The future of PLCs: Trends in open programming and hybrid control

The world of industrial automation is undergoing a profound transformation. For decades, Programmable Logic Controllers (PLCs) have been the backbone of factory automation, process control, and critical infrastructure. Traditionally, PLCs were closed, proprietary systems-robust and reliable, but often inflexible and difficult to integrate with modern IT and OT environments. Today, a new era is emerging, driven by open programming standards, hybrid control platforms, and the convergence of IT and OT. This deep dive explores how open standards like CODESYS, Python, and C/C++ - along with hybrid hardware/software architectures - are reshaping the landscape for automation professionals, offering unprecedented flexibility, integration, and future-proofing.

The rise of open programming standards

From proprietary to open: why it matters

Historically, PLC programming was dominated by vendor-specific languages and tools. This created vendor lock-in, limited innovation, and made it challenging to adapt to new requirements or integrate with third-party systems. The adoption of open standards, most notably IEC 61131-3 and its associated languages, has been a game-changer. CODESYS, an independent, hardware-agnostic development environment, has become the de facto standard for open PLC programming.

CODESYS: The universal language of automation

CODESYS enables engineers to program in their preferred IEC 61131-3 language, but its openness goes further. It supports integration with high-level languages such as Python and C/C++, enabling advanced algorithms, data processing, and connectivity features previously out of reach for traditional PLCs. This means automation professionals can leverage a global ecosystem of libraries, tools, and community support to accelerate development and reduce costs.

Python and C/C++: Bridging IT and OT

The integration of Python and C/C++ into PLC environments is a significant trend. Python, with its simplicity and vast library ecosystem, is ideal for data analytics, machine learning, and rapid prototyping. C/C++ offers high performance and access to low-level system resources. By supporting these languages, modern PLCs become true edge computing platforms, capable of running complex applications, interfacing with cloud services, and enabling Industrial IoT (IIoT) use cases.

Hybrid control platforms: The best of both worlds

What Is a hybrid control platform?

A hybrid control platform combines the deterministic, real-time control of a traditional PLC with the flexibility and computational power of an industrial PC (IPC) or embedded controller. These platforms often run a real-time operating system (RTOS) alongside a general-purpose OS like Linux, enabling both hard real-time control and advanced data processing on the same hardware.

Benefits of hybrid platforms

• Flexibility: Users can deploy standard PLC logic, custom CODESYS applications, and high-level scripts side by side.
  
  
• Integration: Native support for industrial protocols (EtherCAT, PROFINET, Modbus, OPC UA, CANopen, etc.) and IT standards (REST, MQTT, SQL, etc.) enables seamless integration with both legacy equipment and modern digital infrastructure.
  
  
• Scalability: Hybrid platforms can scale from small, embedded controllers to large, distributed automation systems, supporting everything from simple machine control to complex process automation and energy management.
  
  
• Future-proofing: Open architectures and modular hardware/software design ensure that systems can evolve with changing requirements, new technologies, and cybersecurity threats.

Real-world applications and use cases

Energy and hybrid power management

Hybrid controllers like the DEIF iE 250 and iE 350 are designed to manage complex energy systems, integrating diesel generators, solar PV, battery storage, and grid connections. These platforms leverage open programming (CODESYS, Python) to implement custom control strategies, optimise energy flows, and interface with a wide range of inverters and third-party devices. The result is a flexible, future-proof solution that can adapt to evolving energy landscapes and regulatory requirements.

Marine and offshore automation

In marine applications, hybrid PLC platforms enable advanced power management, vessel automation, and integration with navigation and safety systems. Open programming allows shipbuilders and system integrators to customise solutions for specific vessel types, operational profiles, and compliance needs, while maintaining the reliability and certification required for critical operations.

Industrial IoT and edge computing

Modern PLCs are increasingly deployed as edge devices that collect, process, and analyse data close to the source. By supporting open programming and hybrid architectures, these controllers can run machine learning models, perform predictive maintenance, and securely transmit data to cloud platforms, enabling smarter, more responsive industrial systems.

Key trends shaping the future

1. 1. Convergence of IT and OT
   
   The line between Information Technology (IT) and Operational Technology (OT) is blurring. Open programming and hybrid platforms enable seamless data exchange, unified management, and integrated cybersecurity across the entire automation stack. This convergence is essential for Industry 4.0, smart manufacturing, and digital transformation initiatives.
   
   
2. 2. Vendor-neutral ecosystems
   
   Open standards reduce vendor lock-in and foster a competitive, innovative ecosystem. Users can choose best-in-class hardware and software components, integrate third-party solutions, and avoid costly migrations or rewrites when upgrading systems.
   
   
3. 3. Cybersecurity by design
   
   As PLCs become more connected, cybersecurity is paramount. Modern platforms incorporate secure boot, signed firmware, certificate-based authentication, and regular security updates. Open-source components are carefully vetted, and lifecycle management ensures systems remain secure and compliant over time.
   
   
4. 4. Modular, scalable architectures
   
   Hybrid control platforms are designed for modularity—both in hardware (slot-in I/O, expansion modules) and software (function blocks, libraries, APIs). This allows users to build systems that precisely match their needs, and to expand or reconfigure as requirements change.
   
   
5. 5. Advanced analytics and AI at the edge
   
   With support for Python and C/C++, PLCs can now run advanced analytics, machine learning, and AI algorithms directly at the edge. This enables real-time decision-making, reduces latency, and minimises the need for costly data transmission to central servers.

Benefits for automation professionals

Flexibility: Open programming empowers engineers to implement custom logic, integrate new technologies, and respond quickly to changing requirements. Hybrid platforms support a wide range of applications, from simple relay logic to complex process automation and energy management.

Integration: Native support for industrial and IT protocols ensures seamless connectivity across the entire automation landscape. Users can integrate legacy equipment, modern sensors, cloud services, and enterprise systems without costly gateways or middleware.

Future-proofing: Open, modular architectures and active lifecycle management ensure that automation systems can evolve with new technologies, regulatory changes, and cybersecurity threats. This protects investments and reduces total cost of ownership.

Conclusion: Embracing the future

The future of PLCs is open, hybrid, and intelligent. By embracing open programming standards like CODESYS, Python, and C/C++, and adopting hybrid control platforms, automation professionals can unlock new levels of flexibility, integration, and future-proofing. Whether managing complex energy systems, automating critical infrastructure, or enabling smart manufacturing, the next generation of PLCs is ready to meet the challenges of Industry 4.0 and beyond.