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DUAL- AND QUAD-PORT USB HUBS
Appendix A. Troubleshooting
A.1 Troubleshooting Tips
Serial Utility test software is supplied on the included CD-ROM and will be used in
the troubleshooting procedures. By using this software and following these simple
steps, you can eliminate most common problems without calling Technical
Support.
1. If your Hub isn’t working, first check to make sure that USB support is
enabled in the System BIOS and that it’s functioning properly in the
operating system. Use either the Windows 98/Me or Windows 2000 Device
Manager to do this.
2. Make sure that the included software (from the CD-ROM) has been installed
on the machine and that the necessary files are in place to complete the
installation.
3. When the USB Hub is configured properly, the USB Enabled LED (E) will be
lit. This should allow you to use the WinSSD utility (from the CD-ROM ) and
a loopback plug (not included) to check communications. The loopback plug
connects TD to RD. If you decide to test the modem control signals, a full-pin
loopback plug will be required. Details on loopback plugs are included on
WinSSD. (A loopback plug is available by special order from Black Box. Call
Technical Support for details.)
4. When testing the USB Hub in loopback mode, the port LEDs will flash and
echoed data will appear on the screen. The loopback test first transmits a hex
pattern, 55AA, and then a ASCII string of data. If this test passes, then the
USB Hub is ready for use in your application.
5. Please note that if the USB Hub is configured for 2-wire RS-485 with no echo,
a loopback test is not possible. The receiver, in this case, will be turned off
and the test will fail. If you plan on using this device in two-wire mode, test the
Hub in RS-422 mode first. Then configure the Hub for your application.
