reception serial frame

[ikbel borcheni]

I'm using serial line connection to send or receive data.
my problem is that the data reception does not work (no error when debugging)but the function GetLastError returns the error 998.

int CCommunicationSérie::OpenCom(DWORD bauderate,CString portcom)
{
    m_hCom = CreateFile((LPCSTR)portcom,
        GENERIC_READ | GENERIC_WRITE,
        0,
        NULL,
        OPEN_EXISTING,
        0,                      
        NULL);               
    if(m_hCom==INVALID_HANDLE_VALUE)
        return 1;
    if ((m_bPortReady=GetCommState(m_hCom,&m_dcb))==0)
    {
        CloseHandle(m_hCom);
        return 2;
    }
 
    m_dcb.fBinary=1;
    m_dcb.fParity=0;
    m_dcb.fNull = 0; 
    m_dcb.fDsrSensitivity=1;          
    m_dcb.fOutX=0;
    m_dcb.fInX=0;    
    //m_dcb.XonLim =0x02;
    // m_dcb.XoffLim =0x01;
    //m_dcb.EofChar = '$';//
    m_dcb.fAbortOnError=0;
    m_dcb.fErrorChar = 0;
    m_dcb.fOutxDsrFlow=1;
    m_dcb.fOutxCtsFlow=1;
    m_dcb.fDtrControl=DTR_CONTROL_ENABLE;
    m_dcb.fRtsControl=RTS_CONTROL_ENABLE;
 
    m_dcb.DCBlength = sizeof(DCB);
 
    m_dcb.BaudRate =bauderate;
    m_dcb.ByteSize = 8;
    m_dcb.Parity =NOPARITY;
    m_dcb.StopBits =ONESTOPBIT;
 
    m_bPortReady=SetCommState(m_hCom, &m_dcb); 
    if(m_bPortReady==0) { CloseHandle(m_hCom);return 3;}
 
    //vider les tampons
   PurgeComm(m_hCom,PURGE_TXABORT|PURGE_RXABORT|PURGE_TXCLEAR|PURGE_RXCLEAR); 
 
   return 0;
}
 
 

data reception

bool CCommunicationSérie::ReadCom()
{
  //char* read_buffer=new char[4];    
  DWORD nNumberOfBytesToRead=2;
  DWORD NumberOfBytesRead=0;
  LPVOID ReadBuffer=NULL;
  int erreur=0;
  //DWORD size=2;
 
   //DWORD dwErrorMask ;
   //COMSTAT cs; // structure
 
  // ClearCommError(m_hCom, &dwErrorMask , &cs); 
 
      int nBytes = 0;
      if (nBytes=ReadFile (m_hCom,ReadBuffer,nNumberOfBytesToRead,&NumberOfBytesRead,NULL)==1)
      {
       //read_buffer=(char*)ReadBuffer;
         return false;
 
      }
   erreur=GetLastError();          
   return true;
 
 
}
 
 

Thanks for help