Memory Reset - Siemens SIMATIC S7-1500 System Manual

9.5

Memory reset

Basics of a memory reset
A memory reset on the CPU is possible only in the STOP mode.
When memory is reset, the CPU is changed to a so-called "initial status".
This means that:
● An existing online connection between your programming device/PC and the CPU is
● The content of the work memory and the retentive and non-retentive data (applies only to
● The diagnostics buffer, time of day, and IP address are retained.
● Subsequently the CPU is initialized with the loaded project data (hardware configuration,
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.
Memory object
Actual values of the data blocks, instance data blocks
Bit memories, timers and counters
Certain retentive tags from technology objects
(for example, adjustment values of absolute encoders)
Diagnostics buffer entries (retentive area)
Diagnostics buffer entries (non-retentive area)
Counter readings of the runtime meters
Time of day
S7-1500 Automation System
System Manual, 02/2014, A5E03461182-AB
terminated.
manual memory reset by the user) are deleted.
code and data blocks, force jobs). These data are copied from the load memory to the
work memory.
Result:
– If an IP address was set in the hardware configuration ("Set IP address in the project"
option) and a SIMATIC memory card with the project is in the CPU, this IP address is
valid after the memory reset.
– Data blocks no longer have current values but rather their configured start values.
– Force jobs remain active.
Commissioning
9.5 Memory reset
Contents
Initialized
Initialized
Retained
Retained
Initialized
Retained
Retained
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