The Many Faces of Industrial Ethernet [Past and Present]

Ethernet is by far the most widely installed local area network technology, popular in both homes and offices. It is fast, easy to deploy, and adapters are cheap. Most, if not all, computers have a built-in Ethernet interface. These are just some of the reasons why an increasing number of industrial automation vendors militate for the use of Ethernet - as is or with modifications - to support communications on the shop floor. They've made a number of proposals under the generic name "industrial Ethernet," all aimed at the specificities of communications in the industrial environment. Most of the time, however, these proposals are incompatible. Limiting ourselves to the temporal aspects, we look at why Ethernet is generally considered inadequate as a support for computer communications on the factory floor. We also examine possible modifications to obtain an adequate solution based on Ethernet and the proposals that have been recently standardized under IEC 61158 and IEC 61784.