Memory Concept; Memory Areas And Retentivity; Cpu Memory Areas - Siemens CPU 31 Series Technical Data Manual

Memory concept

4.1

Memory areas and retentivity

4.1
4.1.1

CPU memory areas

The three memory areas of your CPU:
Load memory
The load memory is located on the SIMATIC Micro Memory Card (MMC). The size of the
load memory corresponds exactly to the size of the SIMATIC Micro Memory Card. It is used
to store code blocks, data blocks and system data (configuration, connections, module
parameters, etc.). Blocks that are identified as non runtime-related are stored exclusively in
load memory. You can also store all the configuration data for your project on the SIMATIC
Micro Memory Card.
Note
User programs can only be downloaded and thus the CPU can only be used if the SIMATIC
Micro Memory Card is inserted in the CPU.
CPU 31xC and CPU 31x, Technical Data
Manual, 01/2006 Edition, A5E00105475-06
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4-1