FB_FileControl Function Block

This functionblock can open, close, read, write and delete files on the local filesystem

Variables

Name	Type	Default	Description
`FileAccessMode`	SysFile.ACCESS_MODE	`SysFile.AM_APPEND_PLUS`	Append_Plus creates the file if it doesn't exist yet.
`FileHandle`	SysFile.SysTypes.RTS_IEC_HANDLE

Methods

Close PUBLIC

Closes the currently opened file.

Implementation

IF FileHandle <> SysFile.SysTypes.RTS_INVALID_HANDLE THEN
    Close := SysFile.SysFileClose(hFile := FileHandle);
ELSE
    Close := SysDir.CmpErrors.Errors.ERR_INVALID_HANDLE;
END_IF

Delete PUBLIC

Deletes a file specified by name, if it exists.

Parameters

Name	Type	Description
`FileName`	T_MaxString

Implementation

Delete := SysFile.SysFileDelete(szFileName := FileName);

Open PUBLIC

Opens a file

Parameters

Name	Type	Default	Description
`FileName`	T_MaxString	`'filepath/output.xml'`	File name can contain an absolute or relative path to the file. Path entries must be separated with a Slash (/)
`FileAccessMode`	SysFile.ACCESS_MODE	`SysFile.ACCESS_MODE.AM_APPEND_PLUS`

Implementation

FileHandle := SysFile.SysFileOpen(szFile := Filename,
                                  am := FileAccessMode,
                                  pResult := ADR(Open));

Read PUBLIC

Reads a file from disk into the buffer

Parameters

Name	Type	Description
`BufferPointer`	POINTER TO BYTE	Call with ADR();
`Size`	UDINT	Call with SIZEOF();

Outputs

Name	Type	Description
`FileSize`	SysFile.SysTypes.RTS_IEC_SIZE

Implementation

IF FileHandle <> SysFile.SysTypes.RTS_INVALID_HANDLE THEN
    FileSize := SysFile.SysFileRead(hFile := FileHandle, 
                                    pbyBuffer := BufferPointer,
                                    ulSize := Size,
                                    pResult := ADR(Read));
ELSE
    Read := SysDir.CmpErrors.Errors.ERR_INVALID_HANDLE;
END_IF

Write PUBLIC

Writes the contents of the buffer into a file.

Parameters

Name	Type	Description
`BufferPointer`	POINTER TO BYTE	Call with ADR();
`Size`	UDINT	Call with SIZEOF();

Implementation

IF FileHandle <> SysFile.SysTypes.RTS_INVALID_HANDLE THEN
    SysFile.SysFileWrite(hFile := FileHandle,
                         pbyBuffer := BufferPointer,
                         ulSize := Size,
                         pResult := ADR(Write));
ELSE
    Write := SysDir.CmpErrors.Errors.ERR_INVALID_HANDLE;
END_IF

Used by

FB_xUnitXmlPublisher

Declaration source

// This functionblock can open, close, read, write and delete files on the local filesystem
FUNCTION_BLOCK FB_FileControl
VAR
    FileAccessMode : SysFile.ACCESS_MODE := SysFile.AM_APPEND_PLUS; // Append_Plus creates the file if it doesn't exist yet. 
    FileHandle : SysFile.SysTypes.RTS_IEC_HANDLE;
END_VAR