PairGain HLU-431 User manual

HIGAIN LINE UNIT
QUICK INSTALLATION GUIDE
PAIRGAIN TECHNOLOGIES, INC.
ENGINEERING SERVICES
™350-431-116-01/¨
SECTION 350-431-116-01
Model List Number Part Number
HLU-431 1F 150-1504-16

350-431-116-01, Revision 01
ii January 8, 1999 HLU-431 List 1F
Revision History of This Practice
©1999 PairGain Technologies, Inc.
PairGain and HiGain are registered trademarks of PairGain Technologies, Inc.
Information containedin thisdocumentis company private to PairGainTechnologies, Inc.,
and shall not be modified, used, copied, reproduced or disclosed in whole or in 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 January 8, 1999 Initial release

350-431-116-01, Revision 01 Using This Technical Practice
HLU-431 List 1F January 8, 1999 iii
USING THIS TECHNICAL PRACTICE
Two types of messages, identified by icons, appear in the text.
If you have comments or questions about this Technical Practice, you can
send email to [e-mail]. Type the productname
and section number of the document in the subject area of the email message.
INSPECTING SHIPMENT
Upon receipt of the equipment:
•Visually inspect it for any signs of shipping damage. Immediately report
any damage to the shipping agent.
•Check the packing list to ensure complete and accurate shipment of each
listed item. If the shipment is incomplete or inaccurate, contact PairGain
as described in the “Certification and Warranty” on page 25. If you must
store the equipment for a prolonged period, store the equipment in its
original container.
Notes contain information about special circumstances.
Cautions indicate the possibility of equipment damage or
the possibility of personal injury.

Table of Contents 350-431-116-01, Revision 01
iv January 8, 1999 HLU-431 List 1F
TABLE OF CONTENTS
Product Overview ________________________________________1
Features ....................................................................................1
Compatibility............................................................................1
Product Description..................................................................2
Installation ______________________________________________5
HDSL Line Voltage Operation______________________________6
Provisioning _____________________________________________6
Using the SEL and Mode Front Panel Buttons ........................6
Default Settings........................................................................7
Using the Craft port..................................................................7
System Options Settings...........................................................9
Testing_________________________________________________12
Doubler Applications .............................................................12
Alarms....................................................................................13
Loopbacks ..............................................................................14
Four-Character Diagnostic Messages.....................................16
Positron High-voltage Isolation Applications........................17
Appendix A: Specifications________________________________19
Appendix B: Service and Support __________________________20
Technical Support...................................................................20
BBS..........................................................................20
World Wide Web.....................................................21
Returns.....................................................................21
Appendix C: Abbreviations _______________________________23
Certification and Warranty __________________Inside back cover

350-431-116-01, Revision 01 Product Overview
HLU-431 List 1F January 8, 1999 1
PRODUCT OVERVIEW
The PairGain®HiGain®Line Unit Model HLU-431 List 1F is the Central
Office (CO) side of a repeaterless T1 transmission system and is used in
conjunction with the HiGain Remote Unit (HRU) to provide a complete
HiGain High-bit-rate Digital Subscriber Line (HDSL) system.
This guide addresses HLU-431 List 1Foperation when used with and without
doublers. For applications without doublers,the HLU-431 List 1F is directly
connected to the HRU by the two cable pairs. For doubler applications, one
doubler may be used in the HDSL loops between the HLU-431 List 1F and
the HRU.
Figure 1 on page 2 shows the front panel of the HLU-431 List 1F. Table 2 on
page 3 identifies front panel features.
FEATURES
•784 kbps full duplex 2BIQ HDSL transmission on two pairs
•Selectable DS-1 pre-equalizer
•Front panel HDSL S/N margin display
•Front panel status LED
•Selectable loopback voltage
•RS-232 Craft port
•Low voltage (140V) doubler application
•Shelf management interface
COMPATIBILITY
The HLU-431 mounts in the HiGain Remote Enclosure (HRE) or HiGain
Universal Enclosure (HUE) shelves listed below. The HLU-431 slot pins are
shown in Figure 2 on page 4.
•HRE-420, Single-slot indoor
•HRE-422, Dual-slot indoor

Product Overview 350-431-116-01, Revision 01
2 January 8, 1999 HLU-431 List 1F
•HRE-425, Twelve-slot indoor
•HRE-450, Single-slot outdoor
•HRE-454, Four-slot outdoor
•HUE-443, three-slot indoor
PRODUCT DESCRIPTION
Figure 1showsthe frontpanelofthe HLU-431List1F,and Table 2 on page 3
describes the various front panel functions. Table 2 on page 3 describes the
LED functions.
Figure 1. HLU-431 List 1F Front Panel

