Non-Volatile Memory Organization

Introduction

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

File Type

The Modicon M262 Logic/Motion Controller manages the following file types:

System function (/sys)	Description
Operating System (OS)	Controller firmware that can be written to non-volatile memory. The firmware file is applied at next reboot of the controller.

User functions (/usr)	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 and serial line parameters. The parameters specified in the file override the parameters in the executable application at each reset.
Firewall parameters	Settings used to configure the firewall of the M262 Logic/Motion Controller. These settings restrict access to authorized personnel and protocols only. See Firewall Configuration for more information.
Data logging	Files in which the controller logs events as specified by the application.
(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 the 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	Pkg	Temporary file	Internal use	N/A
/usr	App	Application.app	Boot application	Application
		Application.crc	Boot application	–
		Archive.prj ⁽¹⁾	Application source	–
	Cfg	Machine.cfg ⁽¹⁾	Post configuration file	Configuration
		CodesysLateConf.cfg	Name of application to launch.	Configuration
		FirewallDefault.cmd	Default firewall settings. By default, this file does not exist. It can be added optionally.	Configuration
		ntp.conf	Contains the network time protocol (NTP) configuration.	Configuration
		ntp.drift.	Contains the calculated drift of the system clock compared to UTC time.	Configuration
	Log	UserDefinedLogName_1.log	All *.log files created using the data logging functions. You must specify the total number of files created and the names and contents of each log file using the datalogging feature.	log file
	Log	UserDefinedLogName_n.log		–
	pki	–	Certificate store for M262 secured protocols.	–
	Rcp	–	Main directory for recipes.	–
	Syslog	crash.txt⁽¹⁾ LoggerFile_xxx.mel	Record of detected system errors. For use by Schneider Electric Technical Support.	Log file
	Visu	–	Used for the WebVisualisation feature.	–
	_cnc	UserDefinedName.cnc	Pre-programmed control commands	G-code data
	Alarms	Application.alarmstorage.X.sqlite Application.alarmstorage.X.sqlite.metadata	Database of configured alarms	Alarm manager data
	Trend	Application.TrendRecording.X.sqlite Application.TrendRecording.X.sqlite.metadata	Database of configured trends. Refer to Trend Storage Limits.	Trend recorder data
/sd0	–	–	SD card. Refer to Managing Script Files.	–
/sd0	–	User files	–	–
(1) If the files had been created due to specific events or customer requirements.

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

Trend Storage Limits

This table shows the storage limits of the Trend feature:

Element	Limit
Number of variables	255 maximum
Storage size	250 Mb maximum (including 1 Mb if the Alarms feature is used)

For more information on Trend feature, refer to the EcoStruxure Machine Expert Programming Guide.

Files Redirection

When system, program or certain user activity creates specific file types, the M262 Logic/Motion 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.