Design and Analysis of a Real-Time Control Architecture Towards Software-Defined EtherCAT Devices

EtherCAT has been widely adopted in industrial automation and motion control owing to its real-time performance and flexible topology. However, an EtherCAT network with devices from different vendors requires extensive software modification which eventually increases development costs and effort. To address this issue, this paper presents a real-time control architecture focusing on a software-defined approach to easily reconfigure EtherCAT devices with minimal user intervention. This is achieved by simplifying the integration of EtherCAT slaves while exposing required parameters in a configuration interface through an API based on open-source EtherCAT master. We also provide a real-time variation of the POSIX library for a hard real-time multi-tasking environment considering task synchronization. Moreover, the real-time publish-subscribe protocol is also utilized to ensure seamless communication with devices outside of the EtherCAT network. To validate feasibility, practical example involving control of multi-axis robots and real-time performance analysis has been conducted.