3com 7754 User Manual

Page of 80
46
C
HAPTER
 2: I
NSTALLING
 T
HE
 S
WITCH
 7750
Connecting Module 
Cables
This section describes how to connect electrical and optical cables.
Connecting Electrical Port Cables
The 48-port 10/100BASE-T module and 8-port 10/100/1000BASE-T module 
require a RJ-45 connector and category-5 twisted pair cable. See “Electrical Port 
Connector”
 on page 78 for an illustration of the RJ-45 connector and MDI/MDI-X 
pinout details.
Use the following steps to connect the port:
Plug one end of the straight-through cable into the Ethernet RJ-45 port of the 
switch.
Plug the other end of the straight-through cable into 
the RJ-45 port of the hub or LAN Switch.
Ports on 48-port 10/100BASE-T and 8-port 10/100/1000BASE-T modules support 
MDI/MDI-X auto-sensing. 
Connecting Optical Fiber Cables
The following modules require fiber optic cables:
24-port 100BASE-FX MMF FE module
20-port 1000BASE-X-SFP module
1000BASE-SX-MM, 1000BASE-LX-SM-IR, and 1000BASE-LX-SM optional GBIC 
modules for the 4-port 1000BASE-X-GBIC submodule
When connecting optical fiber cables, use the fiber connectors that are 
appropriate for the optical port type of the peer equipment that is connected to 
the local network port module. See “Optical Fiber Cable Connectors” on page 79 
for illustrations of the fiber optic cable connectors.
Single-mode optical fiber cable is used for external connections of the single-mode 
optical port. Multi-mode optical fiber cable is used for external connections of the 
multi-mode optical port. 
Before connecting the optical fiber cable, make sure the type of the connector and 
the optical fiber cable are consistent with the optical port type.
WARNING: When a connector is not inserted in the optical port or when its 
dustproof cover is open, invisible radiation can escape from the optical port. Do 
not stare into the optical port directly. Cover the optical port if there is no 
connector plugged in.
SC fiber connector
The 8-port 1000BASE-X GBIC module requires an SC optical fiber connector.
To attach the SC fiber connector:
Plug one end of the SC fiber connector into the optical port in the module.
Connect the other end of the connector to the corresponding device.