Data Transfer through the Motor Feeder Cable in an Industrial Application

The motor speed control is a typical industrial application where a feedback loop is used in order to transmit control information\´s to the controller using an extra cable dedicated for data transmission. In this paper we discuss the use of the feeder cable itself for communication instead of the extra cable by using the well known technology in domestic applications, the PLC "power line communication". However, the feeder cable is not designed for data transmission for being a noisy environment. Therefore, PLC modems developed for domestic applications may not be suitable. The aim of our study is to highlight limitations and difficulties that obstruct transmission in industry. Also, we underline the use of a PWM filter and a coupling interface with specific characteristics in order to overcome those limitations.