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HLU-431 List 1F January 8, 1999 3
Table 1. Front Panel Features
Features Function
Front panel display Displays four-character status, provisioning, and alarm system
messages.
Systemoptionbuttons
(MODE and SEL) Permits the user options to be monitored and modified without the need of a maintenance terminal. Used to initiate all HiGain
loopbacksandtodisplayDS-1lineparametersandlineunitidentity.
Status LED See Table 2 for status descriptions.
Receive and transmit jacks
SPAN Providessplittingjackaccessto(XMT)andfrom(RCV),theHDSL
span at the DSX-1 interface. Breaks the XMT and RCV paths to
permit test signal insertion and retrieval.
BRG Provides non-intrusive bridging jack access to (XMT) and from
(RCV), the HDSL span at the DSX-1 interface. Allows the two T1
payloads to be monitored.
Craft (RS-232) port Provides bidirectional communication between the unit and an
external terminal to allow configuration and performance
monitoring through the Maintenance terminal screens.
CLEI and ECI bar code
label Provides the human-readable Common Language Equipment Identifier (CLEI) code number and the Equipment Catalog Item
(ECI) bar code number.
List Number Displays the version of the software that relates to the product.
Configuration Number Contains either a five or six-digit warranty configuration number
or a standalone two or three-digit configuration number as
follows:
Digit 1 = Last digit of shipment year
Digits 2 and 3 = Shipment month
Digits 4, 5, and 6 = Configuration number
Table 2. Status LED States
State Description
Green Normal Operation.
Flashing Green HDSL Acquisition.
Flashing Red Minor Alarm.
Red FUSE ALRM.
Yellow Self Test in progress or an HLU-431 List 1F loopback in effect
(CREM) or (NLOC).
Flashing Yellow The HLU-431 List 1F is in an ARMED (pre-loopback) state.

Product Overview 350-431-116-01, Revision 01
4 January 8, 1999 HLU-431 List 1F
Figure 2 shows the card-edge connector pinouts.
Figure 2. Card-edge Connector Pinouts

350-431-116-01, Revision 01 Installation
HLU-431 List 1F January 8, 1999 5
INSTALLATION
Figure 3. Installing the HLU-431 List 1F
To install the HLU-431 into a shelf:
1Slide the unit into the shelf card guides for the desired slot.
2Push the unit in until it touches the backplane card-edge connector and
the retaining latch on the front panel opens.
3Place your thumbs on theHLU-431 frontpanel and push the card into the
card-edge connector until the unit is within the card guides and properly
seated.

HDSL Line Voltage Operation 350-431-116-01, Revision 01
6 January 8, 1999 HLU-431 List 1F
HDSL LINE VOLTAGE OPERATION
The HDSL line voltage is set to 0V on Loop 2 and to -140V on Loop 1. This
setting keeps the HDSL cable pair voltage at or below ground potential,
thereby avoiding corrosion problems that may be caused by cable voltages
more positive than ground.
For both doubler and non-doubler applications, this setting also allows the
HLU-431 List 1F to power single doubler circuits without exceeding 140V
line voltage. This is required when, for example, the HLU-431 List1F is used
with Positron HDSL dc/ac convertor circuits to provide high voltage isolation
between the cable pairs and the HLU-431 List 1F. Such an application occurs
when HiGain is the transport system between utility company power
substations which must be isolated from the cable pair to avoid damage from
Ground Potential Rise (GPR) faults.
PROVISIONING
The HLU-431 List 1F contains a non-volatile RAM (NVRAM) which stores
the system option settings. Use the front panel MODE and SEL buttons or a
PC connected to the Craft port to set the system options. All system options
are retained if shelf power is lost or if the HLU-431 List 1F is unplugged.
Table 3 on page 9 lists the system options for the HLU-431 List 1F.
USING THE SEL AND MODE FRONT PANEL
BUTTONS
To provision the HLU-431 List 1F through the SEL and MODE front-panel
buttons:
1Press the MODE button for approximately 1 second. The message
displayed on thefrontpanelalternatesbetweenthefirstsystem parameter
and its current setting.
2Press the SEL button to step the display through all possible settings of
the parameter being displayed.

