The “Power over EtherCAT” enhancement makes use of IEEE802.3af Power over Ethernet (PoE) function and can be implemented with commercially available chips. Power over EtherCAT suits encoders or linear position sensors, which can now be designed to connect to EtherCAT and be powered using a single, standard Ethernet cable.
Stub lines and star topology together with line, tree and redundant ring EtherCAT topology options are enhanced with the possibility to design EtherCAT devices with just one connector each that are powered over the data line.
The Power over Ethernet standard IEEE802.3af supports up to 13 W per device. For EtherCAT slave devices, the ETG specifies mode A of the standard, which only needs four wires: standard Industrial Ethernet connectors such as the 4-pin M12 can still be used. Devices powered by a separate line can be connected to Power over EtherCAT breakouts without problems. It is also possible to enhance the spec towards the future high power IEEE802.3at standard (PoE Plus or High Power PoE) because this is downwards compatible.
The EtherCAT Technology Group