File Access Restriction Function - Mitsubishi Electric MELSEC Q Series User Manual

11.8.3

File access restriction function

This function restricts accesses to prevent unauthorized editing on files stored on the standard ROM, standard RAM,
or work RAM (when RAM drive is used).
By setting file attributes (a system file attribute and/or a hidden file attribute) to files under the memories described
below, accesses to the files are restricted, and thus the falsifications by unauthorized users or file leaks can be
prevented.
Target memory
Standard ROM (/ROM)
Work RAM (/specified by user)
Standard RAM (/RAM)
SD memory card (/SD)
CompactFlash card (/CF)
USB device (/USB0)
• Attributes of files on the system ROM (/SYSTEMROM) cannot be changed.
• Accessing to the files stored on an SD memory card, CompactFlash card, or USB device can also be restricted.
Since all files can be accessed when an access-authorized SD memory card, CompactFlash card, or USB device
is connected with a module other than a C Controller module, conduct a measure to prevent the removal of the
SD memory card, CompactFlash card, or USB device.
• The access authority cannot be set to a directory using this function.
(1) File attributes
File attributes can be changed with the password set in "File access restriction setting" on the <<Security
settings>> tab of Setting/monitoring tools for the C Controller module.
For details of the file access restriction setting, refer to the following.
Setting/Monitoring Tools for the C Controller Module Version 4 Operating Manual
(a) File attribute setting
Use the attrib() command to set the file attribute on the file to be protected.
The following shows the file attributes that can be used on C Controller module.
Attribute
S: System file attribute
R: Read-only attribute
H: Hidden file attribute
*1 : Operations on the file are allowed when the file name is directly specified.
The system file attribute must be specified to prohibit the operations.
For details of the attrib() command, refer to the manual for Vx Works.
Remark
-
-
-
-
-
Mass storage compatible device
The file operation can be prohibited when the file access restriction is
enabled.
Deleting and writing files can be prohibited.
Files are not displayed on the lists of ls command and FTP file when
*1
the file access restriction is enabled.
CHAPTER 11 BASIC FUNCTIONS
Q24DHC-LS
Q24DHC-V Q24DHC-VG
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CPU module
Q24DHC
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Description
Q26DHC-LS
Q12DC-V
11
Q12DC
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