Energy Efficiency in Industrial Ethernet: The Case of Powerlink

Industrial Ethernet technology enables real-time reliable communications for industrial environments. One of its key features is the use of Ethernet for the communication infrastructure. This provides a very cost-effective solution, as no communication infrastructure has to be designed ad hoc. In the last years, the efficient use of energy in communications has become an area of growing interest. This has triggered efforts that are now underway to develop new standards, like Energy Efficient Ethernet, with the aim of reducing the energy consumption. The proposed changes to existing Ethernet standards allow setting the links in low-power modes when there is little traffic. These changes, introduced by Energy Efficient Ethernet, will have wide implications for Industrial Ethernet. For example, the time needed to enter or exit the low-power modes may be excessive for some industrial applications. The use of low-power modes will make hubs less energy efficient than switches and may cause manufacturers to abandon the production of these devices. In this paper, the implications of Energy Efficient Ethernet on industrial environments are analyzed, and different alternatives are proposed.