Updating process control systems

When legacy control systems are replaced with new technology there is a great opportunity to benefit from modern systems and advanced technology.

By Alex Marcy June 30, 2016

Updating a legacy system with new software is a valid option, but it leaves the advantages of new technology on the table. A control system upgrade should be a time to modernize and streamline to get the most value out of the investment.

Distributed control systems (DCSs), programmable logic controller (PLC), and human-machine interface (HMI) -based control systems have been around for a few decades. What was once cutting-edge technology has now been adapted for today’s mobile and information-centric world. Software development practices like object-oriented programming have been integrated into many platforms, and the opportunity for integration into systems outside of the plant floor are almost too numerous to mention. There are many advantages available by upgrading a process control system. 

Control system upgrade security concerns

One of the most important aspects of a control system upgrade is to take advantage of the latest security technology available. In today’s connected world, security through obscurity is no longer a valid approach to ensuring a control system is safe from malicious access. One way to see the impacts of security vulnerabilities is to read some of the alerts from the Industrial Control Systems Cyber Emergency Response Team (ICS-CERT). The ICS-CERT reports detailed security vulnerabilities with control system software and hardware from many vendors and the ways people have been able to maliciously access control systems with varying results.

As technology ages, as in the case of legacy DCS, PLC, and HMI systems, the chance of a cyber attack increases as security flaws are exposed. This is one reason to maintain software updates throughout the life of the system and consider upgrades to new versions when systems reach the end of their support lifecycles.

Security becomes even more important to consider as control systems are integrated with other software and databases across an organization and are accessible from outside of the facility. This includes not only the control system itself, but all of the support systems required, including operating systems, firewalls, and operational security throughout an organization. 

Optimizing with object-oriented programming

One of the advances with the most impact for control system technology is the use of object-oriented programming. This concept is relatively simple, yet extremely powerful.

Imagine developing a control system in the early 2000s. Given a process with hundreds of pieces of nearly identical equipment, it would take time to copy, paste, rename tags, and test each piece of equipment on an HMI screen. If new instrumentation were added down the road, the equipment would have to go through the development process again.

With an object-oriented environment, one template can be created for each piece of equipment for both the operator interface and logic in the process controller. Tagging can be handled dynamically, requiring only one or two changes to create a new instance of a piece of equipment, and each device will function identically. If similar pieces of equipment have different options these can be handled in the template, no longer requiring multiple copies of the same graphics and code. Making a change down the road requires making the changes at the template, which are then propagated throughout the application. This can save a huge amount of time for development/testing and ongoing maintenance. 

Integration with other systems

Integration with other business systems is another advancement that can be leveraged by installing modern systems.

Process scheduling, downtime tracking, computerized maintenance management, and statistical process control are a few of the integrations that can be used to easily improve overall performance of a system while giving full visibility into manufacturing operations.

Many vendors offer these types of integrations out-of-the-box, requiring a relatively small amount of work to move data between systems. While similar integrations might be possible with legacy systems, they would require a large amount of time and energy, taking valuable resources from the rest of the organization.

As technology advances it offers more functionality, security, and can be easier to implement. Simply replacing an aging system with an updated version of its underlying components can leave a lot of these benefits on the table.

As technology advancements increase, it makes sense to work with vendors and distributors to understand the latest offerings and how they can be put to good use in any facility. It never hurts to understand the migration path forward to a new platform and what features and functionality will be the most beneficial when doing an upgrade.

While migration is an option, taking advantage of a modernization will usually provide an enhanced process control system that can last for many years to come.

Alex Marcy, P.E., is the owner and president of Corso Systems, a system integration firm, headquartered in Chicago, Ill. Corso Systems is a CFE Media content partner. Edited by Emily Guenther, associate content manager, CFE Media, Control Engineering, eguenther@cfemedia.com.


Key Concepts

  • Using more modern control systems and technology provides benefits.
  • Upgrading control systems may reduce the risk of security threats.
  • Modern technology can simplify processes.

Consider this

When would it be more beneficial for a facility to install a software upgrade to an existing system or consider a new process control system?