TwinCAT PLC++: The Next Generation of PC-Based PLC Programming from Beckhoff
If you have spent time working with Beckhoff automation systems, you are already familiar with TwinCAT, the software that holds everything together. From simple control projects to multi-axis servo systems, TwinCAT has been one of the leading platforms for PC-based control since the mid-1990s. Now, after many years, Beckhoff has brought TwinCAT into the AI age. They re-wrote the old compiler, rebuilt the core runtime from scratch, and introduced to us TwinCAT PLC++.
TwinCAT PLC++ features a full redesign of the PLC layer within TwinCAT, leveraging modern software engineering techniques rarely used in industrial control applications. This release is significant for engineers, OEMs, and integrators when choosing their future control stacks.
What Is TwinCAT PLC++ and How Does It Differ from TwinCAT 3?
TwinCAT 3, released in 2011, brought the Beckhoff ecosystem forward significantly from TwinCAT 2. TwinCAT 3 integrated Visual Studio & multi-core CPU support, C++ and MATLAB/Simulink programming alongside IEC 61131-3 languages, and a flexible architecture that let engineers mix PLC, motion control, and safety all within one environment. For many applications today, TwinCAT 3 remains standard, and it continues to be fully supported by Beckhoff after 15 years.
TwinCAT PLC++ adds a lot of features to the TwinCAT 3 ecosystem rather than replacing all of them outright. The biggest changes have come in two areas: the compiler and the runtime architecture.
The result is significant. The same control code that ran on TwinCAT 3 can be executed up to 1.5 times faster on TwinCAT PLC++ without any changes to the programming itself. When you enable compiler-level code optimization — (a technique familiar to C++ and Java developers) but fairly new to PLC — that code may now execute 3 times more rapidly compared to TwinCAT 3.
Pro Tip: Enabling full compiler optimization in TwinCAT PLC++ is the single biggest performance lever available. If your application is cycle-time sensitive, activate it early in development and benchmark performance against your existing TwinCAT 3 build.
What This Means for Hardware Selection and Machine Costs
The gains in potential performance from TwinCAT PLC++ may have an impact on your hardware budgets. If a machine your are developing previously required a mid-range Beckhoff PC — say a C6030 or C6040 — to meet cycle time requirements, the same application running on TwinCAT PLC++ may now meet your performance needs on a lower-spec platform. That means potential savings on IPC hardware per machine, which can up quickly when developing a large control system.
Vice versa, if you are using the same hardware, TwinCAT PLC++ could provide you with additional headroom for code execution. This spare capacity can be used to add functionality that was previously too “expensive” in terms of CPU compute — diagnostics, machine learning, additional safety logic, or tighter motion control may now be possible — all using the same physical controller.
For manufacturers or developers taking products to market, this is not a minor benefit. The ability to defer hardware upgrades or pack more capability into existing IPCs has a measurable impact on hardware costs and competitive status in the marketplace.
IEC 61131-3 4th Edition Compliance and Object-Oriented PLC Programming
A key feature of TwinCAT PLC++ is close compliance with IEC 61131-3, 4th edition. which provides true object oriented programming support for PLCs.
This means automation engineers working with Beckhoff can now write cleaner, more maintainable PLC code using true Object Oriented Programming. Function blocks can be provided with class structures. Private variables are actually private. Reusing code through inheritance is a real option rather than a workaround built on renaming hundreds or thousands of bits and parameters .
This matters quite a bit for larger development projects — packaging lines, multi-zone systems, or machinery with extensive recipe management — where organizing your code had sometimes been a pain point in older PLC platforms.
DevOps Integration: Git, CI/CD, and Automated Testing in TwinCAT PLC++
Also, TwinCAT PLC++ code now has built in confluence with development & operations workflows. Beckhoff’s philosophy appears to be: automation engineering should operate like software engineering. Continuous integration, continuous deployment, and automated quality assurance should be features built into the development pipeline.
TwinCAT 3 already offered source code management through integration with GIT. TwinCAT PLC++ takes this one step further by making engineering faster with automated test pipelines. Compilation times for your code are reduced, project load times are shorter, and the architecture is designed to support automated testing. You are able to run quality checks as part of a project, not only during the commissioning process.
For teams managing different variants of Beckhoff hardware or differences in software & firmware, this can make a positive difference. I remember when version control for PLC code didn’t exist. It was stored on a single engineer’s laptop and emailed as a ZIP file. TwinCAT PLC++ makes professional automation development accessible without requiring engineers to leave the TwinCAT environment.
TwinCAT CoAgent: AI-Assisted Engineering Embedded in TwinCAT PLC++
And as for bringing Beckhoff software into the AI age, TwinCAT PLC++ now comes with TwinCAT “CoAgent” built in. This is an AI copilot tool that generates PLC function blocks, suggests I/O changes, and helps the user with HMI creation using natural language inside of the software development environment.
CoAgent actively reads project structures to generate code suggestions that are “context aware”. Both cloud and on-premise LLM backends are supported for data-sensitive applications.
Migration from TwinCAT 3: Is It Difficult?
TwinCAT PLC++ is designed for easy migration. The new platform is backward compatible with prior versions of TwinCAT software. Existing TwinCAT 3 licenses, EtherCAT I/O configurations, motion tasks, and safety applications can be maintained. Switching to PLC++ creates changes in the PLC programming layer of the software only.
Migration under PLC++ means recompiling existing PLC programs under the PLC++ compiler and resolving any compatibility flags that come up. For well-structured TwinCAT 3 projects following standard IEC 61131-3 practices, migration is typically very simple. Projects that made heavy use of undocumented compiler behaviors or relied on legacy Beckhoff library versions may need additional review.
Migration Tip: Run your existing TwinCAT 3 PLC project through the PLC++ compiler in a development environment first, with a full backup in place. Note any compiler warnings before moving to the optimized build settings. Most clean projects compile without issues.
Who Should Be Paying Attention to TwinCAT PLC++?
There is no reason for ever Beckhoff user to migrate their programs right away. If you are in the middle of a project using TwinCAT3, there is no need to swap things over right away. TwinCAT 3 remains a fully supported piece of software.
You should prioritize TwinCAT PLC++ if starting new machine programs, if you are facing CPU constraints, managing large and complex PLC code bases or anyone adopting a multi-developer software workflow with version control and automated testing requirements.
For integrators working with Beckhoff, understanding TwinCAT PLC++ is going to be important for remaining up to date with the platform’s direction. Beckhoff’s product roadmap signals that PLC++ is the forward path.
Final Thoughts
TwinCAT PLC++ is a clear statement from Beckhoff that the differences between traditional software development & PLC development are closing. The performance improvements are real and measurable. The IEC 61131-3 4th edition compliance brings PLC programming into conformity with decades of software dev best practices.
For anyone invested in the Beckhoff TwinCAT ecosystem, TwinCAT PLC++ is an important development. It is worth taking the time to understand, evaluate, and plan for — whether your migration happens this quarter or in the next machine generation.
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