8 Alarm Metrics ToC Previous Next

8.2 AlarmMetricsType ToC Previous Next index

This ObjectType is used for metric information. The ObjectType is formally defined in Table 108.

Table 108 – AlarmMetricsType Definition

Attribute Value
BrowseName AlarmMetricsType
IsAbstract False

Subtype of the BaseObjectType defined in OPC 10000-5.

References NodeClass BrowseName DataType TypeDefinition Modelling Rule
HasComponent Variable AlarmCount UInt32 BaseDataVariableType Mandatory
HasComponent Variable StartTime UtcTime BaseDataVariableType Mandatory
HasComponent Variable MaximumActiveState Duration BaseDataVariableType Mandatory
HasComponent Variable MaximumUnAck Duration BaseDataVariableType Mandatory
HasComponent Variable CurrentAlarmRate Double AlarmRateVariableType Mandatory
HasComponent Variable MaximumAlarmRate Double AlarmRateVariableType Mandatory
HasComponent Variable MaximumReAlarmCount UInt32 BaseDataVariableType Mandatory
HasComponent Variable AverageAlarmRate Double AlarmRateVariableType Mandatory
HasComponent Method Reset     Mandatory
           
           

An instance of AlarmMetricsType can be added, with a HasComponent reference, to any Object that has its “SubscribeToEvents” bit set within the EventNotifier Attribute. It will collect the Alarm metrics for all Alarm sources assigned to this notifier Object. For example, if Alarm metrics are desired for Tank A Object (see Figure B.3) that is in the HasNotifier hierarchy than an instance of this object would be referenced by the Tank A object. When this object is associated with the Server Object it will report Alarm metrics for the entire Server.

AlarmCount is the total count of Alarms since the last restart of the system or reset of this counter.

StartTime is the time at which the Server started or the time of the last Reset Method invocation, whichever is later.

MaximumActiveState is the maximum time for which an Alarm was in the active state.

MaximumUnAck is the maximum time for which an Alarm was in the unacknowledged state.

CurrentAlarmRate is the sum of Alarms that occurred in the last Rate number of minutes (see 8.3). This sum should not include nuisance Alarms (i.e. chattering alarms). It is updated every Rate number of minutes.

MaximumAlarmRate is the maximum Alarm rate detected since the start of the Server, where the rate is calculated as for CurrentAlarmRate.

MaximumReAlarmCount is the maximum ReAlarmCount for any Alarm.

AverageAlarmRate is the average Alarm rate since the start of the Server or the last invocation of Reset Method, where the rate is calculated as for CurrentAlarmRate.

Reset is a Method that will reset all of the counters, rates or times in this Object

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