eWON Family - eWON Support

General Reference Guide eWON Configuration
Flash Memory zone Size Description
Historical data 1 to 3 MB
Retentive values 64 KB
System Config 256 KB
Communication Config 64 KB
/usr partition 1 to 16 MB
/sys partition 0 to 1 MB
Used for storing historical data. This file system is located in its own partition.
This partition contains 3 files that contain circular data:
• Incremental recordings
• Events logging
• Alarm history logging
Each of those files receives a predefined maximum amount of space. When this
amount of space is reached, then the older data are erased, in order to free space for
the new data.
This is a fixed flash memory block that contains the retentive values.
The dimension of that block does not need to be modified.
The System configuration is:
• All eWON parameters (except COM)
• All Tags definitions
• All Users definitions
The communication configuration needs to be saved in a distinct block in order to
allow formatting any other data in the eWON without risking to loose contact with the
device (Ethernet IP address, PPP configuration etc.).
This configuration uses a fixed memory size and is stored with a special mechanism
that prevents loosing the configuration even if power is lost at any time during the
configuration update.
The only risk is to loose the last modification made after last save occurred.
Communication Configuration consists in all the configuration information that
appears in the ComCfg.txt file.
This partition uses a different file system, allowing to create a larger number of files
and to use a larger total flash memory.
This file system is also very robust in case of power lost during the time when
operations are performed on the files.
This partition can be used through the eWON’s FTP server or using the eWON’s
BASIC scripts.
If the /sys partition does not exists, the program and the configuration are then stored
in this partition (see below: /sys partition).
This partition uses the same file system as the /usr partition described above.
Its function is to store the program and the configuration.
The configuration includes all the information that appear in the config.txt file.
When this partition is formatted, the configuration and the program are erased, but
the current configuration and program are still in memory.
If the eWON is rebooted at that moment, it will use after restarting a default
configuration and an empty program.
When the configuration or the program are saved, the eWON uses this partition to
save a config.sys and a program.sys files. These files are used internally by the
eWON and should not be modified by the user.
If the partition size is set to 0 MB (eWON with only 8MB), then the partition is not
created, and all /sys data are saved in the "/usr" partition.
RG-001-0-EN ver 1.6 eWON® - 22/06/2009 - ©ACT'L sa Page 64