All Sun server platforms are equipped with a number of sensors that measure voltage, temperatures, fan speeds, and other attributes about the system. Each sensor in ILOM contains nine properties describing various settings related to a sensor such as, sensor type, sensor class, sensor value, as well as the sensor values for upper and lower thresholds.
ILOM regularly polls the sensors in the system and reports any events it encounters about sensor state changes or sensor threshold crossings to the ILOM event log. Additionally, if an alert rule was enabled in the system that matched the crossing threshold level, ILOM would automatically generate an alert message to the alert destination defined.