Commissioning
8.5 Memory reset
S7-1500 Automation System
106 System Manual, 01/2013, A5E03461182-01
8.5 Memory reset
Basics of a memory reset
A memory reset on the CPU is possible only in the STOP operating 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
terminated.
● The content of the work memory and the retentive and non-retentive data are deleted.
● Subsequently the CPU is initialized with the loaded project data (hardware configuration,
code and data blocks, force jobs). These data are copied from the load memory to the
work memory. As a result, the DBs no longer have current values but their initial values.
● The diagnostics buffer, the time of day and the IP address are retained, in as far as they
are not set in the project.
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 Contents
Actual values of the data blocks, instance data blocks Initialized
Bit memories, timers and counters Initialized
Certain retentive tags from technology objects
(for example, adjustment values of absolute encoders)
Retained
Diagnostics buffer entries (retentive area) Retained
Diagnostics buffer entries (non-retentive area) Initialized
Operating hours counter Retained
Time of day Retained
To Next Page
Loading...
