Hi all,
 I have a problem to communicate with serial port(COM3:). I am able
to open the handle but cannot send any data.

  1. I connected my motoroala handset to PC through datacable.
  2. I installed valid driver to detec the motorla(V400) handset
  3. I tested the handset through Hypertermal and succssfully sending
any data.
  4. I opened the Control Panel -> Phone and Model window and clicked
the modem tab and I saw that the Motorola handset( Motorola USB modem
) is attached through COM3: port  fo the PC
  5. Then I created a sample C# program to communicate with handeset
through COM3 port . the code is like this:
 
string text = "AT+CKPD=";
int byteCnt = oEnc.GetByteCount(
text.ToCharArray(),0,text.Length,true);
byte[] Buffer = new byte[byteCnt];
int byteEncodeCount = oEnc.GetBytes( text.ToCharArray
),0,text.Length,Buffer,0,true);
hSerialPort = Serial.CreateFile( handleName, Serial.GENERIC_READ |
Serial.GENERIC_WRITE, 0 ,IntPtr.Zero,
                                Serial.OPEN_EXISTING, Serial.FILE_FLAG_OVERLAPPED, IntPtr.Zero
);

           
            if( hSerialPort.ToString() == "-1" )
            {

                    Console.WriteLine( "Un available");
            }

            int ch = 1;
            if( ch == 1 )
               Success = Serial.WriteFile( hSerialPort,Buffer,
Buffer.Length, out BytesWritten, IntPtr.Zero );

    When i debug the code the Serial.WriteFile method is return false
value. and I got the system error code using
Marshal.GetLastwin32Error(), it is giving 126 error code. I searched
in internet description of the 126 error , it says module not found.
    I don't know what to do. I  am imporing only Kernel32.dll in my
sample program. is anything i have to do..?
    please help me on the problem..

Thanks & Regards
kiran kumar
vemulakiran@gmail.com