You may have noticed that the web console has a time out limit. The default is 30 mins.
If you want to change this you need to change the web.config file. (backup this file first before making any changes)
The default location is c:\program files\system center 2012\Operations Manager\WebConsole\WebHost\web.config
Search for <connection autoSignIn=”True” autoSignOutInterval=”30″>
If you set the value to 0 = unlimted