Siemens Simatic PCS 7 Function Manual page 160

Advantages of high availability components
5.5 Operator stations
6. Select the following check boxes as required:
– Synchronization of Tag Logging after the partner server comes back online
– Synchronization of Alarm Logging after the partner server comes back online
– Online synchronization for Alarm Logging
– Synchronization after process connection error
– WinCC client switchover if the process connection is disrupted
7. Click "OK".
Result
The "General" tab in the "Redundancy" dialog can be configured as follows:
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High Availability Process Control Systems (V9.0)
Function Manual, 05/2017, A5E39221836-AA