A control unit includes a communication output terminal associated with a communication signal circuit, and a supply output terminal associated with a supply signal circuit. The communication signal circuit operates to apply a communication drive signal to the communication output terminal in response to a communication control signal, while the supply signal circuit operates to apply a supply operating signal to the supply output terminal in response to a supply control signal. The control unit further includes a controller which operates to direct the supply control signal to the supply control circuit with a particular timing relative to directing the communication control signal to the communication signal circuit. More specifically, the controller directs the supply control signal to the supply signal circuit at a first point in time and then directs the communication control signal to the communication signal circuit after a communication condition is met in an irrigation system.