How to extract datas from a file

2020-02-27T20:38:00.577000Z

little add-on to my explanation :

It says "The return value is the number of successfully read bytes" for the SysFileLib function. but I need the datas or the string that I'm reading...

To do something like that :

admin:=ReadMyConfigFile(filename, paramater1, parameter2,...);
password:=ReadMyConfigFile(filename, paramater1, parameter2,...);

How to extract datas from a file

2020-02-27T20:37:56.567000Z

Hi,

I don't need an example to write datas, I think mine works fine, I have trouble reading a file only.

I have an example to write/read datas with the application note that Wago made on how to use SysFileLib and WagoLibFtp (to send a file on a FTP) but...

What is my problem :

I have a program that writes measures in a file and then send the file on a FTP server. What I'd like to do is : using an FTP client or an SD card, read a configuration file that contains the host ip, password, name of sensors and that kind of a information so I can run the same program on different PLCs and using different sensors without editing the program and only compiling it.
what I can't do is reading the file line by line to extract the host ip, password, etc.

Did I explain well?

Thank you for your help.

How to extract datas from a file

2020-02-27T20:37:55.117000Z

Please find a small example to write a csv-File with help of SyslibFile:
PROGRAM PLC_PRG
VAR
hFile:DWORD;
dwWritten: DWORD;
szFilePath: STRING:= 'C:\test.csv';
szSeperator: STRING(1):= ';';
szCurrent: STRING(2);
wNewLine: WORD:= 2573; (16#0A0D)
iCounter1: INT;
bOnce: BOOL:= TRUE;
iCounter2: INT;
END_VAR
IF bOnce THEN
hFile:= SysFileOpen(szFilePath, 'w');
FOR iCounter2:= 1 TO 5 DO
FOR iCounter1:= 1 TO 5 DO
szCurrent:= CONCAT(INT_TO_STRING(iCounter2), INT_TO_STRING(iCounter1));
dwWritten:= SysFileWrite(hFile, ADR(szCurrent), 2);
IF iCounter1 <> 5 THEN
dwWritten:= SysFileWrite(hFile, ADR(szSeperator), 1);
ELSE
dwWritten:= SysFileWrite(hFile, ADR(wNewLine), SIZEOF(wNewLine));
END_IF
END_FOR
END_FOR
SysFileClose(hFile);
bOnce:= FALSE;
END_IF

READ can be done like this:

IF xDoRead THEN
dwReturn := SysFileRead(File:=hFile, Buffer:=ADR(sBufferIn), Size:=dwSize);
IF dwReturn <> 0 THEN
sBuffer := sBufferIn;
END_IF
xDoRead := FALSE;
END_IF

IF xDoReadLine THEN
    dwReturn := SysFileRead(File:=hFile, Buffer:=ADR(sBufferIn), Size:=1);
    IF dwReturn <> 0 THEN
        IF sBufferIn <> '$R' THEN
            sBuffer := CONCAT(STR1:=sBuffer, STR2:=sBufferIn);
        ELSE
            (* Dummy Read *)
            SysFileRead(File:=hFile, Buffer:=ADR(sBufferIn), Size:=1);
            dwLine  := dwLine + 1;
            sBuffer := '';
        END_IF
    END_IF
END_IF

The read result must be adapted to the syntax of the written file.

Writing can be done also with help of SysfileStream library.
PROGRAM PLC_PRG
VAR
hFile: DWORD;
diReturn:DINT;
NeueZ:STRING:='$n'; ( Neue zeile )
Zeile: INT;

   ValueReal: REAL:=1.23;
   hFileDelete: BOOL;
   FileName:STRING:='D:\temp\w2test.txt';                 (* Speicher ort auf SD Karte *)
    bWriteSystemText: BOOL;

END_VAR

IF bWriteSystemText THEN

            bWriteSystemText:=FALSE;

            hFile:=SysFileStreamFOpen(FileName, 'w');

            IF hFile > 0 THEN

                           FOR Zeile:=1 TO 20 DO
                                                           diReturn:=SysFileStreamFPrintf_Real(hFile, '%6.2f', ValueReal);
                                                           diReturn:=SysFileStreamFPrintf_String(hFile, '%s', ADR(NeueZ));
                           END_FOR;

                           diReturn:=SysFileStreamFClose(hFile);
                           hFile:=0;
            END_IF;

END_IF;

How to extract datas from a file

2020-02-27T20:37:51.281000Z

Hi. I have the some problem (Question).
I have a file (CVS) in the SD Card and I tried to read it, but I can't.
Do somebody help me with an example how to use the sysfilelib (sysfileread, sysfilewrite)

Thanks in advance

How to extract datas from a file

2020-02-27T20:37:49.905000Z

Sorry, but I do not find out your exact problem.
Do you need an example how to read/wrie data from a file?

How to extract datas from a file

2020-02-27T20:37:46.055000Z

Hi,

I'd like to read a file that'd be on the PLC memory to extract datas from it such as initial values for counters, host name, ip addresses, filenames and stuff like that so I could change propreties without compiling the program on CoDeSys.

I know that SysFileOpen/Read/Write exist but I don't see any function or programm that reads through the file and copies the datas from it.

Is it possible ?

Thank you for any help

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