Storage Concept And Startup Types; Overview Of The Memory Concept Of S7-400 Cpus - Siemens SIMATIC S7-400 Manual

Storage Concept and Startup Types

8.1

Overview of the memory concept of S7-400 CPUs

Organization of Memory Areas
The memory of the S7 CPUs can be divided into the following areas:
External load memory
RAM with battery backup
or
retentive flash memory
Integrated load memory
RAM with battery backup
Working memory code
For the program
RAM with battery backup
Process Image of Inputs
And Outputs
Diagnostic buffer
Working memory data
for data
RAM with battery backup
Local data stack
System memory
Contains flags, timers, counters,
Block stack and
interrupt stack
RAM with battery backup
Figure 8-1
S7-400 Automation System, CPU Specifications
Manual, 10/2006, 6ES7498-8AA04-8BA0
Memory areas of the S7-CPUs
Load memory
For project data (blocks, symbols,
comments, configuration and parameter
assignment data)
Working memory
For runtime-relevant blocks
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