Single Series DS staging controller can control mix of heating and cooling outputs to maintain process setpoint; quantity of outputs dedicated to heating and cooling are easily user-configurable. Stager can be set to use output in circular rotation or up-down sequence, and can also accept thermistor input as well as control temperatures under direction of onboard processor. An additional thermistor can be implemented for outdoor temperature compensation. When used with external controller, unit can operate in follow mode and provide 0-20 or 4-20 mA current signal representing needed output percentage. Digital input can also be used for setpoint via Modbus host.