Verilink DDS Lite User Manual

Multi-Rate DDS CSU/DSU

34-00295.C
Octobe r 200 2

ii

Copyright Notice Copyright © 2001 Verilink Corporation. All rights reserved.

This document does not create any express or implied warranty about Verilink or
about its products or services. Verilink’s sole warranty is contained in its product
warranty. The end-user documentation is shipped with Verilink’s products and
constitutes the sole specifications referred to in the product warranty. Verilink has
made reasonable efforts to verify that the information contained herein is accurat e, but
V erilink assumes no responsibility for its use or for any infringement of patents or
other rights of third parties that may result. The customer is solely responsible for
verifying the suitability of Verilink’s products for its use. Specifications are subject to
change without notice.

Manual reorde r # 34-00295
Revision C, October 2002

Trademarks Verilink is a registered trademark Verilink Corporation.

Any named products herein are trademarks of their respective companies.

FCC Requirements

This equipment (Multi-Rate DDS CSU/DSU) has been tested and found to comply
with the limits for a Class A digital device, pursuant to Pa rt 15 of FCC Rules. These
limits are designed to provide reasonable protection against har mfu l interference when
the equipment is operated in a commercial environment. This equipment generates,
uses, and can radiate radio frequency energy and if not installed and used in
accordance with the instruction manual, may cause harmful interference to radio
communications. Operation of this equipment in a residential area is likely to cause
harmful interference in which case the user is req uired to co rrect the interference at his
own expense. This device must also accept any interference received, including
interference that may cause undesired operation.

For use only with a certified Class 2 power supply. See Power Source in
Specifications on page 3.

Changes or modi fications to th is unit not e xpressly a pproved by the
party responsible for complianc e could vo id the user ’s authority to
operate the equi pment.

This equipment complies with Part 15 of the FCC Rules. On the rear or bottom of the
unit is a label that contains the FCC registration number and other information. If
requested, provide this information to the telephone company. Operation is subject to
the following two conditions:

✦ This device may not cause harmful interference.
✦ This device must accept any interference received, including interference that may

cause un desire d oper ation.
This equipment has been tested and found to comply with the limits for a Class A

digital device, pursuant to Part 15 of FCC Rules. These limits are designed to provide
reasonable protection agains t harmful interference when the equipment i s oper at ed in a
commercial environment. This equipment generates, uses, and can radiate radio
frequency energy and if not installed and used in accordance with the instruction
manual, may cause harmful interference to radio communications. Operation of this
equipment in a residential area is likely to cause harmful interference. The user will be
required to correct the interference at his own expense.

Notice to Users of DDS service: The following instructions are provided to ensure
compliance with FCC Rules, Part 68:

1 All direct connections to DDS lines must be made using standard plugs and jacks.

An FCC-compliant telephone cord and modular plug is provided with the
equipment. This equipment is designed to be connected to the telephone network or
premises wiring using a compatible modular jack which is Part 68 compliant.

2 Before connecting the unit, inform the local telephone company of the following

information:

Port ID REN/SOC kbps FIC USOC

Canadian Emissions Requirements

2.4

4.8

9.6

38.4
56
64

3 If the unit appears to be malfunctioning, disconnect it from the telephone lines until

it is determined whether the source of trouble is the equipment or the telephone line.
If the equipment needs repair, do not reconnect it until repaired.

4 The unit has been designed to prevent harm to the DDS network. If the telephone

company finds that the equipment is exceeding tolerable parameters, it can
temporarily disconnect service. In this case, the telephone company will provide
notice, if possible.

5 Under FCC rules, no customer is authorized to repair this equipment. This restriction

applies regardless of warranty status.

6 If the telephone company alters its equipment in a manner that affects the use of this

device, it must give warning so that you have the opportunity for uninterrupted
service. You will be advised of your right to file a complaint with the FCC.

7 If the equipment malfunctions, all repa irs should be performed by our company or

an authorized agent. It is the responsibility of users requiring service to report the
need for service to our company or to one of our authorized agents.

