800xA 5.1 FP4 Alarm&Event list showig abnormal message
The alarm and event list of some signals are showing a message "The Alarm was removed because it doesn't exist in the OPC Server". What is the meaning of this message?
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The Alarm Manager service in System 800xA attempts to take care of deleted alarm conditions.
a) An alarm condition is raised from an OPC AE server capable of OPC AE Refresh.
b) The alarm condition is received by System 800xA and forwarded to subscribers.
c) Engineering is made in the PLC; the alarm block is deleted and PLC is downloaded, or the PLC is cold started and the alarm condition is removed as a result of the restart.
d) OPC AE refresh is triggered, manually (restart, failover) or automatically (AC 800M).
e) The Alarm Manager detects that the alarm condition received in step a) is no longer reported.
f) The Alarm Manager issues a simple event to subscribers to notify them of the alarm condition removal.