76 IBM xSeries 130: User’s ReferenceUSB cables and hubsYou need a 4-pin cable to connect devices to USB 1 or USB 2. If you plan to attachmore than two USB devices, you must use a hub to connect the devices. The hubprovides multiple connectors for attaching additional external USB devices.USB technology provides up to 12 megabits-per-second (Mbps) speed with amaximum of 127 external devices and a maximum signal distance of five meters (16ft). per segment.USB-port connectorsEach USB port has an external connector on the rear of the appliance server forattaching USB- compatible devices.The following table and illustration show the pin-number assignments for the USB-portconnectors on the rear of your appliance server.Ethernet portsYour appliance server comes with two integrated Ethernet controllers. Thesecontrollers provide an interface for connecting to 10-Mbps or 100-Mbps networks andprovide full-duplex (FDX) capability, which enables simultaneous transmission andreception of data on the Ethernet local area network (LAN).To access the Ethernet ports, connect a Category 3, 4, or 5 unshielded twisted-pair(UTP) cable to the RJ-45 connector on the rear of your appliance server.Note: The 100BASE-TX Fast Ethernet standard requires that the cabling in thenetwork be Category 5 or higher.Ethernet port connectorThe following table shows the pin-number assignments for the RJ-45 connector.These assignments apply to both 10BASE-T and 100BASE-TX devices.Table 8. USB-port connector pin-number assignments.Pin Signal1 VCC2 -Data3 +Data4 Ground1 4
