PairGain HLU-319 User manual

HIGAIN LINE UNIT
PAIRGAIN TECHNOLOGIES, INC.
ENGINEERING SERVICES TECHNICAL PRACTICE
™150-319-125-01S¨
SECTION 150-319-125-01
Model List Number Part Number CLEI Code
HLU-319 2E 150-1140-25 T1L1BH43AA
S
E
L
R
C
V
X
M
T
M
O
D
E
M
A
R
G
I
N
(dB)
SETUP
STATUS
R
S
HLU-319
HG HDIAIN
L
2
3
2
B
R
G
L
I
N
E
B
R
G
L
I
N
E

150-319-125-01, Revision 01
ii September 15, 1998 HLU-319 List 2E
Revision History of This Practice
©Copyright 1998 PairGain Technologies, Inc.
PairGain and HiGain are registered trademarks of PairGain Technologies, Inc.
Information contained in this document is company private toPairGain Technologies, 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 September 15, 1998 Initial Release

150-319-125-01, Revision 01
HLU-319 List 2E September 15, 1998 iii
USING THIS TECHNICAL PRACTICE
Two types of messages, identified by icons, appear in the text.
INSPECTING SHIPMENT
Upon receipt of the equipment:
•Unpack each container and visually inspect it for signs of damage. If the equipment has been damaged in
transit, immediately report the extent of damage to the transportation company and to PairGain. Order
replacement equipment, if necessary.
•Check the packing list to ensure complete and accurate shipment of each listed item. If the shipment is short
or irregular, contact PairGain as described in the Warranty. If you must store the equipment for a prolonged
period, store the equipment in its original container.
ABBREVIATIONS
Notes contain information about special circumstances.
Cautions indicate the possibility of equipment damage or the possibility of personal injury.
2B1Q 2Binary1Quaternary
AIS Alarm Indication Signal
AMI Alternate Mark Inversion
B8ZS Bi-polar with 8-zero Substitution
BPV Bipolar Violation
CI Customer Interface
CO Central Office
CLOC Customer Local Loopback
CPE Customer Premises Equipment
CRC Cyclic Redundancy Check.
CSA Carrier Service Area
DCE Data Circuit-Terminating Equipment
DDS Digital Data Service
DL Data Link
DS1 Digital Service, Level 1
DSX-1 Digital System Cross-Connect frame.
ES Errored Seconds
ESF Extended Super Frame
ESF DL Extended Super Frame Data Link
HCDS High Capacity Digital Service
HDSL High-bit-rate Digital Subscriber Line
HDU HiGain Doubler Unit

150-319-125-01, Revision 01
iv September 15, 1998 HLU-319 List 2E
HLU HiGain Line Unit
HRU HiGain Remote Unit
LOS Loss of Signal
LOSW Loss of Sync Word
NEBS Network Equipment Building System
NI Network Interface
NID Network Interface Device
NMA Network Management Administration
NREM Network Remote Loopback
POTS Plain Old Telephone System
PWRF Power Feed
SAIS SmartJack AIS
SF Super Frame
S/N Signal-to-Noise
SPLB Special Loopback
STS Span Terminating Shelf
TSGR Transport System Generic Requirements
UAS Unavailable Seconds
ZBTSI Zero Byte Time Slot Interchange