350-431-116-01, Revision 01 Provisioning
HLU-431 List 1F January 8, 1999 7
3Press the MODE button to select the desired parameter and move to the
next parameter. After you have configured the last parameter, the
display prompts you to confirm the settings.
4Do one of the following:
•Press the SEL button to install the settings.
•Press the MODE button to bypass the settings.
If neither button is pressed in 30 seconds, the settings are bypassed.
DEFAULT SETTINGS
To return the system options back to the original factory default settings:
1Press the SEL button until the DFLT NO message appears.
2Press the SEL button again. DFLT YES displays indicating the factory
default values are now in effect.
To terminate the DFLT mode without setting the factory default values, press
the MODE button or do nothing for 30 seconds.
USING THE CRAFT PORT
The Craft port, a 9-pin RS-232 connector, on the HLU-431 front panel allows
you to use a standard RS-232 cable to connect your system to a maintenance
terminal or PC running a terminal emulation program. Once connected you
can access the maintenance, provisioning, and performance screens.
To provision the HLU-431 through the Craft port:
1Configure the maintenance terminal to the following communication
settings:
•1200 to 9600 baud (9600 baud is recommended)
•Parity: NONE
•8 data bits
•1 stop bit

Provisioning 350-431-116-01, Revision 01
8 January 8, 1999 HLU-431 List 1F
•Hardware Flow Control set to NONE
•VT Terminal Emulation
2Use a serial cable to connect the RS-232 COM port on the maintenance
terminal to the HLU-431 front panel Craft port.
3On each screen, enter the key represented by the letter in parenthesis for
the parameter to be changed.
•Each entry of this letter scrolls the parameter to its next value.
•After all selections have been made, press to exit and to
confirm the changes. This activates the new choices and returns
control to the Main Menu screen.
The following user options cannot be set from the front panel buttons:
Circuit ID, DS0 Blocking, and Margin Alarm Threshold.
If using the Microsoft Windows terminal emulation program,
from the Settings, Terminal Preference menu, deselect
Show
Scroll Bars
and Use Function , Arrow , and Ctrl Keys for
Windows
.
( &

350-431-116-01, Revision 01 Provisioning
HLU-431 List 1F January 8, 1999 9
SYSTEM OPTIONS SETTINGS
Table 3. HLU-431 List 1F System Options
Mode Selection Description
EQL 0(a) Sets the equalizer to DSX-1 for 0 - 133 feet.
133 Sets the equalizer to DSX-1 for 133 - 266 feet.
266 Sets the equalizer to DSX-1 for 266 - 399 feet.
399 Sets the equalizer to DSX-1 for 399 - 533 feet.
533 Sets the equalizer to DSX-1 for 533 - 655 feet.
ZBTS ON Tells HiGain that the ESF frame is operating in its ZBTSI mode.
OFF(a) Tells HiGain that the ESF frame is operating in its normal
non-ZBTSI mode.
ESAL 17 Activates the alarm input signal to the LITESPAN microprocessor
and flashes the red STATUS LED when 17 Errored Seconds (ES)
(17HDSLCRCerrorsoneitherHDSLlooporatotalof17BPVsand
FERR) occur within a 24-hour period.
170 Activates the alarm input signal to the LITESPAN microprocessor
and flashes the red STATUS LED when 170 ES (170 HDSL CRC
errors on either HDSL loop or a total of 170 BPVs and FERR) occur
within a 24-hour period.
NONE(a) Prevents generation of an alarm due to excessive Errored Seconds.
ALM DIS(a) Disables assertion of the Alarm input signal to the LITESPAN
processor from the HLU processor. The HDSL LED still flashes red
for an alarm condition even when the ALM DIS option is chosen.
ENA Enables assertion of the Alarm input signal to the LITESPAN
processor from the HLU processor.
DS0 BLK The DS0 blocking option can only be set through the RS-232
maintenance port with a terminal. The four-character
HLU-431 List 1F front panel LED readout for BLK indicates at least
one channel is blocked.
NONE(a) No channels are blocked.

Provisioning 350-431-116-01, Revision 01
10 January 8, 1999 HLU-431 List 1F
LBTO NONE Disables automatic time-out cancellation of all loopbacks.
20 Sets automatic cancellation of all loopbacks to 20 minutes after
initiation.
60(a) Sets automatic cancellation of all loopbacks to 60 minutes after
initiation.
120 Sets automatic cancellation of all loopbacks to 120 minutes after
initiation.
LPBK DIS Configures the HLU-200 to ignore the 2-in-5 SmartJack loopback
command.
ENA(a) Enables the HLU-200 to respond to the 2-in-5 SmartJack loopback
command.
SPLB GNLB(a) Configures the HiGain system to respond to the generic
(3/4/5/6-in-7) in-band loopback (GNLB) codes.
A1LBand
A2LB Configures the HiGain system to respond to the Teltrend addressable repeater in-band loopback codes.
A3LB Configures the HiGain system to respond to the Wescom
addressable repeater in-band loopback codes.
A4LB Configures the HiGain system to respond to the Wescom Mod 1
addressable repeater in-band loopback codes.
A5LB Configures the HiGain system to respond to the Teltrend Mod 1
addressable repeater in-band loopback codes.
PWRF DIS Disables powering to the HRU or doubler over the HDSL pairs.
ENA(a) Enables powering to the HRU or doubler over the HDSL pairs.
DS1 B8ZS Places both the HLU and HRU into their B8ZS modes.
AMI(a) Places both the HLU and HRU into their AMI modes.
AUTO The HLU and HRU independently monitor their incoming T1 bit
streams for the B8ZS pattern. If either unit detects this pattern, it
enters its B8ZS mode.
Table 3. HLU-431 List 1F System Options (Cont.)
Mode Selection Description

