A new software standard is updating operational technology for the demands of contemporary engineering.
The assets that power the world’s critical infrastructure in sectors such as mining, water, manufacturing, and energy rely on operational technology, or OT, systems for monitoring and control.
Although OT engineering underpins these processes, the international standard used for their software architecture is more than 30 years old. The standard has been updated several times, but its core design remains largely unchanged and is based on tightly coupled, cycle-based control logic.
Now, the industry demands greater flexibility, interoperability, and OT/IT integration.
IEC 61499 is the solution to that demand: a newer, flexible and more powerful standard for the OT world that is suited to incremental migration driven by initial, low-risk actions that demonstrate immediate value for adopters before they commit to deep architectural change.
A core challenge of the IEC 61131-3 standard is that it tightly couples software and hardware, which made it challenging for operators looking to use control software as a modular, event-driven service platform rather than a fixed, proprietary program.
Because this engineered logic program is not easily portable, extensive re-engineering is often required to change an OT system’s hardware or integrate new components. System upgrades become high-risk and infrequent, and control systems cannot easily adopt modern IT architectures.
“Under the old standard, migrating or upgrading OT hardware – especially across different vendors – often meant rewriting, re-testing and re-validating control logic in a completely new software environment. These limited upgrade paths significantly increased engineering effort and cost for customers,” said Ash Khan, Technical Pre-Sales Engineer at Schneider Electric’s Centre of Excellence, Pacific.
“With IEC 61499, your engineering investment is protected thanks to the standard’s portability. It enables users to upgrade or switch hardware at any time, without needing to modify the programming environment or rewrite source code, offering true flexibility and long-term value.”
Responding to today’s demands
The new standard, IEC 61499, is an evolution from IEC 61131-3. Although it was introduced in 2005, its possibilities are increasingly being embraced by industries looking for application portability and interoperability and wanting to bring information technology and OT processes closer together.
“A lot of that comes down to the fact that, until recently, the technology hasn’t been there to be able to leverage it fully. But now we’re in a place where things like Ethernet-based comms is a standard. Twenty years ago, it wasn’t; we were very much on serial comms and other fieldbus protocols.”
Another advantage offered by IEC 61499 is that it has been designed to be event-driven rather than cycle-driven. Cyclic execution models such as IEC 61131-3 require more processing resources and are difficult to scale and are often complex to integrate within OT and IT.
“Even when a piece of code does not need to run, IEC 61131-3 still scans and processes it, which consumes unnecessary processing power,” said Khan.
“In contrast, IEC 61499 remains idle until an event occurs. It then executes only the relevant logic before returning to an idle state. This makes it inherently more efficient and enhances the accuracy of time stamping when events take place. Its event-driven nature also aligns closely with IT protocols like MQTT and IT systems, which are similarly event-driven.”
Khan said that investing in the new standard can pay off long after its introduction and save OT managers from having to solve many unanticipated problems.
“IEC 61499 offers long-term value and continuity, especially when it is time to replace obsolete hardware,” said Khan.
“Traditionally, customers investing in automation technology were looking at a 10 to 15-year lifecycle. But when it came time to upgrade, they had to re-engineer everything from scratch due to software and hardware lock-in.
“With IEC 61499, the engineering effort is portable. Even if you change your hardware, you retain everything you have already built.”
An app store for industrial automation
According to Brodie, one of the greatest strengths of IEC 61499 is in its ability to handle distributed control systems and applications.
“When it was created, the standard focused on that from a pure Internet of Things perspective,” he said.
“But evolutions in the IT space have started to blur the boundaries between what is an IT application and an OT application, and how these different technologies need to operate together.”
UniversalAutomation.Org (UAO) is a consortium of automation users, technology vendors, academics, institutions and startups helping to drive the adoption of IEC 61499. An independent and non-for-profit organisation, UAO’s mission is to drive the next generation of automation standards to help create future-ready systems.
The result is something like an app store for industrial automation; Brodie compares it to Google’s open-source Android phone operating system.
“With UAO, the runtime is universal. It’s given to vendors who can then add their own functionality and features on top of that to provide their own unique value propositions for why you should use their products,” he said.
“But then the build-time environments – the engineering environments – can still deploy applications to all of these different endpoint devices from different vendors.”
That means OT managers can choose the best hardware and software combination for the task at hand. One example Brodie gives is the freedom to choose the best hardware for an application while still using the same engineering tools to program the hardware.
“They might choose a traditional PLC, which uses UAO runtime for a certain application, but they can also choose an industrial PC for other applications,” Khan said.
“It really opens the door for customers to make a choice based on the specific application.”
Although IEC 61499 offers powerful possibilities, even initial, low-risk actions such as edge analytics of OT data, providing insights from combined data from control systems and integration with IT and OT systems.
And OT managers wanting to realise immediate value through low-risk, phased implementation can turn to Schneider Electric as a trusted partner throughout the transition.
“We have our Centre of Excellence team – dedicated application engineers and pre-sales engineers for this technology in Australia and New Zealand.” Khan said.
“Our team works closely with customers to understand their challenges, offer guidance on addressing both current and future needs, and develop solutions that deliver measurable business value.
“Secondly, we’ve got training that we can deliver locally as well as through our global partners. We can also offer specific tailored training to meet the requirements of what our customers need out of their project.”
The next steps
Migration is often perceived as a disruptive, large-scale exercise involving a complete rip and replace of existing systems. However, transitioning to IEC 61499 can be approached incrementally. As a first step, IEC 61499 can be introduced as a value-adding layer alongside existing control systems and operations, without requiring any changes to the current infrastructure.
This approach allows users to familiarise themselves with the new environment while enhancing operations. In the initial monitoring phase, IEC 61499 can deliver value through capabilities such as protocol gateways, microservices, and access to process data that can be used to generate actionable insights for operators and control systems.
Users can continue to develop and refine their applications in monitor mode, and gradually transition them into control mode as existing systems reach end of life. This incremental migration strategy enables users to build confidence at their own pace, deliver ongoing value, and modernise their operations with a future-ready automation ecosystem.