150-319-125-01, Revision 01 Table of Contents
HLU-319 List 2E September 15, 1998 v
TABLE OF CONTENTS
Product Overview_____________________________________________________________________ 1
HLU-319 Features..............................................................................................................................1
Applications .......................................................................................................................................2
Product Description ___________________________________________________________________ 3
Front Panel.........................................................................................................................................3
Status LED...........................................................................................................................4
Front Panel Display.............................................................................................................5
HLU-319 Card-Edge Connectors.......................................................................................................8
Network Management Control Bus.....................................................................................8
Fuse Alarm ..........................................................................................................................8
System Alarm Output Pin....................................................................................................9
Installation__________________________________________________________________________ 10
Provisioning the HLU-319_____________________________________________________________ 11
Setting Options Through SEL and MODE......................................................................................11
Factory Default Values......................................................................................................11
Displaying System Inventory ............................................................................................12
Connecting to a Maintenance Terminal...........................................................................................12
Maintenance ________________________________________________________________________ 13
Navigating the Maintenance Terminal Screens ...............................................................................13
System Spans.....................................................................................................................14
Navigation Keys ................................................................................................................14
Selecting an Option ...........................................................................................................14
Initializing the Maintenance Terminal Screens ...............................................................................15
Maintenance Terminal Main Menu..................................................................................................15
View Span Status .............................................................................................................................16
Span Status Screen: Non-Doubler Applications................................................................16
Span Status Screen: Doubler Applications........................................................................16
Set Clock..........................................................................................................................................18
Set Time.............................................................................................................................19
Set Date..............................................................................................................................19
Update the HRU Time and Date........................................................................................19

Table of Contents 150-319-125-01, Revision 01
vi September 15, 1998 HLU-319 List 2E
System Settings ............................................................................................................................... 20
DS0 Blocking Option........................................................................................................ 20
DS1 Line Code Option...................................................................................................... 21
Margin Alarm Threshold .................................................................................................. 21
HAIS Selections................................................................................................................ 22
System Settings Screen Options ....................................................................................... 22
Circuit ID Option............................................................................................................................. 26
Loopback Menu............................................................................................................................... 26
Loopback Menu: No Doubler........................................................................................... 27
Loopback Menu: One Doubler ......................................................................................... 27
Initiating a Loopback ........................................................................................................ 28
Disable Loopbacks............................................................................................................ 28
View Performance Data .................................................................................................................. 29
Performance Data Screen: No Doubler............................................................................. 30
Performance Data Screen: With Doubler.......................................................................... 31
View Performance History.............................................................................................................. 32
The 7 Day History Screen: No Doubler............................................................................ 32
The 7 Day History Screen: With Doubler......................................................................... 33
View Alarm History........................................................................................................................ 33
Alarm History Screen: No Doubler .................................................................................. 36
Alarm History Screen: With Doubler ............................................................................... 37
System Alarms_______________________________________________________________________ 38
Retiring System Alarms.................................................................................................... 38
Loopback Operation__________________________________________________________________ 39
SmartJack (SMJK) Loopback.......................................................................................................... 39
Generic Loopback Code (GNLB) ................................................................................................... 39
A1LB Loopback Code..................................................................................................................... 39
Addressable Repeater Loopback Functions .................................................................................... 40
Initiating Manual Loopback Sessions .............................................................................................41
Loopback Test Procedures .............................................................................................................. 41
GNLB Loopback Test Procedures...................................................................................................44
HLU-319 A1LB, A2LB and A5LB Test Procedures...................................................................... 45
A3LB and A4LB Test Procedures...................................................................................................47
Specifications________________________________________________________________________ 48

150-319-125-01, Revision 01 Table of Contents
HLU-319 List 2E September 15, 1998 vii
Functional Operation_________________________________________________________________ 50
HDSL Line Voltage...........................................................................................................51
Ground Fault Detect ..........................................................................................................52
Power Consumption.........................................................................................................................52
Power Consumption: Without Doublers............................................................................52
Maximum Power Dissipation:.............................................................................52
Maximum Power Consumption: .........................................................................52
Maximum Current Drain:....................................................................................52
Power Consumption: With Doublers.................................................................................53
Compatibility _______________________________________________________________________ 54
T1 Repeater Shelves and Related Equipment..................................................................................54
Doubler Deployment........................................................................................................................55
Product Support _____________________________________________________________________ 56
Technical Support............................................................................................................................56
Warranty...........................................................................................................................................56
FCC Compliance..............................................................................................................................57
Modifications...................................................................................................................................57
Standards Compliance......................................................................................................................57

Table of Contents 150-319-125-01, Revision 01
viii September 15, 1998 HLU-319 List 2E

