system (TAS) must combine the powerful IT-enabled application, information processing and transactional capabilities of the back-office, enterprise-level business systems, with the real-time performance, determinism, nonstop availability, and specialized physical packaging of industrial process control and supervisory control and data acquisition (SCADA) systems. It must be:
Open enough to interface with any number of field systems, back-office applications and/or data exchanges
Secure enough to prevent unauthorized system access and guard valuable customer information
Flexible enough to smoothly adapt to new product and additive mixes, facility expansions and constantly evolving governmental regulation, all without a hiccup.
In short, a good terminal automation system has to wear many different hats.
In this environment, standards-based interoperability is a key requirement. Why? Because while distributed control systems (DCSs), SCADA systems, programmable logic controllers (PLCs), safety instrumented systems (SISs) and manufacturing execution systems (MESs) all have relatively well-defined functional boundaries; a terminal automation system (TAS) typically encompasses a combination of sub-systems, applications, and functionalities that can include all of the above and many others.
To avoid creating inefficient functional silos, the multiple subsystems must be woven together to create a unified terminal automation system. Ideally, a TAS should have centralized configuration and system management, a common human machine interface, common communications, common database, and common alarming and reporting structures. ARC clients (and others) will recognize that this is consistent with the vision for any collaborative process automation system (CPAS).
In cases where the majority of functionalities are coming from the same vendor, these might not be major issues, since that vendor will assume responsibility for integrating the various functionalities. However, in other cases, interoperability based on established industry standards assumes paramount importance. This includes situations where the owner/operator (or a systems integrator) creates a TAS, using best-in-class functional components from different vendors, or where subsystems from different vendors need to be integrated into a larger, primarily single-vendor TAS. Industry standards can also simplify interoperability between the refinery and tank farm automation systems (if different), between automation systems installed at different terminals, between the TAS and corporate back-office systems and across the supply chain.
Standards and protocols.
A wide variety of networking and communications, software, control and hardware standards applies to petroleum product terminal operations. These include international standards, such as those developed and supported by IEC, ISO, and IEEE; national standards such as those developed and supported by ISA, ANSI, NAMUR, BSI and JSA; information technology (IT) standards, such as those developed and supported by W3C; and industry-specific standards, such as those developed and supported by the American Petroleum Institute. The good news here is that, increasingly, national and international standards organizations are collaborating to unify (or at least harmonize) their standardization efforts.
One example would be the ANSI/ISA-18.2-2009 alarm management standard, which defines layers of protection to help prevent hazards such as occurred at both the BP Texas City Refinery and Buncefield Oil Depot in the UK in 2005. Other examples include:
IEC 61511/ISA 84 process safety standards
IEC 61512/ISA 88 batch control standards
IEC 62264/ISA 95 enterprise to control system standards
IEC 62443/ISA 99 control systems security standards
Where established international standards are not available, a combination of industry standards (such as OPC, FOUNDATION fieldbus, Profibus and HART) and vendor-de facto standards (such as Microsofts .NET application development environment and SAPs NetWeaver integration platform) can also enhance interoperability between different vendors systems, software applications and products.
In short, standards make it easier to create, manage and support a unified TAS environment and simplify interoperability with other automation and information systems at both the plant and enterprise levels.
ARC has published a series of reports and market studies on both collaborative process automation systems and terminal automation systems. For more information, HP readers can visit www.arcweb.com or send an e-mail message to email@example.com. HP
|The author |
Paul Miller is a senior editor/analyst at ARC Advisory Group and has 25 years of experience in the industrial automation industry. He has published numerous articles in industry trade publications. Mr. Miller follows both the terminal automation and water/wastewater sectors for ARC. For more information, readers can contact the author at firstname.lastname@example.org.