3com DUA 1648-5AAA02 Manual Do Utilizador

At frequent intervals you should visually check the Switch. 
Regular checks can give you an early warning of a possible 
failure; any problems can then be attended to when there will be 
least effect on users. Check the following:

If you experience any problems operating the Switch, refer to 
“Problem Solving” on page 41.

To connect a device to the Switch use Category 5 unshielded or 
shielded (screened) 100 Ohm TP cable (or Category 3 cable for a 
10 Mbps connection). The maximum length of cable for each 
connection is 100 m (328 ft). Connect one end of the cable to 
an RJ-45 port on the Switch and the other end to the 
appropriate RJ-45 port on the connecting device.

3Com recommends the use of Category 5e or 6 cables for 
1000BASE-T operation.

The following sections describe how to insert an SFP transceiver 
into an SFP slot.

The following list of approved SFP transceivers is correct at the 
time of publication:

■

3CSFP91 SFP (SX)

■

3CSFP92 SFP (LX)

To access the latest list of approved SFP transceivers for the 
Switch on the 3Com Corporation World Wide Web site, enter 
this URL into your internet browser:

To be recognised as valid, the SFP transceiver must have the 
following characteristics:

■

1000BASE-SX or 1000BASE-LX media type:

■

1000BASE-SX SFP transceiver
Use this transceiver to connect the Switch directly to a 
multimode fiber-optic cable.

■

1000BASE-LX SFP transceiver
Use this transceiver to connect the Switch directly to a 

single-mode fiber-optic cable or to multimode fiber using 

a conditioned launch cable.

If the SFP transceiver is faulty, it will not operate within the 
Switch. See “Problem Solving” on page 41.

Cabling

Check that all external cabling connections are secure 
and that no cables are pulled taut.

Cooling fan

Where possible, check that the cooling fan is operating 
by listening to the unit. The fan is fitted near to the 
front right hand side of the unit (when viewed from the 
front).