ADC HiGain HRU-402 User manual

HiGain
HiGain
USER MANUAL
HRU-402
HiGain REM UNIT
ALM
L
TELEPHONE Co. PROPERTY
LP2
ESF
SF
LP1
B8ZS
AMI
LBK
H
D
S
L
RCV
LEV
D
S
1
0-15
DIS EN
TLOS
LB
XMT
BRG
RCV
RS-232
DCE
BARCODE
HRU-402 List 1 Remote Unit
Product Catalog: 150-1592-01
CLEI: T1L2CW0A
HRU-402 List 3 Remote Unit
Product Catalog: 150-1592-03
CLEI: T1L3KLJD

150-402-100-03
ii November 5, 1998 HRU-402 List 1 and List 3
Revision History of This User Manual
Copyright
November 5, 1998
© 1998 ADC DSL Systems, Inc. All rights reserved.
Trademark Information
ADC is a registered trademark of ADC Telecommunications, Inc. HiGain is a
registered trademark of ADC DSL Systems, Inc. No right, license, or interest to such
trademarks is granted hereunder, and you agree that no such right, license, or interest
shall be asserted by you with respect to such trademark.
Other product names mentioned in this practice are used for identification purposes
only and may be trademarks or registered trademarks of their respective companies.
Disclaimer of Liability
Information containedin this document is company privateto ADC DSL Systems,Inc.,
and shall not be modified, used, copied, reproduced or disclosed in whole or in part
without the written consent of ADC.
Contents herein are current as of the date of publication. ADC reserves the right to
change the contents without prior notice. In no event shall ADC be liable for any
damages resulting from loss of data, loss of use, or loss of profits, and ADC further
disclaims any and all liability for indirect, incidental, special, consequential or other
similar damages. This disclaimer of liability applies to all products, publications and
services during and after the warranty period.
Revision Release Date Revisions Made
01 April 23, 1998 Initial Release
02 November 5, 1998 Addition of HRU-402 List 3
03 May 17, 2002 ADC Rebranding

150-402-100-03 Using This Manual
HRU-402 List 1 and List 3 November 5, 1998 iii
USING THIS MANUAL
Two types of messages, identified by icons, appear in the text.
UNPACK AND INSPECT YOUR SHIPMENT
Upon receipt of the equipment:
•Unpack each container and inspect the contents for signs of damage. If
theequipmenthasbeen damagedin transit, immediatelyreport the extent
of damage to the transportation company and to ADC DSL Systems, Inc.
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 ADC DSL
Systems,Inc.asdescribedin“AppendixC:ProductSupport”onpage57.
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 personal injury or
equipment damage.

Unpack and Inspect Your Shipment 150-402-100-03
iv November 5, 1998 HRU-402 List 1 and List 3

150-402-100-03 Table of Contents
HRU-402 List 1 and List 3 November 5, 1998 v
TABLE OF CONTENTS
Product Overview________________________________________ 1
Features.................................................................................... 2
Applications............................................................................. 3
Product Description ................................................................. 5
Front Panel................................................................. 5
Panel Circuit Board Option.......................................7
Functional Description............................................................. 9
Operational Capabilities ............................................ 9
Local and Line Powering......................................... 11
Simplex Sealing Current Information .....................12
Loopback Design Description................................. 12
SmartJack Set to ENA............................................. 14
SAIS Set to DIS....................................................... 15
Installation ____________________________________________ 16
Inspecting Your Shipment ..................................................... 16
Installing HRU-402 List 1 and List 3 .................................... 16
Testing.................................................................................... 18
Front Panel Messages ............................................................ 19
Connecting to a Terminal Emulator....................................... 23
Using the Maintenance Terminal __________________________ 25
Login...................................................................................... 25
Navigating the HRU Maintenance Menus............................. 28
System Spans........................................................... 28
Navigation Keys ...................................................... 28

