PairGain HiGain HDU-451 User manual

HIGAIN DOUBLER UNIT
PAIRGAIN TECHNOLOGIES, INC.
ENGINEERING SERVICES TECHNICAL PRACTICE
™150-451-103-02•¨
SECTION 150-451-103-02
Model List Number Part Number CLEI Code
HDU-451 3 150-1143-03 T1R3L1W8AA
L
RS 232
1
2
1
2
+
-
V
TELEPHONE CO PROPERTY
PairGain
LOOPBACK
HDU 451
HiGain DOUBLER
UNIT
HDSL IN
HDSL OUT

150-451-103-02, Revision 02
ii September 18, 1998 HDU-451 List 3
Revision History of This Practice
©Copyright 1998 PairGain Technologies, Inc.
PairGain and HiGain are registered trademarks of PairGain Technologies, Inc.
Information contained in thisdocumentis companyprivate toPairGain Technologies, Inc.,
and shall notbe modified, used, copied, reproduced or disclosedin whole orin part without
the written consent of PairGain.
Other product names mentioned in this practice are used for identification purposes only
and may be trademarks or registered trademarks of their respective companies.
Revision Release Date Revisions Made
01 October 3, 1997 Initial release
02 September 18, 1998 Reformat

150-451-103-02, Revision 02 Using This Manual
HDU-451 List 3 September 18, 1998 iii
USING THIS MANUAL
Two types of messages, identified by icons, appear in the text.
See “Abbreviations” on page 32 for a list of abbreviations used throughout
this technical practice.
Notes contain information about special circumstances.
Cautions indicate the possibility of equipment damage or the
possibility of personal injury.

Using This Manual 150-451-103-02, Revision 02
iv September 18, 1998 HDU-451 List 3

150-451-103-02, Revision 02 Table of Contents
HDU-451 List 3 September 18, 1998 v
TABLE OF CONTENTS
Product Overview________________________________________ 1
Description and Features.......................................................... 1
Applications ............................................................................. 2
Functional Description____________________________________ 3
Outside Enclosure Deployment Rules ..................................... 3
Front Panel............................................................................... 7
Loopback Design Description.................................................. 9
Installation ____________________________________________ 10
Inspecting Your Shipment ..................................................... 10
Installing the HDU-451 List 3 ...............................................10
Troubleshooting.....................................................................11
Isolating a Problem.................................................. 11
Solutions to Common Problems.............................. 12
Line Unit Status Menu Messages............................ 13
Monitoring the HDSL System_____________________________ 15
Connecting to the Terminal ................................................... 16
Logging On and Using the Terminal Menus .........................16
Navigating the Terminal Menus ............................................ 17
The Main Menu...................................................................... 18
View Span Status................................................................... 20
View System Settings ............................................................ 22
View Performance Data......................................................... 25
View Performance History .................................................... 26
View Alarm History............................................................... 27

Table of Contents 150-451-103-02, Revision 02
vi September 18, 1998 HDU-451 List 3
Technical Specifications __________________________________29
Pinouts_________________________________________________30
Abbreviations___________________________________________32
Product Support_________________________________________35
Technical Support...................................................................35
Warranty.................................................................................35
FCC Compliance ....................................................................36
Modifications..........................................................................37

150-451-103-02, Revision 02 List of Figures
HDU-451 List 3 September 18, 1998 vii
LIST OF FIGURES
Figure 1. HiGain Installation with Two Doublers.................................. 3
Figure 2. HDU-451 Block Diagram.......................................................4
Figure 3. The HDU-451 List 3 Front Panel............................................7
Figure 4. HiGain Loopbacks. ................................................................. 9
Figure 5. Doubler Log On Screen ........................................................ 17
Figure 6. HDU-451 Main Menu........................................................... 18
Figure 7. Span 1 Status screen.............................................................. 20
Figure 8. System Settings Screen......................................................... 23
Figure 9. Performance Data Span 1 (1 or 2 Doublers).........................25
Figure 10. Performance Data History Span 1 (1 or 2 Doublers)..........26
Figure 11. HLU Alarm History Span 1 (1 or 2 Doublers) ................... 27
Figure 12. HDU-451 List 3 Pin-Outs (active pins are black)............... 30
Figure 13. HDU-451 DB-9 Pin Outs.................................................... 31

