User's Manual
ADCP-75-110 • Issue 2B • July 2001
Page 7
©
2001,
ADC
Telecommunications,
Inc.
1.3 Digital Remote Unit Description
The
DRU,
shown
in
Figure
4,
serves
as
the
cellular
user
servicing
unit
for
the
Digivance
ICS.
The
DRU
provides
the
following
basic
functions:
• RF
interface
to
the
cellular
users
via
an
external
antenna
• Optical
interface
to
the
DHU
or
DEU
• Conversion
of
the
forward
path
digitized
optical
signal
to
a
digitized
RF
signal
• Conversion
of
the
digitized
forward
path
RF
signal
to
the
original
cellular
RF
signal
• Digitizing
of
the
cellular
reverse
path
RF
signal
• Conversion
of
the
digitized
reverse
path
RF
signal
to
a
digital
optical
signal
output
• Transports
alarm
status
via
optical
link
FRONT PANEL
MOUNTING FOOT
(EACH CORNER)
7.0 INCHES
(178 mm)
7.3 INCHES
(185 mm)
2.1 INCHES
(53 mm)
16420-A
Figure 4. Digital Remote Unit
1.3.1 Primary components
The
DRU
consists
of
an
electronic
circuit
board
assembly
that
is
mounted
within
a
powder-
coated
sheet
metal
enclosure.
The
metal
enclosure
provides
a
mounting
point
for
the
electronic
assembly,
serves
as
a
heat
sink,
and
controls
RF
emissions.
The
electronic
circuit
board
assembly
is
not
user
replaceable.
The
DRU
is
designed
for
use
within
a
non-condensing
indoor
environment
such
as
inside
a
building.
All
controls,
connectors,
and
indicators
(except
the
SMA
antenna
connector)
are
mounted
on
the
DRU
front
panel
for
convenient
access.
1.3.2 Mounting
The
DRU
is
equipped
with
four
integral
mounting
feet
that
allow
it
to
be
mounted
on
any
flat
horizontal
or
vertical
surface.
A
typical
location
for
mounting
the
DRU
would
be
above
ceiling
tiles
where
the
optical
fiber
and
power
cables
can
be
concealed
or
on
a
wall.
Slots
are
provided
in
the
mounting
feet
for
securing
the
DRU
to
the
mounting
surface.