Table of Contents 150-402-100-03
vi November 5, 1998 HRU-402 List 1 and List 3
Remote Terminal Main Menu................................................29
View Span Status.....................................................31
System Settings........................................................34
Loopback Menu .......................................................36
View Performance Data...........................................40
View Performance History ......................................42
View Alarm History.................................................44
View System Inventory............................................46
Appendix A: Specifications________________________________48
Card-edge Pinout Connector..................................................50
Additional Features ................................................................51
Bipolar Violation Transparency (BPVT) and
Bit Error Rate (BER) Options..................................51
Remote DS-1 Alarm (RDA) Option ........................52
Alarm Pattern Option (ALMP) Option....................52
DS-1 Line Code Auto Option..................................53
Appendix B: Abbreviations________________________________54
Appendix C: Product Support _____________________________57
Certification and Warranty _________________Inside Back Cover

150-402-100-03 List of Figures
HRU-402 List 1 and List 3 November 5, 1998 vii
LIST OF FIGURES
1. Typical HiGain System.........................................................................1
2. Front Panel ............................................................................................ 5
3. User Option Locations........................................................................... 8
4. HRU-402 Block Diagram.................................................................... 10
5. HiGain System Generic Loopbacks (GNLB)...................................... 13
6. Installing the HRU-402 in a Remote Enclosure.................................. 17
7. dB-9 and dB-25 RS-232 I/O Interfaces............................................... 23
8. Connecting the HRU-402 to a Maintenance Terminal........................ 24
9. Remote Login Screen.......................................................................... 26
10. HiGain HLU-231 Remote Terminal Main Menu................................ 27
11. System Spans....................................................................................... 28
12. Remote Terminal Main Menu............................................................. 29
13. View Span Status Screen for Non-doubler Applications.................... 31
14. Span 5 Status Screen for Four Doubler Applications.......................... 32
15. System Settings Screen ....................................................................... 34
16. Loopback Menu Without Doublers..................................................... 37
17. Loopback Menu with Four Doublers.................................................. 38
18. Performance Data Screen Without Doublers ......................................40
19. Span 5 Performance Data Screen........................................................ 41
20. Performance History Screen for Non-doubler Applications............... 42
21. Span 5 Performance History Screen.................................................... 43
22. Alarm History Screen for Non-doubler Applications......................... 44
23. Four Doublers, Span 1 Alarm History Screen..................................... 46
24. View System Inventory Screen........................................................... 47
25. Card-Edge Pinouts............................................................................... 50

List of Tables 150-402-100-03
viii November 5, 1998 HRU-402 List 1 and List 3
LIST OF TABLES
1. HDSL Loss Over Cables........................................................................3
2. Front Panel Component.........................................................................6
3. Panel Switch Option ..............................................................................9
4. HLU-231 List 8 Four-Character Front Panel Messages......................19
5. Maintenance Terminal Navigational Keys..........................................28
6. Remote Terminal Menu Descriptions..................................................30
7. Span Status Fields and Descriptions....................................................33
8. System Settings Fields and Descriptions.............................................35
9. Loopback Field Messages and Descriptions........................................39
10. Alarm History Fields and Descriptions ...............................................45

150-402-100-03 Product Overview
HRU-402 List 1 and List 3 November 5, 1998 1
PRODUCT OVERVIEW
This user manual describes the HiGain®Remote Units, Models HRU-402
List 1 and List 3. These remote units function as the remote ends of a
repeaterless T1 transmission system. An HRU-402 connectsto a HiGain Line
Unit (HLU) and HiGain Doubler Units (HDUs), creating a HiGain system
that provides 1.544 Mbps transmission on two unconditioned copper pairs
over the full Carrier Service Area (CSA) range. The HRU-402 List 1 is
capable of both local and line powering. The HRU-402 List 3 is only locally
powered, with an expanded input voltage range of -20 to -70 volts.
Figure 1 shows a basic HiGain configuration for a T1 High-bit-rate Digital
Subscriber Line (HDSL) circuit. The HLU is installed at the Central Office
(CO) shelf. The HRU-402 is housed in a remote enclosure at the Customer
Premises Equipment (CPE) site. Optional HDUs provide the ability to
increase the range between the HLU and HRU to five CSA spans. The total
CSA encompasses approximately 60 kft using 19 American Wire Gauge
(AWG) wire.
Figure 1. Typical HiGain System
HRU-402
HDSL Pairs
Span 1
HDSL Pairs
Span 2
DSX-1
To CO DS-1 To CPE
HLU
HiGain CO Shelf Remote enclosureDoubler
enclosure
HDU

