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Cables

Cables

This appendix lists cables that have been tested and verified for use with the Catalyst 3000. It also includes minimum pinout information. If you use a cable that is not listed, you must verify that the cables used in your installation are wired correctly.


Note Incorrectly wired cabling is the most common cause of problems for LAN communications. Working with a qualified LAN cable installer is recommended.

The Stack Port cable is a proprietary cable. It is similar to, but not equivalent to, a SCSI cable. It is available in one-meter lengths only.

This appendix covers the following topics:

Twisted-pair Cable and Connector Pinouts

10BaseT

10BaseT ports on the Catalyst 3000 are always MDI-X. Cabling these ports to different types of equipment will require a straight-through cable or a crossover cable.

Straight-through Cable

A "straight-through" cable is used when connecting two ports that are not set to the same MDI mode or not set to the same MDI-X mode. 10BaseT ports on the Catalyst 3000 are always MDI-X. When connecting these MDI-X ports to ports that are MDI, such as PCs or servers, use a straight-through cable. A straight-through cable has each internal twisted pair of wires connected to the same pin number at each end. The twisted-pair wires must be twisted throughout the entire length of the cable. The wiring sequence must conform to AT&T 258A (not USOC). Figure A-1 shows the wiring diagram for a straight-through cable, and Table A-1, "10BaseT Cable PinOut," is a listing of the signals used on each pin.


Figure A-1: Straight-through Cable Pinout



Pins 1 and 2 must be a twisted pair.

Pins 3 and 6 must be a twisted pair.

Pins 4, 5, 7, and 8 are not used in this application, although they may be wired in the cable.

The following table (Table A-1) lists the pin numbers and their respective signal names for a 10BaseT straight-through cable.


Table  A-1: 10BaseT Cable Pinout
Pin Signal Note
1 TX+

Pins 4, 5, 7, and 8

are not used.

2 TX-
3 RX+
6 RX-

Crossover Cable

For cabling between two switches, the transmit and receive pairs must be reversed. You can do this in one of two ways:


  1. Use a straight cable with one switch port set to MDI and the other set to MDI-X.

  2. Use a crossover cable with both switch ports set to MDI or both ports set to MDI-X.

    Figure A-2 shows the wiring diagram for a crossover cable.



Figure A-2: Crossover Cable Pinout



Pins 1 and 2 at A, must be a twisted pair wired through to pins 3 and 6, respectively, at B.

Pins 3 and 6 at A, must be a twisted pair wired through to pins 1 and 2, respectively, at B.

Pins 4, 5, 7, and 8 are not used in this application, although they may be wired in the cable.

A short crossover cable can be used to adapt a straight-through twisted-pair cable for "cascading" switches through the twisted-pair ports.

100BaseTX Expansion Module

The 100BaseTX expansion module network port is always MDI-X. Cabling to different types of equipment will require a straight-through or a crossover cable.


Note The 100BaseTX cable pinout is the same as the 10BaseT cable pinout. Use the 10BaseT cable information in the previous section for referencing 100BaseTX cables, whether straight or crossover.

Note The only difference between 10BaseT and 100BaseTX cables, is that 10BaseT is a Category 3 cable, and 100BaseTX is a Category 5 cable. (Category 5 cable is usually a little heavier or stiffer than Category 3 cable. Also check if the type of cable is imprinted on the cable jacket.)

AUI Cable


Table  A-2: AUI Cable Pinouts
Transceiver end 15-pin Female Switch end 15-pin Male Signal
2 2 Control In   circuit A
3 3 Data Out   circuit A
4 4 Data In   circuit Shield (common drain)
5 5 Data In   circuit A
6 6 Voltage common
9 9 Control In   circuit B
10 10 Data Out   circuit B
12 12 Data In   circuit B
13 13 Voltage plus (+12 @ 500ma)

For this connection, you can use:

Some longer cables may have all 15 pins wired. See the IEEE 802.3 standards document for definitions of the pins not shown here.

Standard EIA(RS)-232 Cables


Table  A-3: EIA-232 Cable Description
Cable Function Port Type on Terminal, PC, or Modem Standard Cable or Cable Solution

Connecting a terminal or PC to the console port with an EIA(RS)-232-C

25-pin female

Attach a null modem adapter++ (Tandy Null Modem Adapter No. 26-1496 has been tested) to the console port. Then attach a straight-through modem cable to the null modem adapter.

9-pin male

Use a Black Box PC/AT Serial Printer Cable (EVENBPC has been tested). OR:
Attach a null modem adapter to the console port. Then attach a modem cable (EVENBMC and Cablex PC have been tested) to the null modem adapter.

Connecting a modem to the console port

25-pin female or male port

Straight-through EIA-232-C modem cable (standard cable)

* For these cables, the signals DTR (pin 20) and RTS (pin 4) must be on, or high, on your terminal or in your terminal emulation program.

++ The required minimum pinout is provided in the section "Console Connector and Cable Pin-Outs."

Console Connector and Cable Pinouts

The Catalyst 3000 has a DB-9 console port that automatically detects baud rate. The default is 9600 baud; other supported baud rates are 1200, 2400, 4800, and 19200.

Terminal

For a terminal connection, use a null-modem cable or a straight cable with a null modem adapter attached.

Modem

For a modem connection, use a standard modem (straight) cable.

Console Pin Assignments

The following table (Table A-4) and two figures (Figure A-3 and Figure A-4) detail pin assignment information for the cables you can use on the console port of the Catalyst 3000.


Table  A-4: Pinout for the Console Port Connector

Pin Function
1 DCD
2 RXD
3 TXD
4 DTR
5 SIG GND
6 DSR
7 RTS
8 CTS
9 RI

The following figures (Figure A-3 and Figure A-4) detail pin assignment information for the cables you can use on the console port of the Catalyst 3000.


Figure A-3: RS-232-C Null Modem Cable (for Terminal/PC with 25-pin Connector)




Figure A-4: RS-232-C Null Modem Cable (for Terminal/PC with 9-pin Connector)



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