How can we retrieve the data from push device(bio metric device)

See more:

ASP.NET

I have one Biometric device for Attendence,and the device is push device,So I want to retrieve data from the server port where this device is pushing the data,How can I do that.Inmy below mention code the page keeps on loading and giving the error as
"Error: Only one usage of each socket address (protocol/network address/port) is normally permitted ".

What I have tried:

private void ReadServerData()
{
  TcpClient tcpClient = new TcpClient();
  TcpListener tcpListener = new TcpListener(IPAddress.Any,7005);
  tcpListener.Start();
  Socket mySocket = tcpListener.AcceptSocket();
  NetworkStream stream = new NetworkStream(mySocket);
  StreamReader reader;
  StreamWriter writer;
  string received = "";
  while (true)
  {
    tcpClient = tcpListener.AcceptTcpClient();

    stream = tcpClient.GetStream();
    reader = new StreamReader(stream);
    writer = new StreamWriter(stream);
    writer.NewLine = "\r\n";
    writer.AutoFlush = true;
    byte[] bytes = new byte[tcpClient.SendBufferSize];
    int recv = 0;
    while (true)
    {
      recv = stream.Read(bytes, 0, tcpClient.SendBufferSize);
      received += System.Text.Encoding.ASCII.GetString(bytes, 0, recv);

      if (received.EndsWith("\n\n"))
      {
        break;
      }
    }
  }
}