Pin Assignments B-1
Appendix B: Pin Assignments

RJ-45 Port

Figure B-1
RJ-45 Connector
(on the Hub Side)
RJ-45 station ports (MDI-X) can be attached to any devices
which use a standard LAN interface (e.g., a workstation, server
or router). RJ-45 daisy-chain ports (MDI) can be cascaded to a
station port on similar networking devices (e.g., a switch). Use
unshielded twisted-pair (UTP) or shielded twisted-pair (STP)
cable for RJ-45 connections: 100W Category 3, 4 or 5 cable for
10 Mbps connections or 100W Category 5 cable for 100 Mbps
connections. Also be sure that the length of any twisted-pair
connection does not exceed 100 meters.
Pin Assignment for MDI-X
Station Ports 1 ~ 12 Assignment for
Cascade Port 12MDI
1 Input Receive Data + Output Transmit Data +
2 Input Receive Data - Output Transmit Data -
3 Output Transmit Data + Input Receive Data +
6 Output Transmit Data - Input Receive Data -
4,5,7,8 Not Used Not Used
Table B.1 RJ-45 Pin Assignments
Schematics for both straight and crossover twisted-pair cable
are shown below.
Straight-Through Crossover
(Hub) (Adapter) (Hub) (Hub)
1 IRD+ 1 OTD+ 1 IRD+ 1 IRD+
2 IRD- 2 OTD- 2 IRD- 2 IRD-
3 OTD+ 3 IRD+ 3 OTD+ 3 OTD+
6 OTD- 6 IRD- 6 OTD- 6 OTD-