Abstract: A plurality of receptacles in an irrigation controller removably receive a plurality of modules. At least one station module is configured for insertion into a first one of the receptacles and is connectable to a corresponding solenoid actuated valve through a dedicated field valve line and common return line. The station module includes at least one switching device for selectvely providing a first power signal that energizes the corresponding solenoid actuated valve. At least one encoder module is configured for insertion into a second one of the receptacles and is connectable to a multi-wire path for sending encoded signals and a second power signal along the multi-wire path for selectively energizing one of a plurality of solenoid actuated valves connected to corresponding decoder circuits connected along the multi-wire path. A processor executes the stored watering program and controls the station module and/or the encoder module in accordance with the stored watering program.