This digital apparatus does not exceed the Class A limits for radio noise emissions
from digital apparatus set out in the Radio Interference Regulations of the Canadian
Depart m e nt of Com mu nications.

Le prés e nt appareil numéri que n’é me t pas de bruits radioélectriques dé passant les
limites applicables aux appareils numériques (de la class A) prescrites dans le
Règlement sur le brouillage radioélectrique édicté par le ministère des
Commun ications du Canada.

Notice: The Industry Canada label identifies certified equipment. This certification
means that the equipment meets certain telecommunications network protective,
operational and safety requirements. The Industry Canada does not guarantee the
equipment will operate to the user’s satisfaction.

Before installing this equipment, users should ensure that it is permissible to be
connected to the facilities of the local telecommunications company. The equipment
must also be installed using an acceptable method of connection. In some cases, the
company’s inside wi r ing associated with a sing le line in dividual servic e may be
extended by means of a certified connector assembly (telephone extension cord). The
customer should be aware that compliance with the above conditions may not prevent
degradation of service in some situations.

Repairs to certified equipment should be made by an authorized Canadian
maintenance facility de signated by the supplier. Any repairs or alterations made by the
user to this equipment, or equipment malfunctions, may give the telecommunications
company cause to request the user to disconnect the equipment.

Users should ensure for their own protection that the electrical ground connections of
the power utility, telephone lines and internal metallic water pipe system, if present,
are connected together. This precaut i on may be particular ly important in rural areas.

Caution: Users should not attempt to make such connections themselves, but should
contact the appropriate electric inspection authority, or electrician, as appropriat e.

6.0 N 2.4

4.8

9.6

38.4
56
64

04DU5-24
04DU5-48
04DU5-96
04DU5-38
04DU5-56
04DU5-64

Warranty V erilink's product warranty is provided at the end of this document. Returning

Products

Verlink’s policy for produc t return s is covered in the warranty statement that appea rs
at the rear of this document.

iii

RJ - 4 8S jack

iv

Customer Service

Safety Precautions

Verilink offers the following services:

✦ System Engineers at regional sales offices for network design and planning assistance

[phone]

✦ Technical Assistance Center for free 24×7 telephone support during installation,

maintenance, and troublesh ooting at [phone] and support @verilink.com

✦ Return Materials Authorization (RMA) (800) 926- 0085, ext. 2282
✦ Maintenance contracts and leasing plans [phone] , ext. 206
✦ Technical Training on network concepts and Verilink products at (800) 837- 454 6,

ext. 34 6 an d t rain ing@ ve rili nk .com

✦ Web site at www.verilink.com
✦ FAX-On-Demand at [phone]

When handling this equipment, follow these basic safety p recau t i ons to redu ce t he risk
of electric shock and injury:

✦ Follow all warnings and in structions marked on the product a nd in the manual.
✦ Unplug the hardware from the wall outlet before cleaning. Do not use liquid cleaners

or aerosol cleaners. Use a slightly damp cloth for cleaning.

✦ Do not place this product on an unstable cart, stand, or table. It may fall, causing

serious damage to the product.

✦ This product should be operated only from the type of power source indicated on the

marking label and manual. If you are unsure of the type of power supply you are
using, consult your dealer or local power company.

✦ Do not allow anything to re st on the power cord. Do not locate this pro duct where

the cord interferes with the free movement of people.

✦ Do not overload wall ou tlets and extensio n cords, as this can result in fire or ele ctric

shock.

✦ Never push objects of any kind into the unit. They may touch dangerous voltage

points or short out parts that could result in fire or electri c shock. Never spill l iquid
of any k ind on t his equ ipm ent.

✦ Unplug the equipment from the wall outlet and refer servicing to qualified service

personnel under the following conditions:

✧ When the power supply cord or plug is damaged or frayed.
✧ If liquid has been spil led into the product.
✧ If the product has been exposed to rain or water.
✧ If the product has been dropped or if the housing has been damaged.