150-319-125-01, Revision 01 List of Figures
HLU-319 List 2E September 15, 1998 ix
LIST OF FIGURES
Figure 1. HLU-319 Front Panel........................................................................................................................3
Figure 2. HLU-319 Card-Edge Connectors......................................................................................................8
Figure 3. Installing the HLU-319 into a Shelf................................................................................................10
Figure 4. DB-9 RS-232 I/O Pinouts...............................................................................................................13
Figure 5. System Spans..................................................................................................................................14
Figure 6. Maintenance Terminal Main Menu.................................................................................................15
Figure 7. Span Status Screen: No Doubler.....................................................................................................17
Figure 8. Span 1 Status Screen: With Doubler...............................................................................................17
Figure 9. Span 2 Status Screen: One Doubler................................................................................................18
Figure 10. Set Clock Menu.............................................................................................................................18
Figure 11. System Settings Menu...................................................................................................................20
Figure 12. Loopback Menu: No Doubler.......................................................................................................27
Figure 13. Loopback Menu: One Doubler .....................................................................................................27
Figure 14. NLOC Loopback Mode in the Maintenance Terminal Main Menu .............................................28
Figure 15. Performance Data Screen: No Doublers.......................................................................................30
Figure 16. Span 2 Performance Data Screen..................................................................................................31
Figure 17. 7 Day History Screen for Span 1: No Doubler .............................................................................32
Figure 18. 7 Day History Screen Span 1: With Doubler................................................................................33
Figure 19. Alarm History Screen for Span 1: No Doublers...........................................................................36
Figure 20. Alarm History Screen for Span 1: With Doublers........................................................................37
Figure 21. HLU-319 Non-Doubler Loopback Configurations.......................................................................42
Figure 22. HLU-319 Doubler Loopback Configurations...............................................................................43
Figure 23. HLU-319 Block Diagram..............................................................................................................50

List of Tables 150-319-125-01, Revision 01
x September 15, 1998 HLU-319 List 2E
LIST OF TABLES
Table 1. HDSL Loss Over Cables.................................................................................................................................. 2
Table 2. Front Panel Components.................................................................................................................................. 4
Table 3. Status LED Descriptions.................................................................................................................................. 4
Table 4. HLU-319 Front Panel Display Messages ....................................................................................................... 5
Table 5. Navigational Keys on the Maintenance Terminal.......................................................................................... 14
Table 6. Maintenance Terminal Screens...................................................................................................................... 16
Table 7. HLU-319 System Options ............................................................................................................................. 22
Table 8. Errored and Unavailable Seconds Definitions............................................................................................... 29
Table 9. HLU-319 Alarm History Messages .............................................................................................................. 34
Table 10. System Alarms ............................................................................................................................................. 38
Table 11. Addressable 1 (A1LB) Repeater Loopback Commands.............................................................................. 46
Table 12. Addressable 3 (A3LB) Repeater Loopback Commands.............................................................................. 47
Table 13. HLU-319 Power Parameters With HDU-451.............................................................................................. 53

