pdu با C#

[Shadi64]

public SerialPort SP = new SerialPort("COM1");
SP.RtsEnable =false;
SP.DtrEnable = true;
SP.DiscardNull =false;
SP.Handshake = Handshake.None;
SP.BaudRate=9600;
SP.Parity = Parity.None;
SP.ParityReplace = 63;
SP.ReadBufferSize = 10000;
SP.ReadTimeout = 1000;
SP.ReceivedBytesThreshold = 1;
SP.StopBits = StopBits.One;
SP.WriteBufferSize = 10000;
SP.WriteTimeout = 10000;
SP.Encoding =Encoding.ASCII;
SP.DataBits = 8;
if (!SP.IsOpen)
SP.Open();
SP.WriteLine("ATE1\r");
System.Threading.Thread.Sleep(1000);
SP.WriteLine("AT+CMGf=0\r");
SP.DiscardInBuffer();
SP.DiscardOutBuffer();
string PDUCodes;
s = "";
Bln = true;
DR = SVR.GetRow("sp_GetRow");
if (DR.Read())
{
PDUCodes = "079189390500410011000B819021829636F000080016063306 4406270645002006390632064A063206450020";
SP.WriteLine("AT+CMGS=" + ("36" + "\r"));
System.Threading.Thread.Sleep(2000);
SP.WriteLine(PDUCodes + "\r" + char.ConvertFromUtf32(26));

برای ارسال pdu با serial port در C# مشگل دارم ok میدهد ولی send نمیشود