Table of Contents

1

Copyright Notice . . . . . . . . . . . . . . . . . . ii

Trademarks . . . . . . . . . . . . . . . . . . . . . . . ii

FCC Requirements . . . . . . . . . . . . . . . . . ii

Canadian Emissions Requirements . . . iii

Warranty . . . . . . . . . . . . . . . . . . . . . . . . iii

Returning Products . . . . . . . . . . . . . . . iii

Customer Service . . . . . . . . . . . . . . . . . iv

Safety Precautions . . . . . . . . . . . . . . . . iv

About This Manual

What is a R ef er en c e M a nu a l? . . . . . . . .1

Where

to go for Information . . . . . . . . . . . . . . . 1

Conventions . . . . . . . . . . . . . . . . . . . . . . 1

1 General

Introduction . . . . . . . . . . . . . . . . . . . . . . 3

Features . . . . . . . . . . . . . . . . . . . . . . . . . 3

Specifications . . . . . . . . . . . . . . . . . . . . . 3

Network

Interface . . . . . . . . . . . . . . . . . . . . . 3

Mechanical . . . . . . . . . . . . . . . . . . . . 3

Power

Source . . . . . . . . . . . . . . . . . . . . . . . . 4

Industry

Standards . . . . . . . . . . . . . . . . . . . . 4

Environmental . . . . . . . . . . . . . . . . . 4

2 Installation and

Configuration

Introduction . . . . . . . . . . . . . . . . . . . . . . 5

Safety

Summary . . . . . . . . . . . . . . . . . . . . . . . . 5

Wallmount Installation . . . . . . . . . . . . . . 6

Using Ad he si v e Str ip s . . . . . . . . . 6

Using Screws . . . . . . . . . . . . . . . . 6

Connections . . . . . . . . . . . . . . . . . . . . . . 6

DDS

Network

Connection . . . . . . . . . . . . . . . . . . . 6

RS-232 Port

Connection . . . . . . . . . . . . . . . . . . . 7

Power . . . . . . . . . . . . . . . . . . . . . . . . 7

Configuration . . . . . . . . . . . . . . . . . . . . . 8

Network Bit Rate Select . . . . . . . . . . 9

V.54 Loop Operation . . . . . . . . . . . . 9

Data Polarity . . . . . . . . . . . . . . . . . . . 9

Circuit Assurance . . . . . . . . . . . . . . . 9

CTS Control . . . . . . . . . . . . . . . . . . . 9

RTS-to-CTS Delay . . . . . . . . . . . . . 9

Synchronous/

Asynchronous Data . . . . . . . . . . . . . 9

Asynchronous Word Length . . . . . . 10

Signalling

Rate Range . . . . . . . . . . . . . . . . . . 10

Not Used . . . . . . . . . . . . . . . . . . . . . 10

3 Testing

Introduction . . . . . . . . . . . . . . . . . . . . . 11

Indicators . . . . . . . . . . . . . . . . . . . . . . . 11

Network . . . . . . . . . . . . . . . . . . . . . 11

Tx Data . . . . . . . . . . . . . . . . . . . . . . 11

Rx Data . . . . . . . . . . . . . . . . . . . . . . 11

Loop Test . . . . . . . . . . . . . . . . . . . . 11

Loopbacks . . . . . . . . . . . . . . . . . . . . . . 11

Channel

Loop . . . . . . . . . . . . . . . . . . . . . . . . 11

Data
Set

Loop (Non-latching) . . . . . . . . . . . 12

V.54
Channel

Loop . . . . . . . . . . . . . . . . . . . . . . . . 12

2

ABOUT THIS MANUAL

What is a Reference Manual?

Where to go for Information

This is a reference manual. It provides information about unit
installation, configuration, testing and troubleshooting on a
function-by-function basis. It is not a user’s guide containing
step- by-st ep pro ced ures. T his ma nual contai ns spe cifi c
information about a command, menu field, port, etc. Unless
otherwise noted, the information in this manual applies only to
the Verilink Mult i-Rate DDS CSU /DSU (also re ferred to as th e
unit.)

The chapters and appendices in this manual are arranged for
quick reference. It is not necessary to read previous chapters to
understand the subsequent chapters.

1 General - This chapter introduces the unit, lists the features, and

provides specifications.

