Introduction

The memory usage function is used to view:

  • The physical distribution of the PAC memory.

  • The space taken up in the memory by a project (data, program, configuration, system and diagnostic).

It can also be used to reorganize the memory where possible.

NOTE: The memory usage screen is not available in simulation mode. This screen is only available in standard mode when you have built the application.

Procedure

To access the memory usage details of the PAC:

Step

Action

1

Select PLC > Memory Consumption:.

The Memory usage window opens. The memory usage statistics of a project can only be accessed if you have generated its executable in advance.

2

To optimize memory organization, click Pack.
NOTE: If the application has been built and if it is in NOT BUILT state due to a program modification, the screen is accessible, but it corresponds to the application built previously. Modifications will be taken into account at the next build.

Description of the parameters

The following information fields are available:

Parameter

Description

User Data

This field indicates the memory space (in words) taken up by user data (objects relating to configuration):

  • saved Data: located data associated with the processor (%M, %MW, %S, %SW, etc.) or the input/output modules. This data is retained by the CPU in the event of a CPU warm start.

  • saved Declared Data : unlocated data (declared in the data editor) that is retained by the CPU in the event of a CPU warm start.

  • unsaved Declared Data unlocated data (declared in the data editor) that is not retained by the CPU in the event of a CPU warm start.

User program

This field indicates the memory space (in words) taken up by the project program:

  • Constants: static constants associated with the processor (%KW) and the input/output modules; initial data values,

  • Executable code: executable code of the project program, EFs, EFBs and DFB types,

  • Upload information : information for uploading a project (graphic code of languages, symbols, etc.).

Other

This field indicates the memory space (in words) taken up by other data relating to the configuration and the project structure:

  • Configuration: other data relating to configuration (Page0 for a Quantum PAC, hardware configuration, software configuration),

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

  • Diagnostic: information relating to process or system diagnostics, diagnostics buffer,

  • Data Dictionary: dictionary of symbolized variables with their characteristic (address, type....)

Internal memory

This field shows the organization of the PAC's internal memory, for both program and data storage. It indicates the memory space available (Total ), the largest possible contiguous memory space ( Greatest) and the level of Fragmentation (due to online modifications).

Pack

This command is used to reorganize the memory structure.

Memory re-organization

Memory re-organization is activated using the Pack command.

Memory re-organization can be performed in online or offline mode (Even if the PAC is in Run or in Stop).

NOTE: Certain blocks cannot be moved in online mode. You will attain a lower level of fragmentation by re-organizing the memory in offline mode.