4 61190852L2-5, Issue 3 61190852L2-5C
Installing Line Units
The follo ing steps describe ho to install an HTU-C
line unit into the HDSL CO Installation Kit, connect
the line unit to the HDSL circuit, and remove the line
unit.
1. Locate the slot to install the HTU-C on the HDSL
Central Office Installation Kit.
NOTE
Before handling line units, connect the HDSL
Installation Kit to ground and connect the ESD
rist strap to the installation kit.
2. Grasp the HTU-C by its front panel and align it
ith the guides in the slot. Slide it into the slot
until it seats firmly ith the connector at the rear.
3. Connect the HTU-C to the HDSL circuit by
installing a cable bet een the LP1 and LP2
signal jacks on the HDSL Installation Kit and the
HDSL circuit’s loop 1 and loop 2 t isted pairs.
Maintain signal polarity by observing the color
coding of the cable ends. Connect the CO LP1/
LP2 signal jacks to the loop 1 and loop 2 t isted
pairs, respectively, going to the remote end of the
HDSL circuit.
4. To remove an HTU-C, remove the patch cord
connecting the HTU-C to the HDSL circuit.
Pull the ejector lever on the bottom of the
HTU-C, or grasp it by its front panel and gently
pull it from the slot, observing ESD precautions.
Installing Test Cables
The HDSL Installation Kit is connected to the HDSL
circuit by installing test cables bet een the installation
kit’s LP1 and LP2 signal jacks and the t isted pair or
t isted pairs that form the HDSL circuit.
The cables are attached depending on the installation
as follo s:
• For a single-pair HDSL installation, use a test
cable ith a single-bantam end and t o alligator
clips. Insert the cable’s bantam end in the LP1
signal jack, and attach each alligator clip to one
of the ires in the t isted pair.
• For a t o-pair HDSL installation, use a test cable
ith a dual-bantam end and four alligator clips.
Insert the cable’s bantam end in the LP1/LP2
signal jacks, and attach each set of alligator clips
to the ires in the corresponding t isted-pair.
• For ADTRAN HDSL, the loops are insensitive to
tip-ring reversal. For other applications, such as
standard T1 testing, the follo ing describes the
polarity of the test set. The bantam to alligator-
clip test cables in the HDSL Installation Kit
indicate tip-and-ring connectivity as follo s:
– The alligator-clip cable ends are color-coded
red (tip) and green (ring) loop 1, yello (tip)
and black (ring) loop 2.
– The sleeves on the alligator-clip cable ends
are labeled to match their corresponding
bantam end.
– When installing a test cable, maintain signal
polarity by matching the LP1/LP2 bantam
cable ends to the correct alligator-clip ends
(LP1 bantam to loop 1 alligator clips, and LP2
bantam to loop 2 alligator clips). It does not
matter hich t isted-pair is considered loop 1
or loop 2 as long as the designations are
consistent. (See Figure 6).
C A U T I O N
!
SUBJECT TO ELECTROSTATIC DAMAGE
OR DECREASE IN RELIABILITY.
HANDLING PRECAUTIONS REQUIRED.
Figure 6. Test Cables
Loop 1
Loop 2
Red Loop 1 (T)
Loop 1 (R)
Loop 2 (T)
Loop 2 (R)
Green
Yellow
Black
