Non-Volatile Memory Organization

Introduction

The non-volatile memory contains the file system used by the controller.

File Type

The Modicon M241 Logic Controller manages the following file types:

Type

Description

Boot application

This file resides in non-volatile memory and contains the compiled binary code of the executable application. Each time the controller is rebooted, the executable application is extracted from the boot application and copied into the controller RAM (1).

Application source

Source file that can be uploaded from non-volatile memory to the PC if the source file is not available on the PC (2).

Post configuration

File that contains Ethernet, serial line, and firewall parameters.

The parameters specified in the file override the parameters in the executable application at each reboot.

Data logging

Files in which the controller logs events as specified by the application.

HTML page

HTML pages displayed by the web server for the website embedded in the controller.

Operating System (OS)

Controller firmware that can be written to non-volatile memory. The firmware file is applied at next reboot of the controller.

Retain variable

Remanent variables

Retain-persistent variable

(1): The creation of a boot application is optional in EcoStruxure Machine Expert, according to application properties. Default option is to create the boot application on download. When you download an application from EcoStruxure Machine Expert to the controller, you are transferring only the binary executable application directly to RAM

(2): EcoStruxure Machine Expert does not support uploading of either the executable application or the boot application to a PC for modification. Program modifications must be made to the application source. When you download your application, you have the option to store the source file to non-volatile memory.

File Organization

This table shows the file organization of the non-volatile memory:

Disk

Directory

File

Content

Up/Downloaded Data Type

/sys

OS

M241M251FW1v_XX.YY (1)

Firmware of core 1

Firmware

M241M251FW2v_XX.YY (1)

Firmware of core 2

Version.ini

Control file for firmware version

Web

Index.htm

HTML pages served by the web server for the website embedded in the controller.

Website

Conf.htm

 

/usr

App

Application.app

Boot application

Application

Application.crc

Application.map

Archive.prj (2)

Application source

settings.conf (3)

OPC UA configuration

Configuration

OpcUASymbolConf.map (3)

OPC UA symbols configuration

Configuration

Cfg

Machine.cfg (2)

Post configuration file

Configuration

CodesysLateConf.cfg (2)

  • Name of application to launch

  • Routing table (main/sub net)

Configuration

/usr

Log

UserDefinedLogName_1.log

All *.log files created using the data logging functions (see EcoStruxure Machine Expert - Data Logging Functions - DataLogging Library Guide). You must specify the total number of files created and the names and contents of each log file.

log file

UserDefinedLogName_n.log

Rcp

 

Main directory for recipe

Syslog

crashC1.txt(2)

crashC2.txt(2)

crashBoot.txt(2)

This file contains a record of detected system errors. For use by Schneider Electric Technical Support.

Log file

PlcLog.txt (2)

This file contains system event data that is also visible online in EcoStruxure Machine Expert by viewing the Log tab of the Controller Device Editor.

FwLog.txt

This file contains a record of firmware system events. For use by Schneider Electric Technical Support.

/usr

Fdr/FDRS (4) only for TM241CE•

Device1.prm

Parameter files stored by the FDR client device1

FDR

/data

Retained and persistent data

/sd0

SD card. Removable

User files

(1): v_XX.YY represents the version

(2): if any

(3): if OPC UA is configured

(4): the Fdr/FDRS directory is hidden

NOTE: For more information on libraries and available function blocks, refer to Libraries.

Files Redirection

When system, program or certain user activity creates specific file types, the M241 Logic Controller examines the file extension and automatically moves the file to a corresponding folder in non-volatile memory.

The following table lists the file types that are moved in this way and the destination folder in non-volatile memory:

File extensions

Non-volatile memory folder

*.app, *.ap_, *.err, *.crc, *.frc, *.prj

/usr/App

*.cfg, *.cf_

/usr/Cfg

*.log

/usr/Log

*.rcp, *.rsi

/usr/Rcp

Backup Data Logging File

Data logging files can become large to the point of exceeding the space available in the file system. Therefore, you should develop a method to archive the log data periodically on an SD card. You could split the log data into several files, for example LogMonth1, LogMonth2, and use the ExecuteScript command to copy the first file to an SD card. Afterwards, you may remove it from the internal file system while the second file is accumulating data. If you allow the data logging file to grow and exceed the limits of the file size, you could lose data.

NOTICE
LOSS OF APPLICATION DATA
  • Backup SD card data regularly.
  • Do not remove power or reset the controller, and do not insert or remove the SD card while it is being accessed.
Failure to follow these instructions can result in equipment damage.