string ss = "01ac0c01";
            int len = ss.Length / 2;
            byte[] bs = new byte[len];
            int j = 0;
            for (int i = 0; i < ss.Length; i += 2)
            {
                string str = ss.Substring(i, 2);
                bs[j] = (byte)int.Parse(str, System.Globalization.NumberStyles.HexNumber);
                j++;
            }