Nj-Series Instructions Reference Manual (W502 - Omron NJ501-1500 Reference Manual

2 Instruction Descriptions
Precautions for Correct Use
• Execution of this instruction is continued until processing is completed even if the value of Execute
changes to FALSE or the execution time exceeds the task period. The value of Done changes to
TRUE when processing is completed. Use this to confirm normal completion of processing.
• Refer to Using this Section on page 2-2 for a timing chart for Execute, Done, Busy, and Error.
• If a file is open when the operating mode of the CPU Unit is changed to PROGRAM mode or when a
major fault level Controller error occurs, the file is closed by the system. Any read/write operations
that are in progress are completed to the end.
• If a file is open when the power supply it stopped with the power switch, the file is not corrupted.
• If a file is open and the SD Memory Card is removed before the power switch is pressed, the contents
of the file will sometimes be corrupted. Always turn OFF the power supply before removing the SD
Memory Card.
• If a file is open when the power supply is stopped or the SD Memory Card is removed, it will not be
possible to read or write the file even if the SD Memory Card is inserted again.
• If the directory that is specified with DirName is write protected, an error occurs and the directory is
not deleted. However, any files or directories that are not write-protected inside that directory are
deleted.
• An error occurs in the following cases. Error will change to TRUE.
• The SD Memory Card is not in a usable condition.
• The SD Memory Card is write protected.
• If the value of All is TRUE and the directory specified with DirName is being accessed by another
instruction.
• If the value of All is FALSE and the directory specified with DirName contains a file or directory.
• The directory specified by DirName is write-protected.
• The directory that is specified with DirName contains write-protected files or write-protected direc-
tories.
• If more than four SD Memory Card instructions that do not have a FileID variable (i.e., FileWrite-
Var, FileReadVar, FileCopy, DirCreate, FileRemove, DirRemove, and FileRename) are executed
at the same time.
• The directory specified by DirName does not exist.
• The value of DirName exceeds the maximum number of characters allowed in a directory name.
• An error that prevents access occurs during SD Memory Card access.
Sample Programming
Refer to the sample programming that is provided for the FileCopy instruction (page 2-840).
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NJ-series Instructions Reference Manual (W502)