Siemens SIMATIC PCS 7 Function Manual page 183

The "@RM_MASTER_NAME" tag contains the name of the OS server, for example, "Server
1". You can display this tag, for example, in an I/O field of a Graphics Designer picture. Other
applications or scripts can also evaluate these tags. The "@RM_MASTER" tag can also be
changed.
WinCC project is deactivated
A functionally equivalent WinCC project is activated on both OS servers. If the WinCC project
is deactivated on OS Server 1 (master identification), WinCC Redundancy triggers the
following reactions:
● OS Server 2 (standby identification) saves the time of the failure (date and time of day) of
● OS Server 2 reports the failure of OS Server 1 with a process control message in the
● OS Server 2 now takes over the role of the master by setting the @RM_MASTER tag. The
● If the WinCC project is activated again on OS Server 1, OS Server 1 is set as the standby
Gaps in the archive data occur on OS Server 1 during the time it is inactive. As soon as OS
Server 1 returns, the gaps in the data are remedied by the following measures:
● OS Server 2 saves the date and the time of day, marking the return of OS Server 1.
● OS Server 2 reports the return of OS Server 1 with a process control message in the
● The data gaps in the message, process data and user archives of OS Server 1 are filled
● The @RM_MASTER tags remain unchanged in both servers;
Fault-tolerant Process Control Systems (V8.0)
Function Manual, 03/2012, A5E02779471-02
OS Server 1 (master identification).
process control list.
@RM_MASTER_NAME tag is changed accordingly.
and the @RM_MASTER tag is reset. The @RM_MASTER_NAME tags are changed
accordingly.
message list.
by the data from the OS Server 2 memory. Conditions: The options "Synchronization of
Tag Logging after the partner server comes back online" and "Synchronization of Alarm
Logging after the partner server comes back online" must be enabled in the "Redundancy"
dialog box for this.
– OS Server 2 keeps the master identification.
– The @RM_MASTER tag remains set.
– The @RM_MASTER tag for OS Server 1 is reset.
Failure, Switchover and Return of Fault-tolerant Components
6.4 OS server
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