FTD2XX_NET.FTDI.OpenByIndex C# (CSharp) Method

        public FT_STATUS OpenByIndex(UInt32 index)
        {
            // Initialise ftStatus to something other than FT_OK
            FT_STATUS ftStatus = FT_STATUS.FT_OTHER_ERROR;

            // If the DLL hasn't been loaded, just return here
            if (hFTD2XXDLL == IntPtr.Zero)
                return ftStatus;

            // Check for our required function pointers being set up
            if ((pFT_Open != IntPtr.Zero) & (pFT_SetDataCharacteristics != IntPtr.Zero) & (pFT_SetFlowControl != IntPtr.Zero) & (pFT_SetBaudRate != IntPtr.Zero))
            {
                tFT_Open FT_Open = (tFT_Open)Marshal.GetDelegateForFunctionPointer(pFT_Open, typeof(tFT_Open));
                tFT_SetDataCharacteristics FT_SetDataCharacteristics = (tFT_SetDataCharacteristics)Marshal.GetDelegateForFunctionPointer(pFT_SetDataCharacteristics, typeof(tFT_SetDataCharacteristics));
                tFT_SetFlowControl FT_SetFlowControl = (tFT_SetFlowControl)Marshal.GetDelegateForFunctionPointer(pFT_SetFlowControl, typeof(tFT_SetFlowControl));
                tFT_SetBaudRate FT_SetBaudRate = (tFT_SetBaudRate)Marshal.GetDelegateForFunctionPointer(pFT_SetBaudRate, typeof(tFT_SetBaudRate));

                // Call FT_Open
                ftStatus = FT_Open(index, ref ftHandle);

                // Appears that the handle value can be non-NULL on a fail, so set it explicitly
                if (ftStatus != FT_STATUS.FT_OK)
                    ftHandle = IntPtr.Zero;

                if (ftHandle != IntPtr.Zero)
                {
                    // Initialise port data characteristics
                    byte WordLength = FT_DATA_BITS.FT_BITS_8;
                    byte StopBits = FT_STOP_BITS.FT_STOP_BITS_1;
                    byte Parity = FT_PARITY.FT_PARITY_NONE;
                    ftStatus = FT_SetDataCharacteristics(ftHandle, WordLength, StopBits, Parity);
                    // Initialise to no flow control
                    UInt16 FlowControl = FT_FLOW_CONTROL.FT_FLOW_NONE;
                    byte Xon = 0x11;
                    byte Xoff = 0x13;
                    ftStatus = FT_SetFlowControl(ftHandle, FlowControl, Xon, Xoff);
                    // Initialise Baud rate
                    UInt32 BaudRate = 9600;
                    ftStatus = FT_SetBaudRate(ftHandle, BaudRate);
                }
            }
            else
            {
                if (pFT_Open == IntPtr.Zero)
                {
                    LogB.Debug("FTD2XX: Failed to load function FT_Open.");
                }
                if (pFT_SetDataCharacteristics == IntPtr.Zero)
                {
                    LogB.Debug("FTD2XX: Failed to load function FT_SetDataCharacteristics.");
                }
                if (pFT_SetFlowControl == IntPtr.Zero)
                {
                    LogB.Debug("FTD2XX: Failed to load function FT_SetFlowControl.");
                }
                if (pFT_SetBaudRate == IntPtr.Zero)
                {
                    LogB.Debug("FTD2XX: Failed to load function FT_SetBaudRate.");
                }
            }
            return ftStatus;
        }

        private void Open(FTDI port, string description)
        {
            uint deviceCount = 0;

            if (port == null) throw new Exception(description + "is not initialized");
            if (port.IsOpen) {
                Global.ShowError(description + " is already open");
                return;
            }

            // Determine the number of FTDI devices connected to the machine
            if ((ftStatus = port.GetNumberOfDevices(ref deviceCount)) != FTDI.FT_STATUS.FT_OK) {
                throw new FTDI.FT_EXCEPTION("Failed to get number of devices. err: " + ftStatus.ToString());
            }

            // If no devices available, return
            if (deviceCount == 0) throw new Exception("No devices on " + description);

            // Allocate storage for device info list
            FTDI.FT_DEVICE_INFO_NODE[] ftdiDeviceList = new FTDI.FT_DEVICE_INFO_NODE[deviceCount];

            // Populate our device list
            if ((ftStatus = port.GetDeviceList(ftdiDeviceList)) != FTDI.FT_STATUS.FT_OK) {
                throw new FTDI.FT_EXCEPTION("Failed to get device list. err " + ftStatus.ToString());
            }

            int foundIndex = -1;
            for (int i = 0; i < deviceCount; i++) {
                if (ftdiDeviceList[i].Description.ToString().Contains(description)) {
                    foundIndex = i;
                }
                /*
                Console.WriteLine("Device Index: " + i.ToString());
                Console.WriteLine("Flags: " + String.Format("{0:x}", ftdiDeviceList[i].Flags));
                Console.WriteLine("Type: " + ftdiDeviceList[i].Type.ToString());
                Console.WriteLine("ID: " + String.Format("{0:x}", ftdiDeviceList[i].ID));
                Console.WriteLine("Location ID: " + String.Format("{0:x}", ftdiDeviceList[i].LocId));
                Console.WriteLine("Serial Number: " + ftdiDeviceList[i].SerialNumber.ToString());
                Console.WriteLine("Description: " + ftdiDeviceList[i].Description.ToString());
                Console.WriteLine("");
                */
            }
            if (foundIndex < 0) {
                throw new Exception("Failed to find device with description " + description);
            }

            if ((ftStatus = port.OpenByIndex((uint) foundIndex)) != FTDI.FT_STATUS.FT_OK) {
                throw new FTDI.FT_EXCEPTION("Failed to open device. err: " + ftStatus.ToString());
            }
        }