Alarm missing : Alarm Band Showing Flasing Colour and Alarm Sound active
1) Alarm Band Showing Flasing Colour and Alarm Sound is active but when opening alarm list not unacknologed alarm is missing.
How to find out alarm ?
2) When one of the alarm is Manually Blocked by right clicking from the tag from the alarm list , Alarm disappear from the list.
Any way to list alarm which are Manually Blocked ?
What happen when an PLCConnect alarm is manually blocked and connect server is restarted ?
Contact your regional ABB support center for professional support.
You have not submitted any details of the alarm(s), no filter settings, no images, etc. so it is very hard to tell what is going wrong.
Also, there is no such operation as "Block" on the alarm context menu, maybe you meant "Disable"? Disable is an OPC AE operation that will permanently disable the alarm. The disabling feature should only be enabled when so supported from the OPC AE server. I'm not sure PLC Connect support disabling.
E.g if you were using AC 800M Connect (which support disabling) the AlarmCond block in the PLC would enter disabled state (CondState 1 if remember correct). It will remain so until enabled again (possible from PLC code and an alarm list including disabled alarms) or when the AC 800M PLC is cold started.
Obviously, there is an inherent danger with disabling an alarm if the PLC is not made aware of this (or does not support disabling). Likewise, if the alarm list configuration has filtered out disabled alarms the operator need to be told that there is an alarm that is "parked for good". Maybe through a alarm band button / list where disabled alarms are included in the filter.
I once visited an oil & gas installation where alarm disabling was granted to all operators, no lists existed where disabled alarms could be viewed and the system engineers unaware of it all...
... the platform manager was not so happy about me telling him he had some 50 alarms hidden since several months... they ended up removing the disable privilege.
Disabling can be removed totally using the Alarm Collector config in Library Structure or its privilege be raised in Aspect System Structure preventing operators from reaching the verb on the context menu.
If you want more help on the problem, please inject more details, screen captures, etc.
Otherwise, I believe you are best off with asking regional support for assistance.