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 not supported.
The AlertService operates only within a single WinCC OA system.
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 for datapoint elements that
use multi-instance alerts. The setOutOfService() function silently
excludes these elements because restoring the original alert class after returning
to service would cause existing alert instances to be lost. No entry is added to
the Out-of-Service 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.