350-431-116-01, Revision 01 Provisioning
HLU-431 List 1F January 8, 1999 11
FRMG AUTO(a) Configures HiGain to operate in an auto-framing (AUTO) mode in
which it continuously searches the input T1 bit stream for a valid
SF or ESF frame pattern. This feature is required for fractional T1
applications (DS0 blocking) where it ensures proper channel time
slot alignment. While HiGain can also process unframed data in
this AUTO mode, it is recommended that the UNFR mode be used
for all unframed applications. Using theAUTO mode for unframed
applications runs the risk of detecting pseudo-valid frame
sequences, which can affect the data integrity.
UNFR Configures HiGain to operate in an unframed mode. This mode
disables the auto framing process and forces HiGain to function as
a transparent bit pipe.
HAIS 2LP(a) Causes HiGain to transmit the AIS signal at both the HLU and HRU
T1 output ports when both of the HDSL loops are not in sync
(LOSW).
1LP Causes HiGain to transmit the AIS signal at both the HLU and HRU
T1 output ports when either of the two HDSL loops is not in sync
(LOSW) or if a minor alarm occurs.
SAIS ENA(a) Causes the HRUto transmit the AIS signal towards the CI when in
NREM loopback.
DIS Prevents the AIS signal from being transmitted to the NI and
replaces it with the network test signal in the HRU List 6 and 8 or
by a quiet termination (LOS) in the HRU List 7.
MARG 0 to
15 dB The Margin Alarm Threshold determines the minimum allowable margin below which an alarm will occur.
4(a) Default value.
CONF YES Confirms that all operating modes (listed in this table) are to be
updated to their current selections.
NO(a) Prevents the most recently selected operating mode selections
from being updated. They remain as they were before the system
options settings mode was entered.
(a) Factory default settings.
Table 3. HLU-431 List 1F System Options (Cont.)
Mode Selection Description

Testing 350-431-116-01, Revision 01
12 January 8, 1999 HLU-431 List 1F
TESTING
The HLU-431 List 1F four-character front panel display has many useful
system diagnostic messages. These messages are listed in Table 4 through
Table 7. This display turns on when poweris initially applied to theHLU-431
List 1F. To conserve power, the display only remains on for 5 minutes if
neither the MODE or SEL buttons are pressed. The use of either button
activates the four-character display and restarts the 5-minute power-control
timer.
DOUBLER APPLICATIONS
The low voltage limit (140V) of the HLU-431 HDSL power supply limits its
doubler applications to just one doubler. It can power one doubler and one
remote unit if the doublers are one of the following: HDU-404, HDU-407 or
HDU-409. The remote must be an HRU-402. If any other HiGain doublers or
remote units are used, then the remote unit must be locally powered.

350-431-116-01, Revision 01 Testing
HLU-431 List 1F January 8, 1999 13
ALARMS
Only one alarm can be displayed at a time on the front panel display,
therefore, only the highest priority alarm is displayed if more than one alarm
exists. The following table lists the alarms in order of priority.
Table 4. Status Menu Alarm Messages
Message Full Name Description
ALRM Alarm Condition Exists A system alarm condition is in effect.
LLOS Local Loss of Signal No signal at the HLU-431 List 1F local T1
interface.
RLOS Remote Loss of Signal No signal at the HRU remote T1 interface.
LOSW Loss of Sync Word HDSL Loop 1 or 2 has lost sync.
H1ES or
H2ES HDSLLoop1or2Errored Second Loop 1 or 2 CRCs have exceeded the user selected ES threshold.
DS1 Digital Service 1 DS1 input BPVs at the HRU have exceeded the
user selected ES threshold.
RAIS or
LAIS Remote Alarm Indicating Signal Indicates an AIS pattern of all ones is being transmitted from the remote or T1 output port.
MAL1 or
MAL2 Margin Alarm 1 or 2 The margin on HDSL Loop 1 or 2 has dropped below the threshold (1 to 15 dB) set by the user.
CHREV Channels Reserved The Loop 1 and 2 HDSL pairs are reversed at the
HRU input port. Loop 1 is specified to carry the
(-)simplexdcvoltage, and Loop2 isspecifiedto
carry the (+) simplex dc voltage.
ACO Alarm Cut-off A minor alarm occurred and was retired to an
ACO condition after pressing the SEL button on
the HLU front panel.

