Specifications

Page 10–2
FOCUS System Manual
10.2 Application
The DE1 Transceiver Module, with its T1/E1
electrical interface, is used when a FOCUS node
is connected to a higher rate communication
system, such as PDH, SONET or SDH, into fiber
optic cables or digital microwave. This enables
FOCUS to be a feeder multiplexer into one of the
DE1 ports from the higher rate multiplexer.
The FOCUS chassis containing the DS1/DE1
Transceiver Module can be up to 50/133 feet
(15/40 meters) away from the higher rate multi-
plexer system. In a typical installation, however,
the FOCUS is placed within several feet of the
higher rate multiplexer.
While the DE1 module can be used with all
FOCUS Maintenance modules, the DS1 can only
be used with the MV2/MV3 configuration.
10.3 Installation
A FOCUS chassis is typically shipped with the
DS1/DE1 Transceiver Module already installed,
along with the other common equipment and the
specified channel modules. We recommend that
you set up the entire chassis in a test setting,
attach any necessary wiring or cables, and test its
functionality before installing it in an operating
network. Likewise, if you are adding a new or
replacement DS1/DE1 Transceiver Module to
your system, we also recommend you first install
and test it in a test chassis.
If your DS1/DE1 Transceiver Module came
already installed in the chassis, you can skip Steps
1 and 3 in the Hardware Installation and
Connections instructions that follow. If your DE1
Transceiver Module came separately, complete all
the steps.
The FOCUS chassis provides two double-size
slots for transceiver modules. These are labeled
XCVR-1 and XCVR-2 on the front of the chassis.
XCVR1-1 and XCVR1-2 are defined as the “A”
and “B” transceivers on a DE1 Module installed in
the XCVR-1 position. XCVR2-1 and XCVR2-2
are defined as the “A” and “B” transceivers on a
DE1 Module installed in the XCVR-2 position.
10.3.1 Hardware Installation and
Connections
To install the FOCUS DE1 Transceiver Module,
complete the following steps:
1. Insert the DE1 Transceiver Module into the
chassis.
In an operational chassis containing pretested
common equipment (except for the DE1
Transceiver Module), carefully insert the DE1
Transceiver Module into the top and bottom
grooves of one of the two transceiver slots. If
you are installing just one transceiver module
in the chassis, we recommend putting it in the
slot labeled XCVR-1. Slide it all the way in
until it is well seated in the slot. Lock it into
place using the black inject/eject lever on the
front of the module.
2. Connect the proper wiring to the module’s
interface.
The pin assignments for the module’s DB25
female connector are shown in Figure 10-1.
Carefully wire a DB25 male connector for
your equipment. Note that the interface is
designed to accommodate two DE1
Transceiver Modules, with each having single
or dual transceivers. You need to connect
wires only for the number of transceivers
actually present.
For example, if you are connecting one DE1
Transceiver Module with dual transceivers to
two external DS1 ports, wire the pins for both
transceivers. If you are connecting to a single
external DS1 port, you need only wire the pins
for a single transceiver.
A DB15/RJ-45C (see Figure 10-5) type
interface is available for installations using
that type of cabling. Although TX/RX circuits
benefit most by using balanced twisted pair,
we do offer an interface for installations using
unbalanced coaxial cable. Fig. 10-7 shows a
BNC interface for use in unbalanced 75Ω
coaxial cable installations. Note that an
external ground is required.