2
Section 61246026L6-5, Issue 2
61246026L6-5B
Part Number
Description
1242002LX .............. 220/E220 HTU-C
1242016LX .............. 3192 HTU-C
1242023LX .............. DDM+ HTU-C
1244001LX .............. Low Voltage E220 HTU-C
1244002LX .............. Litespan HTU-C
1244041LX .............. Low Voltage T400 HRE
1244042LX .............. Low Voltage 819A HRE
1244044L1 ............... Low Voltage 439 HRE
1245001LX .............. Low Voltage E220 HTU-C
1245002L6 ............... Litespan HTU-C
1245003LX .............. Low Voltage DDM+ HTU-C
1245004LX .............. Low Voltage 3192 HTU-C
1245005L1 ............... HLSS HTU-C
1245006L6 ............... T200 HTU-C
1181101L1 ............... Total Access HTU-C
1246001LX .............. E220/220 HTU-C
1246003LX .............. DDM+ HTU-C
1246004LX .............. 3192 HTU-C
1245045LX .............. 239 HRE
1245041LX .............. T200 HRE
1246041LX .............. T200 HRE
1246045LX .............. 239 HRE
The Low Voltage HTU-R can be deployed in
circuits using one HTU-C and one HTU-R. The
Low Voltage HTU-R can also be deployed with one
HTU-C M and up to two Low Voltage HREs in
circuits requiring reach beyond standard CSA
requirements. The Low Voltage HTU-R will not
power an external T1 NIU.
The HTU-R terminates local loop HDSL signals
originating from the Central Office (CO) unit and
transforms the HDSL signal into traditional DS1
signals to be delivered to the customer.
The HDSL local loop operates as two independent
subsystems each operating over a single twisted
pair. The HTU-R communicates over these two
twisted pairs to the HTU-C located at the CO. Each
subsystem carries half of the total bandwidth along
with a small amount of overhead used for
maintenance and performance monitoring related
functions. The unit is span powered by the HTU-C.
The effective range of an ADTRAN HDSL-based
T1 circuit can be extended using the ADTRAN
HDSL Range Extenders (HREs). An HRE can
double the deployment range of standard HDSL and
extend the digital subscriber loop serving range up
to 24 kft with one HRE or 36 kft with two HREs on
24-gauge twisted pair wire.
For more information on HREs, refer to the
appropriate ADTRAN practices.
The Low Voltage HTU-R (P/N 1246026L6) can be
used with any Low Voltage HRE and any HTU-C to
provide a fully span-powered extended range HDSL
circuit. Span powering meets all requirements of
Class A2 voltages as specified by Bellcore
GR-1089-CORE.
Revision History
This practice has been reissued to update the unit
illustations and remove a note regarding the DS1
transmit level setting.
Electrical Code Compliance
Table A shows the UL/CUL Telecommunications
Codes for the HTU-R. The HTU-R complies with
the requirements covered under UL 1459 third
edition and is intended to be installed in an
enclosure with an Installation Code (IC) of “B”
or “E.”
NOTE: This product is intended for
installation in RESTRICTED ACCESS
LOCATIONS only.
2. INSTALLATION
After unpacking the unit, immediately inspect it for
possible shipping damage. If damage is discovered,
file a claim immediately with the carrier, then
contact ADTRAN customer service (see
subsection 10 of this practice).
Except for DS1 (Tx) output level, the HTU-R is
provisioned by the HTU-C. The settings on the
HTU-C are encoded and transmitted to the HTU-R
once the circuit has achieved synchronization. As
with other provisioning options, enabling the NIU
feature of the HTU-R is selected at the HTU-C.
Table A. UL/CUL Telecommunications Codes
Code
Input
Output
IC
A
--
TC
X
X
PC
C
C
