Electric Rotary Joints are used when power or electric signals must be transferred from a stationary to a rotating structure. Fieldbuses, with increasingly high data rates, are required and used in order to increase output and performance of automatic machines. Servotecnica has offered for many years Electric Rotary Joints able to transmit as well,besides electrical power, Fieldbuses with data rates up to 100 Mbps, such as EtherCAT, PROFINET, SERCOS III, Powerlink etc. This is made possible thanks to the sliding contact technology and to special skill when mounting.