Omron CJ2 CPU UNIT SOFTWARE User Manual page 269

Data File Names
Data files do not contain information indicating what data is stored, i.e., what memory area is stored. Be
sure to give file names that indicate the contents, as shown in the examples below, to aid in file man-
agement.
Examples: D00100.IOM, CIO0020.IOM
Data from the beginning of the file will be written starting at the address specified in I/O memory even if
the data originally written to the data file (IOM, TXT, or CSV) is not from the same area. For example, if
CIO data in a file is written to the DM Area from a Programming Device, the data will be read to the DM
Area of the CPU Unit without any indication that the area is different.
Additional Information
Data files with the TXT and CSV format contain hexadecimal (0 to 9, A to F) data that allows the
I/O memory numerical data to be exchanged with spreadsheet programs.
ASCII data in I/O memory can be saved as a text file by using the TWRIT(704) (WRITE TEXT
FILE) ladder programming instruction or the Memory Card processing function WRITE_TEXT ( )
in ST language.
Additional Information
The following illustration shows the binary data structure of a data file (ABC.IOM) containing four
words from I/O memory: 1234 hex, 5678 hex, 9ABC hex, and DEF0 hex. The user, however,
does not have to consider the data format in normal operations.
I/O memory
• Structure of CSV and TXT Data Files with Single-word Fields
The following illustration shows the data structure of a CSV data file (ABC.CSV) with single-word
fields containing four words from I/O memory: 1234 hex, 5678 hex, 9ABC hex, and DEF0 hex.
I/O memory
CJ2 CPU Unit Software User's Manual
XX
XX
1234
to
5678
XX
9ABC
12
DEF0
34
56
78
9A
BC
DE
F0
Contents of ABC.IOM
1
31
2
32
33 3
Converted
1234
4
to ASCII 34
5678
,
2C
9ABC
35 5
DEF0
6
36
37 7
8
38
,
2C
to
Contents of ABC.CSV
48 bytes (used by system)
8 bytes
4 bytes
Delimiter
1234,5678,9ABC,DEF0
4 bytes
The file displayed as text.
Delimiter
7 File Operations
7-17
7