Siemens SIMATIC PCS 7 Function Manual page 200

Failure, Switchover and Return of Fault-tolerant Components
6.4 OS server
after process connection error" option must be selected in the "General" tab of the
"Redundancy" dialog box for this.
● The OS partner server saves the date and the time of day marking the return of the OS
server.
● The data gaps in the archives of the failed OS server are updated by the data from the
memory of the OS partner server. The process data of all automation systems (even those
that have not failed) are synchronized.
● When the process connection is restored, this is announced by a process control message
in the message list.
PC station identified as faulty
In PCS 7, the PC stations are preset in such a way that the network adapters are automatically
deactivated when a PC station is identified as faulty. Depending on the Autostart settings, a
manual reboot is required or an automatic reboot of the server is triggered.
Note
Terminate process mode on redundant systems
If the process mode of the PC station is to be terminated manually and the redundancy partner
of the PC station is not available, a corresponding message points out this situation. In this
case, you can cancel the process for terminating process mode. These actions are logged.
Additional information
● Online help for
200
WinCC
Fault-tolerant Process Control Systems (V8.1)
Function Manual, 11/2014, A5E34878832-AA