With the Ethercat P approach from Beckhoff, both the 24 V (DC) supply of the Ethercat P slaves and the connected sensors/actuators are integrated in a four-wire cable. The system and sensor supply and the peripheral voltage for actuators are coupled directly to the wires of the 100 Mbit/s cable - electrically isolated from each other with up to 3 A current for each of the connected components. The new approach also enables power daisy-chaining directly via the subscribers. Depending on the power requirements of the devices, between ten and 15 devices can be connected to an Ethercat P line in this way.

Shortly after Beckhoff presented the solution exactly one year ago, the technology extension to Ethercat was also included in the work of the Ethercat Technology Group (ETG). The result - a first draft of the official specification document - has now been published by the ETG, as its spokesperson Martin Rostan announced yesterday at a press conference. The 'ETG.1030 EtherCAT P Specification' defines the basics of Ethercat P as an extension of the physical layer of Ethercat technology. As such, all other documents relating to the Ethercat standards into which Ethercat P is integrated have also been extended accordingly.

To enable device developers to implement the technology now, Beckhoff has published an 'Ethercat P Application Note' at the same time as the ETG specification documents. As a guide to implementing the technology, this deals with the corresponding expansion of the Ethercat interface, including connectors, electrical specifications and recommendations for EMC-compliant design. In addition, the application note provides information on various design specifications, particularly with regard to the use and connection of supply voltages, and describes the calculation principles for currents and voltages in the network.

In addition to products from Beckhoff, the first Ethercat P devices from third-party suppliers can already be seen at the ETG stand. Leuze, for example, is showing several barcode readers and TR-Electronic is presenting an encoder with the corresponding interface.

All documents are available for download on the Ethercat Technology Group website.