IBM 21Y Maintenance Manual

Contents

Installing options 69USB cables and hubsYou need a 4-pin cable to connect devices to USB 1 or USB2. If you plan to attach more than two USB devices, youmust use a hub to connect the devices. The hub providesmultiple connectors for attaching additional external USBdevices.USB technology provides up to 12 megabits-per-second(Mbps) speed with a maximum of 127 external devices anda maximum signal distance of five meters (16 ft.) per seg-ment.USB-port connectorsEach USB port has an external connector on the rear of theserver for attaching USB compatible devices.The following table shows the pin-number assignments forthe USB-port connectors on the rear of the server.Ethernet portThe server comes with an integrated Ethernet controller.This controller provides an interface for connecting to 10-Mbps or 100-Mbps networks and provides full-duplex (FDX)capability, which enables simultaneous transmission andreception of data on the Ethernet local area network (LAN).To access the Ethernet port, connect a Category 3, 4 or 5unshielded twisted-pair (UTP) cable to the RJ-45 connectoron the rear of the server.Note: The 100BASE-TX Fast Ethernet standard requiresthat the cabling in the network be Category 5 orhigher.Configuring the Ethernet controllerWhen you connect the server to the network, the Ethernetcontroller automatically detects the data-transfer rate(10Mbps or 100Mbps) on the network and then sets thecontroller to operate at the appropriate rate. That is, theEthernet controller will adjust to the network data rate,whether the data rate is standard Ethernet (10BASE-T), FastEthernet (100BASE-TX), half duplex (HDX), or full duplex(FDX). The controller supports half-duplex (HDX) and full-duplex (FDX) modes at both speeds.The Ethernet controller is a PCI Plug and Play device. Youdo not need to set any jumpers or configure the controller forthe operating system before you use the Ethernet controller.However, you must install a device driver to enable the oper-ating system to address the Ethernet controller. The devicedrivers are provided on the ServerGuide CDs.Table 13. USB-port connector pin-number assignmentsPin Signal1 VCC2 -Data3 +Data4 Ground