Load And Working Memory; Memory Functions - Siemens SIMATIC ET 200S Manual

8.4.2

Memory functions

Introduction
You use the memory functions to generate, modify or erase user programs and
individual blocks. The memory functions also allow you to archive your own project
data in order to ensure the retentivity of your data.
General: Downloading the user program using the PD/PC
The complete user program is downloaded to the IM 151-7 CPU from the MMC
using the PD/PC. In certain situations, all of the blocks stored in the load memory
may be erased when the user program is downloaded.
In the load memory, blocks occupy the space specified under "Load Memory
Requirement" in the "General Block Properties".
Programming device
Stored on
Code blocks
Data blocks
Comments
Figure 8-4
The program cannot be started until all of the blocks have been loaded.
Note
The function is only permitted when the CPU is in STOP mode.
The load memory remains empty if loading could not be completed owing to a
power failure or invalid blocks.
ET 200S IM 151-7 CPU Interface Module
A5E00058783-04
the hard disk
Symbols

Load and working memory

Functions of the IM 151-7 CPU
MMC
6ES7 953 8Lx00 0AA0
Load memory
Code blocks
Data blocks
Working memory
Process-related
parts of the code
and data
blocks
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