PairGain HIGAIN HRU-412 User manual

HIGAIN REMOTE UNIT
PAIRGAIN TECHNOLOGIES, INC.
ENGINEERING SERVICES TECHNICAL PRACTICE
SECTION 150-412-171-04
Model List Number Part Number CLEI Code
HRU-412 7A 150-1103-71 T1L2CL0A

150-412-171-04, Revision 04
ii November 23, 1999 HRU-412 List 7A
Revision History of This Practice
©Copyright 1999 PairGain Technologies, Inc.
PairGain and HiGain are registered trademarks of PairGain Technologies, Inc. Other
product namesmentionedin this practice are usedfor identification purposes onlyandmay
be trademarks or registered trademarks of their respective companies.
Information containedin this documentis company private to PairGain Technologies,Inc.,
and shall not be modified, used, copied, reproduced or disclosed in whole or in part without
the written consent of PairGain.
Information furnished by PairGain Technologies is believed to be accurate and reliable.
However, no responsibility is assumed by PairGain Technologies for its use; nor for any
infringement of patents or other rights of third parties which may result from its use. No
license is granted by implication or otherwise under any patent or patent rights of PairGain
Technologies. PairGain Technologies reserves the right to change specifications at any
time without notice.
Revision Release Date Revisions Made
01 September 18, 1997 Initial release
02 September 18, 1998 Reformat
03 February 19, 1999 Update local and line powering
04 November 23, 1999 Correct line powering specifications

150-412-171-04, Revision 04 Using This Technical Practice
HRU-412 List 7A November 23, 1999 iii
USING THIS TECHNICAL PRACTICE
Three types of messages, identified by icons, appear in the text.
DOCUMENTATION
If you have comments on this PairGain document, send an email to
[e-mail]. Type the product name and the
section number of the document in the subject area of the email message.
INSPECTING THE SHIPMENT
Upon receipt of the equipment:
•Unpack each container and visually inspect the contents 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
describedin theWarrantylocatedinsidethebackcover.Ifyou muststore
the equipment for a prolonged period, store the equipment in its original
container.
Notes contain information about special circumstances.
Caution symbols indicate the possibility of equipment
damage or the possibility of personal injury.
The Electrostatic Discharge (ESD) Susceptibility symbol
indicates that a device or assembly is susceptible to damage
from electrostatic discharge.

Inspecting the Shipment 150-412-171-04, Revision 04
iv November 23, 1999 HRU-412 List 7A

150-412-171-04, Revision 04 Table of Contents
HRU-412 List 7A November 23, 1999 v
TABLE OF CONTENTS
Overview _______________________________________________ 1
Applications ____________________________________________ 2
Front and Rear Panel_____________________________________ 3
Installation _____________________________________________ 9
Install the HRU-412 List 7A....................................................9
Installation Test...................................................................... 10
Remote Login __________________________________________ 11
Connecting to a Maintenance Terminal................................. 11
Logging On and Off............................................................... 13
Remote Terminal Main Menu................................................ 14
Loopbacks _____________________________________________ 15
Appendix A - Specifications_______________________________ 18
Pinouts.................................................................................... 19
Craft Port................................................................................ 20
Insertion Loss......................................................................... 21
Appendix B - Functional Description_______________________ 22
Operational Capabilities......................................................... 22
Local and Line Powering....................................................... 22
Appendix C - Product Support____________________________ 24
Technical Support.................................................................. 24
World Wide Web................................................................... 24
Returns................................................................................... 25
Appendix D - Glossary___________________________________ 27
Certification and Warranty__________________Inside Back Cover

List of Figures 150-412-171-04, Revision 04
vi November 23, 1999 HRU-412 List 7A
LIST OF FIGURES
1.HRU-412 List 7A Front Panel................................................................3
2.HRU-412 List 7A Rear Panel.................................................................7
3.Connecting to a Maintenance Terminal................................................11
4.HRU-412 List 7A Loopbacks...............................................................15
5.HRU-412 List 7A Pinouts.....................................................................19
6.Craft Port Wiring..................................................................................20
LIST OF TABLES
1.HRU-412 List 7A Front Panel Components...........................................4
2.Rear Panel Components..........................................................................8
3.Remote Terminal Main Menu Items.....................................................14
4.HDSL Loss Over Cables.......................................................................21

