Ethernet systems are widespread in the office communication for cable based networks. The collision domain principle prevented in the past the use in the automation area because of the lack of strictly deterministic data transfer. Therefore a variety of field-bus systems have been invented for the different applications and requirements in automation.

The development and introduction of Ethernet Powerlink as an open standard offers entirely new options by use of a straightforward and standardized communication system from office level to field-bus level. On the field-bus level the connection via Ethernet is realized by a managing device, called the Managing Node, ensuring a collision free real time data exchange to the I/O modules, the Controlled Nodes. On the other hand the office level can be connected through the asynchronous part in the protocol directly to the real time components in the network.