PairGain HIGAIN HRU-412 User manual

HIGAIN REMOTE UNIT
PAIRGAIN TECHNOLOGIES, INC.
ENGINEERING SERVICES TECHNICAL PRACTICE
™150-412-106-06d¨
SECTION 150-412-106-06
Model List
Number Part Number CLEI Code
HRU-412 6 150-1103-06 T1LIEF04AA
L
TELEPHONE CO PROPERTY
L
P
2
OK
MAR
ES
OK
MAR
ES
ESF
SF
ERR
ZS
AMI
BPV
B8
NET
CI
LOS
LOS
L
P
1
C
O
D
E
C
I
L
I
N
E
M
O
N
C
I
L
I
N
E
M
O
N
L
O
C
R
E
M
F
R
M
R
S
X
M
T
R
C
V
L
B
A
L
M
+
-
60 mA
MON
2
3
2
HDSL
DS1
HRU 412
H G REM UNIT
IAIN

150-412-106-06, Revision 06
ii October 28, 1998 HRU-412 List 6
Revision History of This Practice
©Copyright 1998 PairGain Technologies, Inc.
PairGain, and HiGain are registered trademarks of PairGain Technologies, Inc.
Information contained in this documentis company private toPairGain Technologies, Inc.,
and shallnot bemodified, used, copied,reproduced or disclosed in whole orinpart 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
04 November 15, 1994 Minor updates
05 September 22, 1998 Reformat
06 October 28, 1998 Update cover

150-412-106-06, Revision 06 Using This Technical Practice
HRU-412 List 6 October 28, 1998 iii
USING THIS TECHNICAL PRACTICE
Two types of messages, identified by icons, may appear in the text.
ABBREVIATIONS
Notes contain information about special circumstances.
Cautions indicate the possibility of equipment damage or
the possibility of personal injury.
AMI Alternate Mark Inversion
BER Bit Error Rate
BPV Bipolar Violations
B8ZS Bipolar with Eight Zero Subsitution
CI Customer Interface
CO Central Office
CPE Customer Premise Equipment
CRC Cyclic Redundancy Check
CSA Carrier Service Area
ES Errored Seconds
ESF Extended Superframe
HDSL High-bit-rate Digital Subscriber Line
HLU HiGain Line Unit
HRU HiGain Remote Unit
NI Network Interface

Abbreviations 150-412-106-06, Revision 06
iv October 28, 1998 HRU-412 List 6
RLEV Receive Level
SF Super Frame
SNR Signal-to-Noise Ratio
SPLB Special Loopback
ZBTSI Zero Byte Time Slot Interchange

150-412-106-06, Revision 06 Table of Contents
HRU-412 List 6 October 28, 1998 v
TABLE OF CONTENTS
Overview _______________________________________________ 1
Applications ____________________________________________ 2
Functional Description____________________________________ 3
Operational Capabilities........................................................... 3
Front Panel Features ................................................................ 4
Rear Panel Features.................................................................. 7
Installation _____________________________________________ 9
Unpack and Inspect the Shipment............................................ 9
Install the HRU-412 List 6....................................................... 9
Installation Test...................................................................... 11
Configure, Provision, and Monitor Performance _____________ 12
Connect a Dumb Terminal..................................................... 12
Logging On and Using the Menus......................................... 13
View Span Status..................................................... 16
Set Clock ................................................................. 17
System Settings ....................................................... 19
View Performance Data .......................................... 20
View Performance History...................................... 21
View Alarm History ................................................ 22
Loopbacks _____________________________________________ 24
Specifications __________________________________________ 26
Product Support________________________________________ 28
Technical Support.................................................................. 28
Warranty ................................................................................ 28
FCC Compliance.................................................................... 29
Modifications ......................................................................... 30

List of Figures 150-412-106-06, Revision 06
vi October 28, 1998 HRU-412 List 6
LIST OF FIGURES
Figure 1. HRU-412 List 6 Front Panel ...................................................4
Figure 2. HRU-412 List 6 Rear Panel.....................................................7
Figure 3. HRU-412 List 6 Pinouts........................................................10
Figure 4. HRU-412 List 6 Craft Port Wiring........................................12
Figure 5. Remote Log On Screen. ........................................................14
Figure 6. Main Menu, Local Log On....................................................15
Figure 7. Span Status Screen, No Doublers in Use ..............................16
Figure 8. Span Status Screen, Doublers in Use ....................................17
Figure 9. Set Clock Screen ...................................................................18
Figure 10. System Settings Menu.........................................................19
Figure 11. Performance Data Screen....................................................20
Figure 12. Performance History Screen................................................21
Figure 13. Alarm History Screen..........................................................22
Figure 14. HRU-412 List 6 Loopbacks ................................................24