150-412-171-04, Revision 04 Overview
HRU-412 List 7A November 23, 1999 1
OVERVIEW
ThePairGain®HiGain®Remote Unit, Model HRU-412 List 7A, isthe remote
end of a repeaterless T1 transmission system. An HRU-412 List 7A connects
to a HiGain Line Unit (HLU-231, HLU-232, HLU-319, or HLU-388),
creating a HiGain system that provides 1.544 Mbps transmission on two
unconditioned copper pairs over the full Carrier Service Area (CSA) range.
The CSA encompasses approximately 12,000 feet (3658 m) of AWG 24 wire
or 9,000 feet (2743 m) of AWG 26 wire, including bridge taps and gauge
changes. A HiGain system utilizes 2B1Q High-bit-rate Digital Subscriber
Line (HDSL) transmission technology.
The HRU-412 List 7A features:
•Customer Interface (CI)
•Front-panel DS1 and HDSL LEDs
•Front-panel loopback button
•Signature resistance on DS1 and HDSL ports
•Generic and addressable repeater loopback activation codes
•Metallic SmartJack loopback (conforms to TR-TSY-00312)
•Provisioning switches for customer premise equipment current, receive
level, and transmit loss of signal-initiated loopback or alarm
•Line or local power options
•Support for 3 span line powering
•Sealing current
•Front panel jacks for test access
•Craft port
•CPE current monitoring test points
•Front-panel HDSL margin threshold indicator for each loop
•Lightning and power cross protection on HDSL and DS1 interfaces
•784 kbps full-duplex 2B1Q HDSL transmission on two pairs
•DSO blocking support

Applications 150-412-171-04, Revision 04
2 November 23, 1999 HRU-412 List 7A
The HRU-412 List 7A supports PairGain’s 1-by-1 Protection Switching
System, and it can be line powered or locally powered with a metallic sealing
current option that is compatible with all HiGain line and doubler units. The
HDSL line resistive signature across both HDSL ports is 180 k
 .
APPLICATIONS
A HiGain system, consisting of a HiGain line unit and a HiGain remote unit,
provides a quick and cost-effective way of delivering T1 High Capacity
Digital Service (HCDS) to customers over copper wire pairs. The HiGain
system can be deployed on two unconditioned, non-loaded copper wire pairs
without repeaters, and without the need for bridged tap removal or binder
group separation.
A HiGain system operates with a variety of other T1, POTS, Digital Data
Service (DDS) equipment, or other HiGain systems sharing the same cable
binder group. HiGain systems provide temporary or permanent DS1 service
and can provide a means of deploying service in advance of fiber optic
transmission systems.

150-412-171-04, Revision 04 Front and Rear Panel
HRU-412 List 7A November 23, 1999 3
FRONT AND REAR PANEL
Figure 1 shows the front view of the HRU-412 List 7A.Table 1 describes the
unit’s front panel components.
Figure 1. HRU-412 List 7A Front Panel

Front and Rear Panel 150-412-171-04, Revision 04
4 November 23, 1999 HRU-412 List 7A
Table 1. HRU-412 List 7A Front Panel Components
Name Function
Test points Allow measurement of the 60 mA CPE current. The current is related
to the voltage measurement across the + and - test points by the
following relationship: CPE CURRENT=1 mA / 1 mV. Typical readings
range from 55 to 65 mV which equate to a 55 to 65 mA current range.
Receive (RCV)
and transmit
(XMT) jacks
Provide splitting and monitor access to the CPE DS1 interface. The
jacks are isolated from the CPE DS1 metallic interface by a
transformer.
Alarm LEDs The REM LOS LED is steady red indicating a loss of signal (LOS) at the
T1 input to the HLU. This LOS condition causes the HRU-412 to
transmit the alarm indicating signal (AIS) pattern toward the CPE.
The LOC LOS LED is steady red indicating a loss of signal (LOS) at the
T1 input to the HRU-412. This LOS condition transmits the AIS pattern
toward the DSX-1 (TLOS Disabled) or to execute a logic loopback in
the HRU-412 (TLOS Enabled).
Loopback (LB)
LEDs
The NET LED is steady green indicating the HRU-412 is in a loopback
state in which the signal from the network is looping back to the
network.
The CI LED is steady yellow indicating the HRU-412 is in a loopback
state in which the signal from the customer interface (CI) is looping
back to the CI.
CODE LEDs The B8ZS LED is steady green indicating that the user DS1 code
option is set to B8ZS.
The AMI LED is steady yellow indicating that the user DS1 code option
is set to AMI.
The BPV LED is steady red indicating that the user DS1 code option is
set to BPV.
If the user DS1 code option is set to AUTO, the lit LED indicates what
DS1 signal is being received.
Note that the settings are made on the HLU.
Framing LEDs The framing option is set on the HLU.
The ESF LED is steady green indicating that the framing pattern of the
received signal is Extended Super Frame (ESF).
The SF LED is steady yellow indicating that the framing pattern of the
received signal is Super Frame (SF).
The ERR LED is steady red indicating that a DS1 frame error has
occurred. No frame LED lights when the HRU-412 input pattern is
unframed or when the framing option is set to UNFR (unframed).

