Siemens Simatic S7-1500 / ET 200MP - CPU Memory Reset

Commissioning
12.6 CPU memory reset
Automation system
System Manual, 01/2023, A5E03461182-AK
271
12.6 CPU memory reset
Basics of a memory reset
The CPU must be in STOP mode for a memory reset.
A memory reset returns the CPU to its "initial state".
Memory reset means:
• An existing online connection between your programming device/PC and the CPU is
terminated.
• The content of the work memory and the retentive and non-retentive data are deleted
(with manual memory reset).
• The diagnostics buffer, time of day, and IP address are retained.
• Subsequently the CPU is initialized with the loaded project data (hardware configuration,
code and data blocks, force jobs). The CPU copies this data from the load memory to the
work memory.
Result:
– If you set an IP address 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.
Detecting a CPU memory reset
The RUN/STOP LED flashes yellow at 2 Hz. After completion, the CPU switches to STOP. The
RUN/STOP LED is on (constant yellow light).
Result after memory reset
The following table provides an overview of the contents of the memory objects after
memory reset.
Table 12- 4 Memory objects after memory reset
Memory object
Contents
Actual values of the data blocks, instance data blocks
Initialized
Bit memories, timers and counters
Initialized
Retentive tags of technology objects
(e.g. adjustment values of absolute encoders)
Retained
Diagnostics buffer entries
Retained
IP address
Retained
Device name
Retained
Counter readings of the runtime meters
Retained
Time of day
Retained
CPU operating state: RUN/STOP
1)
The CPUs retain the RUN or STOP state.
1)
Only with standard, F-CPUs/compact CPUs as of article number 6ES751x-xxx02-0AB0/6ES751x-1CK01-0AB0