Originally created by: Primitive Source

Hello, I am a bit of a newbie to the whole programming world but have learnt a fair bit over the passed few months. My latest stumbling block is writing to a csv file created in my programme on the pi. I can create the file successfully, and write to it each time a :BOOL is triggered TRUE. However each time I trigger this switch, I overwrite the existing data. I am using .CAA library.

Where am i going wrong in the code below, this is taken from the example in the help section and amended slightly for my string/ triggers. I first of all create a file with one case/one :BOOL name RUN. Then the file is opened again in the Append mode by :BOOL named FiWr but still seems to overwrite each time is triggered rather than adding to the end of the file

Var
RUN: BOOL;
FiWr: BOOL;
FINSTR:= CONCAT(SEMFINSTR,'$R$N');
csvwrite:= UDINT:=0;
END_VAR

xFileStdInit:= RUN;

IF NOT xFileStdInit THEN
filop(xExecute:=FALSE);
filcl(xExecute:=FALSE);
filwr(xExecute:=FALSE);
filrd(xExecute:=FALSE);
xFileStdInit:=TRUE;
uiFileStdState:=0;
ELSE
CASE uiFileStdState OF
0:( create a new file )
filop.sFileName:=sFileName;
filop.eFileMode:=FILE.MODE.MRDWR;
filop.xExclusive:=TRUE;
filop( xExecute:=TRUE);
IF filop.xDone THEN
hFile:=filop.hFile;
uiFileStdState:=1;
END_IF
IF filop.xError THEN
( error handling)
;
END_IF
1:( close file - TestFile.txt )
filcl.hFile:=hFile;
filcl( xExecute:=TRUE);
IF filcl.xDone THEN
uiFileStdState:=2;
END_IF
IF filcl.xError THEN
( error handling)
;
END_IF

    2:(* end of example *)
        ;
END_CASE

END_IF

IF NOT FiWr THEN
filop(xExecute:=FALSE);
filcl(xExecute:=FALSE);
filwr(xExecute:=FALSE);
filrd(xExecute:=FALSE);
FiWr:= TRUE;
csvwrite:=0;
ELSE
CASE csvwrite OF
0:( create a new file )
filop.sFileName:=sFileName;
filop.eFileMode:=FILE.MODE.MAPPD;
filop.xExclusive:=TRUE;
filop( xExecute:=TRUE);
IF filop.xDone THEN
hFile:=filop.hFile;
csvwrite:=1;
END_IF
IF filop.xError THEN
( error handling)
;
END_IF

    1:(* write text in the file *)
        filwr.hFile:=hFile;
        filwr.pBuffer:=ADR(FINSTR);
        szFileSize1:=SIZEOF(FINSTR);
        filwr.szSize:=szFileSize1;
        filwr.udiTimeOut:=100000;    (* 100ms Timeout *)
        filwr( xExecute:=TRUE);
        IF filwr.xDone THEN
            csvwrite:=2;
        END_IF
        IF filwr.xError THEN
            (* error handling*)
            ;
        END_IF

    2:(* close file  - TestFile.txt *)
        filcl.hFile:=hFile;
        filcl( xExecute:=TRUE);
        IF filcl.xDone THEN
            csvwrite:=4;
        END_IF
        IF filcl.xError THEN
            (* error handling*)
            ;
        END_IF

    3:(* end of example *)
        ;
END_CASE

END_IF

I hope you can help

Hi Primitive Source,

it seems we have kind of the same problem here, but you are one step ahead of me. So I also want to write & read a csv-file in a certain directory. As my code is mostly similar and you wrote

Zitat:
I can create the file successfully, and write to it each time a :BOOL is triggered TRUE.

I want to ask you: Where is your file stored? And where in your code do you influence on where it's going to be stored?
Did you solve your problem? I know it's been one year already, but hopefully you care to help me a bit

Kind regards,
SpeedyG

Are you opening the file in write W or append A mode?

I've not looked at your library, but the one I used allowed me to open the file with append to add data - just be careful the file doesn't get too large.

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