150-412-171-04, Revision 04 Front and Rear Panel
HRU-412 List 7A November 23, 1999 5
HDSL LEDs The LP1 OK LED flashes green while HDSL Loop 1 is synchronizing
with the HLU. The LED is a steady green indicating that Loop 1 is
properly synchronized with the HLU.
The LP1 MAR LED is steady yellow when the HRU-412 margin on
HDSL Loop 1 has dropped below the user-defined margin threshold
value. This indicator flashes yellow at a slow rate indicating that loss
of sync word (LOSW) exists in Span 1, Loop 1 of the HDSL pair
between the HLU and the doubler or HRU-412. If using doublers, this
indicator flashes yellow at a rapid rate indicating that LOSW problem
exists in Span 2, Loop 1 of the HDSL pairs.
The LP1 ES LED flashes red every second that a CRC error is detected
on loop 1 from the upstream doubler or line unit.
The LP2 OK LED flashes green while HDSL Loop 1 is synchronizing
with the HLU. The LED is steady green indicating that Loop 2 is
properly synchronized with the HLU.
The LP2 MAR LED is steady yellow when the HRU-412 margin on
HDSL Loop 2 has dropped below the user defined margin threshold
value. This indicator flashes yellow at a slow rate indicating that a loss
of sync word (LOSW) exists in Span 1, Loop 2 of the HDSL pair
between the HLU and the doubler. this indicator flashes yellow at a
rapid rate indicating that a LOSW problem exits in Span 2, Loop 2 of
the HDSL pairs between the first and second doublers.
The LP2 ES LED flashes red every second that a CRC error is detected
on Loop 2 from the upstream doubler or line unit.
Craft port Provides an RS-232 connection for a maintenance terminal. The
terminal allows access to the maintenance, provisioning, and
performance monitoring menus and screens.
Loopback button Places the HRU-412 in loopback mode.
Card handle Pull the card handle to remove the HRU-412 from the shelf slot.
Table 1. HRU-412 List 7A Front Panel Components (Cont.)
Name Function

Front and Rear Panel 150-412-171-04, Revision 04
6 November 23, 1999 HRU-412 List 7A
Configuration
number
For some products the configuration number may contain 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.
Digit 2 and 3 - Shipment month.
Digits 4, 5, and 6 - Configuration number.
The configuration number identifies the version of the product. New
configuration numbers usually accompany changes in the last two
characters of the CLEI code.
The configuration number can also be found on a small bar label that
also contains the Julian date code. The configuration number appears
as either a stand-alone CFG xx number or as a 15-character number
comprised of the part number and a 3-character extension. For
example, the number 150-2404-15-x03 is comprised of the part
number and an x03 configuration number. This gummed label may be
attached to the PC board or to the front panel.
Table 1. HRU-412 List 7A Front Panel Components (Cont.)
Name Function

150-412-171-04, Revision 04 Front and Rear Panel
HRU-412 List 7A November 23, 1999 7
The HRU-412 List 7A rear panel features are shown in Figure 2 and
described in Table 2.
Figure 2. HRU-412 List 7A Rear Panel