2 Installation and Configuration - This chapter describes unit

installation, port and power connections, and switch settings.

3 Testing - This chapter describes the indicators, test switch, and

loopbacks.

Conventions The following table lists the conventions used throughout this

manual.

Convention Description

Notices call attention to important features or instructions.
Cautions alert you to personal safety risk, system damage, or data loss.
Warnings alert you to the risk of severe personal injury.

italics Italics denote new terms or emphasis.

underline Default settings are underlined.

2 ABOUT THIS MANUAL

ENERAL

G

1

Introduction The Multi-Rate DDS CSU/DSU is a cost-effective DDS

CSU/DSU that allows connecting your computer or other data
terminal equipment directly to the digital network without any
network access device. The unit transfers data at up to 64 kbps in
point-to-point or multipoint applications. It also accepts line rates
ranging from 2.4 to 64 kbps and performs
asynchronous-to-synchronous conversions.

The Multi-Rate DDS CSU/DSU is powered by an external wall
mount power supply. Easy configuration and setup is done using
DIP sw itches. T he Mult i-Rat e DDS C SU/DS U can int ellige ntly
respond to V.54 loopbacks initiated from the central office or
other equipment.

Features

✦ Network connection is RJ- 48S
✦ Equipment interface is RS-232 presented on a DB-25 connector
✦ DDS s ervic e t er mina tion
✦ Subrate capability from 2.4 to 64 kbps
✦ Asynchronous-to-synchronous conversion capability
✦ V.54 loopback response
✦ LED indicators
✦ 115 VAC external power supply
✦ Space-saving design can be desktop or wall mounted
✦ Standard 5-year warrant y

Specifica tions

Network

Interface

Mechanical Mounting: desktop or wallmount

Line Rate: 2.4, 4.8, 9.6, 19.2, 28, 38.4, 56, and 64 kbps
Line Code: AMI
Line Impedance: Balanced 135 Ω
Input Signal: +1 to −40 dB (ALBO)
Output Signal: 3.0 V (±15%) base-peak into 135 Ω,

1.5 V (±15%) at the 9.6 kbps line rate

Line Protection: 1000 V lightning, input/output

Dimensions: 1.25" H, 3.50" W, 5.75" D
We ight: 1 pound

4 CHAPTER 1: GENERAL

Power

Source

Industry

Standards

Exte rnal : Inpu t: 11 5 VAC

Output: 9 VAC, 750 mA

FCC Compliance: Part 15 Class A Subpart B, Part 68
U.S. Safety: UL 1950
Canadian Safety: CSA C22.2 No. 950-95
Industry Canada: CS- 03, Issue 8
Bellcore GR-1089 -CORE

Environmental Operating Temp: 0° to 50°C (32° to 122°F)

Storag e Temp : −20° to 70°C (−4° to 158°F)
Humidity: 95% max (non- condensing)

NSTALLATION AND

I

2

C

ONFIGURATION

Introduction This chapter contai ns inform ation and instructions required to

prepar e the Verilink Mu lti-Ra te DDS CSU/D SU for us e.
Included are initial inspection procedures, mounting instructions,
configurat ion guidelines, connection and powering information.

Safety Summary

Unpacking
and
Inspection

This manual contains information and warnings that must be
follow ed to en sure s afe ope ratio n and reta in the equip ment in a
safe condition.

This WARN ING sig n denot es a pote ntial ha zard to the

operator. It calls attention to a procedure or practice that, if
not correctly performed or adhered to, could result in injury or loss
of life. D o not pro ceed be yond a WA RNING sign unt il the
indica ted cond itio ns are full y unde rstood and met .

Caut ion: U nits ar e susce ptible t o dama ge caus ed by stati c

electricity. Use ESD (electrostatic discharge) precautionary
measures, such as wearing electrostatic grounding straps.

This un it is car efully packa ged to pr event dama ge in ship ment .
Upon receipt, inspect the shipping container for dam age. If the
shipping container or cushioning material is damaged, notify the
carrier immediately and make a notation on the delivery receipt
that the container was damaged (if possible, obtain the signature
and name of the person making delivery). Retain the packaging
material until verifying the contents of the shipment are complete
and the unit has been checked both mechanically and electrically.

