C / C++ / MFC

  DCB dcb;
   HANDLE hCom;
   BOOL fSuccess;
   TCHAR *pcCommPort = TEXT("COM3");
   char DataBuffer[] = "AT+FCLASS=8";
    DWORD dwBytesToWrite = (DWORD)strlen(DataBuffer);
	char Data2[]="ATDW2289759";
	
    DWORD dwBytesWritten = 0;
	DWORD dwBytesRead = 0;
    char ReadBuffer[BUFFER_SIZE] = {0};
   hCom = CreateFile( pcCommPort,
                    GENERIC_READ | GENERIC_WRITE,
                    0,    // must be opened with exclusive-access
                    NULL, // default security attributes
                    OPEN_EXISTING, // must use OPEN_EXISTING
                    0,    // not overlapped I/O
                    NULL  // hTemplate must be NULL for comm devices
                    );

   if (hCom == INVALID_HANDLE_VALUE) 
   {
       // Handle the error.
       printf ("CreateFile failed with error %d.\n", GetLastError());
       return (1);
   }

   // Build on the current configuration, and skip setting the size
   // of the input and output buffers with SetupComm.

  // SecureZeroMemory(&dcb, sizeof(DCB));
   dcb.DCBlength = sizeof(DCB);
   fSuccess = GetCommState(hCom, &dcb);

   if (!fSuccess) 
   {
      // Handle the error.
      printf ("GetCommState failed with error %d.\n", GetLastError());
      return (2);
   }

  
	dcb.BaudRate = CBR_2400;     // set the baud rate
	dcb.ByteSize = 8;             // data size, xmit, and rcv
	dcb.Parity = NOPARITY;        // no parity bit
    dcb.StopBits = ONESTOPBIT;    // one stop bit

   fSuccess = SetCommState(hCom, &dcb);

   if (!fSuccess) 
   {
      // Handle the error.
      printf ("SetCommState failed with error %d.\n", GetLastError());
      return (3);
   }

   _tprintf (TEXT("Serial port %s successfully reconfigured.\n"),pcCommPort);
	
	//WriteFile(hCom,"AT+FCLASS=8",sizeof("AT+FCLASS=8"),&len,0);

   if( FALSE == WriteFile(hCom,           // open file handle
                               DataBuffer + dwBytesWritten,     // start of data to write
                               dwBytesToWrite - dwBytesWritten, // number of bytes to write
                               &dwBytesWritten, // number of bytes that were written
                               NULL))            // no overlapped structure		
                    printf("Could not write %s to file (error %d)\n",DataBuffer, GetLastError());
   else
	   _tprintf(TEXT("Wrote %d bytes successfully.\n"), dwBytesWritten);
      if( FALSE == ReadFile(hCom, ReadBuffer, BUFFER_SIZE-2, &dwBytesRead, NULL) )
    {
        printf("Could not read from file (error %d)\n", GetLastError());
   }
   else
	   printf("%s",ReadBuffer);

dwBytesWritten = 0;
if( FALSE == WriteFile(hCom,           // open file handle
                               Data2 + dwBytesWritten,     // start of data to write
                               (DWORD)sizeof(Data2) - dwBytesWritten, // number of bytes to write
                               &dwBytesWritten, // number of bytes that were written
                               NULL))            // no overlapped structure		
 printf("Could not write %s to file (error %d)\n",Data2, GetLastError());
else
_tprintf(TEXT("Wrote %d bytes successfully.\n"), dwBytesWritten);
if( FALSE == ReadFile(hCom, ReadBuffer, BUFFER_SIZE-2, &dwBytesRead, NULL) )
{
printf("Could not read from file (error %d)\n", GetLastError());
}
else
printf("%s",ReadBuffer);

SandipG wrote:

Does this command work in HyperTerminal

while(1)
   {	
		if(kbhit())
		{
			key=getch();
			if(key=='x')
			{
				CloseHandle(hCom);
				exit(0);
			}
			switch(key)
			{
			case '1':
// code to issue command ATDW2289759\r\n
}
}
}