Modern motion systems demand ultra-fast deterministic communication with precise multi-axis synchronization. So, engineers are turning to realtime Ethernet-based industrial protocols.
Neyram Hemati, PhD
Ankit Barad | Applied Motion Products
Realtime motion control depends on fast, deterministic communication and precise synchronization across multiple axes. Among Ethernet-based technologies:
- EtherCAT delivers the highest synchronization accuracy and speed.
- EtherNet/IP provides unmatched PLC integration and interoperability.
- PROFINET IRT offers deterministic performance while supporting mixed industrial traffic.
Meanwhile, CANopen, CAN FD, and traditional serial networks continue to deliver proven reliability for distributed, embedded, or cost-sensitive applications.
Current state of industrial communications
Industrial communications today are based on EtherCAT, EtherNet/IP, and PROFINET IRT as well as widely used legacy and serial options such as CANopen, CAN FD, and RS-232/RS-485 (Modbus RTU). Each protocol is discussed in terms of architecture, timing, and application suitability. Product examples from some manufacturers illustrate how multi-protocol motion control platforms enable engineers to align communication strategies with performance, integration, and cost objectives.
As industrial automation grows more complex, the communication infrastructure connecting drives, controllers, and sensors has become a critical design element rather than a background utility. Modern multi-axis motion control systems — such as those in robotics, packaging, and semiconductor manufacturing — need sub-microsecond synchronization, deterministic data transfer, and reliable realtime performance potentially across networks of dozens of axes.
Enterprise and industrial systems can integrate over modern Ethernet-based architectures to link PLCs, drives, sensors, HMIs, and IT infrastructure into unified and deterministic control networks. In fact, Ethernet-based industrial protocols deliver better speed, synchronization, and scalability than legacy serial and CAN-based networks.
Ethernet-based fieldbus technologies have emerged as the dominant solution, combining high bandwidth, precise synchronization, and flexible topologies. At the same time, traditional networks such as CAN and serial protocols continue to play an important role in cost-sensitive or embedded applications.
Some manufacturers have responded to these evolving requirements by developing motion-control devices that natively support multiple industrial communication standards. This flexibility allows system designers to choose the most effective protocol for each application, whether optimizing for ultra-fast synchronization, seamless PLC integration, or reliable low-cost control.
Enterprise and industrial systems integrate over modern Ethernet-based architectures to link PLCs, drives, sensors, human machine interfaces (HMIs), and IT infrastructure into unified and deterministic control networks.
Ethernet-based realtime protocol:
Ethernet for Control Automation Technology (EtherCAT)
Developed by Beckhoff, EtherCAT is known for its exceptional performance and efficiency. Using a “processing-on-the-fly” approach, data is read and written by each device as a single Ethernet frame passes through the network, minimizing latency.
With cycle times down to 12.5 µsec and jitter below 1 µsec, EtherCAT supports highly synchronized motion profiles for torque, velocity, and position control. Its distributed clock mechanism ensures sub-microsecond timing alignment. The protocol scales to thousands of nodes and offers flexible topologies — making it suitable for CNC, robotics, and high-speed packaging systems.
Ethernet-based realtime protocol:
EtherNet/IP
Ethernet Industrial Protocol or EtherNet/IP is an industrial communication protocol based on standard Ethernet and the Common Industrial Protocol or CIP. It’s designed to connect controllers, drives, and I/O devices. In motion control, it uses implicit UDP messaging for realtime cyclic transfer of position, velocity, and torque data between a PLC and drives, enabling precise, synchronized multi-axis motion, while explicit TCP messaging handles configuration, diagnostics, and parameter changes. By combining standard Ethernet hardware with fast, deterministic communication, EtherNet/IP allows high-speed, coordinated motion control with interoperability across devices from different vendors.
Its ability to operate on standard Ethernet infrastructure allows for star, ring, or line topologies and seamless information and operational technology (IT/OT) integration. EtherNet/IP is especially prevalent in North American automation markets and supported by a broad vendor ecosystem.
Rockwell Automation is a leading supplier of motion control products with CIP motion.
Ethernet-based realtime protocol:
PROFINET Isochronous Realtime (IRT)
PROFINET IRT extends PROFINET RT with deterministic, time-sliced communication for synchronized motion control. Cycle times as low as 250 µsec and jitter below 1 µsec make it well-suited for precision automation and robotics. IEEE 1588 PTP synchronization and hardware-assisted switching ensure tight timing and efficient coexistence of realtime and standard Ethernet traffic.
Legacy and serial protocols
CANopen and CAN FD: The CAN family of protocols remains essential for cost-sensitive or embedded systems. CANopen delivers deterministic communication up to 1 Mbps using priority-based arbitration, while CAN FD increases payload size (up to 64 bytes) and data rate (up to 8 Mbps), enabling higher throughput without sacrificing reliability. These are common in mobile robotics, textile machinery, and modular automation.
RS-232, RS-485, and Modbus RTU: Serial protocols continue to serve as dependable solutions for legacy or simple distributed systems. RS-232 supports short-distance point-to-point links, while RS-485 enables multi-drop connections up to 1,200 meters. When paired with Modbus RTU, these links provide structured master-slave communication for sensors, drives, and controllers. Though slower and less deterministic, serial remains a practical bridge between older equipment and modern Ethernet-based networks.
Component suppliers offering multi-protocol support
Some suppliers of motors, drives, and other motion components offer comprehensive product ranges that support leading industrial communication protocols. This multi-protocol capability lets engineers build motion systems that meet diverse technical, integration, and cost requirements.
Neyram Hemati is a Lecturer in the Department of Mechanical Engineering at San Jose State University, San Jose, Calif. Ankit Barad is an application controls engineer at Applied Motion Products.
Applied Motion Products | applied-motion.com
Application Engineering Group | [email protected]
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