event appears in event list that certain alarms could not be acknowledged
What I wanted to say was.
This topic has been discussed several times on AKS in the past, hence my short answer. Dig with Google for more details.
0. AC 800M PLC assumed.
1. Use afwapplogviewer tool to enable the Events and Acknowledges logs. Repeat problem with acknowledge. Study result on acknowledge call and what OPC AE server return. The PLC must send "Enabled, Inactive, Acknowledged" update for alarm to clear.
2. Use Control Builder M, go online with application in controller, browse to alarm emitting object, right click --> Alarm Conditions. Study conditions state. Idle alarm is state 2.
3. Extract raw standing alarm status from source OPC AE server using a 3rd party OPC AE client (eg MrCrilfe.exe)
Compare 1-2-3 and try to backtrack origin of discrepancy between PLC and HMI.
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