/// <summary>
        /// Send unknown request
        /// </summary>
        /// <returns>KWPResult</returns>
        public KWPResult sendUnknownRequest()
        {
            LogDataString("sendUnknownRequest");
            //Console.WriteLine("sendUnknownRequest");
            KWPReply reply = new KWPReply();
            KWPResult result;

            //Send request
            //Mode = 0x3E
            //PID = no PID used by this request
            //Expected result = 0x7E
            result = sendRequest(new KWPRequest(0x02, 0x3E), out reply);
            Console.WriteLine(reply.ToString());
            if (reply.getMode() != 0x7E)
                return KWPResult.NOK;
            else
                return result;
        }
        /// <summary>
        /// sendEraseRequest sends an erase request to the ECU.
        /// This method must be called before the ECU can be flashed.
        /// </summary>
        /// <returns>KWPResult</returns>
        public KWPResult sendEraseRequest()
        {
            LogDataString("sendEraseRequest");

            KWPReply reply = new KWPReply();
            KWPReply reply2 = new KWPReply();
            KWPResult result = KWPResult.Timeout;
            int i = 0;

            //First erase message. Up to 5 retries.
            //Mode = 0x31
            //PID = 0x52
            //Expected result is 0x71
            result = sendRequest(new KWPRequest(0x31, 0x52), out reply);
            Console.WriteLine("Erase(1) " + reply.ToString());
            if (result != KWPResult.OK)
                return result;
            while (reply.getMode() != 0x71)
            {
                System.Threading.Thread.Sleep(1000);
                result = sendRequest(new KWPRequest(0x31, 0x52), out reply);
                Console.WriteLine("Erase(2:" + i.ToString() + ") " + reply.ToString());
                if (i++ > 15) return KWPResult.Timeout;
            }
            if (result != KWPResult.OK)
                return result;

            //Second erase message. Up to 10 retries.
            //Mode = 0x31
            //PID = 0x53
            //Expected result is 0x71
            i = 0;
            result = sendRequest(new KWPRequest(0x31, 0x53), out reply2);
            Console.WriteLine("Erase(3) " + reply2.ToString());
            if (result != KWPResult.OK)
                return result;
            while (reply2.getMode() != 0x71)
            {
                System.Threading.Thread.Sleep(1000);
                result = sendRequest(new KWPRequest(0x31, 0x53), out reply2);
                Console.WriteLine("Erase(4:" + i.ToString() + ") " + reply2.ToString());
                if (i++ > 20) return KWPResult.Timeout;
            }

            //Erase confirm message
            //Mode = 0x3E
            //Expected result is 0x7E
            result = sendRequest(new KWPRequest(0x3E, 0x53), out reply2);
            Console.WriteLine("Erase(5) " + reply2.ToString());

            return result;
        }
        public KWPResult sendEraseMemorySpaceRequest(Int32 StartAddress, Int32 Length)
        {
            /*02 FLASH memory erasure
            1 start address (high byte)
            2 start address (middle byte)
            3 start address (low byte)
            4 stop address (high byte)
            5 stop address (middle byte)
            6 stop address (low byte)
            */
            Int32 StopAddress = StartAddress + Length;
            LogDataString("sendEraseRequest");

            KWPReply reply = new KWPReply();
            KWPReply reply2 = new KWPReply();
            KWPResult result = KWPResult.Timeout;
            int i = 0;

            //First erase message. Up to 5 retries.
            //Mode = 0x31
            //PID = 0x51
            //Expected result is 0x71
            byte[] a_data = new byte[6];
            int bt = 0;
            //a_data[0] = (byte)(StartAddress >> 24);
            a_data[bt++] = (byte)(StartAddress >> 16);
            a_data[bt++] = (byte)(StartAddress >> 8);
            a_data[bt++] = (byte)(StartAddress);
            //a_data[4] = (byte)(Length >> 24);
            a_data[bt++] = (byte)(StopAddress >> 16);
            a_data[bt++] = (byte)(StopAddress >> 8);
            a_data[bt++] = (byte)(StopAddress);

            requestSequrityAccess(true);
            KWPRequest req = new KWPRequest(0x31, 0x50, a_data);

            result = sendRequest(req, out reply);
            Console.WriteLine("Erase(1) " + reply.ToString());
            /*if (result != KWPResult.OK)
                return result;
            System.Threading.Thread.Sleep(10000);
            result = sendRequest(new KWPRequest(0x31, 0x53, a_data), out reply);
            Console.WriteLine("Erase(2:" + i.ToString() + ") " + reply.ToString());
            */
            if (result != KWPResult.OK)
                return result;

            result = sendRequest(new KWPRequest(0x3E, 0x50), out reply2); // tester present???
            Console.WriteLine("reply on exit " + reply2.ToString());

            return result;
        }
        /// <summary>
        /// This method sends a KWPRequest and returns a KWPReply.
        /// </summary>
        /// <param name="a_request">The request.</param>
        /// <param name="a_reply">The reply.</param>
        /// <returns>KWPResult</returns>
        private KWPResult sendRequest(KWPRequest a_request, out KWPReply a_reply, int expectedLength)
        {
            int _maxSendRetries = 3;
            KWPResult _kwpResult = KWPResult.Timeout;
            LogDataString("sendRequest");