Front and Rear Panel 150-412-171-04, Revision 04
8 November 23, 1999 HRU-412 List 7A
Table 2. Rear Panel Components
Switch Setting Function
I-CPE 0Sets the CPE current to 0 mA.
60 Sets the CPE current to 60 mA to power an external NID.
The CPE current control signals terminate on pins 32 and 34 of
the card-edge converter. These access pins are for factory test
only. Single-slot remote enclosures and seven-slot enclosures
use the pins to control the CPE options. These enclosures must
be optimized for 0 mA current to prevent a conflict between
external connections to pins 32 and 34 and the settings of the
I-CPE switch.
TLOS-LB DIS Prevents the HRU-412 from entering its logic loopback state
when a loss of the T1 XMT signal from the CPE causes the HLU to
transmit the AIS signal toward the DSX-1.
EN Allows the HRU-412 to enter its logic loopback state when a loss
of the T1 XMT signal from the CPE causes the HLU to transmit the
AIS signal toward the DSX-1. While in this loopback state, the
HRU-412 transmits the AIS signal toward the CPE and returns the
network signal back to the network. The HLU displays TLOS on its
front panel display. This condition remains until a valid T1 signal
is received from the CPE or until the 3-in-5 in-band loopdown
command is issued by the CO. Once the TLOS initiated loopback
occurs, it will not reoccur until the CPE T1 signal has been
reapplied and then removed. This feature prevents the HRU-412
from oscillating into and out of TLOS loopback when a loopdown
command is issued in the absence of a T1 signal from the CPE.
Do not enable the TLOS option when the HRU-412 is used with
List 6 line units that do not support this feature. These line units
cannot loopdown an HRU-412 that is in a TLOS loop-up state
when they receive the 3-in-5 in-band loopdown command.
RLEV 0Configures the T1 RCV level to 0 dB. This sets the T1 output signal
level from the HRU-412 toward the NI to 0 dB. Use this setting
when the HRU-412 is not functioning as a NID but is connected to
an external NID. It allows the external NID to set the appropriate
NI level.
15 Configures the T1 RCV level to -15 dB. This sets the T1 output
signal level from the HRU-412 toward the NI level to -15 dB. This
setting is recommended when the HRU-412 functions as a NID.
JP2 Allows the enabling or disabling of the sealing current. To enable,
connect JP2 across both terminals. To disable (default), remove
the jumper from the inner terminal and leave it attached to the
outer terminal only.

150-412-171-04, Revision 04 Installation
HRU-412 List 7A November 23, 1999 9
INSTALLATION
INSTALL THE HRU-412 LIST 7A
For indoor installation, the HRU-412 List 7A mounts in the following
PairGain shelves:
•HRE-421 (double-width, single mount)
•HRE-422 (double-wide, double mount)
•HRE-424 (double-wide, four-unit wall mount)
•HRE-420 (single-wide, single mount)
•HRE-427 (seven-unit wall or rack mount)
•HRE-425 (12-slot wall or rack mount).
For outdoor installation, the HRU-412 List 7A mounts in the following
shelves:
•HRE-454 (four-unit)
•HRE-450 (single-unit)
•400 Mechanics-type shelves.
To install the HRU-412:
1Ensure that the shelf is correctly mounted and wired (refer to the shelf’s
technical practice for additional information).
2Slide the unit into the card guides for the desired slot, then push the unit
back until it touches the backplane card-edge connectors.
3Place your thumbson the front panel and push the unit into the card-edge
connector until it is secured in the card guides.
Be sure to wear an antistatic wrist strap. Avoid touching
static-sensitive components on the circuit board.

Installation 150-412-171-04, Revision 04
10 November 23, 1999 HRU-412 List 7A
When locally powered, the HRU-412 can be configured to provide 15 mA
(short loop) to 10 mA (long loop) metallic sealing current toward all versions
of the HLU over the two HDSL pairs. JP2, shown in Figure 2, allows the
sealing current to be enabled or disabled. To enable the sealing current,
connect JP2 across both terminals. To disable the sealing current, remove the
jumper from the inner terminal and attach it to the outer terminal. The factory
default setting is disabled.
INSTALLATION TEST
Perform the following procedure to test the HRU-412.
1Press the loopback button (see Figure 1for the location of this button) for
at least 5 seconds.
Verify that the LB NET LED is steady green, indicating that the
HRU-412 is in a digital network remote (NREM) loopback state. If
possible, verify that the HLU front panel displays NREM.
2Have the CO transmit a T1 test signal to the HLU.
Measure the return (loop) signal to verify it is error free. If the signal is
not error free, remove the HRU-412 from loopback by pressing the
loopback button for five seconds. The LB NET LED turns off.
3Have the CO send the HLU 4-in-7 in-band loop-up (NLOC) for five
seconds.
Verify that the HLU front panel displays NLOC.
4Repeat step 2.
If the test passes, a problem exists in the cable pair or in the HRU-412.
If the test fails, the problem is at the CO.
5Check that the proper ports are in use for the HDSL and DS1 pair by
using an ohmmeter to verify that the HDSL ports have a 180 k

