Automatic Memory Reset - Siemens SIMATIC S7-1500 System Manual

How can I tell if the CPU is performing a memory reset?
The RUN/STOP LED flashes yellow at 2 Hz. After completion the CPU goes into STOP
mode, and the RUN/STOP LED is switched on (unchanging yellow).
Result after memory reset
The following table provides an overview of the contents of the memory objects after
memory reset.
Table 10- 5
Memory object
Actual values of the data blocks, instance data blocks
Bit memories, timers and counters
Certain retentive tags of technology objects
(for example, calibration values of absolute encoders)*
Diagnostics buffer entries (retentive area)
Diagnostics buffer entries (non-retentive area)
IP address
Counter readings of the runtime meters
Time of day
* The retentive tags of technology objects are retained, but the contents of certain tags are partially
reinitialized.
10.6.1

Automatic memory reset

Possible cause of automatic memory reset
The CPU executes an automatic memory reset if an error occurs that prevents normal
further processing.
Causes for such errors can be:
● User program is too large, and can't be completely loaded into work memory.
● The project data on the SIMATIC memory card are damaged, for example because a file
was deleted.
● If you remove or insert the SIMATIC memory card and the backed-up retentive data
differs in structure from that of the configuration on the SIMATIC memory card.
Automation system
System Manual, 12/2014, A5E03461182-AC
Memory objects after memory reset
Commissioning
10.6 CPU memory reset
Contents
Initialized
Initialized
Retained
Retained
Initialized
Retained
Retained
Retained
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