Mitsubishi MELSEC Q Series Reference Manual page 225

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3 WHEN COMMUNICATING USING THE QnA COMPATIBLE 3E/3C/4C FRAMES OR 4E FRAME
4) The file number of an already registered file can be checked using the
functions described in Sections 3.8.6, 3.8.16, and 3.8.17.
On a QnACPU, when registering a new file, the unused file numbers
can be checked using the read file number usage status function
described in Section 3.8.16 (3). (This cannot be checked in a
Q/LCPU.)
(e) Number of file requests, total number of registered files, and number of file
information
These data values indicate the number of files requested by the user,
number of files registered in the designated drive, and number of files that
return file information when reading the file information.
1) Data communication in ASCII code
The value given in the reference section relevant to the corresponding
function is converted to a 4-digit (hexadecimal) ASCII code and
sequentially transmitted beginning from the most significant digit ("0").
2) Data communication in binary code
The 2-byte value given in the reference section relevant to the
corresponding function is sequentially transmitted from the low byte (L:
bits 0 to 7).
(f) Number of characters of file name, filename, extension, and attribute
This is used to designate the file to be read, written, registered, etc.
1) For file name, extension, and location of files stored in Q/L/QnACPU
modules, refer to the user's manual (function explanation, program
fundamentals) of the CPU module used.
POINT
Files not described in the user's manual (function explanation, program
fundamentals) of the CPU module used may also be shown for file control. Do not
access them since they are for the system use.
2) When registering a new file or changing the file name, designate the
filename (maximum 8 single-byte characters) and extension according
to the file naming convention of the programming tool.
3) The number of characters of file name, filename, extension, and
attribute are handled in the following manner. The data order during
data communication differs depending on the command used;
however, it is the same whether communicating in ASCII code or in
binary code.
(Pattern 1) For Q/LCPU files
• Files to be accessed should be designated using the following data
order.
File name + "." + Extension
• The number of characters specified above should be designated as
the number of characters in the file name.
• The following example shows how to designate the data when the
file name is ABC.QPG.
The number of characters of file name: 7
File name: "ABC.QPG"
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