List of Tables 150-451-103-02, Revision 02
viii September 18, 1998 HDU-451 List 3
LIST OF TABLES
Table 1. HDSL Loss over Cables ..........................................................2
Table 2. Deployment Rules for the HRE-423 and HRE-450
Enclosures .......................................................................................5
Table 3. Deployment Rules for the HRE-454 Enclosure .......................6
Table 4. The Features of the HDU-451 Front Panel ..............................8
Table 5. HLU-451 Status Menu Messages ..........................................13
Table 6. Terminal Navigational Keys ..................................................18
Table 7. Main Menu Options ...............................................................19
Table 8. Span Status Screen Fields ......................................................21
Table 9. System Settings Screen Fields ...............................................23
Table 10. Alarm History Fields ...........................................................28

150-451-103-02, Revision 02 Product Overview
HDU-451 List 3 September 18, 1998 1
PRODUCT OVERVIEW
PairGain’sHiGainModel HDU-451 List3 lowpower Doubler Unit(Figure 3
on page 7) extends the range of the HiGain repeaterless T1 transmission
system. When installed between a HiGain Line Unit (HLU) with
doubler-powering capability, and a HiGain Remote Unit (HRU), the
HDU-451 enables 1.544Mbps transmissionover an extended Carrier Serving
Area (CSA) rangeof approximately 24,000 feet of 24 AWG or 18,000 feet of
26 AWG wire. Customers can use two doublers in series to triple the normal
CSA range (36,000 feet on 24 AWG).
The HDU-451mounts in a single slot ofany industry standard 400mechanics
shelf or in equivalentenclosures manufactured byPairGainTechnologies.All
HiGain modules comply with the applicable requirements of
TR-TSY-000063 (Network Equipment Building System (NEBS) Generic
Equipment requirements) and TR-TSY-000499 (Transport System Generic
Requirements - TSGR).
DESCRIPTION AND FEATURES
HDU-451 List 3, HiGain Doubler Unit features:
•Powered by any doubler-compatible HLU - no local power required
•Front Panel HDSL Status Display
•Front panel jacks for test access
•Lightning and power cross protection on the HDSL interfaces (both
sides)
•Front Panel Doubler loopback LED indicator
•Low power dissipation

Product Overview 150-451-103-02, Revision 02
2 September 18, 1998 HDU-451 List 3
APPLICATIONS
The primary application of the HDU-451 HiGain Doubler is to extend the
delivery of T1 High Capacity Digital Service (HCDS) to customers over
metallic cable pairs, up to 24,000 or 36,000 feet (24 AWG). A doubler
application is shown in Figure 1 on page 3. A maximum of two HDU-451
units can be used in tandem on the same circuit.
Table 1 on page 2 provides a guide for the loss of various cable gauges at
196 kHz and 135 ohms. The table applies to the HDSL cable pairs between
the HLU and the HDU-451 as well as between the HDU-451 and a second
HDU-451 or theHRU. Add 3 dB for each bridged tap and 1 dB for each cable
gauge change.
The HiGain system operates with any number of other T1, POTS, Digital
Data Service (DDS) or other HiGain Systems sharing the same cable binder
group.
In orderto achieve optimum performance, the electricallength(196 kHz loss)
of all doubler spans should be as close as possible to being equal. This
arrangement usually results in the highest operating loop margins.
Use Table 1 when calculating the electrical length of each span. If it is not
possible to make all spans equal, then choose the span lengths to reduce the
total power consumption of the HLU that powers the doublers. This is done
by minimizing the length of Span 1 and maximizing the length of Span 3.
Table 1. HDSL Loss over Cables
Cable Gauge Loss @ 196 kHz(dB/kft) Ohms per kft
26/0.4mm 3.880 83.3
24/0.51mm 2.841 51.9
22/0.61mm 2.177 32.4
19/0.91mm 1.535 16.1

150-451-103-02, Revision 02 Functional Description
HDU-451 List 3 September 18, 1998 3
Figure 1. HiGain Installation with Two Doublers.
FUNCTIONAL DESCRIPTION
HiGain utilizes PairGain’s Two-Binary, One-Quaternary (2B1Q) HDSL
transceiver systems to establish two full-duplex 784 kbps data channels (total
of 1.568 Mbps) between the HLU and a remotely mounted HRU. Each
HDU-451 increases the total span of the CSA by approximately 12,000 feet
(24 AWG) or 9,000 feet (26 AWG).
A block diagram of the HDU-451 is shown in Figure 2 on page 4. The
HDU-451 power supply usesthe 100 to 200 Vdc power feed voltage received
on the simplex pairs to produce +5V and -5 Vdc required by the HDU-451
circuitry. The power feed is passed to the HDSL output, via the Output Span
Voltage Control relay, to power one other HiGain module, either a second
HDU-451 or the remote HRU.
The maximum power dissipation of the HDU-451 is 6 watts.
OUTSIDE ENCLOSURE DEPLOYMENT RULES
Take care when deploying the HDU-451 in sealed multislot outside
enclosures, such as the PairGain 3-slot HRE-423 or 4-slot HRE-454
enclosures. To avoid excessive heat build up, follow the deployment rules
shown in Table 2 on page 5 (HRE-423 and HRE-450) or Table 3 on page 6
NID
SMJK
HRU-412
LIST 7*
HDSL
Doubler
2
HDU-451
HDSL
Doubler
1
HDU-451
HDSL
SPAN 1 SPAN 2 SPAN 3
Central
Office
HLU-231
(List 6D/3D)
HLU-319
(List 2/3)
DSX
9,000' 26 AWG
12,000' 24 AWG
9,000' 26 AWG
12,000' 24 AWG -22.5 dB Max.
9,000' 26 AWG or 12,000' 24 AWG (without Doubler)
9,000' 26 AWG
12,000' 24 AWG
*Two Doubler application requires the locally powered HRU-412, List 7.
Any HRU-412 can be used for single Doubler applications.

