Omron SYSMAC CJ - REFERENCE MANUAL 08-2008 Reference Manual page 1149

File Memory Instructions
Note
Description
string. Do not include the filename extension; the .IOM, .TXT, or .CSV exten-
sion is added automatically.
D2
F1
D2+1 F3
D2+38
F73
1. Be sure that the character string containing the pathname and filename
does not exceed the end of the data area.
2. If the specified directory does not exist, the File Missing Flag (A34311) will
be turned ON and the file data will not be written.
Write the pathname and filename in ASCII beginning with the leftmost byte of
D2, as shown in the following example for \ABC\XYZ.IOM. (The extension is
added automatically.)
D2
D2+1
D2+2
D2+3
D2+4
For information on creating directories from the ladder program, refer to Sec-
tion 5 File Memory Functions in the SYSMAC CS/CJ Series Programmable
Controllers Programming Manual (W394).
S: First Source Word
S specifies the starting address containing the data that will be written to the
file memory. Data is read by absolute PLC memory addresses, so
FWRIT(701) will continue reading source data from the next data area if the
number of words being read exceeds the end of the data area specified in S.
During normal instruction processing, FWRIT(701) is used only to start writing
of the file memory. The instruction execution times given toward the end of
this manual are thus the times required to start writing, not to complete it.
Actual writing (transfer) is performed by the file access processing in periph-
eral servicing. Therefore, once FWRIT(701) has been executed, writing is
continuously executed even if the execution condition is OFF in following
cycles. When transfer has been completed, the File Memory Operation Flag
(A34313) will turn OFF. This flag can be used for exclusive control of file mem-
ory instructions.
The time required to complete data transfer for FWRIT(701) will depend on
the amount of data being transferred, the service time allocated to file access
processing, and other conditions. As a guideline, the transfer times for a cycle
time of 10 ms for a file in the root directory with the default service time set-
tings will be 1.97 s (new file) or 1.33 s (existing file) for 1,024 words and 6.64 s
(new file) or 6.12 s (existing file) for 9,999 words.
The source data is read from absolute internal memory addresses in RAM, so
the entire block of data will be read even if the data spans two or more data
areas. For example, if the first destination address is in the Work Area but the
amount of data exceeds the capacity of this area, FWRIT(701) will continue
reading data at the beginning of the next area (in this case, the Timer Area).
Refer to Appendix D in the CS/CJ-series Programmable Controllers Operation
Manual (W339) for a memory map showing the location of data areas in RAM.
When FWRIT(701) is executed, the number of words or fields specified in D1
and D1+1 is written to A346 and A347 (Number of Data to Transfer) and this
value is decremented by 1 as each word or field is transferred. The content of
Store the character string beginning
F2
with the leftmost byte in D2.
F4
The entire pathname and filename can
be up to 74 characters (bytes) long,
including the initial slash character and
F74
ending null character.
'\ ' 'A' D2 5C
'B' 'C'
D2+1 42
'\ ' 'X'
D2+2 5C
'Y' 'Z'
D2+3 59
NUL
D2+4 00
Section 3-26
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43
58
5A
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