Hdsl4 System Testing - ADTRAN 3192 H4TU-C Installation And Maintenance Practice

Span Powering options
The 3192 H4TU-C uses a DC-to-DC converter to derive
its internal logic and span powering voltages from the
–48 VDC office supply. The 3192 H4TU-C can span
power an H4TU-R and up to two H4Rs as listed above.
The 3192 H4TU-C is default enabled for span powering
mode. The 3192 H4TU-C can be set to have span power
disabled when the H4TU-R is locally powered and no
H4Rs are on the circuit.
CAUTION
Disabling the span power removes all voltage
from the HDSL2 loop. This will result in an
absence of sealing current which could have an
adverse effect on circuit continuity over an
extended period of time.
The 3192 H4TU-C is capable of span powering the
H4TU-R and two H4Rs by applying –190 VDC power
to the local loop. The span powering voltage is less than
–200 volts with GFI protection to less than 5 mA. The
span powering supply is current limited to approxi-
mately 150 mA.
Refer to Figure 3. The differential span power output
voltage is measured between Loop 1 and Loop 2
(reference to Loop 1) and is typically –185 VDC.
Loop 1 will show a typical voltage of –6 VDC with
respect to ground potential, while the Loop 2 potential
is typically –191 VDC with respect to ground potential.
SPAN POWER
TC PAM
REGULATOR
HDSL4
Figure 3. 3192 H4TU-C Span Powering
Diagram
61223404L2-5A
T
LOOP 1
(-6 VDC)
R
-185 VDC
SPAN CURRENT
T1
LOOP 2
(-191 VDC)
R1
Issue 1, December 2003
H4TU-C Alarm Outputs
Each H4TU-C has a built-in fuse for the –48 VDC
power feed. If this fuse blows, a shelf alarm will be
activated, and all front panel indicators will be off. A
blown fuse indicates the card has malfunctioned and
should be replaced. This fuse is not designed to be
replaced in the field.
In order to avoid a shelf alarm, the H4TU-C element can
be provisioned to have the external alarms disabled.
This will disable all DSX and DS1 alarms.

4. HDSL4 SYSTEM TESTING

The ADTRAN HDSL4 system provides the ability to
monitor the status and performance of the DSX-1
signals, DS1 signals, and HDSL4 loop signals. Detailed
performance monitoring is provided via management
access of the front panel RS-232 port. These features are
valuable in troubleshooting and isolating any system
level problems that may occur at installation or during
operation of the HDSL4 system. The following subsec-
tions describe additional testing features.
H4TU-C Bantam Jacks
The front panel of the 3192 H4TU-C contains metallic
splitting bantam jacks for both nonintrusive
(monitoring) and intrusive (terminating) DSX-1 test
access. See Figure 4 for details for specific jacks.
T
DSX-1
R
DSX-1
MON
Rx
EQ
Rx
EQ
Tx
DSX-1
MON
Tx
T1
DSX-1
R1
Figure 4. H4TU-C Bantam Jack Arrangement
H4TU-C
HDSL4
HDSL4
LOOP 1
LOOP 1
H4TU-C
LOOP DC
DATA
POWER SOURCE
PUMP
HDSL4
HDSL4
LOOP 2
LOOP 2
5