6
61190852L2-5, Issue 3
61190852L2-5C
WARNING
On a live HDSL circuit, potentially dangerous
voltage may be present on the loop 1 and loop 2
signals. Use extreme caution when accessing
these signals.
1. Install an HTU-C or other line unit in the HDSL
CO Installation Kit.
NOTE
Before handling the line unit, make sure the
HDSL Installation Kit is connected to ground
and the ESD wrist-strap is connected to the
HDSL Installation Kit.
2. Install a test cable to make the following
connections. Be sure to maintain signal polarity
with the test cable. Connect the CO LP1 signal
jack to the loop 1 twisted-pair, and connect the
CO LP2 signal jack to the loop 2 twisted-pair.
3. When the HDSL CO Installation Kit is ON, the
HTU-C or other line unit will power the two
loops.
T1 BERT Testing of an HDSL Circuit
This section describes how to perform a T1 Bit-Error
Rate Test (BERT) using an HDSL Installation Kit and
a T1 BERT tester (See
Figure 9
).
With a single HDSL Installation Kit and T1 BERT
tester, a loopback test of the cable span can be
performed from the central office end or from the
remote end. With CO and Remote HDSL Installation
Kits and two BERT testers, an end-to-end test of the
entire cable span can be performed. The directions for
performing the BERT test are as follows.
1. Install test cables to make the following
connections between the T1 BERT tester and the
HTU-C installed in the HDSL Installation Kit.
For an end-to-end test, make the connections at
both ends of the cable span.
•
Connect the BERT tester’s DSX-1 RX jack to
the DS1 line receive jack on the front of the
HTU-C or HTU-R.
•
Connect the BERT testers DSX-1 TX jack to
the DS1 line transmit jack on front panel of
the HTU-C or HTU-R.
Figure 9. T1 BERT Testing of an HDSL Circuit
Remote/Repeater Shelf
End-to-End BERT
Serving Office
DS1 Receive
DS1 Transmit
Central Office Powering Shelf
LP1/LP2
LP1/LP2
Customer
Equipment
HDSL
Circuit
CAUTION:
RISK OF ELE
CTRICAL
SHOCK. MA
XIMUM
VOLTAGES U
P TO
-200 VDC M
AY BE
PRESENT ON
TELECOM
CIRCUITS.
1190851L2
HDSL 851 R
EPEATER/RE
MOTE
ESD
GND
RPTR. C.O.
CABLE PAIRS
RPTR. TO REM
OTE
CABLE PAIRS
LP1 LP2
LP1 LP2
REMOTE
CABLE PAIRS
DS1
LP1 LP2
RX TX
RPTR
IN
OUT
T1 BERT
Tester
CAUTION:
RISK OF EL
ECTRICAL
SHOCK. M
AXIMUM
VOLTAGES U
P TO
-200 VDC M
AY BE
PRESENT O
N TELECOM
CIRCUITS.
1190852L2
HDSL 852
CO POWER
REMOTE
LP1 LP2
DS1
TX RX
ESD
GND
DSX-1
LBO
B8ZS
FRM
ESF
NIU LB DI
S
LB TIMEO
UT DIS
533
399
266
133
0
EXT
1246001L2
LBK
ALM
DSX
DSL
TX
RX
TX
RX
M
O
N
E
Q
HTU-
CM
AMI
UFRM
SF
EN
EN
12345
T1 BERT
Tester
DS1 Receive
DS1 Transmit
Serving Office
T1 BERT
Tester
DS1 Receive
DS1 Transmit
Central Office Powering Shelf
Loopback BERT
LP1/LP2 Signals
HDSL
Circuit
CAUTION:
RISK OF EL
ECTRICAL
SHOCK. M
AXIMUM
VOLTAGES U
P TO
-200 VDC M
AY BE
PRESENT O
N TELECOM
CIRCUITS.
1190852L2
HDSL 852
CO POWER
REMOTE
LP1 LP2
DS1
TX RX
ESD
GND
DSX-1
LBO
B8ZS
FRM
ESF
NIU LB DI
S
LB TIMEO
UT DIS
533
399
266
133
0
EXT
124600
1L2
LBK
ALM
DSX
DSL
TX
RX
TX
RX
M
O
N
E
Q
HTU-
CM
AMI
UFRM
SF
EN
EN
12345
Remote End
Loopback
NOTE
As an alternative to the front panel DS1 signal
jacks, use the DSX RX and TX jacks located just
above the line unit slot on the HDSL Installation
Kit. These jacks correspond to line unit operation,
which means that the BERT tester’s DS1 transmit
jack must be connected to the installation kit’s
DSX TX jack, and the tester’s DS1 receive jack
to the installation kit’s DSX RX jack.
2. Install a test cable to connect the HDSL
Installation Kit to the HDSL circuit. For end-
to-end test, make the connections at both ends of
the cable span.
•
Connect the HDSL Installation Kit LP1
signal jack to the loop 1 twisted pair.
•
Connect the HDSL Installation Kit LP2
signal jack to the loop 2 twisted pair.
3. If a loopback BERT test is being performed, loop
back the far end.
4. Turn ON the HDSL Installation Kit and
T1 BERT tester. If an end-to-end test is being
run, turn on both installation kits and testers.
5. Run a T1 BERT test over the HDSL cable span.
