Writing a string to a file using FB_FilePuts in TwinCAT

[karlek]

Hello to everyone,

I am trying to achieve simple writing of a string to a text file in TwinCAT. The code I am using can be found below. Problem is that fPuts FB call gives me an error code 0x703 ("Unknown or invalid nMode or ePath parameter."). Beckhoff online documentation states that for using FB_FilePuts "The file must previously have been opened in the text mode." So where am I making a mistake?

Thank you in advance

PROGRAM MAIN
VAR

anInput1 AT %I* : INT;
napon : INT;
cb1anIn1 AT %Q* : BYTE:=1;

otvoriDatoteku : FB_FileOpen;
zatvoriDatoteku : FB_FileClose;
fPuts : FB_FilePuts;

hFile : UINT;

bFileOpen : BOOL;
bFileOpenBusy : BOOL;
bFileOpenError : BOOL;
nFileOpenErrId : UDINT;

bFileCloseBusy : BOOL;
bFileCloseError : BOOL;
nFileCloseErrId : UDINT;

bFilePuts : BOOL;
bFilePutsBusy : BOOL;
bFilePutsError : BOOL;
nFilePutsErrId : UDINT;

END_VAR

otvoriDatoteku(bExecute:=FALSE);

otvoriDatoteku(
sNetId:='5.11.48.178.1.1',
sPathName:='c:\TestFile.txt',
nMode:=FOPEN_MODEAPPEND OR FOPEN_MODETEXT,
ePath:=PATH_GENERIC,
bExecute:=TRUE,
bBusy=>bFileOpenBusy,
bError=>bFileOpenError,
nErrId=>nFileOpenErrId);

hFile:=otvoriDatoteku.hFile;

fPuts(bExecute:=FALSE);

fPuts(
sNetId:='5.11.48.178.1.1',
hFile:=hFile,
sLine:='linija1$L',
bExecute:=TRUE,
bBusy=>bFilePutsBusy,
bError=>bFilePutsError,
nErrId=>nFilePutsErrId);

zatvoriDatoteku(bExecute:=FALSE);

zatvoriDatoteku(
sNetId:='5.11.48.178.1.1',
hFile:=hFile,
bExecute:=TRUE );

 

[JoanM]

You are making a simple mistake:

Function blocks usually need more than one scan cycle to finish their tasks to perform the desired task, in order to improve what you are getting I would do:

PROGRAM MAIN
VAR

anInput1 AT %I* : INT;
napon : INT;
cb1anIn1 AT %Q* : BYTE:=1;

otvoriDatoteku : FB_FileOpen;
zatvoriDatoteku : FB_FileClose;
fPuts : FB_FilePuts;

hFile : UINT;

bFileOpen : BOOL;
bFileOpenBusy : BOOL;
bFileOpenError : BOOL;
nFileOpenErrId : UDINT;

bFileCloseBusy : BOOL;
bFileCloseError : BOOL;
nFileCloseErrId : UDINT;

bFilePuts : BOOL;
bFilePutsBusy : BOOL;
bFilePutsError : BOOL;
nFilePutsErrId : UDINT;

BState : BYTE := 0;

END_VAR

CASE BState OF
  0:
    otvoriDatoteku(bExecute:=FALSE);
    BState := BState + 1;

  1:
    otvoriDatoteku(
    sNetId:='5.11.48.178.1.1',
    sPathName:='c:\TestFile.txt',
    nMode:=FOPEN_MODEAPPEND OR FOPEN_MODETEXT,
    ePath:=PATH_GENERIC,
    bExecute:=TRUE,
    bBusy=>bFileOpenBusy,
    bError=>bFileOpenError,
    nErrId=>nFileOpenErrId);
    BState := BState + 1;

  2:
    otvoriDatoteku();
    IF (NOT otvoriDatoteku.bError AND NOT otvoriDatoteku.bBusy)
    THEN
       hFile:=otvoriDatoteku.hFile;
       fPuts(bExecute:=FALSE);
       BState := BState + 1;
    END_IF

  3:
    fPuts(
    sNetId:='5.11.48.178.1.1',
    hFile:=hFile,
    sLine:='linija1$L',
    bExecute:=TRUE,
    bBusy=>bFilePutsBusy,
    bError=>bFilePutsError,
    nErrId=>nFilePutsErrId);

...

I'm sure you have got the main idea.

Good luck!

 

[karlek]

Yes, thank you very much. I found similar example on Beckhoff site (http://infosys.beckhoff.com/english...ibsystem/html/tcplclibsys_fb_fileopen.htm&id=) but didn't get the idea of checking the .bBusy variable.

Just one more question - what exactly is the purpose of call otvoriDatoteku();? I found out that without it the variable .bBusy gets stuck at TRUE.

 

[JoanM]

If you want a function to be processed you must call it, the same happens with FB's, you have to execute them to ensure they will do something.

Good luck!