Cpu Memory Reset; Introduction - Siemens Simatic ET200pro Operating Instruction

7.5

CPU memory reset

7.5.1

Introduction

Basics of a memory reset
A memory reset on the CPU is possible only in the STOP mode.
During memory 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
terminated.
● The content of the work memory and the retentive and non-retentive data (applies only to
manual memory reset by the user) are deleted.
● 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"
– Data blocks no longer have current values but rather their configured start values.
– Force jobs remain active.
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 7- 4 Memory objects after memory reset
Memory object
Actual values of the data blocks, instance data blocks
Bit memories, timers and counters
Retentive tags of technology objects (e.g. adjustment values of absolute encoders)
Diagnostics buffer entries (retentive area)
Diagnostics buffer entries (non-retentive area)
IP address
Device name
Counter readings of the runtime meters
Time of day
CPU 1516pro-2 PN (6ES7516-2PN00-0AB0)
Operating Instructions, 09/2016, A5E35873416-AA
option) and a SIMATIC memory card with the project is in the CPU, this IP address is
valid after the memory reset.
Commissioning
7.5 CPU memory reset
Contents
Initialized
Initialized
Retained
Retained
Initialized
Retained
Retained
Retained
Retained
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