The XW90LT (outside size is 38x185 mm) controller is a microcomputer controller suitable for medium temperature or low temperature forced air cooling system. 6 relay outputs control compressor, evaporator fan, electric defrost (or hot gas defrost), lighting, one alarm and one custom output. It can provide a built-in real-time clock (RTC) that can be used for cycle defrost control 6 times a day, and can also be divided into two situations: holidays and working days. "Day and night" can be different set points, this function is suitable for energy saving operation when day and night electricity charges are different. Two NTC or PTC sensor inputs (the first and second temperature probes), the first is used to control the storage temperature, and the second can be placed on the evaporator to control the defrost termination temperature and wind The fan's evaporator start-stop temperature. One of the two digital inputs can be defined as the third temperature probe (the third probe needs to be specified when ordering). The fourth temperature probe can be used to measure the condensation temperature (alarm) or to measure and display the temperature at a certain point. The parameter list can be uploaded or downloaded through the programming key (Hot Key) interface. In this interface, by using an external communication converter XJ485CX to convert to ModBUS-RTU protocol, it can be connected to the network of DIXELL's XWEB series monitoring system. The controller provides a fully functional configurable parameter table system that can be easily programmed by the user via keypad buttons.