150-412-106-06, Revision 06 List of Tables
HRU-412 List 6 October 28, 1998 vii
LIST OF TABLES
Table 1. HDSL Loss Over Cables.......................................................... 2
Table 2. HRU-412 List 6 Front Panel Components .............................. 5
Table 3. Rear Panel Components .......................................................... 8
Table 4. HRU-412 List 6 Alarm History Screen Definitions............... 23

List of Tables 150-412-106-06, Revision 06
viii October 28, 1998 HRU-412 List 6

150-412-106-06, Revision 06 Overview
HRU-412 List 6 October 28, 1998 1
OVERVIEW
The PairGain®HiGain®Remote Unit Model HRU-412 List 6 is the remote
end of a repeaterless T1 transmission system. An HRU-412 List 6 connects
to aHiGain Line Unit (HLU),creating aHiGain system which provides 1.544
Mbps transmission on two unconditioned copper pairs over the full Carrier
ServiceArea (CSA)range. The CSA encompasses approximately 12,000 feet
of AWG 24 wire or 9,000 feet 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 6 complies with ANSI T1E1.4, T1.403-1989, and
T1E1.4/92-002R2 technical standards and recommendations. The HRU-412
List 6 mounts in a single slot of an industry standard 400 Mechanics type
shelf. The system also complies with GR-63 Core of Network Equipment
Building System (NEBS) Generic Equipment requirements, and Transport
System Generic Requirements (TSGR) common requirements
TR-TSY-000499.
The HRU-412 List 6 features:
•Customer Interface (CI)
•Front panel DS1 and HDSL LEDs
•Generic and addressable repeater loopback activation codes
•Metallic Smart-Jack loopback (conforms to TR-TSY-000312)
•Provisioning switches for customer premise equipment current, receive
level, and transmit loss of signal-initiated loopback or alarm
•HDSL line powered—no local power required
•Front panel jacks for test access
•Craft port
•CPE current monitor test points
•Front panel HDSL margin threshold indicator for each loop
•Lightning and power cross protection on HDSL and DS1 interfaces
•784kbps full-duplex 2B1Q HDSL transmission on two pairs
•DS0 blocking support

Applications 150-412-106-06, Revision 06
2 October 28, 1998 HRU-412 List 6
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.
The general guidelines for HiGain system usage are that each loop must have
less than 35 dB of loss at 196 kHz, with 135 ohm driving and terminating
impedances.
Table 1 provides a guide for the loss over various cable gauges at 196 kHz
and 135 ohms. The table applies to the HDSL wire pairs between the HiGain
line unit and the HiGain remote unit. When specific loop insertion loss data
is unavailable, add 3 dB for each bridged tap and 1 dB for each cable gauge
change.
The dc cable resistance determines the simplex powering resistance path of
the loops. The maximum allowable resistance for a HiGain system is
800 ohms over two HDSL simplex loops. This means, for example, where
12 kft of AWG 24 wire equals 34.08 dB (insertion loss), resistance is at 622
ohms which is well below the limit of 800 ohms.
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.
Table 1. HDSL Loss Over Cables
Cable Gauge Loss at 196 kHz
(db/kft) Ohms per kft
26/0.4mm 3.88 83
24/0.51mm 2.84 52
22/0.61mm 2.18 32
19/0.91mm 1.54 16

150-412-106-06, Revision 06 Functional Description
HRU-412 List 6 October 28, 1998 3
FUNCTIONAL DESCRIPTION
This section describes the functions of the HRU-412 List 6.
OPERATIONAL CAPABILITIES
HiGain utilizes PairGain’s 2B1Q HDSL transceiver system to establish two
full-duplex784 kbpsdatachannelsbetween the HLU and a remotelymounted
HRU-412 List 6. This provides a total transmission capacity of 1.568 Mbps
between the two units.
The HRU-412 power supply converts the powerfeed voltage received on the
simplex wire pairs to voltages and currents required by the HRU-412
circuitry. The power supply generates +5,-5 and 30 Vdc outputs. The 30 Vdc
output converts to a 60 mA current feed to power a Network Interface Device
(NID). The HRU-412 List 6 cannot power a NID and another product
simultaneously.
The HRU-412 dissipates 5.5 Watts of power and may consume up to 7 Watts
when feeding 60 mA of simplex current to the CI.

