The T600MEP-1 is a programmable thermostat for control of single- or two-stage unitary rooftop units with economizers. The T600MEP-1 thermostat provides exceptional accuracy through the use of a unique Proportional-Integral (PI) time proportioning algorithm. The algorithm virtually eliminates temperature offset associated with traditional, differential-based on/off thermostats. The T600MEP-1 also uses an adaptive control logic algorithm to control the space temperature during recovery to minimize overshoot while providing maximum comfort. Economizer functions include a 0 to 10 VDC control signal, dry bulb changeover strategy, adjustable minimum position, and mix air setpoint control. Additionally, the menu driven backlit display, plain text menus, and five keys on the T600MEP-1 make programming the thermostat easy and intuitive. . Johnson Controls. Johnson Controls. T600MEP-1.