Discrete attribute runtime behavior: alarms
- Last UpdatedJul 19, 2024
- 1 minute read
The time stamp for when the alarm becomes active or inactive is the most recent time stamp of the corresponding input value, if any; if there is no time stamp, the AppEngine scan time is used.
When alarms are enabled, you can set an individual limit, deviation, ROC, or state alarm to be enabled, silenced, or disabled. This setting only applies to the individual alarm. No other alarm settings for the object are affected, and the setting is not propagated to contained objects.
The actual behavior is based upon the most restrictive enable/silence/disable AlarmMode in the object hierarchy.
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If the object has an AlarmMode of Enable, and the individual alarm's AlarmMode setting is silenced, the alarm is silenced. If the alarm's AlarmMode setting is disabled, the alarm is disabled.
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If the object has an AlarmMode of Silence, either directly or by another object higher in the hierarchy, and the individual alarm's AlarmMode setting is enabled, the alarm is silenced. If the alarm's AlarmMode setting is disabled, the alarm is disabled.
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If the object has an AlarmMode of Disable, either directly or by another object higher in the hierarchy, and the individual alarm's AlarmMode setting is enabled or silenced, the alarm is disabled.
When alarms are enabled, you can set an individual alarm to be inhibited. The inhibition setting applies only to an individual alarm. No other alarm settings for the object are affected, and the setting is not propagated to contained objects. If alarms are not inhibited, the alarm behavior is determined by the AlarmMode setting.