Automatic Memory Reset - Siemens SIMATIC ET 200SP System Manual

Commissioning
10.7 CPU memory reset
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 (permanently lit yellow).
Result after memory reset
The following table provides an overview of the contents of the memory objects after
memory reset.
Memory object
Actual values of the data blocks, instance data blocks
Bit memory, timers and counters
Retentive tags from technology objects
(for example, adjustment 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 from technology objects are retained but the content of specific tags is partly re-
initialized.
10.7.1

Automatic memory reset

Possible cause of an 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 cannot be completely loaded into work memory.
● The project data on the SIMATIC memory card is corrupt, 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.
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Content
Initialized
Initialized
Retained
Retained
Initialized
Retained
Retained
Retained
Distributed I/O system
System Manual, 12/2015, A5E03576849-AF