The size of XW20L is 38*185mm, it is a digital controller suitable for the application of shutdown defrosting and normal temperature refrigeration. There are two ways relay outputs control compressor and lighting separately(configurable). It is able to provide a built-in real-time clock(DTC) that can. It is used for cycle defrosting control 6 times a day, and can also be divided into two situations: holidays and working days. "Day and night Time" can be a different set point, this feature is suitable for energy saving operation when the electricity bill is different during the day and night. It also provides for four-way NTC or PTC sensor input, the first way is used to control the temperature of the the room, and the second way can be placed on the evaporator to control the defrost termination temperature. One of the digital inputs can be defined as the third temperature probe. The fourth temprature probe. The fourth temperature probe is uses to measure the condensation temperature(alarm) or to measure and display the temperature at a certain point. The HOT KEY output can be connected to the unit, and by using the external module XJ485-CX to convert to ModBUS-RTU protocol, it can be connected to dlXEL's X-WEB series monitoring system and network. The contrloller can be programming key. The controller provides a full-featured configurable parameter table system the can be easily programmed by the user via keyboard button.