Several trends have already impacted the distributed control system (DCS) market and are likely to continue over the next few years. These include both product- and technology-related trends and general industry trends.
More intelligent I/O
The DCS input/output (I/O) subsystem is responsible for inputting hundreds or often thousands of different process measurements and other inputs into the system, and outputting control signals to a large number of valves, actuators, motors and other plant final-control elements. I/O represents one of the most significant parts of the DCS. Traditionally, I/O is a significant cost element. However, DCS suppliers are working to reduce both the cost and complexity of their I/O systems by incorporating more intelligence and programmability into the devices.
Shift in I/O type
Fifteen years ago, the traditional process analog input came from a sensor producing a 4-mA to 20-mA analog signal, and the typical analog output was a 4-mA to 20-mA signal. Discrete signals involved various combinations of voltages and currents. Each signal type had a dedicated type of circuit board for the individual signals.
Today, in a greenfield plant, most of the I/O supplied is on some type of bus network. Brownfield plants are also installing more bus I/O. However, with the large installed base of tra-ditional 4-mA to 20-mA I/O, the transition is very slow. Major expansions or revamps in brownfield plants consider bus I/O when the sensors and final control elements are also part of the project. There is also a growing trend to adding more wireless I/O and associated field devices, particularly for process and equipment monitoring applications.
Need for network consulting services
As the lines between automation and IT are blurring with increasing usage of commercial off-the-shelf (COTS) technology, the network infrastructure of the DCS and the network architecture for plant information are becoming increasingly more intertwined. End users now often rely on the expertise of suppliers for consulting to set up these networks in a safe and secure manner.
DCS suppliers started incorporated server virtualization a few years ago. Common uses of this technology include engineering development and simulation for training. Virtualization is not appropriate for all parts of the DCS. Sometimes, the dedicated hardware will perform a given task better than a virtual server. A good example is the real-time process controller in a DCS, where speed, determinism and high reliability are major design considerations for the operation and safety of the plant. Conversely, a virtual server performing many applications on one box can be a good choice for offline applications such as control configuration, simulation and training.
With more open and interoperable, largely COTS-based automation systems, cyber security is becoming more important as end users struggle with potential risks, both internal and external to the DCS. Most suppliers now address this threat with active programs, either inhouse or through partnerships. As part of a defense-in-depth cyber-security strategy, network fire walls and strategically placed switches are required to help prevent the propagation of external viruses and intrusions. Internal threats from disgruntled employees or other internal access points must be addressed with such things as USB locks and software to monitor internal automation system network activity. Furthermore, network maintenance practices that are common in the IT worldsuch as automatic software updates, anti-virus updates and bug fixesmust be modified for the mission-critical, 24/7 industrial environments in which DCSs typically operate.
Just as people today find it hard to live without their smartphones in their daily lives, increasingly, process operators and production supervisors are relying on the ability to access data anywhere, anytime to do their job functions. DCS suppliers address this trend by supplying tablet technology for roving operators and smartphones for alerts and condition monitoring. This trend toward increasing mobility will grow in importance in the future.
There has been much talk in the industry about developments underway to move selected DCS applications to the cloud, a reference to moving applications to remote, Internet (public) or intranet (private) servers. However, the control-automation industry is very conservative by nature, and, presently, this trend is just talk. ARC believes that, ultimately, selected DCS applications will migrate to private and, in some cases, even public clouds. For now, end users are wary. HP
|The author |
||Barry Young has over 25 years of professional experience in the process control and industrial automation industry. Prior to joining ARC, he served as a project manager for New England Controls, where he helped design and implement automation solutions for a variety of high-profile clients in the life sciences, utility, pulp and paper and other industries. Prior to New England Controls, he handled a variety of responsibilities within the global Invensys/Foxboro Company organization. Mr. Young has a BS degree in management engineering from Worcester Polytechnic Institute, and has completed MBA courses at Bryant University. He is a member of the Project Management Institute. |