确认没有'；不工作.Teltonika FM5300

这是我的代码示例。它不起作用。我以正确的形式｛0x01｝发送了确认，但设备始终只返回IMEI。有人能解决这个问题吗？

    static void Main(string[] args)
    {
        TcpListener list = new TcpListener(new IPEndPoint(IPAddress.Any, 2065));
        TcpClient client;
        Console.WriteLine("Listening... 'n");
        list.Start(1);
        list.Server.NoDelay = true;
        while (true)
        {
            Console.WriteLine("Waiting for client...'n");
            client = list.AcceptTcpClient();
            Console.WriteLine("Client connected ");
            byte[] imei = new byte[8192];
            NetworkStream ns = client.GetStream();
            if (ns.CanRead)
            {
                ns.Read(imei, 0, (int)client.ReceiveBufferSize);
            }
            Console.WriteLine(Encoding.ASCII.GetString(imei, 0, imei.Length));
            byte[] ack = new byte[1] {0x01};
            if (ns.CanWrite)
            {
                ns.Write(ack, 0, ack.Length);
            }
            client.Close();
        }
    }