Representative End User Clients
Representative Automation Clients
Representative Software Clients
Virtualized edge/cloud automation architectures will be the topic of a session at the ARC European Industry Forum in Barcelona on May 4-6, 2026. For now, let’s look back at the precursor to the virtual PLC and try to understand why it never really took off.
Why the Soft PLC Fell Short
Introduced in 1995, the concept of the soft PLC once promised to revolutionize industrial automation. Envisioned as a flexible, software-based alternative to traditional hardware PLCs, it was ahead of its time. Yet, despite its potential, the soft PLC never managed to gain widespread traction. Today, the virtual PLC is emerging as its successor, but will it be able to overcome the hurdles that held back its predecessor?
The soft PLC’s main advantage was its ability to run on a standard PC, alongside other machine control and data collection software However, the industrial landscape of the mid-1990s was not ready. Most plants relied on offline-configured operator terminals, many still using cathode ray tube displays. Visualization software was just beginning to gain popularity, but there was little consensus on interface standards. Keypad terminals were considered safer than touch screens, and the idea of using a PC mouse in a factory was met with skepticism.
Another major barrier was the lack of IT-trained operators. When a machine failed, maintenance teams preferred to swap out hardware modules rather than troubleshoot software problems on a Windows desktop. This hands-on approach was familiar and effective, thus making the transition to software-based control systems unattractive.
Virtually controlled production in Audi body shop @Audi AG
The Rise of Industry Software
Fast forward 30 years, and the automation landscape has transformed. Today, software plays a central role in industrial solutions and a new generation of operators and maintenance personnel is comfortable with digital tools. AI-driven engineering and diagnostics simplify complex tasks, allowing humans to focus on higher-level decision-making.
In the 1990s, machine builders tried to consolidate all automation tasks within the PLC. Suppliers added programming options like structured text to the controllers, as demands for data processing and analytics grew. However, PLCs were never designed for such complexity, resulting in cumbersome workflows. The solution was to pair an industrial PC (IPC) with the controller - delegating visualization and data processing to the IPC, while the PLC handled core control functions.
What Makes the Virtual PLC Different?
Unlike the standalone soft PLC, the virtual one is designed for large-scale deployments, managing fleets of dozens or hundreds of PLCs. For years, manufacturers have struggled with the costs and challenges of maintaining hardware, firmware, and program versions across multiple devices. Cross-vendor, version control tools were limited and often failed to cover all aspects of automation, including visualization programs and configuration files.
The IT sector addressed these issues long ago by standardizing hardware and networking, shifting the focus to software management. The virtual PLC applies this philosophy to industrial automation, turning the controller into a software asset that can be centrally managed using familiar IT tools. This approach promises greater efficiency and scalability, with fewer personnel required for oversight. The operational technology (OT) world is now learning to appreciate how compelling this argument is.
Building the Right Foundation
Successful software management depends on a robust IT architecture. Commercial enterprises have largely moved their software assets to public or private clouds, reducing the need for local hardware maintenance. But for manufacturers, the decision to adopt cloud models for critical processes—such as machine control—remains complex.
While public clouds are suitable for enterprise applications like ERP and website management, critical plant operations often favor private clouds. These single-tenant environments can be hosted on-premise or by third-party providers, offering greater control and security. For many manufacturers, an on-premise private cloud, sometimes called a “plant cloud” or “plant server”, is the preferred solution.
To deploy virtual PLCs, manufacturers must establish environments that leverage modern IT technologies while addressing specific OT requirements. Many industrial companies lack in-house expertise for this transition and rely on external consulting partners. As the boundaries between IT and OT blur, consultancies are hiring personnel with specialized manufacturing knowledge to support these migrations.
Conclusion
The virtual PLC represents a new chapter in industrial automation, building on lessons learned from the soft PLC’s shortcomings. By embracing IT-driven architectures and centralized software management, manufacturers can unlock new efficiencies and capabilities. The question remains: will the virtual PLC fulfill its promise and reshape the future of automation, or will it face challenges similar to those that doomed its predecessor? Only time will tell.