Industrial powerline communication for machine tools and robotics

Nowadays, machining systems worldwide are on a very high level, regarding mechanics as well as control technology. Therefore, in the case of challenging sub-assemblies like drive and control systems and technological components (e.g. high-frequency spindles and processing heads) the emphasis should be placed on the integration of these components in specialised machine and plant configurations, especially by reducing the interfaces with a new communication system. In the future, technological innovations can be primarily expected from the introduction of highly integrated mechatronic machine modules. The concept of this new powerline communication system is the transmission of data and power for a drive unit over a common power cable. This can be achieved by high-frequency modulation of the data onto the cable. In this paper, the basic conditions for the industrial powerline communication are presented. First an overview is given on the existing communication systems in production technology. As an essential requirement the transfer function of the transmission channel is analysed. Further, the disturbances on the transmission channel are discussed. The final essential requirement is the compliance with the standards regarding elimination of disturbances, conducted as well as radiated. For proof of functionality the Orthogonal Frequency Division Multiplex- (OFDM-) transmission method is applied. This is implemented in two modems which have been set up within a demonstration system.