For an EtherCAT system with several devices in a line topology, the need quickly arises for EtherCAT infrastructure components that support other topologies or a change in physical layer. The family of the EtherCAT junctions allows the star topology: when connected to the EtherCAT network, up to seven additional EtherCAT subgroups can be supplied with communication from the junction. After that, further junctions can be connected in turn. The junctions are visible as devices in EtherCAT and, as is usual with Ethernet, they re-establish the electrical communication to the connected devices so that they can also be used for line extensions if distances of more than 100 m have to be overcome. This also makes Hot Connect operation possible, i.e. the connection/disconnection of network parts during operation.

The media converters are also often used for long distances: The distance between two EtherCAT devices can be up to 20 km if, for example, optical fiber cables are laid and connected to the CU1521-0010 media converter. If the insensitivity of the section to EMC interference is most important for shorter sections, a POF section with CU1561 may be the right choice. This family was also specially designed to meet the requirements of an EtherCAT network: visible in EtherCAT and thus capable of bus diagnostics, low impact on the passing EtherCAT frame. In order to operate EtherCAT Terminals at the endpoint of the segment, a suitable EK15xx EtherCAT Coupler can be used directly instead of a CU15xx converter.

Advantages:

• a great deal of freedom in designing the topology due to different infrastructure device formats
• suitable for control cabinet installation in the IP20 version or for outdoor use in IP67
• infrastructure devices visible on the EtherCAT bus and thus included in the diagnostics
• no limitations on real-time quality and data throughput
• full support for distributed clocks