An irrigation system comprises an irrigation controller that receives user input and provides a power signal and command and message data to an encoder. The encoder encodes the command and message data onto the power signal to provide a data encoded power waveform that is sent over a two-wire path. The irrigation system further comprises one or more decoders in communication with the two-wire path to receive the data encoded power waveform and one or more irrigation valves in communication with the one or more decoders. The data encoded power waveform provides power to the decoders and the decoders decode the command and message data from the data encoded power waveform to control the irrigation valves according to the user input.