Terminology » EtherCAT : Working, Advantages and Disadvantages

EtherCAT : Working, Advantages and Disadvantages

ethercat data communication networking

Introduction : EtherCAT (Ethernet for Control Automation Technology) is a high performance, real time industrial Ethernet protocol designed for automation and control applications. Originally developed by Beckhoff Automation, it has become an open international standard (IEC 61158). It is supported worldwide by the EtherCAT Technology Group.

EtherCAT Features & Working

  • EtherCAT is known for its unique “processing on the fly” principle, in which data is read and written by devices as Ethernet frames pass through them. This offers extremely fast cycle times and precise synchronization.
  • Instead of storing and forwarding frames like standard ethernet, it processes data while the frame passes through each device.
  • Each slave device reads data addressed to it and inserts its own data into the frame - all in hardware with minimal delay. This allows cycle times of less than 100 µs and synchronization accuracy of less than 1 µs.
  • Physical layer : standard Ethernet (100BASE-TX, Cat5e cable), with master-slave architecture.

Advantages of EtherCAT

Following are some of the benefits of EtherCAT.

  1. It offers extremely fast cycle times and low jitter.
  2. It supports various topologies such as line, tree, star, ring etc.
  3. It supports thousands of nodes with little drop in performance.
  4. It uses standard ethernet hardware including cables, connectors, NICs etc.
  5. It supports built-in error detection.
  6. It’s one frame can serve all devices and no per device overhead is needed.

Disadvantages of EtherCAT

Following are some of the drawbacks of EtherCAT.

  1. It is more complex than traditional fieldbuses such as Profibus, CANopen etc.
  2. Slave devices need EtherCAT specific hardware which increases their cost compared to RS-485/Modbus devices.
  3. It is not directly interoperable with standard ethernet devices without gateways.

Conclusion: With its ability to connect thousands of nodes, flexible topology options, and sub-microsecond accuracy, EtherCAT is widely used in robotics, CNC machines, motion control, factory automation and process industries. It provides the speed and determinism of specialized fieldbuses while leveraging standard Ethernet hardware, making it a powerful and scalable solution for modern industrial networks.