Experimental analysis of frequency inverter noise on single pair Ethernet communication

Industrial Ethernet in factory and process automation requires real time capabilities. Therefore, robustness is a key feature in industrial communication. The major source of noise are variable speed drives that generate impulsive noise. In this publication, we propose an application-related classification of the impact of industrial electromagnetic interference on data transmission. This classification is based on the modelling of a specific type of application. We model the application via variable speed drives. The drive profiles are taken from actual applications in intralogistics. We describes and measure noise emitted by frequency inverters. The measurement setup is described. It comprises generation of noise by frequency inverters, coupling noise from mains to communication cabling and measuring the noise and its effect on communication. Single pair Ethernet (SPE) cables, modulation and line coding are used according to 802.3cg. The measurements indicate that the main noise source is the switching of the power electronics. Different rotation speeds and torques have an effect on the time-variant appearance of noise but not on noise level. With the measurements, we analyse the impact of the noise on a 2-PAM-Communication.