Sending Data using LAN port

I am trying to send data through lan port using port:1080;

The following code is working fine till MessageId1:127,

when MessageId1:128 or more than that code not working

MessageId0=000;

MessageId1=128;

public void SenData()

{

hexString = "007" + MessageId0 + MessageId1 + "000003000000000" + MessageId0 + MessageId1 + "002";

HexString2Ascii(hexString);

msgSend = System.Text.Encoding.ASCII.GetBytes(Label1.Text);

stream.Write(msgSend, 0, msgSend.Length);

}

private string HexString2Ascii(string hexString)

{

StringBuilder sb = new StringBuilder();

for (int i = 0; i <= hexString.Length - 3; i += 3)

{

sb.Append(Convert.ToString(Convert.ToChar(Int32.Parse(hexString.Substring(i, 3), System.Globalization.NumberStyles.Number))));

}

Send = sb.ToString();

return sb.ToString();

}

pls Suggest any changes in code.

pls Help guys!

thanks !