File System - Siemens CP 243-1 Operating Instructions Manual

1.8

File system

How it works
A file system is available on the CP 243-1 to permanently store Web and configuration files.
This file system uses flash memory technology and provides a storage capacity of 8 Mbytes
minus the memory needed for administration of the flash file system.
Note
The amount of memory actually available in the file system can be called with the HTML
page "CP 243-1 Information" (ships with the CP 243-1) via a Web browser at the following
address:
http://<destination IP address>/__S7Sys/it_info.htm
Due to the formatting of the file system, the amount of memory specified on this page cannot
always be fully utilized.
The file system supports path and file names up to a total length of 254 characters. The drive
name of the flash file system (/flash:) is also included in these 254 characters. This means
that, after the drive name is deducted, 247 characters remain for a maximum path including
the file name. The actual file name and every name of a directory can have a maximum
length of 99 characters. The maximum nesting depth of the directories is 19.
The following characters must not be used in either the file or directory name:
\ ; / ; < ; > ; " ; : ; * ; ?
Note
We recommend that you store files in suitable subdirectories and not in the root directory.
The CP 243-1 has no real-time clock for the date or time. For this reason, all files stored in
the file system of the CP 243-1 have the date 01.01.1980 and the time 00:00.
Access
The file system can only be accessed via the FTP server of the CP 243-1. The file system
does not distinguish between upper case and lower case letters.
Restriction
NOTICE
The life of a file system based on flash memory technology is primarily determined by the
total number of write or delete operations performed on it. This means that such a file
system is not suitable for fast cyclic write or delete operations.
CP 243-1
Operating Instructions, 03/2012, C79000-G8976-C244-02
Application and properties
1.8 File system
33