150-319-125-01, Revision 01 Product Overview
HLU-319 List 2E September 15, 1998 1
PRODUCT OVERVIEW
The PairGain®HiGain®HLU-319 List 2E is the Central Office (CO) side of a repeaterless T1 transmission
system. When used in conjunction with a HiGain remote unit (HRU), the system provides 1.544 Mbps
transmission on two unconditioned copper pairs over the full Carrier Service Area (CSA) range. The
HLU-319 can be used in applications with or without HiGain Doubler Units (HDUs).
The CSA includes loops up to 12,000 feet of 24 AWG or 9,000 feet of 26AWG wire, including bridged taps. The
HiGain system uses HDSL (High-bit-rate Digital Subscriber Line) transmission technology as recommended by
Bellcore TA-TSY-001210. The HiGain system complies with TR-TSY-000063 (Network Equipment Building
System (NEBS) Generic Equipment requirements) and TR-TSY-000499 (Transport System Generic
Requirements—TSGR) common requirements.
HLU-319 FEATURES
•Selectable DS-1 pre-equalizer
•130 to 200 Vdc HDSL line power for HDU and HRU
•Ground fault-detection circuit
•Front panel HDSL Signal/Noise (S/N) margin display
•Compatible with Span Terminating Shelf (STS) high-density shelves
•Selectable loopback activation codes
•Craft (RS-232) maintenance port
•Network Management Administration (NMA) interface
•Non-volatile front panel operator setup
•Front panel DS1 splitting and bridge access
•Lightning and power cross protection on HDSL interfaces
•784 kbps full duplex 2B1Q HDSL transmission on two wire pairs
•Front panel status LED
•On/Off front panel display power cycling
•DS1 LOS detector (125 consecutive zeros)
•Margin threshold alarm
•HDSL AIS (Alarm Indicating Signal) and Smart-Jack AIS options
•Easy return to factory default user settings
•Circuit ID option
•Low power consumption

Product Overview 150-319-125-01, Revision 01
2 September 15, 1998 HLU-319 List 2E
APPLICATIONS
HiGain systems provide a cost-effective, easy-to-deploy method for delivering T1 High Capacity Digital Service
(HCDS) over metallic pairs.
•The service is deployed over two unconditioned, non-loaded copper pairs, yet it demonstrates a quality that
is competitive with fiber optics.
•Conventional, in-line, T1 repeaters are not required.
•Cable pair conditioning, pair separation and bridged tap removal are not required.
Each loop must have no more than 35 dB of loss at 196 kHz, with driving and terminating impedances of 135 Ω.
Table 1 provides a “loss” guide forthe various cable gauges at 196 kHz and 135 Ω. The table applies to the HDSL
cable pairs between the HLU, HRU, and HDU modules. In the absence of specific insertion loss measurement
data, add 3 dB for each bridged tap and 1 dB for each cable gauge change.
In general, HiGain systems:
•operate with any number of other T1, POTS, Digital Data Service (DDS) or other HiGain systems sharing the
same cable binder group
•can be used with customers requiring DS1 service on a temporary or permanent basis
•provide a means of quickly deploying service in advance of fiber-optic transmission systems
With a HiGain system, service can be provided within hours. Fiber optic systems can be installed at a leisurely
pace and cut-over from the installed HiGain system when convenient to do so. The installed HiGain system can
then be easily removed and utilized elsewhere.
Table 1. HDSL Loss Over Cables
Cable Gauge (AWG/mm) Loop Loss at 196 kHz
(dB/kft)
Loop Resistance
(Ohms per kft)
26 AWG/0.4 mm 3.88 83
24 AWG/0.51mm 2.84 52
22 AWG/0.61mm 2.18 32
19 AWG/0.91mm 1.54 16

150-319-125-01, Revision 01 Product Description
HLU-319 List 2E September 15, 1998 3
PRODUCT DESCRIPTION
The HLU-319 includes:
•A front panel featuring:
–A status display
–System option buttons
–Status LED
–DSX-1 access jacks
–Craft port
–CLEI and bar code numbers
–Warranty Control number
•Card-edge connectors
FRONT PANEL
The HLU-319 front panel is shown in Figure 1. The front panel components are described in Table 2.
Figure 1. HLU-319 Front Panel
M
O
D
E
S
E
L
HLU-319
HiGain HD
L
R
C
V
B
R
G
M
A
R
G
I
N
(dB)
B
R
G
X
M
T
L
I
N
E
L
I
N
E
PairGain
R
S
2
3
2
System option buttons
Front panel display
Craft port
DSX-1 access jacks
Card handle
(configuration number and
CLEI/ECI bar code on handle)
Status LED SETUP
STATUS

