The DS18B20+ is a programmable resolution 1-wire digital thermometer in 3 pin TO-92 package. This digital thermometer provides 9bit to 12bit celsius temperature measurements and has an alarm function with non-volatile user programmable upper and lower trigger points. The DS18B20 communicates over a 1-wire bus that by definition requires only one data line (and ground) for communication with central microprocessor. In addition, the device can derive power directly from data line (parasite power) by eliminating need for an external power supply. Each DS18B20 has a unique 64bit serial code stored in on-board ROM which allows multiple DS18B20 devices to function on the same 1-wire bus. Thus, it is simple to use one microprocessor to control many DS18B20 devices distributed over a large area. Applications that can benefit from this feature include HVAC environmental controls, temperature monitoring systems inside buildings, equipment or machinery, process monitoring and control systems.