USB Driver / 634 Hardware not recognised


New member
I am having a heck of a time with USB drivers. I have tried on 2 different XP machines with the same results. I have a CFA-634-TMC-KU V2.2 ( SN 281214A) and have tried on Win XP 32 bit on 64 bit hardware and Win XP 32 bit on 32 bit hardware.

When the USB LCD is connected Win XP pops up with "USB <-> Serial" and asks for a driver. If I point it at the drivers : (with or without 533 support), windows says the drivers doesnt contain info about my hardware.

When I poke in the control panel the Device Instance ID string for the hardware is USB\VID_0403&PID_6001\12345678 but this doesnt appear in any of the driver files.

Is there a bigger issue or am I doing something wrong?

Many thanks,
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New member

I went through the 2 .inf files in the distribution for the 634 with a text editor.
These are the files named FTDIport.inf and FTDIbus.inf. I found the references for my hardware in the line were set to FC09:


So I changed them all to:


and then XP happily took the drivers.
All working now :)

But I'd still be interested to know if this is a common issue and what caused it.


CF Support2


Thank you for the information.

Looks like we need to some cleaning up of our USB driver files and some additional verification. Our older XP drivers have been certified and fully tested. The CFA634 you have is one rev back on the hardware - it is likely using an older "B" chip for the USB interface. In theory, it should not matter as the driver is the same.

We'll take a look and see if we can get to the bottom of things.

Thanks again!