Product Description 150-319-125-01, Revision 01
4 September 15, 1998 HLU-319 List 2E
Status LED
Table 3 describes the functions of the Status LED on the front panel.
Table 2. Front Panel Components
Front Panel Feature Function
Front panel display Displays four-character status, provisioning, and alarm system messages.
System option buttons (MODE and
SEL)
Permit the user options to be monitored and modified without using a
maintenance terminal. Used to initiate all HiGain loopbacks and to display
DSX-1 line parameters and line unit identity.
Status LED See Table 3 for status descriptions.
DSX-1 access jacks
LINE Provides splitting jack access to (XMT) and from (RCV), the HDSL line at the
DSX-1 interface. Breaks the XMT and RCV paths to permit test signal insertion
and retrieval.
BRIDGE 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 bar code labels Provides the human-readable Common Language Equipment Identifier (CLEI)
code number and the Equipment Catalog Item (ECI) bar code number.
Configuration Number (warranty
control number) and CLEI/ECI bar
code
Indicates the beginning year and month of the warranty. Also indicates the
unit’s configuration number. For example, a configuration number of “80107”
would indicate a warranty beginning in the year 1998 (8), during the month of
January (01), and the unit’s configuration number of 7 (07).
Table 3. Status LED Descriptions
LED Status Description
Green Normal operation.
Flashing green HDSL acquisition.
Red Fuse alarm.
Flashing red Minor alarm.
Yellow Self Test is in process or an HLU-319 Customer Remote Loopback
(CREM) or a Network Local Loopback (NLOC) is in effect.
Flashing yellow HLU-319 is in an Armed state.

150-319-125-01, Revision 01 Product Description
HLU-319 List 2E September 15, 1998 5
Front Panel Display
The front panel display (Figure1) is used with the MODE and SEL buttons to display system diagnostic messages.
Refer to Table 4 for a listing of the four-character messages.
The front panel display turns on when power is initially applied to the HLU-319. To conserve power, the display
only remains on for five minutes. The use of the MODE or SEL buttons activates the front panel display and
restarts the five-minute, power-control timer.
Table 4. HLU-319 Front Panel Display Messages
Message Full Name Description
NONE No Alarms No alarms.
LLOS Local Loss of Signal No signal from HLU-319 local DSX-1 interface.
RLOS Remote Loss of Signal No signal from HRU- remote DS1 interface.
LOSW1 Loss of Sync Word 1 HDSL loop 1 has lost sync.
LOSW2 Loss of Sync Word 2 HDSL loop 2 has lost sync.
H1ES HDSL Loop 1 Errored Second Loop 1 CRCs have exceeded the user-selected ES
threshold.
H2ES HDSL Loop 2 Errored Second Loop 2 CRCs have exceeded the user-selected ES
threshold.
DS1 Digital Service 1 T1 input BPVs, at either the HLU-319 or HRU, have
exceeded the user-selected ES threshold.
DS0 DS0 Blocked Channels: NONE or BLK Indicates status of DS0 blocked channels. NONE indicates
that no channels are blocked. BLK indicates that some
channels are blocked.
MNGD Managed The HLU-319 is being managed by the HMU-319
management unit. In this state, the front panel Craft port is
disabled.
RAIS Remote Alarm Indicating Signal Indicates an AIS (all ones) pattern is being transmitted from
the remote T1 output port.
LAIS Local Alarm Indicating Signal Indicates an AIS (all ones) pattern is being transmitted from
the local T1 output port.
MAL1 Margin Alarm 1 The margin on HDSL loop 1 has dropped below the
threshold (0 to 15 dB) set by the user. Setting the threshold
to 0 inhibits the margin alarm.
MAL2 Margin Alarm 2 The margin on HDSL loop 2 has dropped below the
threshold (0 to 15 dB) set by the user. Setting the threshold
to 0 inhibits the margin alarm.
CHREV Channels Reversed The loop 1 and 2 HDSL pairs are reversed at the HRU line
input port. Loop 1 is specified to carry the (-) simplex dc
voltage, and loop 2 is specified to carry the (+) simplex dc
voltage.
ACO Alarm CutOff A minor alarm occurred and was retired to an ACO
condition after pressing the SEL button on the HLU-319
front panel.
LBPV Local Bipolar Violation A bipolar violation was received at the DSX-1 input to the
HLU-319.

