Siemens MOBY FC 56 Technical Description page 34

MOBY Commands
WRITE: Write data to an existing file (see chapter 4.2.5)
S A certain number of bytes is written to the existing file ("length" parameter in
UDT 50) from DAT_DB_number.
S The WRITE command overwrites existing file data from logical address 0 with
length "length." If the data length "length" specified in the WRITE command is
shorter than the already existing file length, the old data remains valid starting
at the logical address "length" up to the end of the file.
READ: Read data from a file (see chapter 4.2.6)
The complete file (see WRITE ) is read into the specified data block
DAT_DB_number/DAT_DB_address.
DELETE: Delete existing file (see chapter 4.2.7)
S The specified file (file name) is removed from the directory.
S All file data is lost.
S The DELETE command is only permissible on SLGs with access rights
(priority) "D."
S A delete-protected file cannot be deleted. Use the ATTRIB command before
deletion.
ATTRIB: Assign attributes (write or delete protection) to file (see chapter 4.2.8)
S A write or delete protection attribute can be assigned to the specified file. This
file cannot then be overwritten or deleted.
S An attribute assigned to a file can be removed (sub_command_1 = 0). The file
can then be overwritten or deleted again.
S The attribute assigned to a file is stored in the directory.
COVER: Protect MDS structure (see chapter 4.2.9)
The data structure of a data carrier can be protected against "unauthorized
access". An "unauthorized access" occurs if any user (e.g. supplier) wants to
execute the following write operations on the MDS.
S delete file or add data
S increase or decrease file length
S format data carrier, if already formatted
S delete or assign attribute
A data memory layout (i.e., a specified DIR + FAT structure) specified by the
authorized user (i.e., super user) cannot be changed or destroyed.
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FC 56
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