Functional Description 150-412-106-06, Revision 06
4 October 28, 1998 HRU-412 List 6
FRONT PANEL FEATURES
Figure 1 shows the front view of the HRU-412 List 6. Table 2 describes the
HRU-412 List 6 front panel components.
Figure 1. HRU-412 List 6 Front Panel

150-412-106-06, Revision 06 Functional Description
HRU-412 List 6 October 28, 1998 5
Table 2. HRU-412 List 6 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 transformer isolated from the CPE DS1 metallic interface.
Alarm LEDs REM LOS LED lights red to indicate a loss of signal (LOS) at the T1 input
to the HLU. This LOS condition causes the HRU-412 List 6 to transmit the
alarm indicating signal (AIS) pattern toward the CPE.
LOC LOS LED lights red to indicate a loss of signal (LOS) at the T1 input
to the HRU-412 List 6. This LOS condition transmits the AIS pattern
toward the DSX-1 (TLOS Disabled) or to execute a logic loopback in the
HRU-412 List 6 (TLOS Enabled).
Loopback
(LB) LEDs
NET LED lights green to indicate the HRU-412 List 6 is in a loopback state
in which the signal from the network is looping back to the network.
CI LED lights yellow to indicate the HRU-412 List 6 is in a loopback state
in which the signal from the customer interface (CI) is looping back to the
CI.
Code LEDs B8ZS LED lights green to indicate that the user DS1 code option is set to
B8ZS.
AMI LED lights yellow to indicate that the user DS1 code option is set to
AMI.
BPV LED lights red to indicate 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 these settings are made on the HLU.
Framing
LEDs
ESF LED lights green to indicate that the framing pattern of the received
signal is Extended Super Frame (ESF).
SF LED lights yellow to indicate that the framing pattern of the received
signal is Super Frame (SF).
ERR LED lights red to indicate that a DS1 frame error has occurred.
No frame LED lights when the HRU-412 List 6 input pattern is unframed
or when the framing option is set to UNFR (unframed).
Note that the framing option is set on the HLU.

Functional Description 150-412-106-06, Revision 06
6 October 28, 1998 HRU-412 List 6
HDSL LEDs LP1 OK LED flashes green while HDSL Loop 1 is synchronizing with the
HLU. The LED lights green to indicate that loop 1 is properly synchronized
with the HLU.
LP1 MAR LED lights yellow when the HRU-412 List 6 margin on HDSL
loop 1 has dropped below the user-defined margin threshold value. This
indicator flashes yellow at a slow rate to indicate that a loss of sync word
(LOSW) exists in span 1, loop 1 of the HDSL pair between the HLU and the
doubler or HRU-412 List 6. If using doublers, this indicator flashes yellow
at a rapid rate to indicate that a LOSW problem exists in span 2, loop 1 of
the HDSL pairs.
LP1 ES LED flashes red every second that a CRC error is detected on loop
1 from the upstream doubler or line unit.
LP2 OK LED flashes green while HDSL Loop 1 is synchronizing with the
HLU. The LED lights green to indicate that loop 2 is properly synchronized
with the HLU.
LP2 MAR LED lights yellow when the HRU-412 List 6 margin on HDSL
loop 2 has dropped below the user-defined margin threshold value. This
indicator flashes yellow at a slow rate to indicate 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 to indicate that a
LOSW problem exists in span 2, loop 2 of the HDSL pairs between the first
and second doublers.
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 dumb terminal. The ASCII terminal
allows access to the maintenance, provisioning, and performance
monitoring menus and screens.
Loopback
button
Places the HRU-412 List 6 in loopback mode.
Card handle Pull on the card handle to remove the HRU-412 List 6 from the shelf slot.
WCN label Provides the warranty control number for the HRU-412 List 6.
Table 2. HRU-412 List 6 Front Panel Components (Cont.)
Name Function

150-412-106-06, Revision 06 Functional Description
HRU-412 List 6 October 28, 1998 7
REAR PANEL FEATURES
The HRU-412 List 6 rear panel features are shown in Figure 2. Table 3
describes the features.
Figure 2. HRU-412 List 6 Rear Panel
I-CPE 0
60
TLOS-LB DIS
EN
RLBO 0
-15
Manual Switches