Product Description 150-319-125-01, Revision 01
6 September 15, 1998 HLU-319 List 2E
SIG1 Signal 1 The HLU-319 and the first doubler transceivers are trying to
establish contact on loop 1 of
span 1.
S2L1 Signal 2 Loop 1 The first doubler is trying to establish contact with either the
HRU or the second doubler transceivers on loop 1 of
span 2.
S2L2 Signal 2 Loop 2 The first doubler is trying to establish contact with either the
HRU or the second doubler transceivers on loop 2 of
span 2.
S3L1 Signal 3 Loop 1 The second doubler and HRU transceivers are trying to
establish contact on loop 1 of span 3.
S3L2 Signal 2 Loop 2 The second doubler and HRU transceivers are trying to
establish contact on loop 2 of span 3.
ACQ1 Acquisition 1 The HLU-319 and the first doubler multiplexers are trying to
synchronize over loop 1 of span 1.
ACQ2 Acquisition 2 The HLU-319 and the first doubler multiplexers are trying to
synchronize over loop 2 of span 1.
A2L1 Acquisition 2 Loop 1 The first doubler is trying to synchronize with either the
HRU or the second doubler multiplexers on loop 1 of
span 2.
A2L2 Acquisition 2 Loop 2 The first doubler is trying to synchronize with either the
HRU or the second doubler multiplexers on loop 2 of
span 2.
A3L1 Acquisition 3 Loop 1 The second doubler and the HRU multiplexers are trying to
synchronize on loop 1 of span 3.
A3L2 Acquisition 3 Loop 2 The second doubler and the HRU multiplexers are trying to
synchronize on loop 2 of span 3.
BAD RT? No response from HRU The HLU-319 is not receiving any HRU, and therefore the
HRU’s integrity is questionable.
LIST XXXX HLU-319 List number To display the List number, press the MODE button for
three seconds.
VER XXXX HLU-319 software version number To display the software version, press the MODE button for
three seconds.
FRM Frame: SF, ESF, UNFR, None Defines the type of frame pattern being received from the
DSX-1. To display frame pattern, press the MODE button for
three seconds.
SIG2 Signal 2 The HLU-319 and the first doubler transceivers are trying to
establish contact on loop 2 of
span 1.
FERR Framing Bit Error Framing bit error occurred at the
HLU-319 input.
ARM HiGain system is Armed The HiGain system is Armed and ready to respond to
Intelligent Repeater loop codes.
SMJK Smart-Jack Loopback The loopback at HRU (remote) toward network initiated by
either the (2 in 5) in-band loopback code or the out-of-band
ESF data link loopback code.
Table 4. HLU-319 Front Panel Display Messages (Cont.)
Message Full Name Description

