Table Of Contents
Connecting to 10BASE-T and 100BASE-TX Devices
Connecting to 1000BASE-T Devices
Cable and Adapter Specifications
Two Twisted-Pair Cable Pinouts
Four Twisted-Pair Cable Pinouts for 10/100 Ports
Four Twisted-Pair Cable Pinouts for 1000BASE-T Ports
Connectors and Cables
This appendix describes the connectors, cables, and adapters that you use to connect the switch to other devices.
Connector Specifications
These sections describe the connectors used with the Catalyst 2940 switches and contains this information:
10/100 Ports
The 10/100 Ethernet ports use standard RJ-45 connectors and Ethernet pinouts with internal crossovers, as shown by an X in the port label on the switch, as shown in Figure B-1.
Figure B-1 Port Labels Showing Internal Crossovers
These ports have the transmit (TD) and receive (RD) signals internally crossed so that a twisted-pair straight-through cable and adapter can be attached to the port. Figure B-2 shows the pinout.
Figure B-2 10/100 RJ-45 Pinouts
When connecting 10/100 ports to other devices, such as servers, workstations, and routers, you can use a two or four twisted-pair, straight-through cable wired for 10BASE-T and 100BASE-TX. Figure B-6 shows the two twisted-pair, straight-through cable schematics. Figure B-8 shows the four twisted-pair, straight-through cable schematics.
When connecting the ports to other devices, such as switches or repeaters, you can use a two or four twisted-pair, crossover cable. Figure B-7 shows the two twisted-pair, crossover cable schematics. Figure B-9 shows the four twisted-pair, crossover cable schematics.
You can use Category 3, 4, or 5 cabling when connecting to 10BASE-T devices. You must use Category 5 cabling when connecting to 100BASE-TX devices.
Note
Use a straight-through cable to connect two ports only when one port is designated with an X. Use a crossover cable to connect two ports when both ports are designated with an X or when both ports do not have an X.
10/100/1000 Ports
The 10/100/1000 Ethernet port on the Catalyst 2940-8TT-S switch uses a standard RJ-45 connector. Figure B-3 shows the pinout.
Figure B-3 RJ-45 Pinouts for 10/100/1000 Port
Connecting to 10BASE-T and 100BASE-TX Devices
When connecting the ports to 10BASE-T and 100BASE-TX devices, such as servers, workstations, and routers, you can use a two or four twisted-pair, straight-through cable wired for 10BASE-T and100BASE-TX. Figure B-6 shows the two twisted-pair, straight-through cable schematics. Figure B-8 shows the four twisted-pair, straight-through cable schematics.
When connecting the ports to 10BASE-T- and 100BASE-TX devices, such as switches or repeaters, you can use a two or four twisted-pair, crossover cable. Figure B-7 shows the two twisted-pair, crossover cable schematics. Figure B-9 shows the four twisted-pair, crossover cable schematics.
You can use Category 3, 4, or 5 cabling when connecting to 10BASE-T devices. You must use Category 5 cabling when connecting to 100BASE-TX devices.
Connecting to 1000BASE-T Devices
When connecting the ports to 1000BASE-T devices, such as servers, workstations, and routers, you must use a four twisted-pair, Category 5, straight-through cable wired for 10BASE-T, 100BASE-TX, and 1000BASE-T. Figure B-10 shows the straight-through cable schematics.
When connecting the ports to other devices, such as switches or repeaters, you must use a four twisted-pair, Category 5, crossover cable. Figure B-11 shows the crossover cable schematics.
Note
Note
100BASE-FX Port
The 100BASE-FX port on the Catalyst 2940 8TF-S uses an MT-RJ connector, shown in Figure B-4. This port uses 50/125- or 62.5/125-micron multimode fiber-optic cabling.
You can connect a 100BASE-FX port to an SC port on a target device by using one of the MT-RJ fiber-optic patch cables listed in Table B-1. Use the Cisco part numbers in Table B-1 to order the patch cables that you need.
Figure B-4 MT-RJ Connector
SFP Module Slot
The Catalyst 2940-8TF-S switch has a slot for SFP modules that provide fiber-optic uplink ports.
Figure B-5 shows an SFP module connector for a fiber-optic connection.
Figure B-5 SFP Module Connector
Warning
Warning
Console Port
The console port uses an 8-pin RJ-45 connector. You can connect a switch to a PC through the console port and the supplied RJ-45-to-DB-9 adapter cable. If you want to connect a switch to a terminal, you need to provide an RJ-45-to-DB-25 female DTE adapter. You can order a kit (part number ACS-DSBUASYN=) with that adapter from Cisco. For console-port and adapter-pinout information, see Table B-2 and Table B-3.
Cable and Adapter Specifications
These sections describe the cables and adapters used with Catalyst 2940 switches.
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Two Twisted-Pair Cable Pinouts
Figure B-6 and Figure B-7 show the schematics of two twisted-pair cables for 10/100 ports.
Figure B-6 Two Twisted-Pair Straight-Through Cable Schematic for 10/100 Ports
Figure B-7 Two Twisted-Pair Crossover Cable Schematic for 10/100 Ports
Four Twisted-Pair Cable Pinouts for 10/100 Ports
Figure B-8 and Figure B-9 show the schematics of four twisted-pair cables for 10/100 ports.
Figure B-8 Four Twisted-Pair Straight-Through Cable Schematic for 10/100 Ports
Figure B-9 Four Twisted-Pair Crossover Cable Schematic for 10/100 Ports
Four Twisted-Pair Cable Pinouts for 1000BASE-T Ports
Figure B-10 and Figure B-11 show the schematics of four twisted-pair cables for the 10/100/1000 port.
Figure B-10 Four Twisted-Pair Straight-Through Cable Schematic for 10/100/1000 and 1000BASE-T GBIC Module Ports
Figure B-11 Four Twisted-Pair Crossover Cable Schematics for 10/100/1000 and 1000BASE-T GBIC Module Ports
Cable and Adapter Pinouts
This section describes the cable and adapter pinouts and also describes how to identify a rollover cable.
Connecting to a PC
Use the supplied RJ-45-to-DB-9 adapter cable to connect the console port to a PC running terminal-emulation software. Table B-2 lists the pinouts for the console port and the RJ-45-to-DB-9 adapter cable.
Connecting to a Terminal
Use the supplied RJ-45-to-DB-9 adapter cable and an RJ-45-to-DB-25 female DTE adapter to connect the console port to a terminal. Table B-3 lists the pinouts for the console port, the adapter cable, and the RJ-45-to-DB-25 adapter.
Note
Identifying a Rollover Cable
You can identify a rollover cable, also known as a "crossover" cable, by comparing the two modular cable ends. Hold the cable ends side-by-side, with the tab at the back, right plug, as shown in Figure B-12.
Figure B-12 Identifying a Rollover Cable
On a rollover cable, the wire connected to the pin on the outside of the left plug should be the same color as the wire connected to the pin on the outside of the right plug.
