Alarm limits

Standard normal operating values for the analog and rate records lie within certain High and Low limits. When a measured value exceeds the High limit, or goes below the Low limit, a state alarm is generated to indicate that a condition requires attention.

A second set of limits, known as High-High and Low-Low, are above and below the High and Low limits. When a measured value exceeds the High-High, or goes below Low-Low limits, a state alarm is generated to indicate that a critical condition has occurred.

Note: Typically, a higher severity is assigned to High-High / Low-Low conditions than to the High/Low conditions.