A Bi-Directional Thermostatic Controller operates in the same manner as a Single Directional Controller, except output can operate in both heating and cooling modes. Controllers with a bi-directional output are used for maintaining a constant temperature within an enclosure surrounded by an ambient environment with a much larger temperature swing. This is commonly experienced in an outdoor environment. Laird Thermal Systems offers a microcontroller based device with integrated temperature control for cooling and heating of thermoelectric assemblies requiring precise temperature control. The TC-XX-SR-54 has three programmable fan outputs, alarm output relay and alarm condition LEDs. The parameters will be programmed by Laird Thermal Systems according to customer specifications.