Multiple Boards



Back again… Got a problem with running 2 3001 boards with a a USB 2.0 Mini-Doc on a DUB-H4 4 port hub. The Mini-Doc has a NEC D720112 chip. No Idea what’s in the hub… When the two 3001 boards are plugged into the hub by themselves, they both work. When I add the Mini-Doc, I get an “unknown hardware” error for the second 3001 board. If I plug the Mini-Doc into a port on the PC all is well… has anyone seen compatibility problems like this? It looks like a re-numeration problem to me…




Hi Bill-

The “Unknown Hardware” is associated with any number of USB-level problems. Here, we have most often seen that with bad ports on a PC. In particular, the front USB ports of a lot of cases have pigtail wires that connect the ports to the motherboard on a small jumper. Unfortunately, these cables sometimes don’t maintain signal integrity for the high-speed USB 2.0 signals.