Product Overview 150-402-100-03
2 November 5, 1998 HRU-402 List 1 and List 3
FEATURES
•Front panel with:
–Receive (RCV) and Transmit (XMT) Bridged (BRG) access jacks
for testing
–Digital Service Level 1 (DS-1) and HDSL status Light Emitting
Diodes (LEDs)
–Craft port access (RS-232 dB-9 connector)
•American National Standards Institute (ANSI) T1.403 DS-1 Network
Interface (NI)
•Generic and addressable repeater loopback activation codes
•Powering options:
–List 1 allows line or local power
–List 3 allows local power only with expanded input voltage range
•Optional sealing current
•Lightning and power cross protection on HDSL and DS-1 interfaces
•784 kbps full-duplex 2 Binary 1 Quaternary (2B1Q) HDSL transmission
on each of two pairs
•Digital Signal Level 0 (DS0) blocking
•Compatible with ADC 1 x 1 protection switching system using the
HRE-422 List 5 remote enclosure.
•Narrow 200-type mechanics (half-width 400 mechanics)
•Lower power consumption
•Supports one to five span circuits
•Ultra-low wander
The features of the HRU-402 List 1 and List 3 are identical
except for powering capabilities. The HRU-402 List 1 can
be line-powered or locally powered with -48 volts. The
HRU-402 List 3 is locally powered only with an expanded
input voltage range from -20V to -70V.

150-402-100-03 Product Overview
HRU-402 List 1 and List 3 November 5, 1998 3
•Improved DS-1 auto mode
•Bipolar Violation Transparency (BPVT) and Bit Error Rate (BER)
options
•Remote DS-1 Alarm (RDA) option
•Alarm Pattern (ALMP) option
•DS-1 Line Code auto options
APPLICATIONS
HRU-402 List 1 and List 3 provide a cost-effective and easy-to-deploy
method for delivering T1 service over a single metallic pair. Conventional,
in-line T1 repeaters, cable pair conditioning, pair separation, and bridged tap
removal are not required. The HRU-402 List 3 is powered locally by an
expanded voltage range from -20V to -70V. This allows operation in sites
where the traditional -48V is not available.
Each cable pair loop has less than 35 dB of loss at 196 kHz with 135Ωdriving
and terminating impedances. Table 1 provides a guide for the loss of various
cable gauges at 196 kHz and 135Ω. Table 1 applies to the HDSL cable pairs
between the HLU, HRU, and HDU modules. Without specific insertion loss
measurement data, add 3 dB for each bridged tap and 1 dB for each cable
gauge change.
Table 1. HDSL Loss Over Cables
Cable Gauge Loss at 196 kHz (dB/kft) Ωper kft
26 AWG (0.4 mm) 3.88 83
24 AWG (0.51 mm) 2.84 52
22 AWG (0.61 mm) 2.18 32
19 AWG (0.91 mm) 1.54 16

Product Overview 150-402-100-03
4 November 5, 1998 HRU-402 List 1 and List 3
HRU-402 List 1 and List 3:
•operate with any numberof T1, Plain Old Telephone Service (POTS), or
other HiGain systems sharing the same cable binder group.
•can be used with customers requiring T1 service on a temporary or
permanent basis.
•provide a means of quickly deploying service in advance of fiber-optic
transmission systems.
•are easily installed allowing service to be provided within hours. Fiber
optic systems can be installed and cut-over from the installed HiGain
system. The installed HiGain system can then be easily removed and
utilized elsewhere.
HRU-402 List 1 and List 3 can be used with all HiGain doublers and doubler
compatible line units for two or three span applications. HRU-402 List 1 and
List 3 can also be used with the following line and doubler units for four and
five span applications:
•HLU-231 List 8x
•HLU-319 List 5x
•HLU-388 List 5x
•HDU-409, HDU-407, or HDU-404

