By Jeremy Benjamin | 19th September 2025 | SCADA, Building Management Systems | Data Centres
I was at the DCD Connect event in London this week and was kindly invited to the Schneider Electric briefing on the latest trends and development in the Data Centre space.
I was especially intrigued by the presentation given by Steven Brown, the Vice President for Digital Energy Solutions at Schneider Electric. Which has compelled me to write this article.
Steven presented a topic and shared his ideas about something, or some things rather, that I have been harping on about for the last 10 years or so…
Firstly, the importance of early engagement between system control design teams and their counterparts in the mechanical and electrical design departments. In my opinion this is a no brainer, and we should all just get on with it, which is why I wasn’t planning to focus on this too much here. Only to say that the concept of de-coupling naming conventions in design documentation to those within the control system in order to simplify commissioning and integration processes was great.
And secondly, the shift from traditional Building Management (BMS) systems over to Supervisory Control and Data Acquisition (SCADA) systems and architectures which have traditionally been a staple of large, complex and safety critical infrastructure and industries such as nuclear, oil & gas, rail and water. Having worked in all these industries to a greater or lesser extent over the years, I am deeply passionate about this topic as I see the clear benefits and opportunities SCADA systems have by utilising Programable Logic Controllers (PLCs) and Remote Terminal Units (RTUs) within Data Centres.
As buildings, utilities, and infrastructure systems become more complex, the need for reliable, scalable, and secure control solutions is increasing.
PLCs (industrial automation) and BMS (facilities management) have traditionally served different domains and needs. However, if I use Data Centres as a prime example, the evolving design, use and needs from these buildings is allowing the advantages of PLC/SCADA to highlight the inevitable convergence of these two technologies.
We already know that BMS systems with their reliance on proprietary protocols have traditionally performed a role within the building services and facilities management space. And that SCADA systems are used to control and oversee complex industrial applications and processes. The convergence of these two domains raises an important question: can PLC-based SCADA solutions deliver greater long-term benefits than conventional BMS in building environments? Let’s explore that question by comparing their technical, economic, and operational characteristics.
Reliability & Robustness
PLCs which focus on rapid, cyclic on-prem executions complemented by RTUs which provide more event-driven processing capabilities where remote telemetry is required, are engineered to function under extreme conditions, often with extended lifespans exceeding 20 years. Their fault tolerance, hot-swappable modules, and redundancy mechanisms ensure minimal downtime. By contrast, BMS controllers designed for commercial environments often have shorter lifecycles and may lack the redundancy features required.
Scalability & Flexibility
SCADA systems scale seamlessly across campuses, cities, and utilities. They are protocol-agnostic and capable of integrating new systems with minimal disruption. BMS solutions typically scale less effectively, constrained by proprietary protocols and vendor ecosystems. For multi-site organizations or adaptive reuse of buildings, PLC-based architectures offer clear flexibility advantages.
Data & Analytics
SCADA platforms natively include historian databases, enabling high-resolution data capture and long-term trending. This capability facilitates predictive maintenance, root-cause analysis, and AI integration. BMS solutions often provide limited data logging, with sampling intervals and storage capacity restricted by design, reducing their utility for advanced analytics
Interoperability & Standards
PLC-based systems support a broad range of open industrial protocols such as Modbus, OPC UA, and Profibus. This makes them highly interoperable with third-party devices and emerging IoT technologies. BMS platforms, although aligned with standards like BACnet or LonWorks, can still suffer from vendor-specific implementations that inhibit full interoperability.
Cybersecurity
Industrial SCADA systems are increasingly aligned with standards such as IEC 62443 and NERC CIP, embedding defense-in-depth strategies. By contrast, many BMS solutions have historically prioritized ease of access over security, leaving them vulnerable to intrusion. As cyber threats targeting critical infrastructure grow, the hardened nature of SCADA represents a decisive advantage.
Cost & Lifecycle Value
While PLC/SCADA systems demand higher initial investment, their robustness, longevity, and lower downtime costs often result in lower total cost of ownership (TCO). BMS platforms may appear cost-effective in the short term but can incur higher lifecycle expenses due to replacement cycles, system integration challenges, and vendor lock-in.
The boundaries between BMS and SCADA are blurring as buildings become smarter, more connected, and more data-driven. Emerging technologies such as digital twins, AI-powered optimization, and IoT sensors are increasingly reliant on high-quality, high-frequency data collection—an area where SCADA platforms excel. Meanwhile, IT/OT convergence is driving demand for secure, integrated systems that can bridge the gap between operational infrastructure and enterprise IT networks. Hybrid architectures, where PLC/SCADA systems manage mission-critical operations while BMS platforms handle comfort and user interfaces, are likely to become common. This trend underscores a future where industrial automation principles play a central role in the evolution of smart buildings.