A High-Performance CAN-like Arbitration Scheme for EtherCAT

EtherCAT is a popular Ethernet-based solution conceived for connecting devices at the shop floor in industrial environments. Even though it features very high communication efficiency, that permits thousands of I/O points to be periodically exchanged between controlling devices and decentralized periphery with cycle times well below 1 ms, it is not able to cope in a proper way with event-driven systems, where lots of devices may be producing asynchronous information in a sporadic and unpredictable way. In this paper, some modifications to the basic EtherCAT protocol are proposed which enable CAN-like arbitrations to take place in such networks, so as to achieve a true priority-based access scheme.