150-402-100-03 Product Overview
HRU-402 List 1 and List 3 November 5, 1998 5
PRODUCT DESCRIPTION
This section provides a brief description of the major components that
comprise HRU-402 List 1 and List 3.
Front Panel
Figure 2 and Table 2 identify the HRU-402 List 1 and List 3 front panel
components. Table 2 also describes the functions of the front panel
components.
Figure 2. Front Panel
Alarm LED
Loopback LED
TLOS loopback switch
CLEI/ECI bar code label
Loopback control button
DS1 receive level switch
RS-232 Craft port
Extraction handle
DS1 transmit and receive
bridging jacks
HDSL LEDs
DS1 framing LEDs
DS1 code LEDs
HRU-402
HiGain REM UNIT
ALM
L
TELEPHONE Co. PROPERTY
LP2
ESF
SF
LP1
B8ZS
AMI
LBK
H
D
S
L
RCV
LEV
D
S
1
0-15
DIS EN
TLOS
LB
XMT
BRG
RCV
RS-232
DCE
Configuration number label
(inside handle)

Product Overview 150-402-100-03
6 November 5, 1998 HRU-402 List 1 and List 3
Table 2. Front Panel Component
Name Function
Alarm (ALM) LED Shows alarm states for remote and local Loss of Signal (LOS).
Solid red indicates a LOS condition at HRU T1 input.
Blinking red indicates a LOS condition at HLU T1 input.
HDSL LEDs Displays HDSL Loop 1 (LP1) and Loop 2 (LP2) conditions.
Solid green indicates HDSL loop is in sync.
Blinking green 1 time per second indicates the HDSL loop is trying
to acquire sync.
Blinking green 4 times per second indicates a margin alarm
condition on the HDSL loop.
Blinking green 10 times per second indicates a Cycle Redundancy
Check (CRC) error on the HDSL loop.
OFF indicates no activity on the HDSL loop.
DS-1 Framing (FRM)
LEDs
Indications for framing patterns.(a) If DS-1 framing is set to
unframed, the LEDs will not light.
Solid green indicates Extended Super Frame (ESF). The light
blinks one time per second when a frame error is indicated.
Solid green indicates Super Frame (SF). The light blinks one time
per .5 second when a frame error is indicated.
DS-1 Code LEDs Indications for DS-1 code options.(a)
DS-1 Code Option=Bipolar with 8-Zero Substitution (B8ZS): Solid
green indicates that the DS-1 line code option is set to B8ZS. The
solid green light does not indicate the actual DS-1 line code being
received, which may be Alternate Mark Inversion (AMI) or B8ZS.
The light blinks one time per second when a string of excessive
zeros is detected.
DS-1 Code Option=Auto: Solid green indicates the DS-1 code is
being detected as B8ZS.
DS-1 Code Option=AMI: Solid green indicates that the user DS-1
line code option is set to AMI. This light blinks one time per
second when a Bipolar Violation (BPV) is detected.
DS-1 Code Option=Auto: Solid green indicates that the user DS-1
line code is being detected as AMI.
Loopback (LPBK)
LED
Shows loopback states to and from the Network (NET) and to and
from the Customer Interface (CI) and an ARMED condition.
Solid yellow indicates Network Remote Loopback (NREM).
Blinking 1 per second indicates Customer Local Loopback (CLOC)
loopback state.
Blinking 4 per second indicates the HRU is in an ARMED state.
Continued

150-402-100-03 Product Overview
HRU-402 List 1 and List 3 November 5, 1998 7
Loopback (LPBK)
Control button
Press the button for five seconds to activate a remote loopback
towards the Network Remote Loopback (NREM) state. The unit
can be unlooped by either pressing the LPBK control button in
again for five seconds or by the standard loopdown coded
messages.
Also provides the ability to control NREM.(b)
DS-1 Receive (RCV)
Level (LVL) Switch
Sets DS-1 RCV level.
0 sets the DS-1 receive level towards the CI to 0 dB.(c)
-15 sets the DS-1 receive level towards the CI to a -15 dB.
Transmit Loss of
Signal (TLOS)
Loopback (LB)
Switch
Enables (ENA) or Disables (DIS) TLOS loopback option.
Disables the TLOS option.(c)
Enables the TLOS option.
DS-1 XMT and RCV
Bridging jacks
Provides bridging test and monitor access jacks to the CPE DS-1
interface. Provides both monitor and test access capability.
See Figure 4 for circuit details.
RS-232 Craft port Provides bidirectional communication between the unit and an
external maintenance terminal through an RS-232 interface to
allow configuration and performance monitoring through the
Maintenance Terminal menus. See the section “Connecting to a
Terminal Emulator” on page 23 for operating procedures.
CLEI/ECI Bar code
label
Contains human-readable Common Language Equipment
Identifier (CLEI) code number and Equipment Catalog Item (ECI)
bar code number.
Configuration
number label
Contains either a five-digit 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 and 5 = Configuration number
Extraction handle Handle used to remove the HRU-402 from the remote enclosure.
(a) If DS-1 signals are not detected, the ESF, SF, Bipolar with 8-Zero Substitution (B8ZS)
and Alternate Mark Inversion (AMI) LEDs will not light.
(b) Any existing loopbacks are terminated before NREM loopback is activated.
(c) Default Setting.
Table 2. Front Panel Component (Continued)
Name Function

