Air conditioning control mode

* Modes: auto, cool, dry, fan and heat
* FAN: high, medium and low
* Over heat/cold protection for room coil pipe
* In heat mode, defrost according to temperature difference of inlet and outlet air
* Lack of cooling agent (liquid) protection.
* Out-door fan controlled by a standalone output to make defrost effect well
* Blow residual heat function
* 3 minutes protecting delay to restart the compressor
* Panel control all functions, LED digits display
* Avoid cold wind in heat mode
* Two temperature sensors
* Wind direction control
* Emergent on/off key
* Auxiliary heater control
* Inline/offline timer
* Sleep