Table of Contents
Advertisement
The 220 H4TU-C is capable of span powering the
H4TU-R and two H4Rs by applying simplex current
to the local loop. From 30 to 155 mA of loop current
is coupled onto the HDSL4 span to power the
H4TU-R and two H4Rs when deployed. The span
powering voltage is less than –190 volts with GFI
protection to less than 5 mA. See Figure 2.
SPAN POWER
TC PAM
REGULATOR
HDSL4
Figure 2. H4TU-C Span Powering Diagram
H4TU-C Alarm Outputs
Each H4TU-C has a built-in fuse for the –48 VDC
power feed. A blown fuse indicates the card has
malfunctioned and should be replaced.
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 subsections describe additional testing
features.
H4TU-C Bantam Jacks
The front panel of the H4TU-C contains metallic
splitting bantam jacks for both nonintrusive
(monitoring) and intrusive (terminating) DSX-1 test
access.
61222401L1-5C
Figure 3 illustrates the complete bantam jack
arrangement and details for specific jacks.
T
LOOP 1
R
SPAN CURRENT
T1
LOOP 2
R1
Figure 3. H4TU-C Bantam Jack Arrangement
H4TU-C Loopbacks
The H4TU-C responds to two different loopback
activation processes.
First, loopbacks may be activated using the craft
interface of the 220 H4TU-C. The Loopbacks and
Test Screen, which provides for the H4TU-C and
H4TU-R loopbacks, is described in Section 5 of this
practice.
Second, the H4TU-C responds to the industry standard
for HDSL4 loopbacks. A detailed description of these
loopback sequences is given in Appendix A.
This unit is transparent to framing. If a framed or
unframed loopback control sequence is sent, then the
unit will initiate the proper loopback command.
(Refer to Appendix A, Table A-1.)
T
DSX-1
R
DSX-1
MON
Rx
EQ
Rx
H4TU-C
DATA
PUMP
EQ
Tx
DSX-1
MON
Tx
T1
DSX-1
R1
H4TU-C
HDSL4
HDSL4
LOOP 1
LOOP 1
LOOP DC
POWER SOURCE
HDSL4
HDSL4
LOOP 2
LOOP 2
5
Advertisement
Table of Contents
