635 USB driver - conflict


New member
I have used USB CFA-635 for a while without problems on a Advantec PCI CPU-card P-III
w/VGA/82562/Audio/C socket 370 815E
Intel 1,2 GHz Pentium III, Tualatin, 512Mb PC
On the PC we also have a PCI-1603 2port RS232/Curentloop
PCI card

We have nopw switch the main board to a
Advantec PCI CPU-card SlotPC, w/LAN/VGA/LVDS/CFC
Intel 1,1 GHz PentiumM,
SODIMM 512Mb PC2700
(still with the same Current loop card).

In both cases the OS is Win2000

When the USB drivers (cf-usb-2154b.exe) are installed on the new board the leds are only flashing and we can see some patterns on the LCD display, but its not possible to access the display (also tested with CrystalFonz test program). When this happens we are not able to open the Current Loop COM port (COM3/COM4) even if CrystalFontz COM ports are set to COM6/COM7 (and also tested with COM11/COM12).

This seems to be an IRQ conflict or a base address conflict.

Otto Milvang
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CF Mark

Have you tried connecting a powered USB hub between the new CPU-card and the 635?

Im just wondering if the new card for some reason cannot supply enough power to the 635.


New member
Thans for your answer.
The unit works fine with a USB-HUB.
It seems that we only got 4.5V from our new board (4.8 V on the old one).

I turned of the backlight and stored that as a startup configuration, but without any success. I guess we need an external power for this.


New member
Have now solved the problem. Added a 9V battery, and used a 7805 chip to get 5V. Replaced 5V from USB connector with my new power supply.
USB LCD Displays - Graphic and Character LCDs with a Keypad