Technical data

Memory areas and retentive memory
2.3 Summary of retentive behavior
Structure and Use of the CPU Memory
Function Manual, 01/2013, A5E03461664-01
17
Diagnostic buffer
With the S7-1500 CPUs, a portion of the diagnostic buffer is retentive. The number of
retentive diagnostic buffer entries depends on the type of CPU. The latest entries in the
diagnostic buffer are retained after power failure, and are not affected by a memory reset
The retentive portion of the diagnostic buffer can only be deleted by resetting to factory
settings. The entries in the diagnostic buffer allocate no storage space in the retentive
memory.
Operating hours counter
The operating hours counters of the S7-1500 CPUs are retentive and are not affected by a
memory reset. By resetting to factory settings, the clock time is set to zero.
Clock time
The clock time of the S7-1500 CPUs is retentive and is not affected by a memory reset. By
resetting to factory settings, the operating hours counters are set to 01/01/2012 00:00:00.
Reference
You can find additional information on Memory Reset and Resetting to Factory Settings in
the S7-1500 Automation System
(http://support.automation.siemens.
com
/WW/view/en/59191792) system manual.