Parameterizing the Mobile Panel   
5.8 General settings 
  Mobile Panels 2nd Generation 
114  Operating Instructions, 09/2018, A5E33876626-AC 
When the retentivity of the alarm buffer is activated, the retentive alarm data is backed up 
every two seconds to the internal flash memory of the HMI device. With a high number of 
alarms, the internal flash memory is subject to an equally high number of read and write 
cycles. 
If the retentivity of the alarm buffer is deactivated, the alarm buffer is emptied and the 
retentive alarm data is no longer backed up to the internal flash memory. This means the 
internal flash memory is used less with a high number of alarms. 
 
Note 
Safety-related alarms are also affected 
If the retentivity of the alarm buffer is
 deactivated, safety-related alarms too are no longer 
backed up to the internal flash memory.
 
Backing up data before deactivating the retentivity 
When you deactivate the retentivity of the alarm buffer and still need the data in the alarm 
buffer, back up t
his data before deactivating the retentivity in a log. 
Changing the retentivity behavior using the configuration 
As of WinCC (TIA Portal) V15.1 you can also change the retentivity behavior with the 
"Persistent alarm buffer" function under "Runtime settings
 > Alarms > General". Default 
setting in the configuration is "activated". For the project transfer, the setting is applied from 
the configuration in the Control Panel. If you change the setting in the Control
 
Panel after the 
project transfer, the changed 
setting is retained until the next project transfer. 
Requirement  
The Control Panel is open.  
Procedure 
Proceed as follows: 
1.  Open the "OP Properties" dialog using the "OP" icon. 
2.  Change to the "Message Buffer" tab. 
 
3.  You activate or deactivate the retentive message buffer with the "Persistent Message 
Buffer Enabled..." option, default setting is "activated". 
4.  Confirm your entries with "OK". 
5.  Restart the HMI device, see section "Restarting the HMI device (Page 101)".