User Manual
ADCP-75-136 • Issue 1 • November 2002
Page 50
©
2002,
ADC
Telecommunications,
Inc.
6.
The
PORT
OK/NOK
LED
will
turn
either
blinking
red
or
green.
If
the
LED
turns
blinking
red,
the
optical
port
is
faulty.
Replace
the
optical
transceiver
and
then
recheck
system
operation.
If
the
LED
turns
green,
the
optical
port
is
good.
Proceed
to
step
7
to
continue
the
test
procedure.
7.
Place
the
PORT
ON/OFF
switch
in
the
OFF
position
(press
O).
8.
Disconnect
the
loopback
from
the
DHU
or
supporting
DEU.
9.
Clean
and
then
reconnect
the
optical
fiber
connectors
to
the
DHU
or
DEU
optical
port.
10.
Disconnect
the
optical
connectors
at
the
DRU
optical
port
or
remote
DEU
host
port
(far
end
of
fiber).
11.
Clean
the
optical
fiber
connectors
and
then
using
an
LC
optical
adapter,
connect
the
loopback
to
the
connectors
as
shown
in
Figure
26.
16768-B
OPTICAL
ADAPTER
OPTICAL
LOOPBACK
OPTICAL
CONNECTOR
NOTE: iF THE DISTANCE BETWEEN THE DHU/DEU AND THE
DRU EXCEEDS THE DISTANCE SHOWN BELOW, THE
REMOTE LOOPBACK TEST WILL NOT WORK.
62.5 MICRON MULTI-MODE FIBER - 250 METERS
50 MICRON MULTI-MODE FIBER - 375 METERS
9 MICRON SINGLE-MODE FIBER - 5 KILOMETERS
Figure 26. Optical Fiber Loopback Test
12.
Insert
a
dust
plug
into
the
DRU
optical
port
or
remote
DEU
host
port.
13.
At
the
DHU
or
supporting
DEU,
place
the
PORT
ON/OFF
switch
in
the
ON
position
(press
I).
14.
The
PORT
OK/NOK
LED
will
turn
either
blinking
red
or
green.
If
the
LED
turns
blinking
red,
one
of
the
optical
fibers
is
faulty.
Refer
to
Subsection
6.4.2
to
isolate
which
fiber
is
at
fault.
If
the
LED
turns
green,
the
optical
fibers
are
good.
Proceed
to
step
14
to
finish
the
test
procedure.
15.
At
the
DHU
or
supporting
DEU,
place
the
PORT
ON/OFF
switch
in
the
OFF
position
(press
O).
16.
Disconnect
the
loopback
and
the
optical
adapters
from
the
optical
fiber
connectors.
17.
Place
a
dust
cap
over
the
connector
for
each
optical
fiber
18.
Remove
the
dust
plug
from
the
DRU
optical
port
or
remote
DEU
host
port.
19.
Plug
the
loopback
into
the
DRU
optical
port
or
DEU
host
port
as
shown
in
Figure
27.
20.
If
testing
a
DRU
that
is
powered
by
the
DHU
or
by
a
supporting
DEU,
place
the
PORT
ON/OFF
switch
in
the
ON
position
(press
I).