This article uses Berghof’s B-Nimis MC-Pi Plus Controller and the CAA.File library to list the File and Folder installed on the USB stick.

Let’s enjoy FA.

Reference Video

Codesys.Let’s List-up the items in an USB Directory!

Foreword

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CAA.File

This is the library CAA.File used in this article.

FILE_DIR_ENTRY

This data structure holds information on directory entries.

Variables	Type	Description
sEntry	CAA.FILENAME	Directory or file name
szSize	CAA.SIZE	file size
xDirectory	BOOL	TRUE: DirectoryFALSE: File
xExclusive	BOOL	TRUE: exclusive Access modeFALSE: Multiple access modes possible.
dtLastModification	DT	Last update datee.g.2006-05-08-00:00:00

DirList

The FB reads the directory entry and the information is written to the structure “deDirEntry” of type “FILE_DIR_ENTRY”. Then, if the FB cannot find any more entries, the error message “ERROR.NO_MORE_ENTRIES” is generated and the entry in the structure “deDirEntry” is deleted.

VAR_INPUT

Variables	Type	Description
xExecute	BOOL	Rising edge: Start of operationFalling edge: output reset
hDir	CAA.HANDLE	directory handle

VAR_OUTPUT

Variables	Type	Description
xDone	BOOL	Action successfully executed.
xBusy	BOOL	TRUE=FB running
xError	BOOL	TRUE=FB error
eError	ERROR	Local library error ID(5106-FILE_NO_MORE_ENTRIES: no further entries)
deDirEntry	FILE_DIR_ENTRY	directory entry

DirOpen

This FB opens the specified directory.

VAR_INPUT

Variables	Type	Description
xExecute	BOOL	Rising edge: Start of operationFalling edge: output reset
sDirName	CAA.FILENAME	Directory name, absolute or relative path specification

VAR_OUTPUT

Variables	Type	Description
xDone	BOOL	Action successfully executed.
xBusy	BOOL	TRUE=FB running.
xError	BOOL	TRUE = FB error
eError	ERROR	Local library error ID(5106-FILE_NO_MORE_ENTRIES: no further entries)
hDir	CAA.HANDLE	directory handle

DirClose

This FB closes access to the specified directory.

VAR_INPUT

Variables	Type	Description
xExecute	BOOL	Rising edge: Start of operationFalling edge: output reset
hDir	CAA.HANDLE	directory handle

VAR_OUTPUT

Variables	Type	Description
xDone	BOOL	Action successfully executed.
xBusy	BOOL	TRUE=FB running.
xError	BOOL	TRUE = FB error
eError	ERROR	Local library error ID(5106-FILE_NO_MORE_ENTRIES: no further entries)

Implementation

Enable SSH Server

To enable the Berghof Controller’s SSH Server, go to Webserver > SSH Server > Enabled.

Check the USB

Access SSH using the Berghof Controller and use the lssub command to Check if the USB is recognised.

ssh root@192.168.0.40

root@S-01030303-0100-00116:~ lsusb
Bus 001 Device 003: ID 0424:9e00 Standard Microsystems Corp.
Bus 003 Device 002: ID 0424:9e00 Standard Microsystems Corp.
Bus 001 Device 005: ID 0424:2240 Standard Microsystems Corp.
Bus 001 Device 004: ID 0403:6015 Future Technology Devices International, Ltd Bridge(I2C/SPI/UART/FIFO)
Bus 002 Device 002: ID 0424:5744 Standard Microsystems Corp.
Bus 001 Device 006: ID 0424:2740 Standard Microsystems Corp.
Bus 001 Device 002: ID 0424:2744 Standard Microsystems Corp.
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 004: ID 058f:6387 Alcor Micro Corp. Flash Drive
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
root@S-01030303-0100-00116:~

Next, use the ls command to list-up the Files in the USB.

root@S-01030303-0100-00116:~ cd /media/usb1/

root@S-01030303-0100-00116:/media/usb1 ls
20241217171509RN070656411JP4WTRLRhl9142b8dcbe7d7958f743649d354428d4.pdf
20241218090205EN357413577JPc4ZRf5RV9142b8dcbe7d7958f743649d354428d4.pdf
CreatefromCodesys
System Volume Information
tes2
test1.text

Add Library

Import the CAA File and CAA Types libraries to Codesys into the project.

GVL – gUSBFileList

Create a Global Variables List.

stFileDirEntry stores the Directory/File information obtained when DirList FB is executed.
diMaxIndex is the maximum validation Index
xSearch=TRUE starts a search.