150-319-125-01, Revision 01 Product Description
HLU-319 List 2E September 15, 1998 7
NREM Network Remote Loopback The loopback at HRU (remote) toward network initiated
from CO (network) by either the Intelligent Line Repeater
(ILR) number 2 code, the HLU-319 front panel Manual
Loopback push buttons, the HRU front panel push button,
or the maintenance terminal.
NLOC Network Local Loopback The loopback at HLU-319 (local) toward network initiated
from CO (network) by either the Intelligent Office Repeater
(IOR) code, the HLU-319 front panel Manual Loopback
push buttons, or the maintenance terminal.
CLOC Customer Local Loopback The loopback at HRU (local) toward CI initiated from CPE
(customer) by either the ILR number 2 code, the HLU-319
front panel Manual Loopback push buttons, or the
maintenance terminal.
CREM Customer Remote Loopback The loopback at HLU-319 (remote) toward customer
initiated from CPE (customer) by either the IOR code, the
HLU-319 front panel Manual Loopback push buttons, or 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 DS1
input from the CI when ENAbled at the HRU-412, List 6 or
List 7, via its TLOS switch option.
SELF-TEST Self-test The HLU-319 is in self-test mode, which occurs whenever
the power is turned on.
ALRM Alarm condition exists A minor alarm has occurred.
1=xx HDLS Loop 1 Margin Indicates the power of the received HDSL signal on loop 1
relative to noise. Any value of 06 or greater is adequate for
reliable system operation.
2=yy HDSL Loop 2 Margin Indicates the power of the received HDSL signal on loop 2
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, or that an
HRU that is drawing the correct amount of power over good
cable pairs but cannot communicate with the HLU-319.
PWR FEED OPEN Power Feed Open Indicates an open circuit in the Tip and Ring of either HDSL
pair.
PWR FEED OFF Power Feed Off HDSL span power has been turned off by setting the PWFD
option to DIS.
CODE Line Code: AMI, B8ZS The line code that the HLU-319 is receiving at the DSX-1
interface, if the DS1 option is set to Auto. Otherwise, this
code mimics either of the other two DS1 line code settings.
To view the code, press the MODE button for three seconds.
Table 4. HLU-319 Front Panel Display Messages (Cont.)
Message Full Name Description

Product Description 150-319-125-01, Revision 01
8 September 15, 1998 HLU-319 List 2E
HLU-319 CARD-EDGE CONNECTORS
Figure 2 shows the HLU-319 card-edge connectors. Active pins are highlighted in black.
Figure 2. HLU-319 Card-Edge Connectors
Network Management Control Bus
The HLU-319 provides a Network Management Control Bus on Pin 7 of the card-edge connector. This allows
the various PairGain Management System protocols to manage the HLU-319 through the HMU-310 HiGain
Management Unit.
Fuse Alarm
Pin 10 on the card-edge connector is a Fuse Alarm that driven to -48 V whenever its on-board fuse opens. It
emulates the function of the Fuse Alarm output from Pin 10 of normal HD (High Density) repeaters. Pin 10 is
connected to Pin 5 of the 1184Alarm Card (slot 1 in HD shelf) and causes the 1184 Fuse ALM LED to light when
the Pin 10 signal is activated. Its normally floating output must never be driven above ground or below -80 V. It
can sink a current of 10 mA. The HLU-319 does not support the BPV function (Pin E) of normal HD repeaters.

150-319-125-01, Revision 01 Product Description
HLU-319 List 2E September 15, 1998 9
System Alarm Output Pin
Pin H on the card-edge connector is the HLU-319 System Alarm output pin. The following notes apply to Pin H:
•Pin H replaces the Local Loss of Signal alarm on normal HD (3192) repeaters.
•The normally floating output of Pin H can connect to Pin 1 of the 1184 or 3192-9F Alarm Card in position
29 of the HD shelf.
•The HLU-319 forces pin H to +5V (maximum of 10 mA) for a system alarm condition. Pin H then remains
at +5V for the duration of the alarm condition.
•If the Wescom 1184 Alarm Card is installed in the shelf, its LOS LED lights for every minor alarm.
•The HLU-319 Status LED flashes red for the duration of a minor alarm condition.
•Setting the ALM option to DIS only prevents the minor alarm output alarm bus on pin H from being activated
when a system alarm occurs. The Status LED still flashes red and the ALRM message still displays.
Pin H must never be taken above +5V or below -60V.

Installation 150-319-125-01, Revision 01
10 September 15, 1998 HLU-319 List 2E
INSTALLATION
To install the HLU-319:
1Slide the HLU-319 into the card guides for the desired slot, then push the unit back until it touches the
backplane card-edge connector and the retaining latch on the front panel opens (Figure 3).
Figure 3. Installing the HLU-319 into a Shelf
2Place your thumbs on the HLU-319 front panel and push the HLU-319 into the card-edge connector until it
is entirely within the card guides and the retaining latch closes. This indicates that the card is properly seated.
This product contains static-sensitive components. Be sure to ground yourself properly before
touching the HLU-319.