Reference Manual

Table Of Contents
Product Data
OVP for External Alarm
It is possible to connect 16 external alarms to the DF. Each alarm
connection is provided with over-voltage protection. (One OVP module
protects two alarm connections.)
PCM Overvoltage Module
This module contains overvoltage protection for the PCM lines.
If the PCM lines are terminated in equipment outside the RBS
equipment room, these lines must be protected by overvoltage
protectors (OVP) in the DF. Failure to do so might damage the
DXU-21, if a voltage transient is transported along the cable.
RBS 2206 is designed for 100/120
balanced (twisted pair) cable. If
75
unbalanced (coaxial) cable is to be connected, the module must
contain a balun card that converts 75
unbalanced to 100/120
balanced line.
A by-pass relay card can be installed in the module to bypass the
transmission network during power failure.
Distribution Module
This unit supervises the OVP and controls the by-pass relay if by-pass
relay is used. It can also distribute +24 V DC to external transmission
equipment.
Earthing
The DF is provided with a short earth cable which is to be connected to
the earth collection bar. The DF must be placed close to the earth
collection bar, therefore the earth cable must not be extended.
5.5.2 Transmission Adapter (Optional)
P008218A
Figure 36 Transmission adapter (TA)
The Transmission Adapter (TA) is a unit that contains a balun
(balanced/unbalanced transformer) for transforming 75
unbalanced to
120
balanced cable. It is provided with two BNC connectors for
connection of the 75
coaxial cable.
It is intended for mounting directly on the transmission link connector
(G-703) on the cabinets connection eld, see Figure 32 on page 91.
94 (421)
EN/LZT 720 0008 R1A
2001-06-26
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