Has anyone run into problems using FTDI direct driver functions while using VISA to write/read to a VCP in same VI? When I use the direct diver alone in a labview VI I see FT_STATUS = FT_OK from the point of opening the device to reads, writes and closing. I have a board with a micro and FT232RL for the USB and a RS-232 connection on a separate buffered port on the micro. I am trying to put together a VI to echo messages into USB and out RS-232 and vise-versa. I can get this to work using a VI (FTDI example LabVIEW_String_7.0 with while loop added) with direct driver functions and another serial Port terminal which is written in C#. I think there is an issue using the direct driver so I have been trying to get a VCP to work for the USB connection to the FTDI converter - but no luck so far.
Which FTDI direct driver are you utilizing in LabVIEW? How are you making the calls to this driver?
Are you trying to make one direct call and one VCP call to the same FTDI chip? The 232HL creates two VCP (COMn and COMn+1). Device Info List says there are two devices. I can't throw a loopback on, right now, but I can open COMn with VISA and Device Index 1 (but not 0) with the driver - no errors.