Transient alarm suppression

Transient alarm suppression is invoked when a status or multistate record changes state or an analog record changes between the High/Low alarm states. Transient alarm suppression can filter out alarms caused by expected short-term value spikes that should not require any Controller action.

For example, transient alarm suppression is configured for an interface where two pipelines meet and have different controlling companies on the upstream and the downstream. The interface has metering and other telemetry sensors such as pressure sensors. A valve is closed far downstream on the portion of the pipeline that does not use AVEVA Enterprise SCADA telemetry. As the pressure in the pipeline changes, the child goes into alarm and the hold-off timer is triggered. Since the alarm was triggered by a valve closure from another company not using AVEVA Enterprise SCADA, the child in this example does not have a parent.

When triggered, the alarm hold-off timer records the child’s current state and marks the child as alarm-suppressed. When the alarm hold-off timer expires, the system determines if it should generate an alarm by comparing the current state of the child to the recorded state at the time the hold-off timer was triggered.

The alarm hold-off timer is not triggered anew if a new telemetry value is received for the child while the alarm hold-timer is in effect.