4.6 Severity, quality, and comment

Comment, Severity and Quality are important elements of Conditions and any change to them will cause Event Notifications.

The severity of a Condition is inherited from the base Event model defined in 10000-5. It indicates the urgency of the Condition and is also commonly called alarm priority or ‘priority’, especially in relation to Alarms in the ProcessConditionClassType. Severity is defined to have a range of 1-1000, but this range includes Alarms and other events that are not considered Alarms. For Alarms it is recommended that Severities above 400 be used. The 400-1000 range for Alarms should be further subdivided based on the severity of the Alarm. For an example of how Severity ranges are subdivided for diagnostics see 10000-26 LogRecord Severity Mapping.

A Comment is a user generated string that is associated with a certain state of a Condition.

Quality refers to the quality of the data value(s) upon which this Condition is based. Since a Condition is usually based on one or more Variables, the Condition inherits the quality of these Variables. E.g., if the process value is “Uncertain”, the “Level Alarm” Condition is also questionable. If more than one variable is represented by a given condition or if the condition is from an underlining system and no direct mapping to a variable is available, it is up to the application to determine what quality is displayed as part of the condition.