Maxim(Dallas) 1-Wire Thermometer (DS1820/DS18S20/DS18B20).AlarmOutputPin
Summary
The Alarm Digital Output pin of the component or element
Description
You can connect this pin to any other pin that can accept Digital( Boolean ) data.
The value of this pin will be True if there has been alarm condition before the last reading from the thermometer.
After each reading the alarm detection starts again.