Unlocated Data

This zone contains unlocated data:

  • Boolean and numerical data

  • EFB and DFB

Located Data

This zone contains located data (State Ram):

Address

Object address

Data use

0xxxxx

%Qr.m.c.d,%Mi

output module bits and internal bits.

1xxxxx

%Ir.m.c.d, %Ii

input module bits.

3xxxxx

%IWr.m.c.d, %IWi

input register words of input/output modules.

4xxxxx

%QWr.m.c.d, %MWi

output words of input/output modules and internal words.

User Program

This zone contains the executable codes of the application.

  • program code

  • code associated with EFs, EFBs and the management of I/O modules

  • code associated with DFBs

  • initial variable values

This zone also contains the necessary information for downloading the application: graphic codes, symbols etc.

Operating System

On 140 CPU 31••/41••/51•• processors, this contains the operating system for processing the application. This operating system is transferred from an internal EPROM memory to internal RAM on power up.

Application Backup

A Flash EPROM memory zone of 1435K8, available on processors 140 CPU 31••/41••/51••, can be used to backup the program and the initial values of variables.

The application stored in this zone is automatically transferred to internal RAM when the PLC processor is powered up (if the PLC MEM switch is set to off on the processor front panel).

Other Information

Other information relating to the configuration and structure of the application are also stored in the memory (in a data or program zone depending on the type of information).

  • Configuration: other data relating to the configuration (hardware configuration, software configuration).

  • System: data used by the operating system (task stack, etc.).

  • Diagnostics: information relating to process or system diagnostics, diagnostics buffer.