The present inventive disclosures are generally directed to an improved means to precisely measure temperature at a location remote from a central controller and a means to control heater and/or cooler power at that remote location with a temperature setpoint that is adjustable at the central-controller location, with a remote device/unit connected to the central controller using no more than two wires, employing specialized time-sliced alternating operating modes via those two wires in which high-accuracy current-based temperature readings are transmitted back to a central controller in one mode, and thermal-device power is provided in the other mode. The improved system is, as a result, both very cost-efficient and mass-efficient for controlling a multitude of thermal zones.