In fire alarm terminology, the signal used when a monitored condition is not in its normal state is a supervisory signal. This type of signal is sent to indicate that essential equipment or a monitored device (such as a sprinkler valve, a damper, a pump, or a switch that must stay in a specific position) is not in its required position. It flags that action is needed to restore normal operation, but it does not mean there is an active fire or require immediate evacuation like an alarm would. For example, if a sprinkler valve is closed or a valve position sensor shows an abnormal condition, the system issues a supervisory signal to alert building personnel to correct the condition. A freeze signal would indicate freezing conditions affecting the system, an alarm signal is for actual fire or detecting conditions that require occupant warning, and the term off-normal describes the condition itself but the standard signal used to convey that state is supervisory.