This specification makes use of the Institute of Electrical and Electronics Engineers’ IEEE802.3af Power over Ethernet (PoE) functionality, and can be implemented with commercially available chips, the ETG said. The Power over EtherCat enhancement was finalized at the recent fall meeting of the ETG Technical Committees, which took place near Frankfurt, Germany.
Stub lines and star topology together with line, tree and redundant ring have always been among the EtherCat topology options. This flexibility is now 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 Watts 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 four-pin M12 can still be used. Devices powered by a separate line can be connected to Power over EtherCat breakouts without problems, the ETG said. It is also possible to enhance the specification toward the future high-power IEEE802.3at standard (PoE Plus or High Power PoE) because this is downwards compatible.
Power over Ethernet chips are available from several vendors and the first Power over EtherCat devices are expected to be shown at the SPS/IPC/Drives show Nov. 25-27 in Nuremberg, Germany.
EtherCat Technology Group