EtherCAT Coupler - Introduction

An EtherCAT coupler is required in order to connect EtherCAT Terminals with E-bus-communication (series ELxxxx, ESxxxx, EMxxxx) to an EtherCAT network. This coupler relays the communication from the higher-level EtherCAT network to the terminals, or functions as a master itself and generates telegrams. Beckhoff offers different components for different application scenarios.

The selection of the correct coupler depends on the following criteria:

• is a local small controller needed?
• is the coupler to be connected via copper cable or optical fiber cable?
• is the coupler to be addressed via IP or is it located in the unswitched network?
• is the coupler to be controlled via EAP (EtherCAT Automation Protocol) or EtherCAT Device Protocol?
• required protection class: IP20 or higher?
• is the coupler to be plugged in at different places at the network using the HotConnect technique?

A coupler connects the added terminals to the right; it can be connected to the higher level network to the left. Couplers that support the EtherCAT Device Protocol ‘to the left’ must be connected there to an EtherCAT master.

Fig.1: EtherCAT coupler communication diagram