Product Overview 150-402-100-03
8 November 5, 1998 HRU-402 List 1 and List 3
Panel Circuit Board Option
HRU-402 List 1 and List 3 has user options that must be set before you install
the unit into a shelf or an enclosure. Two of these options, DS-1 RCV LVL
and TLOS, are located on the front panel. A third option, Sealing Current
(SCURR), is located at the back of the panel circuit board adjacent to the
card-edge connector as shown in Figure 3. The Sealing Current S1 switch
allows you to either disable or enable the current flow over the HDSL pairs
(see Table 3). The HRU-402 List 1 has a local power option to force the use
of local power or line power.
See “Simplex Sealing Current Information” on page 12 for further
information.
Figure 3. User Option Locations
Sealing current
(SCURR)
Local power (HRU-402 List 1 only)
(LPWR)
S1

150-402-100-03 Product Overview
HRU-402 List 1 and List 3 November 5, 1998 9
FUNCTIONAL DESCRIPTION
This section describes the functions of the HRU-402.
Operational Capabilities
HiGain utilizes ADC’s 2B1Q HDSL transceiver system to establish two
full-duplex784 kbps datachannelsbetween the HLU anda remotely mounted
HRU-402. This system provides a total capacity of 1.568 Mbps between the
twounits. HDSL technologyalsoprovides full-duplexservicesatstandardT1
rates over copper wires between an HLU and an HRU-402, which comprise
one HiGain system. A block diagram of the HRU-402 is shown in Figure 4
on page 10.
Table 3. Panel Switch Option
Name Function
Sealing Current- Rear Unit Switch S1
Disable (DIS)(a)
(a) Denotes factory setting.
Prevents the flow of simplex sealing current over the HDSL pairs
towards the upstream unit.
Enable (ENA) Allows the flow of simplex sealing current over the HDSL pair towards
the upstream unit. This simplexed sealing current is polarity-sensitive
and will not flow if the HDSL loops adjacent to the HRU are reversed.
Reversed loops are indicated by a CHREV message in the Alarms line of
the Span Status Maintenance screen.
Local/Line Power - Rear Unit S1 (HRU-402 List 1 only)
Disable (DIS)(a) Directs the HRU-402 List 1 to Line Power mode where it obtains power
from the upstream line unit over the HDSL pairs.
Enable (ENA) Directs the HRU-402 List 1 to Local Power made where it obtains power
from the -48V supply applied to the edge connector pin 35 (-) and 17 (+).
If -48V of local power is not present, the HRU reverts to Line Power
mode.

Product Overview 150-402-100-03
10 November 5, 1998 HRU-402 List 1 and List 3
The HRU-402 List 1 power supply converts the 90 to 200 Vdc power that is
received on the simplex pairs (or the -48V input when locally powered) to
voltage and currents required by the remote unit circuitry. The
HRU-402 List 3 power supply converts the -20 to -70 Vdc local power to
voltages and currents required by the remote unit circuitry.
The HRU-402 can be used with the HLU-232 line unit to form an automatic
1 by 1 protection switch system. Refer to the HiGain Line Unit Model
HLU-232 practice (section number: 150-232-100-xx) for more details. For
this application, the HRE-422 List 5 remote enclosure must be used. This
enclosure provides access to the HRU-402 protection switch output, on
pin 12, which controls the protection switching function.
Figure 4. HRU-402 Block Diagram
HDSL1
XCVR
HDSL2
XCVR
Microprocessor
RLEV 0
-15
Protection
Protection
Factory Test
(Do Not Use)
BRG
T
R
T1
R1
BRG RCV
DS-1/TX
49
55
TX
5
15
13
20
12
7Protection
Switch
Control
20
R
T
HDSL1
1Chassis
Ground
47
41
R1
T1
HDSL2
Protection
Switch
Power Framer
Loopback
CLOC
TLOS
NREM
SMJK
35
LocalPower(a)
17
-
+Sealing
Current
Option
(SCURR)
Local Power
option
(LPWR) (b)
(a) HRU-402 List 1 requires -48V for local power applications. HRU-402 List 3 requires -20V to -70V.
(b) HRU-402 List 1 only.
Circuit
Ground
S1
S1
Power
Supply
DS-1/
RCV

