Memory Areas Of The Im 151-7 Cpu; Memory Concept - Siemens SIMATIC ET 200S Manual

Functions of the IM 151-7 CPU
8.4

Memory concept

8.4.1

Memory areas of the IM 151-7 CPU

Organization
The memory of the IM 151-7 CPU can be divided into three areas:
IM 151-7 CPU
MMC
Load memory
Figure 8-3
Load memory
The load memory is installed on a SIMATIC micro memory card (MMC). It is used
to record code and data blocks as well as system data (configuration, connections,
module parameters, etc.).
Blocks which are designated as non-process-related are recorded in the load
memory.
The complete configuration data for a project can also be stored on the MMC.
Your program in the load memory (MMC) is always retentive. When downloaded, it
is stored on the MMC such that it is unaffected by power failures and is not erased
by memory resets.
Note
The IM 151-7 CPU can only be operated with the MMC inserted.
8-12
Memory areas of the IM 151-7 CPU
Working memory
System memory
ET 200S IM 151-7 CPU Interface Module
A5E00058783-04