transmit-to-receive resistive signature and that the DS1 ports have a
15
 transmit-to-receive resistive signature.
Measure the return (loop) signal to verify it is error free.
6If using an external Network Interface Device (NID), set the I-CPE
switch (On the back panel of the HRU-412 List 7A; see Figure 2) to
60 mA and verify the NID has power. Check that voltage across the front
panel test points (60 mA MON) measures between 55 mV and 65 mV.
7Enable the sealing current option (JP2 connected). Use a milli-amp meter
to verify transmit or receive current in either HDSL pair.

150-412-171-04, Revision 04 Remote Login
HRU-412 List 7A November 23, 1999 11
REMOTE LOGIN
The HRU-412 List 7A supports remote login through a maintenance terminal
or PC connected to its front-panel RS-232 craft port. Remote login creates
menus and screens for the HRU-412 that are identical to those at the HLU.
Once logged on you can access the Remote Terminal Main Menu screens to
view system settings and status, and initiate loopbacks. You can also access
the HRU-412 performance monitoring capabilities.
CONNECTING TO AMAINTENANCE TERMINAL
Figure 3. Connecting to a Maintenance Terminal

Remote Login 150-412-171-04, Revision 04
12 November 23, 1999 HRU-412 List 7A
The HRU-412 front-panel craft port allows you to use a standard serial cable
to connect your system to a maintenance terminal or PC running a terminal
emulation program.
1Connect a standard 9-pin serial terminal cable to the craft port, a DB-9
female connector, on the HRU-412.
2Connect the other end of the terminal cable to the serial port on the
maintenance terminal.
3Start a terminal emulation program such as ProComm (emulating a
VT-100 terminal).
4Configure the maintenance terminal to the following communication
settings:
•9600 baud
•No parity
•8 data bits
•1 stop bit
•Hardware flow control to OFF
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.

150-412-171-04, Revision 04 Remote Login
HRU-412 List 7A November 23, 1999 13
LOGGING ONAND OFF
To log on and access the Remote Terminal Main Menu screens using the
maintenance terminal:
1Press the several times to activate the autobaud feature and
display the Remote Login screen.
2Press the key to perform a remote login to the HiGain
Maintenance Terminal screens.
•The Remote Terminal Main Menu items (see Table 3 on page 14)
are replications of the HLU screens. Depending on the HLU
attached to the HRU-412 List 7A, remote provisioning may be
available. Refer to the HLU technical practice for details.
•The Performance Monitoring Menu items provide special network
surveillance features that monitor network performance and help
track problems.
3From the Remote Terminal Main Menu screen, type the appropriate
letter to select the item you wish to view. (Table 3 on page 14 shows an
example of different screens which may be available. The HLU
determines the screens available for viewing at the remote unit.)
4When completed, terminate the remote session by pressing for remote
logoff. Terminating the remote session allows other units in the circuit,
such as doublers, or the HLU itself, to initiate an RS-232 session. An
active session at any module prohibits active sessions at all other circuit
modules.
SPACEBAR
ENTER
L

Remote Login 150-412-171-04, Revision 04
14 November 23, 1999 HRU-412 List 7A
REMOTE TERMINAL MAIN MENU
The Remote Terminal Main Menu items are explained in Table 3.
Table 3. Remote Terminal Main Menu Items
Name Function
View Span Status Allows viewing of span status between the HLU and the HRU-412
including span status for doubler devices (multi-span applications).
Set Clock Allows setting of time and date parameters at the HRU.
System Settings Allows viewing of all system settings.
View
Performance Data
Allows viewing of the Errored Seconds (ES) and Unavailable Seconds
(UAS) for the HLU to HRU-412 span (non-doubler applications) and
any additional spans (doubler applications) in 15-minute intervals
over a 4-hour time period.
View
Performance
History
Allows viewing of the ES and UAS for the HLU to HRU-412 span
(non-doubler applications) and any additional spans (doubler
applications) in 24-hour intervals over a 7-day period.
View Alarm
History
Allows viewing of alarm conditions for the HLU to HRU-412 span
(non-doubler applications) and any additional spans (doubler
applications).