Installing updates and service packs   
3.3 Checking plant status 
  Compendium Part D - Operation and Maintenance (V9.0) 
22  Operating Manual, 02/2018, A5E43228948-AA 
Redundancy status on the OS server 
The following internal variables of the "Redundancy" group can be checked in the variable 
management area on the OS server to determine the redundancy status of the OS server. 
The values of the internal variables can be determined in the OS server's WinCC Explorer at 
runtime. These are displayed in the "Value" column. 
 
 
When attempting to deactivate runtime on one of the two redundant servers, a check is 
made in the system to see whether there is a redundancy problem and this will be indicated 
in the event of an error. 
@RM_MASTER  The @RM_MASTER variable is set to identify the server com-
puter as the master. The @RM_MASTER variable will be reset if 
the server computer is in "standby". 
@RM_MASTER_NAME  The computer name of the master server is specified in the 
@RM_MASTER_NAME variable. 
This variable contains the computer name of the OS server. 
@RM_OFFLINE_UA_NAME  Used for diagnostic purposes, a separate variable is created 
with a corresponding archive name for each user archive.