150-402-100-03 Product Overview
HRU-402 List 1 and List 3 November 5, 1998 11
Local and Line Powering
The HRU-402 List 1 can be line or locally powered. The remote unit always
chooses the local -48 Vdc from the power supply attached to pair 35 (-) and
17 (+) of the card-edge connector. To set local or line power for the HRU-402
List 1, switch the Local Power (LPWR) switch S1 to ENA (see Figure 3 on
page 8 for switch location). When LPWR is set to DIS, the HRU must be line
powered.
The HRU-402 List 3 is locally powered. It cannot be line powered. This
feature makes the HRU-402 List 3 compatible with remote cellular phone
sites located in high voltage power towers. Such applications require the
HRU to beCD isolated fromthe network to avoid damage due to ground fault
potential risk. The -20 to -70 wide input voltage range also makes the
HRU-402 List 3 compatible with the standard -24V power supplier common
to cellular phone sites. The remote unit uses the powersource attached topins
35(-) and 17(+) of the card-edge connector (Figure 25 on page 50).
The earlier versions of the HLU-231 (Lists 1, 2, 3, 3A and 4) must first have
their Power Feed (PWRF) user option set to DIS when connected with a
locally powered HRU-402 List 3 unit.
The following line units automatically turn off their line power supply when
they are connected to a local powered HRU-402:
•List 6 and higher versions of the HLU-231
•All versions of the HLU-319 and HLU-388
Refer to the appropriate HLU user manual if you need more information
about its local powering capabilities.
If local power is lost to an HRU-402 List 1, the lost span loses sync. When
the HLU or HDU attempts to reestablish sync, it detects that the remote unit
is not locally powered and applies line power to it. The remote then powers
up and operates normally if it is within range to support line powering.
The HRU-402 List 1, when locally powered, must use a -48V power supply
capable of 110mA capacity (5.2 W).

Product Overview 150-402-100-03
12 November 5, 1998 HRU-402 List 1 and List 3
The HRU-402 List 3 must be locally powered with a -20V to -70V local
power supply with 250mA output current capacity (5.0 W).
A Teltrend© WPS-2005 Wall-Mount Power Supply (-48V and 250 mA) is
capable of powering two HRU-402 units. The 2005 provides spade lugs to
access its -48V output.
You can reach Teltrend at: 1 (800) TEL-TREN.
Simplex Sealing Current Information
The HRU-402 can source from 30 mA (short loop) to 20 mA (long loop) of
simplex sealing current towards the upstream unit over the two HDSL pairs.
The SCURR (S1) switch, located on the printed circuit board at the back of
the unit, allows this sealing current to beenabled(ON)or disabled (OFF).See
“Panel Circuit Board Option” on page 8 for further information.
The simplex sealing current flow is blocked if it is used with HDU-451
List 1, 2, 3 or 3B doublers. These doublers are only compatible with the
metallic sealing current of earlier remote units. To provide a path through
which the simplexed sealing current can flow, the following doublers must be
used with the HRU-402:
•HDU-451 List 4, 4B
•HDU-437, HDU-439 List 1 or List 1B
•HDU-409, HDU-404, and HDU-407
Loopback Design Description
Loopbacks permit you to perform isolated diagnostic tests at specific points
of the circuit. The transmitted signal is returned to the sending device after
passing through a data communications link or network. This allows you to
compare the returned signal with the transmitted signal and to determine if
there is a problem with the circuit. Ideally, personnel performing loopback
testing are in direct communication with each other in order to correlate
messages displayed at both the HRU and HLU during the test.
The HRU-402 supports up to five span applications.