The use of power networks as a communication medium is currently under development. Power line communication (PLC) is a recent technology that allows interconnecting high-speed multimedia equipment while using the conventional domestic electric network. This paper deals with the use of this technology over pulsewidth-modulation (PWM) networks in motor-drive applications. The originality stands on the frontier of two distinct domains-communication and energy. First, the performance of the PLC technology conceived for domestic applications is evaluated when used over a PWM network. Operating limits and main difficulties encountered are underlined. Based on the requirements of the PWM network, new PLC modems are developed and tested. Experimental results presented in this paper show the capacity of these modems to overcome the hostile environment due to the inverter and to guarantee reliable communication over the PWM network.