Hitachi US7070447-001 manual 10BASE-TX Ports, 1. RJ-45 Connector pin assignments

Draft Level—Hitachi Confidential

HiSpeed Switch Troubleshooting Guide

❒Line transmission modes on the 10/100BASE-TX ports support both half-duplex and full-duplex operations. By definition, the CSMA/CD protocol is half-duplex where data can be transmitted and received in both directions, but only at one direction at a time. Therefore, 10BASE-TX ports operate in half-duplex mode only.

10BASE-TX Ports

The 10BASE-T port connections are provided for the 10 Mbps Ethernet segment or nodes to attach to the HiSpeed switch. The RJ-45 jacks accept standard Category 3, 4, or 5 copper unshielded twisted pair (UTP) cable connections. Pin assignments for the standard RJ-45 connector are given in Table 4-1. The HiSpeed switches are shipped with the 10BASE-T connectors configured as MDI-X (media-dependent interface-crossover). These ports connect over straight cables to the network interface controller (NIC) card in a node or server, similar to a conventional Ethernet repeater hub. If you are connecting to another Ethernet hub or Ethernet switch, you need a crossover cable unless an MDI connection exists on the associated port of the attaching device (see “Connecting 10BASE-T Ports” on page 2-8 for a description of the crossover cable).

The 10 Mbps ports operate in half-duplex mode only, and each port has an associated LED that indicates link status of the line.

Table 4-1. RJ-45 Connector pin assignments

Pin MDI-X Signal

1Receive data + (RD+)

2Receive data - (RD-)

3Transmit data + (TR+)

4Not used

5Not used

6Transmit data - (TD-)

7Not used

8Not used

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