File Management on Memory Cards

At a Glance

The tables below set out the methods for using the memory card once it has been formatted.

NOTE: The operations presented below only concern the Modicon M580 and M340 range.

The table below sets out the method for creating a file and adding information to it.

Step	Action	Related function	Comment
1	Create the file	CREATE_FILE	Returns the identifier (file descriptor) which will be used by the other functions.
2	Set the file attributes	SET_FILE_ATTRIBUTES	Optional
3	Display available space	GET_FREESIZE	Optional This function can be called at any time.
4	Positioning in the file	SEEK_FILE
5	Write data into the file	WR_DATA_TO_FILE
6	Close the file	CLOSE_FILE

The table below sets out the methods for opening a file to read it or write data into it.

Step	Action	Related function	Comment
1	Open the file	OPEN_FILE	Returns the identifier (file descriptor) which will be used by the other functions.
2	Retrieve the file attributes	GET_FILE_INFO	Optional
3	Position in the file	SEEK_FILE	Optional
4	Display available space	GET_FREESIZE	Optional This function can be called at any time.
5	Write data	WR_DATA_TO_FILE
6	Position in the file	SEEK_FILE
7	Read data	RD_FILE_TO_DATA
8	Close the file	CLOSE_FILE

The table below sets out the method for deleting a file

Step	Action	Related function
1	Delete the file	DELETE_FILE

The number of files that may be open at the same time is limited to 16.

The number of files that can be created depends on the storage capacity of the memory card.

The functions can only be used in the MAST task.

The memory card must have DATA-STORAGE rights to be able to use these functions.