Functional Description 150-451-103-02, Revision 02
4 September 18, 1998 HDU-451 List 3
(HRE-454). These tables limit the number of doublers that can be housed
reliably in either the HRE-423 or HRE-454 enclosures. In the tables:
•the maximum ambient temperature column refers to the outside air
temperature
•the occupied slots column designates which slots (1, 2, 3, or 4) can be
occupied for each condition
For example, if the occupied slots for the HRE-423 are 1 and 3, the doublers
are located in slots 1 and 3 with slot 2 empty. If the occupied slots for the
HRE-454are 2 and 4,the doublers are located in slot 2 and 4 with slots 1 and
3 empty. If other then the specific slot arrangements are used, then the next
lower temperature deployment rule must be used.
For example, if slots 1 and 2 or 3 and 4 are used in the HRE-454, instead of
slots 2 and 4, then use the deployment rules that apply when slots 1, 2, and 4
are occupied. All of the applications in Table2 and Table 3 that exceed 115ºF
meet the requirements of Section 10.2.1.3 of TA-NWT-001210. This Section
requires that HDSL equipment deployed in outside enclosures shall operate
in a temperature, ambient outside the housing, of -40ºF with no solar load, to
+115ºF with maximum solar load and maximum power dissipation.
The doubler may also be enclosed in the PairGain single-slot HRE-450
outdoor enclosure. Its thermal limits are also shown in Table 2.
Figure 2. HDU-451 Block Diagram.
POWER
SUPPLY
5 TIP 1
15 RING 1
HDSL
IN
XCVR
HDSL
OUT
XCVR
HDSL
FRAMER
HDSL OUTPUT 1
55 TIP
49 RING
HDSL OUTPUT 2
MICROPROCESSOR
12 12
HDSL 1 HDSL 2
TIP 1 41
RING 1 47
HDSL INPUT 2 330 K
TIP 7
RING 13
HDSL INPUT 1 330 K
+5V
-5V
180K
180K
100 to 200V
-
+
1
2
FRAME GND

150-451-103-02, Revision 02 Functional Description
HDU-451 List 3 September 18, 1998 5
Table 2. Deployment Rules for the HRE-423 and HRE-450 Enclosures
Orientation Occupied Slots Solar Loada
a. Full Solar Load = Maximum sunlight exposure per TR-TSY-000057.
None = Inside, underground or fully shaded.
Max Ambient Temp
HRE-423
Vertical 1, 2, 3 Full 120ºF
Vertical 1, 2, 3 None 130ºF
Vertical 1, 2 Full 130ºF
Vertical 1, 2 None 140ºF
Vertical 2Full 140ºF
Vertical 2None 150ºF
Horizontal 1, 2, 3 Full 110ºF
Horizontal 1, 2, 3 None 120ºF
Horizontal 1, 2 Full 120ºF
Horizontal 1, 2 None 130ºF
Horizontal 2Full 130ºF
Horizontal 2None 140ºF
HRE-450
Either 1Full 150ºF
Either 1None 160ºF

Functional Description 150-451-103-02, Revision 02
6 September 18, 1998 HDU-451 List 3
Table 3. Deployment Rules for the HRE-454 Enclosure
Orientation Occupied Slots Solar Loada
a. Full Solar Load = Maximum sunlight exposure per TR-TSY-000057.
None = Inside, underground or fully shaded.
Max Ambient Temp
Vertical 1, 2, 3, 4Full 115ºF
Vertical 1, 2, 3, 4None 125ºF
Vertical 1, 2, 4Full 125°F
Vertical 1, 2, 4None 135°F
Vertical 2, 4Full 135°F
Vertical 2, 4None 145°F
Vertical 2Full 145°F
Vertical 2None 155°F
Horizontal 1, 2, 3, 4Full 105°F
Horizontal 1, 2, 3, 4None 115°F
Horizontal 1, 2, 4Full 115°F
Horizontal 1, 2, 4None 125°F
Horizontal 2, 4Full 125°F
Horizontal 2, 4None 135°F
Horizontal 2Full 135°F
Horizontal 2None 145°F

