Defrost unit with RTC for open counters Panel controller with two automatically alternating day/night setpoints Up to six defrost cycles a day Clock with 20-day back-up battery Third sensor to display product temperature and for the night-time thermostat Up to four outputs for:compressor,evaporator fans,defrost and alarm TTL serial port for remote display unit or RS485 for data interchange with PC. Applications : open refrigerated counters for shops and supermarkets,both static or ventialated, in which defrosting must take place at well-defined times.