Why the Trend of Moving Robot Control into PLCs Matters

At Outlier Automation, I lead programming and design for complex industrial machinery, often involving a mix of robotics, precision motion and tightly integrated automation. Over the past few years, I have noticed a clear shift from major automation vendors. More of them are beginning to offer robot kinematics or programming directly inside the main machine PLC instead of relying on a separate robot controller.

Though this change may appear subtle, it represents an important evolution in how automated systems can be conceived and built. By moving robot control more tightly into the PLC, machines can become more capable and flexible. 

This approach also has the potential to be more cost effective for manufacturers. It can reshape how integrators architect motion systems and how end users maintain and scale their equipment.

Why this shift is happening

Traditional robot controllers introduce complexity manufacturers do not always see upfront. They require separate programming environments, separate diagnostic workflows and often separate worker skillsets to maintain.  These differences can leave robots treated as standalone subsystems, even though tighter integration could make machines more powerful.

Modern industrial CPUs and real-time operating systems are now powerful enough to handle the calculations that once required proprietary hardware and software.  

Bringing more robot control into the PLC can take several forms. One approach involves directly commanding robots while leaving the kinematics inside the robot controller, such as Stäubli’s UniVAL, KUKA’s mxAutomation, or Siemens Simatic Robot Integrator using the “Standard Robot Command Interface” standard.  

In this setup, the PLC sends motion commands to the robot, which eliminates most of the programming work on the robot side, although the robot controller still executes the paths and trajectories.  A major advantage here is the ability to command many different robot brands from a single programming language and automation platform. It can also reduce many communication handshakes, especially when the PLC already manages other machine functions that need to coordinate with the robot. 

Another approach is to remove the robot controller entirely and let the PLC directly command the robot’s servo joints, performing all the calculations and supervisory tasks required to move the arm. This method demands far more processing power, but it also decouples the system from specific robot hardware and software. The result is a highly adaptable design and programming environment that allows machinery to be developed with fewer vendor constraints. Examples in this area include Beckhoff’s Kinematic Transformation and Rockwell Automation’s Unified Robot Control. 

The benefits of having robot motion on one platform

Centralizing more robot control in the PLC simplifies training by allowing technicians to work within one engineering environment instead of switching between multiple proprietary tools. This consolidation can reduce the effort required for changeovers, recipe adjustments and production ramp-ups, since all motion logic behaves consistently and is maintained in a single place. 

Just as importantly, tighter integration improves machine coordination. When every axis in the system, including its robotics, runs under a single motion platform, the equipment can more easily integrate with data-intensive and future-forward technologies such as AI- and machine learning-based vision systems that adapt robot movements. It can also synchronize more smoothly with upstream and downstream processes and reduce cycle time lost to communication delays or mismatched control strategies.

Whether the PLC is issuing high-level commands or fully calculating the robot’s kinematics, the result is a cleaner and more maintainable automation architecture. Machine builders gain greater freedom to select or design their own robot hardware based on mechanical requirements instead of software ecosystems.  

As physical and virtualized PLC performance continues to grow and vendors standardize around common motion interfaces, the line between traditional robotics and machine control will likely continue to fade. This convergence supports the broader shift toward software-defined automation and positions manufacturers for a future where flexibility, adaptability and rapid reconfiguration are essential.

G Brooks-Zak, is co-founder of Outlier Automation, an integrator member of the Control System Integrators Association (CSIA). For more information about Outlier Automation, visit its profile on the CSIA Industrial Automation Exchange. 

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