150-451-103-02, Revision 02 Functional Description
HDU-451 List 3 September 18, 1998 7
FRONT PANEL
Figure 3 shows the front panel of the HDU-451 List 3 and Table 4 describes
its features.
Figure 3. The HDU-451 List 3 Front Panel

Functional Description 150-451-103-02, Revision 02
8 September 18, 1998 HDU-451 List 3
Table 4. The Features of the HDU-451 Front Panel
Feature Function
+/- V Jacks These two test jacks enable you to monitor the input voltage feed on
the HDSL line. Typical values range from 130V to 200V, based on
the distance from the HLU or first HDU-451.
Loopback LED Shows the current loopback status. The LED has the following
states:
•Green indicates loopback NDU1 or NDU2 is active.
•Yellow indicates loopback CDU1 or CDU2 is active.
•Flashing Yellow indicates the doubler is in an armed state ready
to accept a 16-bit intelligent loopback command issued at the
HLU or HRU DS1 inputs.
HDSL IN LEDs Two LEDs indicate the status of the two HDSL input line pairs: HDSL
IN 1 and HDSL IN 2. These indicators have the following states:
Flashing Green indicates synchronization is being attempted with
the HLU.
Green indicates HDSL frame synchronization between the HLU and
HDSL input.
Flashing Red indicates an HDSL error
Yellow indicates a Margin alarm at this HDSL port.
HDSL OUT LEDs Two LEDs indicate the status of the two HDSL output line pairs:
HDSL OUT 1 and HDSL OUT 2. These indicators have the following
states:
Flashing Green indicates synchronization is being attempted with
the HRU or a second HDU-451.
Green indicates HDSL frame synchronization between the HDSL
output and the HRU or a second HDU-451.
Flashing Red indicates an HDSL Error.
Yellow indicates a Margin alarm at this HDSL port.
Craft (RS-232) port Provides bidirectional communication between the unit and an
external terminal to allow performance monitoring through the
maintenance terminal screens.

150-451-103-02, Revision 02 Functional Description
HDU-451 List 3 September 18, 1998 9
LOOPBACK DESIGN DESCRIPTION
Figure 4 on page 9 shows the complete family of loopbacks that a HiGain
system can execute. Four of these loopbacks (NDU1, NDU2, CDU1, and
CDU2) occur in the doubler. Theseloopbacks can be initiated from the HLU
maintenance port, the HLU front panel push-button, and from a family of
Special Loopback (SPLP) in-band loopback commands. Figure 4 lists the
Generic, SPLP, in-band loop-up commandsetforthe four doubler loopbacks:
110000 (2 in 6) for NDU1, 111000 (3 in 6) for NDU2, 111100 (4 in 6) for
CDU1 and 111110 (5 in 6) for CDU2. Refer to the appropriate HLU practice
for more details regarding the other doubler loopback commands.
Figure 4. HiGain Loopbacks.
DSX-1 CI
DS-1
Loopbacks
toward
customer
Loopbacks
toward
network
HDSLSPAN
HLU
NLOC
AIS**
AIS
AIS
AIS
AIS
AIS
AIS
AIS
SMJK*
TLOS
NREM
CLOC
HRU
HRU
HRU
HRU
HRU
HDSLSPAN
HDSLSPAN
SPAN1
SPAN1
SPAN2
SPAN2
SPAN3
SPAN3
HDSLSPAN
HDSLSPAN
HDSLSPAN
HLU
HLU
HLU
CREM
ELU
ELU
ELU
ELU
2in5
3in7
4in7
6in7
6in7
4in6 5in6
2in6 3in6
LOGIC
NDU1
CDU1
NDU2
CDU2
HDUHDU
HDU HDU
HLU
HLU
HLU
HLU
HRU
HRU
HRU

