/// <summary>
        /// Closes and destroys the com port.
        /// </summary>
        protected void Destroy()
        {
            // Cancel I/O, kill receiver & close port.
            if(this.portOpen)
            {
                this.port.Cancel();
                if(this.rxThread != null)
                {
                    this.rxThread.Abort();
                    this.rxThread = null;
                }
                this.port.Close();
                this.portOpen = false;
            }

            // Reinit resources.
            this.dcb    = null;
            this.port   = null;
            this.stats  = null;
            this.props  = null;
            this.tmout  = null;
            this.rxOvr  = null;
            this.txOvr  = null;
            this.escape = null;
            this.writeEvent = null;
            this.recvrEvent = null;
            return;
        }
        /// <summary>
        /// Create & opens the com port and configures it with the required settings.
        /// </summary>
        /// <param name="cfg">Reference to port user config.</param>
        /// <returns>True if port opened successfully.</returns>
        protected bool Create(SerialCnfg cfg)
        {
            // If port already open, return.
            if(portOpen)
            {
                this.CommError("Com Port Already Open.");
                return false;
            }

            // Init members.
            this.fault = "";
            this.rxThread = null;
            this.writeEvent = new ManualResetEvent(false);
            this.recvrEvent = new ManualResetEvent(false);

            // Copy config to DCB.
            this.dcb = new Win32DCB(cfg);

            // Create handle to comm port.
            this.port = new Win32Com();
            if((this.portOpen = this.port.Open(cfg.PortName, true)) == false)
            {
                this.CommError(this.port.Fault);
                return false;
            }
            this.portName = cfg.PortName;

            // Instantiate support classes.
            this.stats  = new Win32Status();
            this.tmout  = new Win32Tmout();
            this.props  = new Win32Props();
            this.escape = new Win32Escape(port.Handle);

            // Set read/write timeouts.
            this.tmout.WriteConstant = cfg.TxTmoConst;
            this.tmout.WriteMultiplier = cfg.TxTmoMulti;
            if(this.tmout.Set(this.port.Handle) == false)
            {
                this.CommError(this.tmout.Fault);
                this.Destroy();
                return false;
            }

            // Overide OS default queue sizes.
            if((cfg.RxQueLen != 0) || (cfg.TxQueLen != 0))
            {
                if(this.props.Set(this.port.Handle, (uint)cfg.RxQueLen, (uint)cfg.TxQueLen) == false)
                {
                    this.Destroy();
                    this.CommError(this.props.Fault);
                    return false;
                }
            }

            // Get the current properties.
            if(this.props.Get(this.port.Handle) == false)
            {
                this.Destroy();
                this.CommError(this.props.Fault);
                return false;
            }

            // Set flow control limits.
            this.dcb.Limits(cfg, this.props.RxCurSize);

            // Update the port settings.
            if(this.dcb.Set(this.port.Handle) == false)
            {
                this.Destroy();
                this.CommError(this.dcb.Fault);
                return false;
            }

            // XON/OFF extended functionality.
            this.escape.XOFFavailable = true;

            // RTS extended functionality.
            if(cfg.RtsControl == PinState.Disable)
                this.escape.RTS = false;
            else if(cfg.RtsControl == PinState.Enable)
                this.escape.RTS = true;
            else if(cfg.RtsControl == PinState.Handshake)
                this.escape.RTSavailable = false;

            // DTR extended functionality.
            if(cfg.DtrControl == PinState.Disable)
                this.escape.DTR = false;
            else if(cfg.DtrControl == PinState.Enable)
                this.escape.DTR = true;
            else if(cfg.DtrControl == PinState.Toggle)
                this.escape.DTR = false;
            else if(cfg.DtrControl == PinState.Handshake)
                this.escape.DTRavailable = false;

            // Create TX overlap memory pointer.
            this.txOvr = new Win32Ovrlap(this.port.Handle, this.writeEvent.Handle);

            // Set the receiver mode.
            this.immediate = cfg.ReceiveMode;

            // Start the receiver thread.
            this.rxThread = new Thread(new ThreadStart(ReceiveThread));
            this.rxThread.Name = "COMReceiver";
            this.rxThread.Priority = ThreadPriority.AboveNormal;
            this.rxThread.Start();

            // Wait for receive thread to start.
            this.recvrEvent.WaitOne(500, false);

            // Port opened OK.
            return true;
        }