Help with programming low-level VIs for D2XX driver on FT4222

[Skoda3]

I have this FTDI chip: FT4222H is a USB2.0 to Quad-SPI/I2C interface Device Controller

I must comunicate with it using Labview.

Can You reference me to some good examples of LV code? Can You suggest easy way to realize the comunication?

[K C]

Hi,

Start with the examples from FTDI found here.

And search this forum.

When you have some specific questions you can come back again and ask them here.

Kees

[xilinx_guy]

So...after a lot of heartache, and trial and error, I had to access the FT4222 with 32-bit Labview while my main application is in 64-bit Labview.  You need to have all your accesses to the FT4222 device in 32-bit version of Labview.  Yeah-it sucks, but it is what it is.  FTDI is no help here, as they do not have a DLL that works with 64-bit LV at this time.  I even tried writing a wrapper around the FTDI DLL and could not get it to work properly.  However, LV allows you to communicate with VI running separately via Datasocket, AND you can do it between 32-bit and 64-bit versions.

If you are interested and if this message gets back to you, reach out to me.  I'll show you what I did to do this.

Kindest regards

John

[rolfk]

I'm sceptical about your claim that FTDI has no 64-bit DLL that is usable from within LabVIEW. The download here https://ftdichip.com/products/ft4222h/ definitely contains 64-bit DLLs in the imports\LibFT4222\dll\amd64\ and it looks, smells and quakes like a legit 64-bit DLL.

It is the 4222 layer on top of the D2XXX driver, so you need to have that installed too. And yes I mean installed, just having it next to your libFT4222-64.DLL won't work unless they both are located in the same directory as your EXE file.

Windows only will search for dependencies in the directory the process is located in or in one of the system directories or a directory listed in your PATH environment variable. The directory a calling DLL is located in has absolutely no special meaning for the Windows search.

[xilinx_guy]

Hello Rolf

Here is what I experienced when using the FTDI "64-bit" version of the ftd2xx.dll..

When I used the "import shared DLL" feature in Labview, everything came in cleanly once I resolved the dependencies.  I wrote a very simple VI using only the FT_OpenEx() and FT_Close VIs.  Yes, 64-bit Labview is able to open a handle to the device driver and find the FT4222 device without a problem.  FT_OpenEx() returns a ZERO, which means everything is OK.  HOWEVER, running FT_Close returns a "1", which means invalid handle.  No other VIs from the importing of the DLL worked.  They always returned an error.  Well, actually I think one other VI worked, which listed all USB devices.  Other than that, I was not able to get the more useful VIs to work in 64-bit Labview.  I wrote a simple console app in Visual Studio using C.  My simple C program using the same DLL worked just fine.

Rather than keep beating myself on my head to get this working in 64-bit Labview, I just wrote a 32-bit VI because I know that works with the ftd2xx.dll.  I then used a datasocket from a 64-bit VI to provide access to it.  It actually works very nicely, and it gave me another tool to use.  I was able to perform all the functions I need to access the FT4222 device on my product.

I have performed an extensive search on this topic--even on FTDI's knowledge base.  FTDI recognizes there is a problem.  They just don't have Labview anymore to help us resolve it.  If you are able to get the 64-bit Labview working with the FTDI DLLs, I'd love to hear about it.

Kind regards

John