{attribute ‘qualified_only’}
VAR_GLOBAL
stFileDirEntry:ARRAY[0..99]OF FILE.FILE_DIR_ENTRY;
diMaxIndex:INT:=19;
xSearch:BOOL;
END_VAR

MAIN

This is the Flow of this MAIN program.

First, initialise all FBs, open Directory> and list the Items in it.Then there is a Counter in the Step Flow, which is always compared to the Max Counter (you could list up infinitely, but it is not very practical).

If the current Counter is less than the MaxCount setting, then ListUP the next item.
If the current Counter is greater than the MaxCount setting, >END
If File/Directory not found > End

VAR

This is the variable definition of the program.

PROGRAM pTest2
VAR
dirHandle : CAA.HANDLE;
　FB_DirList : FILE.DirList ;
FB_DirOpen : FILE.DirOpen;
FB_DirClose : FILE.DirClose;

xExecute :BOOL;
xClose :BOOL;
xList :BOOL;
xSearch :BOOL;
FB_TON :TON;
R_TRIG_ListDone :R_TRIG;
END_VAR

VAR
iStep :INT;
iMaxCount :INT;
iCounter :INT;
iResetCounter :INT;
END_VAR

VAR CONSTANT
ciStep00_Init :INT:=0;
ciStep10_Open :INT:=10;
ciStep20_List :INT:=20;
ciStep25_List :INT:=25;
ciStep30_Close :INT:=30;
ciStep399_End :INT:=399;
END_VAR

Program

This is the program created for the Flow mentioned earlier.

//01.Start to search
//02.List the data
//02.1.Store to GVL
//99.Close the Handle

CASE iStep OF
ciStep00_Init:
iMaxCount:=gUSBFileList.diMaxIndex;
xSearch:=gUSBFileList.xSearch AND iStep =0;
xExecute:=FALSE;
xList:=FALSE;
xClose:=FALSE;
iCounter:=0;
IF NOT FB_DirClose.xBusy
AND NOT FB_DirClose.xError
AND NOT FB_DirList.xBusy
AND NOT FB_DirList.xError
AND NOT FB_DirOpen.xBusy
AND NOT FB_DirOpen.xError
AND xSearch
THEN
FOR iResetCounter:=0 TO iMaxCount DO
gUSBFileList.stFileDirEntry[iResetCounter].dtLastModification:=DT#1970-1-1-0:0:0;
gUSBFileList.stFileDirEntry[iResetCounter].sEntry:=”;
gUSBFileList.stFileDirEntry[iResetCounter].szSize:=0;
gUSBFileList.stFileDirEntry[iResetCounter].xDirectory:=FALSE;
gUSBFileList.stFileDirEntry[iResetCounter].xExclusive:=FALSE;
END_FOR
FB_TON(IN:=TRUE,PT:=T#0.01S);
IF FB_TON.Q THEN
xSearch:=FALSE;
iStep:=ciStep10_Open;
FB_TON(IN:=FALSE);
END_IF;
END_IF

ciStep10_Open:
xExecute:=TRUE;
IF NOT FB_DirOpen.xError
AND FB_DirOpen.hDir <>0 THEN
iStep:=ciStep20_List;
END_IF

ciStep20_List:
xList:=TRUE;
IF R_TRIG_ListDone.Q THEN
gUSBFileList.stFileDirEntry[iCounter]:=FB_DirList.deDirEntry;
iCounter:=iCounter+1;
IF iCounter >= iMaxCount
THEN
iStep:=ciStep30_Close;
ELSE
iStep:=ciStep25_List;
END_IF
ELSIF FB_DirList.xError THEN
iStep:=ciStep30_Close;
END_IF

ciStep25_List:
xList:=FALSE;
IF NOT FB_DirList.xDone THEN
iStep:=ciStep20_List;
END_IF

ciStep30_Close:
xClose:=TRUE;
IF FB_DirClose.xDone THEN
gUSBFileList.xSearch:=FALSE;
iStep:=ciStep399_End;
END_IF

ciStep399_End:
iStep:=ciStep00_Init;

END_CASE

R_TRIG_ListDone(CLK:=FB_DirList.xDone);

FB_DirOpen(
xExecute:=xExecute
,sDirName:=’/media/usb1′
,hDir=>dirHandle
);

FB_DirList(
xExecute:=xList
,hDir:=dirHandle);

FB_DirClose(
xExecute:=xClose
,hDir:=dirHandle
);