USB to RS-422 & RS-485 Adapter
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Troubleshooting
1. Windows 98SE cannot find drivers for my device
This error can occur if the VID and PID programmed into the device EEPROM do not match those listed in
the INF files for the driver. The VID and PID programmed into the device EEPROM may be found by using
the USBView utility from the FTDI website. These can then be checked against the VID and PID entries in
the driver INF files. If they do not match, that driver cannot be installed the VID and PID entries in the driver
INF files. If they do not match, that driver cannot be installed for that device without either re-programming
the device EEPROM or modifying the list of VID and PID numbers in the INF files. Please note that only your
own company VID and PID or FTDI's VID (0x0403) and FTDI PID issued for use by your company should be
used in the EEPROM and INF/INI files.
2. Windows 98SE forces a reboot after installing a device
This problem can occur if an application is accessing a file while the New Hardware Wizard is trying to copy it.
This usually occurs with the FTD2XX.DLL file. If installing a D2XX device, selecting not to restart the
computer then unplugging and re-plugging the device may allow the device to function properly without
restarting. Restarting the machine will allow the device to work correctly.
3. Driver installation fails and Windows 98SE gives error code 10
Windows error code 10 indicates a hardware error or failed driver installation. This error may appear if a
device has insufficient power to operate correctly (e.g. plugged into a bus powered hub with other devices),
or may indicate a more serious hardware problem. Also, it may be indicative of USB root hub drivers being
incorrectly installed. Please refer to the example schematics on the FTDI website for standard device
configurations. If the error persists, please contact the FTDI support department.
4. Device hangs randomly during operation under Windows 98SE
This is not caused by the driver, but is a hardware compatibility problem. Some newer USB 2.0 hubs and
host controllers can be susceptible to noise and can cause random device failures. This can be overcome by
fitting 47pF capacitors to ground on the USBDP and USBDM lines on the USB connector side of the 27W
series resistors.
5. Windows 98SE complains about missing .CAT files
Files with the .cat extension are signature files issued by Microsoft that indicate a device driver is WHQL
certified. If a driver is not certified, there will be no .cat files available.
When installing drivers in Windows 98SE or Windows ME, the user is prompted to locate the .cat files if the
operating system cannot find them. If the driver is not certified but you wish to install it anyway, the files may
be skipped by clicking the "Skip" button.
6. Windows 98SE complains about missing ftccomms.vxd file
