FTDI invalid handle on some computers

[rolfk]

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@dkim2 wrote:

Yes.

dkim2_2-1737668487604.png

dkim2_1-1737668436154.png

This is the real problem! FT_Close is defined as:

FT_STATUS FT_Close(FT_HANDLE ftHandle);

NOT

FT_STATUS FT_Close(FT_HANDLE *ftHandle); // WRONG

Change that Pass: Pointer to Value to Pass: Value, et voila! It works! And yes, for the FT_Open() it needs to remain as Pass: Pointer to Value.

When I install the driver, the file in syswow64 is the ftd2xx.dll not ftd2xx64.dll, although I am using the call library function on the ftd2xx64.dll from LabVIEW. Could this be an issue?

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SysWOW64, despite its name, contains binary files for 32-bit applications! The 64-bit binaries are located in System32! And I have no idea what you are talking about with ftd2xx64.dll. They are both called ftd2xx.dll.

[Andrey_Dmitriev]

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@rolfk wrote: I have no idea what you are talking about with ftd2xx64.dll. They are both called ftd2xx.dll.

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Hmmm, on my PC the officially deployed from FTDI and signed library is also called ftd2xx64:

Screenshot 2025-01-24 12.56.11.png

ftd2xx.dll is not exists in %WINDIR%\system32, at least not on my PC.

[rolfk]

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@Andrey_Dmitriev wrote:

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@rolfk wrote: I have no idea what you are talking about with ftd2xx64.dll. They are both called ftd2xx.dll.

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Hmmm, on my PC the officially deployed from FTDI and signed library is also called ftd2xx64:

Screenshot 2025-01-24 12.56.11.png

ftd2xx.dll is not exists in %WINDIR%\system32, at least not on my PC.

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As the image shows in the other message for the device properties, it seems to have installed ftd2xx.dll in both SysWOW64 and System32. It's what I have observed in some systems too, but I'm not currently using any FTDI hardware.

rolfk_0-1737721236502.png

The latest driver 2.12.36.4 from FTDI seems to indeed install the ftd2xx64.dll in system32. Go figure.

[dkim2]

Thank you so much, this solved the issue.

[maddogmilner]

You absolute legend! I have been wrestling with this exact issue for several days now. I adjusted the OpenEx function handle to Unsigned Pointer-sized Integer and all subsequent handles to U64 values and it worked! Basically, make it 64-bit!

Thank you very much!

[Jeff_Long]

Thank you, Rolfk!  This problem was bedeviling me!!