Installation 150-451-103-02, Revision 02
10 September 18, 1998 HDU-451 List 3
INSTALLATION
This section describes the installation process for the HDU-451 List 3.
INSPECTING YOUR SHIPMENT
When you receive the equipment, inspect it for signs of damage. If damage
has occurred, immediately report the extent of damage to the transportation
company and to PairGain Technologies, Inc. (see “Product Support” on
page 35 for more information).
INSTALLING THE HDU-451 LIST 3
The HDU-451 mounts in the following PairGain Remote Enclosures:
•HRE-423 (three-slot, double-width, outdoor, above or below ground)
•HRE-454 (four slot, outdoor, above or below ground)
•HRE-450 (single-slot, outdoor, above ground)
•HRE-420 (single-slot, indoor)
•HRE-422 (two slot, single width, indoor)
The HDU-451 also mounts in any industry-standard 400-type multi-mount
shelves. Pin-outs used by the HiGain Doubler Unitare shown in Figure 12 on
page 30.
The number of HDU-451 List 3 units that you can deploy in a doubler
enclosure is determinedby the ambient temperature and the solar loading.See
“Outside Enclosure Deployment Rules” on page 3 for further information.
To install the HDU-451 List 3:
1Mount and cable the HiGain Remote Enclosure as described in the
appropriate enclosure document.
2Slide the doubler unit into the card guides for the desired slot, then push
the unit into the enclosure until it is seated in the card edge connector.

150-451-103-02, Revision 02 Installation
HDU-451 List 3 September 18, 1998 11
3Push the unit into the card edge connector until it is entirely within the
card guide. The unit should snap into place, indicating that the unit is
properly seated.
4Check the indicator lights on the front panel:
•If the HLU in the CO is operational, the HDSL IN LED indicators
light within 30 seconds.
•If the HRU at the customer site is installed and operational, the
HDSL OUT LED indicators light and remain lit within 1 minute.
If the LEDs do not light properly, continue with the “Troubleshooting”
section for possible problems and solutions.
TROUBLESHOOTING
This section provides step by step troubleshooting procedures for common
problems.
Thefour-character front panel display on the line unitthat powers the doubler
provides additional information that may be useful in solving a problem.
Table 5 on page 13 shows the messages that can appear on the line unit front
panel display.
Isolating a Problem
The front panel HDSL IN (loop) 1 and (loop) 2 LEDs identify thecable pairs
coming into the doubler from the upstream location. The pairs are identified
by the polarity of the simplex voltage that is applied to them by the upstream
unit,the HLU or the HDU-451. Loop 1 has the - simplex voltage. Loop 2 has
the + simplex voltage.
To isolate the source of a problem, swap the input pairs. In this case, the
HDU-451 continues to identify loop 1 as the - pair and loop 2 as the + pair. If
the problem remains with the same pair, as identifiedby theHDU, before and
after the pairs are swapped, the problem is upstream or towards the pair.
For example, assume the HDSL IN 1 LED is flashing red, indicating errors
on loop 1. If the pairs areswapped and theHDSL IN 1LED continues to flash
the indicated problem is towards the upstream cable pair or attached
equipment. If the HDSL 2 IN LED begins flashing, the problem lies towards
the HDU-451 unit itself.

Installation 150-451-103-02, Revision 02
12 September 18, 1998 HDU-451 List 3
Solutions to Common Problems
This section lists several common problems and describes possible solutions.
If the LEDs do not light:
•Verify the HLU is installed and operational in the central office. Verify
proper cabling between the Doubler Enclosure and the central office.
•Measure 100 to 200V dc at the HDU-451 front panel jacks (+/-V). This
voltage peaks every15 seconds as the HLU powers up.If less than 130V
dc is present, suspect cabling or the HLU. Only the line units equipped
with a high voltage power supply can work with doublers. All such line
units have list numbers that end with a “D.” Other HLU versions may
syncwiththe HDUbut may not provide reliable operationand shouldnot
be used.
If the HDSL OUT LEDs do not light:
•Verify that the HRU at the customer site is installed and operational in
the central office. All HRU Remote Units, except List 8, have an HDSL
input signature resistance of 180 kOhms between the Tip and Ring on
each loop. The HDSL input part resistance for the List 8 HRU-4Ds is 10
Ohms.
•Verify that the central office HLU complies with the second bullet in the
previous problem description.
If the HDSL LEDs flash green continuously:
•If the OUT LEDs are flashing,verify that the HRU isoperational and the
cables between the HDU-451 and HRU are intact.
•If the IN LEDs are flashing, verify that the HLU is operational and the
cables between the HLU and HDU-451 are intact.
If the HDSL IN LEDs light when the HDSL OUT LEDs flash:
•No HRU at the remote end. Measure the input resistance of the HDSL
path of the HRU at the HDU-451. The HRU HDSL input has a signature
resistance of 180 kOhms or 10 Ohms between the Tip and Ring on each
loop.
•Loop resistance or attenuation is out of specification.The loop resistance
should be less than 800 ohms, attenuation should be less that or equal to
35 dB.