Testing 350-431-116-01, Revision 01
14 January 8, 1999 HLU-431 List 1F
LOOPBACKS
The HLU-431 List 1F loopback messages are listed in the following tables.
A block diagram showing the GNLB locations and their activation codes are
shown on page 13.
Table 5. Status Menu Loopback Messages (with and without Doublers)
Message Full Name Description
SMJK SmartJack Loopback Loopback at HRU (remote) toward the
Channel Bank Assembly (CBA) initiated by
either the (2-in-5) in-band loopback code or
the out-of-band ESF data link code.
NREM Network Remote Loopback Loopback at HRU (remote) toward the CBA
initiated by upstream in-band codes or from
the maintenance terminal.
NLOC Network Local Loopback Loopback at HLU (local) toward the CBA
initiated by upstream in-band codes or from
the maintenance terminal.
CLOC Customer Local Loopback Loopback at HRU (local) toward CI initiated
from CPE (customer) by in-band codes or
from the maintenance terminal.
CREM Customer Remote Loopback Loopback at HLU (remote) toward customer
initiated from CPE (customer) by in-band
codes or from the maintenance terminal.
ARM Armed The HiGain system detected the IR loopback
(2-in-5) arming code.
TLOS Transmit Loss of Signal
(Loopback) HRU is in a logic loopback state caused by a loss of its T1 input from the CI, if enabled at
the HRU by its TLOS switch option.
Table 6. Status Menu Loopback Messages: (Doublers Only)
Message Full Name Description
NDU1 Network Doubler 1
Loopback The loopback at doubler 1 toward the CBA initiated by in-band codes, or the maintenance
terminal.
CDU1 Customer Doubler 1
Loopback Theloopback atdoubler 1towardCI initiatedby in-band codes or the maintenance terminal.

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HLU-431 List 1F January 8, 1999 15
Figure 4. Loopback Functions

Testing 350-431-116-01, Revision 01
16 January 8, 1999 HLU-431 List 1F
FOUR-CHARACTER DIAGNOSTIC MESSAGES
The HLU-431 diagnostic messages are listed in the table below.
Table 7. Four-Character Front Panel Messages
Message Full Name Description
FERR Framing Bit Error
Occurred Framing bit error occurred at HLU T1 input.
LBPV Local Bipolar Violation A bipolar violation has been received at the T1
input to the HLU-319.
SIG 1 or 2 Signal 1 or Signal 2 The HLU and HRU or first HDU transceivers are
trying to establish contact with each other on
Loops 1 or 2 of Span 1.
S2L1 or 2(a) Signal 2 Loop or
Loop 2 The first Doubler and the HRU transceivers are trying to establish contact with each other on
Loops 1 or 2 of Span 2.
ACQ 1 or 2 Acquisition 1 or
Acquisition 2 The HLU and HRU or first HDU multiplexers are trying to establish synchronization over each of
Loops 1 or 2 of Span 1.
A2L1 or 2(a) Acquisition 2 Loop 1
or Loop 2 The first HDU and the HRU multiplexers are trying to establish synchronization with each
other on Loops 1 or 2 of Span 2.
ACO Alarm CutOff A minor alarm has occurred, and been retired to
anACO condition,bypressing the SELbuttonon
the HLU front panel.
Self Test TheHLUisinaself-testmode. Thisoccursevery
power ON/OFF cycle.
ALRM Alarm Condition
Exists A minor alarm condition is in effect.
1=xx or 2=yy HDSL Loop Margins Indicates the power of the received HDSL signal
on each loop relative to noise. Any value of ‘06’
or greater is adequate for reliable system
operation.
PWR FEED
SHRT Power Feed Short Indicates a short between the two HDSL pairs in Span 1. This same message can occur with an
HRUthatisdrawingthecorrectamountofpower
over good cable pairs but cannot communicate
with the HLU.
PWR FEED
OPEN Power Feed Open Indicates an open circuit in the Tip and Ring of either HDSL pair in Span 1.