Functional Description 150-412-106-06, Revision 06
8 October 28, 1998 HRU-412 List 6
Table 3. Rear Panel Components
Switch Setting Function
I-CPE 0* Sets the CPE current to 0 mA.
60 Sets the CPE current to 60 mA to power an external NID.
TLOS-LB DIS* A loss of the T1 XMT signal from the CPE causes the HLU to
transmit the AIS signal toward the DSX-1 and does not cause the
HRU to enter its logic loopback state.
EN A loss of the T1 XMT signal from the CPE forces the HRU to enter
its logic loopback state (TLOS in Figure 14). While in this state, the
HRU transmits the AIS signal toward the CPE and returns the
Network signal back to the network. The HLU displays TLOS in
the front panel display. This condition remains in effect until a valid
T1 signal is received from the CPE or until a loopdown command
is issued. Once the TLOS-initiated loopback has occurred, it cannot
occur again until the CPE T1 signal has been reapplied and then
removed. This feature prevents the HRU from oscillating into and
out of TLOS loopback when a loopdown command is issued in the
absence of a T1 signal from the CPE.
RLBO 0* Configures the T1 RCV LBO to 0 dB. This sets the T1 output signal
level from the HUR toward the NI to 0 dB. This setting is
recommended when the HRU is connected to an external NID. It
allows the external NID to set the appropriate NI level.
15 Configures the T1 RCV LBO to -15 dB. This sets the T1 output
signal level from the HRU toward the NI level to -15 dB. This setting
is recommended when the HRU functions as a NID.
* Default setting

150-412-106-06, Revision 06 Installation
HRU-412 List 6 October 28, 1998 9
INSTALLATION
This section describes how to install the HRU-412 List 6.
UNPACK AND INSPECT THE SHIPMENT
Upon receipt of the equipment:
1Unpack the container and visually inspect the product for signs of
damage. If the equipment has been damaged in transit, immediately
reportthe extentofthe damage to the transportation company and toyour
sales representative.
2Verify the contents using the packing list to ensure complete and
accurate shipment.
If you must store the equipment for a prolonged period, store it in the
original container.
INSTALL THE HRU-412 LIST 6
For indoor installation, the HRU-412 List 6 mounts in the following shelves:
•PairGain’s HRE-421 (double-width, single-mount)
•HRE-422 (single-wide, two-slot)
•HRE-424 (double-wide, four-slot wall mount)
•HRE-420 (single-wide, single-slot)
•HRE-427 (seven-slot wall or rack mount)
•HRE-425 (12 slot wall or rack mount)
For outdoor applications, the HRU-412 List 6 mounts in the following
shelves:
•HRE-454 (four-slot)
•HRE-450 (single-slot)
•400 Mechanics-type shelves

Installation 150-412-106-06, Revision 06
10 October 28, 1998 HRU-412 List 6
The HRU-412 List 6 pin-outs are shown in Figure 3. The active pins are
shown in black.
Figure 3. HRU-412 List 6 Pinouts
To install the HRU-412 List 6:
1Ensure that the shelf is correctly mounted and wired (refer to the shelf’s
technical practice for additional information).
2Slide the HRU-412 List 6 into the card guides for the desired slot, then
push the unit back until it touches the backplane card-edge connectors.

150-412-106-06, Revision 06 Installation
HRU-412 List 6 October 28, 1998 11
3Place your thumbs on the HRU-412 List 6 front panel and push the
HRU-412 List 6 into the card-edge connector until it is secured in the
card guides.
INSTALLATION TEST
Perform the following procedure to test the HRU-412 List 6.
1Press the loopback button (see Figure1for the locationof thisbutton) for
at least five seconds.
Verify that the LB NET LED lights green, indicating that the HRU-412
List 6is 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-412List 6fromloopback by pressingthe
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.
If possible, 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
List 6. 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 ohm-meter to verify that the HDSL ports have a 180k transmit
to receive resistive signature and that the DS1 ports have a 15 ohm
transmit to receive resistive signature.
Measure the return (loop) signal to verify it is error free.
6If using an external NID, set the I-CPE switch (located on the back panel
of the HRU-412 List 6; see Figure 2) to 60 mA and verify the NID has
power. Check that the voltage across the front panel test points (60 mA
MON) measures between 55 mV and 65 mV.
7Enable the sealing current option(JP2connected). Usea milli-amp meter
to verify transmit or receive current in either HDSL pair.

Configure, Provision, and Monitor Performance 150-412-106-06, Revision 06
12 October 28, 1998 HRU-412 List 6
CONFIGURE, PROVISION, AND
MONITOR PERFORMANCE
The following sections describe how to perform configuration, provisioning
and performance monitoring functions using the HRU-412 List 6 menus and
screens.
CONNECT ADUMB TERMINAL
Connect a dumb terminal:
1Connect a standard 9-pin serial terminal cable to the Craft port, a DB-9
femaleconnector, on the HRU-412 List 6. See Figure 4 for the Craft port
wiring diagram.
Figure 4. HRU-412 List 6 Craft Port Wiring