Powerlink and openSAFETY deliver power and data over slip ring

Machine modularisation calls for a decentralised architectures, so control and drive components often need to be installed on moving machine parts, and sometimes on rotating parts. Power and data for these components is normally provided via slip rings.

At the Nuremberg SPS/IPC/DRIVES show, the Ethernet Powerlink Standardisation Group (EPSG) exhibited an assembly with B&R ACOPOSmulti65 drives on a rotating machine part. Using a Cobham slip ring, the 24V power supply, 750V DC bus, and control data was supplied using Powerlink and openSAFETY.

Claiimed to be a first in industrial applications, data at a rate of 100Mbit/s and the DC bus voltage were simultaneously transferred via the slip ring. Martial Favrat, Head of Engineering and Product Quality Manager at Cobham, states: "Our engineers were impressed with the stability and EMC compliance of the Powerlink protocol. We performed comprehensive tests so we can guarantee the transmission quality of our slip rings." Powerlink uses individual frames, so data transfer reliability is naturally higher than that of protocols using summation frames.