Methods and apparatus for controlling a lighting fixture utilizing a communication protocol transmitted over the power line that feeds the lighting fixture. Data may be transmitted to a plurality of lighting fixtures (40) via altering the output voltage transmitted to the lighting fixture through switching of a transformer (120) connected to the output voltage. Data may be received at a lighting fixture (40) via receiving an encoded output voltage and comparing the voltage level of a plurality of sine cycle periods of the output voltage to determine an incoming data packet. One or more aspects of the lighting fixture (40) may be controlled based on the received data.