Alarm shelving restrictions and notes
This reference summarizes current restrictions, supported system scenarios, and operational notes for the IEC 62682 alarm shelving feature.
Distributed systems
Distributed systems (DIST) are now supported. Alarm shelving,
suppression, and out-of-service configuration are available for alerts originating
from distributed systems, giving engineers a complete environment overview.
Redundancy
Redundant systems are fully supported.
The AlertService is based on the Manager Service API (MSA). It runs on both sides of a system configured for Redundancy.
The state is synchronized between redundancy partners.
After a failover, all shelving, suppression, and out-of-service states are preserved.
Sum alerts
Sum alerts are not considered for alarm shelving.
Shelving a base alert does not automatically shelve the associated sum alert.
Multi-instance alerts
Multi-instance alerts are a specific alert type where the alert class is determined dynamically at raise-time rather than being configured statically on the alert handler. This distinguishes them from regular alerts where the alert class is defined in the alert handler configuration.
The AlertService does not support out-of-service mode or suppression for datapoint
elements that use multi-instance alerts. Both setOutOfService() and
suppression silently exclude these elements because restoring the original alert
class afterwards would cause existing alert instances to be lost. No entry is added
to the Out-of-Service Overview panel or the Suppressed Alert Handler overview panel
for excluded elements.
CNS consistency
When engineering changes are made to the CNS structure, suppression and out-of-service assignments are not propagated automatically.
The AlertService provides inconsistency detection capabilities.
Verify and update suppression and out-of-service assignments after structural changes to the CNS.