File Allocation Table - Siemens S7-300 Configuration Manual

1. Identifies the addressed file DB based on the entry in the file allocation table.
2. Checks the bits in the file DB header (see /10/ (Page 230)); the write function is executed
3. Writes the file content to the user data area of the file DB on the CPU. At the beginning of
4. When the write function is completed, the NEW bit is also set in the file DB header and
5. The FTP server sends a message about the file transfer event to the FTP client.
Transfer mode for file transfer
File transfer only uses the binary mode. To change to this mode, enter the command
"binary" in the input console after logging on.
9.3.3

File allocation table

Meaning
In the FTP server role, the Advanced CP requires information on how the data blocks used
in the S7 station for file transfer are mapped to files. You store this file assignment table in
the file_db.txt file in the file system of the Advanced CP.
Structure
The file allocation table has two areas in which the allocations are stored row-oriented
according to the scheme shown in the following example:
● Rack/slot assignment of the CPU
● DB assignment
Configuring and commissioning S7 CPs for Industrial Ethernet
Configuration Manual, 09/2013, C79000-G8976-C182-13
only when the following applies:
LOCKED bit = 0
NEW bit = 0
WRITEACCESS bit = 1
the write function, the LOCKED bit is set and reset when writing is completed.
the current date entered in the DATE_TIME field.
Note
If you specify a file for the transfer that is not included in the file allocation table, the
requested file system operation is executed on the current folder.
File management and file access with FTP/FTPS
9.3 Advanced CP as FTP server for the S7 CPU data
153