3Com MSR 30 Network Router User Manual


 
FIC-1E1/FIC-2E1/FIC-4E1 and FIC-1E1-F/FIC-2E1-F/FIC-4E1-F 165
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To extend an E1 120-ohm balanced twisted-pair cable, you can select a network
connector with an RJ-45 receptacle at each end to connect the cable to another
120-ohm balanced twisted-pair cable.
In addition, you are available with 75-ohm-to-120-ohm adapters.
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E1 cable, coaxial connector, network connector, and 75-ohm-to-120-ohm adapter
are all optional accessories. Please order them together with E1/FIC-2E1 and
FIC-1E1-F/FIC-2E1-F. By default, they are not provided.
Interface cable of the FIC-4E1/FIC-4E1-F
FIC-4E1/FIC-4E1-F provides two types of 1-to-4 adapter cables: 120-ohm 4E1 and
75-ohm 4E1. At one end of both cables is a DB-25 connector for connecting the
router, and at the other end are four DB-15 connectors for connecting E1 cables.
You can distinguish between them by the main label text: “4E1-120ohm-CAB” for
the 120-ohm 4E1 adapter cable and “4E1-75ohm-CAB” for the 75-ohm 4E1
adapter cable.
As shown in the following two figures, both cables look similar except that the
75-ohm 4E1 adapter cable uses eight coaxial cables but the 120-ohm 4E1 adapter
cable uses four twisted-pair cables.
Figure 202 120-ohm 4E1 adapter cable