Twincat FileRead/Invalid or unknown file handle

PlayerByNature · Mar 1, 2010

Guys,

I get error ID 'Invalid or unknown file handle' when I want to read a file after opening it in Twincat.

The first time I tried to read it, it worked.

After changing my structure of the ReadBuffer instance(FILEDATA) I get this error.

All my files are in the correct directory.

I see some strange things happening with the 'file handler' address. Everytime when opening the file, the address is different?

Code:

fbFileRead(sNetId:='',
              hFile:=hFile,
              pReadBuff:=ADR(FILEDATA),
              cbReadLen:=SIZEOF(FILEDATA),
              bExecute:=bFileRead,
              bBusy=>bFileReadBusy,
              bError=>bFileReadError,
              nErrId=>nFileReadErrorId,
              cbRead=>nFileReadCount,
              bEOF=>bFileReadEOF);

Kind regards

SteveMaves · Mar 1, 2010

Hi PlayerByNature, The file handle should be unique, it should be different every time you open the file. You only have to open a file once, once you get a handle too it, you can use that handle as long as you want, are you trying to open the file more than once?

If your code isn't proprietary, upload your code on a here via an attachment and I'll give it a look. Otherwise PM me and I'll talk to you via e-mail.

PlayerByNature · Mar 2, 2010

Steve, yes, the fileopen function was hanging in a constant loop. But the handler was the same value in every cycle.

Roger Christopher · Mar 14, 2010

Make sure you call the fb with the execute input set to False when you have finished with it, otherwise it will never see another rising edge on it's input

Roger

Twincat FileRead/Invalid or unknown file handle

PlayerByNature

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SteveMaves

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PlayerByNature

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Roger Christopher

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