Hello,

I have downloaded the CoDeSys V2.3.8 Demo (with CoDeSys SP PLC WinNT V2.4 ).

I´m testing the SysLibShm.lib (located in "C:\Program Files\Common Files\CAA-Targets\3S\Lib_PLCWinNT").

My project compiles without errors, but when I try to run it, I get the following error:

"#81: Access violation in 'Access violation Task = New Task'"

The error occurs when I try to execute the following code:

hMyShMem := SysShmOpen('MyShMem', 0, SIZEOF(aRxBuffer) + SIZEOF(aTxBuffer));

My project source code is:

Program Test

VAR

hMyShMem: DWORD := 0;

aTxBuffer: ARRAY[0..63] OF BYTE;

aRxBuffer: ARRAY[0..63] OF BYTE;

dwRet: DWORD;

dwTxErrorCounter: DWORD := 0;

dwRxErrorCounter: DWORD := 0;

END_VAR

IF (hMyShMem = 0) THEN

hMyShMem := SysShmOpen('MyShMem', 0, SIZEOF(aRxBuffer) + SIZEOF(aTxBuffer));  <--------------- ERROR!!!!!

ELSE

dwRet := SysShmRead( hMyShMem, 0, ADR(aRxBuffer), SIZEOF(aRxBuffer));

IF (dwRet = SIZEOF(aRxBuffer)) THEN

    ;

ELSE

    dwRxErrorCounter := dwRxErrorCounter + 1;

END_IF



dwRet := SysShmWrite( hMyShMem, SIZEOF(aRxBuffer), ADR(aTxBuffer), SIZEOF(aTxBuffer));

IF (dwRet = SIZEOF(aTxBuffer)) THEN

    ;

ELSE

    dwTxErrorCounter := dwTxErrorCounter + 1;

END_IF

END_IF

Any idea why this error is occurring?

What means this error message?

Did anyone already use this library? Any example?

Thanks a lot!

Billo

I have no experience with this and also no demo application, but the error is caused by not using a pointer.

I think it should be something like:

hMyShMem := SysShmOpen('MyShMem', 0, ADR(dwSize));

Thanks TimvH!

TimvH hat geschrieben:
I have no experience with this and also no demo application, but the error is caused by not using a pointer.
I think it should be something like:
hMyShMem := SysShmOpen('MyShMem', 0, ADR(dwSize));