A method for communicating data in a rail vehicle consist includes transmitting first data at a first rail vehicle of the consist over a power supply conductor to a second, different rail vehicle in the consist, where at least one rail vehicle of the consist receives direct electrical power from the power supply conductor. The method also includes monitoring the power supply conductor for second data at the first rail vehicle and receiving the second data over the power supply conductor at the first rail vehicle for use by a first system onboard the first rail vehicle. In one aspect, the transmitting step comprises transmitting the first data over one or more of a catenary line or a third rail that supplies the electrical power.