            KWPReply reply = new KWPReply();
            RequestResult result;
            a_reply = new KWPReply();
            //<GS-11012010> was allemaal 1000
            int keepAliveTimeout = 1000;
            //Console.WriteLine("Checking KWP device open");
            if (!m_kwpDevice.isOpen())
                return KWPResult.DeviceNotConnected;

            // reset the timer for keep alive (set to 1 seconds now)
            if (stateTimer == null)
                stateTimer = new System.Threading.Timer(sendKeepAlive, new Object(), keepAliveTimeout, keepAliveTimeout);
            stateTimer.Change(keepAliveTimeout, keepAliveTimeout);

            m_requestMutex.WaitOne();
            int _retryCount = 0;
            result = RequestResult.Unknown; // <GS-11022010>
            while (_retryCount < _maxSendRetries && result != RequestResult.NoError)
            {
                LogDataString(a_request.ToString());
                result = m_kwpDevice.sendRequest(a_request, out reply);
                if ((int)reply.getLength() != expectedLength)
                {
                    result = RequestResult.InvalidLength;

                }
                if (result == RequestResult.NoError)
                {
                    a_reply = reply;
                    LogDataString(reply.ToString());
                    LogDataString(""); // empty line
                    m_requestMutex.ReleaseMutex();
                    //return KWPResult.OK;
                    _kwpResult = KWPResult.OK;
                }
                else
                {
                    LogDataString("Timeout in KWPHandler::sendRequest");
                    m_requestMutex.ReleaseMutex();
                    //return KWPResult.Timeout;
                    _kwpResult = KWPResult.Timeout;
                }
            }
            return _kwpResult;
        }
        /// <summary>
        /// This method sends a KWPRequest and returns a KWPReply.
        /// </summary>
        /// <param name="a_request">The request.</param>
        /// <param name="a_reply">The reply.</param>
        /// <returns>KWPResult</returns>
        private KWPResult sendRequest(KWPRequest a_request, out KWPReply a_reply)
        {
            LogDataString("sendRequest");

            KWPReply reply = new KWPReply();
            RequestResult result;
            a_reply = new KWPReply();
            //<GS-11012010> was allemaal 1000
            int keepAliveTimeout = 1000;
            //Console.WriteLine("Checking KWP device open");
            if (!m_kwpDevice.isOpen())
                return KWPResult.DeviceNotConnected;

            // reset the timer for keep alive (set to 1 seconds now)
            if (stateTimer == null)
                stateTimer = new System.Threading.Timer(sendKeepAlive, new Object(), keepAliveTimeout, keepAliveTimeout);
            stateTimer.Change(keepAliveTimeout, keepAliveTimeout);

            m_requestMutex.WaitOne();

            LogDataString(a_request.ToString());
            Console.WriteLine("KWP send request: " + a_request.ToString());
            result = m_kwpDevice.sendRequest(a_request, out reply);
            a_reply = reply;
            if (result == RequestResult.NoError)
            {
                LogDataString(reply.ToString());
                LogDataString(""); // empty line

                m_requestMutex.ReleaseMutex();
                return KWPResult.OK;
            }
            else
            {
                LogDataString("Timeout in KWPHandler::sendRequest: " + result.ToString());
                Console.WriteLine("Timeout in KWPHandler::sendRequest: " + result.ToString());
                m_requestMutex.ReleaseMutex();
                return KWPResult.Timeout;
            }
        }
        /// <summary>
        /// Send a request for a sequrity access with one out of two methods to 
        /// calculate the key.
        /// </summary>
        /// <param name="a_method">Key calculation method [1,2]</param>
        /// <returns>true if sequrity access was granted, otherwise false</returns>
        private bool requestSequrityAccessLevel()
        {
            LogDataString("requestSequrityAccessLevel");
            KWPReply reply = new KWPReply();
            KWPResult result;
            byte[] seed = new byte[2];
            byte[] key = new byte[2];
            // Send a seed request.
            KWPRequest requestForKey = new KWPRequest(0x27, 0x05); // TODO: What is this for T8?
            Console.WriteLine("requestSequrityAccessLevel request for key: " + requestForKey.ToString());
            result = sendRequest(requestForKey, out reply);
            Console.WriteLine("requestSequrityAccessLevel request for key result: " + reply.ToString());

            if (result != KWPResult.OK)
                return false;
            if (reply.getData().Length < 2)
                return false;
            seed[0] = reply.getData()[0];
            seed[1] = reply.getData()[1];
            key = calculateKey(seed);
            // Send key reply.
            KWPRequest sendKeyRequest = new KWPRequest(0x27, 0x06, key);
            Console.WriteLine("requestSequrityAccessLevel send Key request: " + sendKeyRequest.ToString());
            result = sendRequest(sendKeyRequest, out reply);
            Console.WriteLine("requestSequrityAccessLevel send Key reply: " + reply.ToString());
            if (result != KWPResult.OK)
            {
                Console.WriteLine("Security access request was not send");
                return false;
            }

            //Check if sequrity was granted.
            Console.WriteLine("Mode: " + reply.getMode().ToString("X2"));
            Console.WriteLine("Data: " + reply.getData()[0].ToString("X2"));
            if ((reply.getMode() == 0x67) && (reply.getData()[0] == 0x34)) // WAS [0]
            {
                Console.WriteLine("Security access granted");
                return true;
            }

            Console.WriteLine("Security access was not granted: " + reply.ToString());
            return false;
        }