If the contents of the shipment are incomplete or, if there is
mechanical damage or defect, notify Verilink. If the shipping
container is also damaged, or the cushioning material shows
signs of stress, notify the carrier of the damage as well as
Verilink . Keep the sh ippin g mate rials fo r the carr ier ’s inspecti on.
Verilink will arrange for repair or replacement without waiting
for claim settlement.

6 CHAPTER 2: INSTALLATION AND CONFIGURATION

Supplied
Materials

Wallmount Installation

The Multi-Rate DDS CSU/DSU is shipped from the factory
with the following standard equipment.

✦ external AC power supply
✦ refer ence ma nual
✦ adhesi ve st rip
✦ phone cable

Using Adhesive Strips

1 Selec t a plac e close to a 115 VAC outlet with cleara nce fo r the

signal and power cables. The indicators and switches should be
easily accessible.

2 Verify the mounting surface is clean.
3 Cut the adhesive strip to the desired length and affix the backing

of one piece to the underside of the unit.

4 Attach the other adhesive strip to the piece on the underside of

the unit.

5 Remov e the b ackin g to exp ose th e sti cky su rface.
6 Press the underside of the unit firmly against the selected place.

Using Screws

1 Selec t a plac e close to a 115 VAC outlet with cleara nce fo r the

signal and power cables. The indicators and switches should be
easily accessible.

2 Vertica lly p lace tw o #6 sc rews 3-13⁄32 inches apart at the

selected place. Leave the screws out about an eighth of an inch.

3 Place the upright unit over the screws until the holes engage and

slide t he unit do wn unt il it lock s.

Connections The Multi-Rate DDS CSU/DSU has three interface connectors:

an RJ-48C DDS network connector, a 3-pin power connector,
and an RS-232 connector.

DDS

Network

Connection

The netw or k DDS faci lity
interfa ce is a st andar d
RJ-48C (8 - pin) modular
jack with the following
pinout.

Table 2-1 DDS Network Connection

Pin Assignment

1 Network Transmit Out
2 Network Transmit Out
3 – 6 Not Used
7 Network Data In
8 Network Data In

Connect ions 7

RS-232 Port

Connection

The RS-232 connector is a standard DB -25 female, configured as
a DCE p ort.

The RS-232 pin assignments are shown in Ta ble 2-2. Only
circuits serviced by the unit are l isted. All unbalanced bipolar
inputs and outputs meet RS-232C physical and electrical
specifications. The asynchronous mode is ITU V.22 compliant.

Power Plug the connector from the power supply into the unit. Plug the

transformer into an appr opriate outlet. This applies power to the
unit.

Ta ble 2-2 Equipme nt Connec tion

Circuit RS-232 Signal Function (Note: All other pins are open.) DCE
101 1 Frame Ground - This circuit is used to terminate shields. Gnd
102 7 Signal Ground - This circuit is used as the return reference

Gnd

for unbalanced signals.

103 2 Transmit Data - This input is used for synchronous TD from

In

the DTE. It is transmitted on the DDS side.

104 3 Receive Data - This output is the data decoded from the

Out

incomi ng DDS receive data.

105 4 Request To Send - This input is a control line from the DTE

In
indicating data is to be transmitted. When RTS is On (space),
the data transmitter, the zero suppression circuitry, and the
CTS a re e n ab led. When RTS is Off, the t ra ns m itter send s id le
code and the CTS is forced Off.

106 5 Clear To Send - This output is a DCE response, indicating

Out
that either RTS is On or S1- 7, position B, is forcing CTS On.
When S1- 6 is in position B, RTS and DCD must be On for
CTS to be On.

107 6 Data Set Ready - This output is On when the unit is powered. Out
109 8 Data Carrier D etect (DCD) - This outp ut is O n when th e

Out
correct data or zero suppression code is being received and
DSR is On. It is Off when either DSR is Off, the DDS
receiver has lost sufficient signal to operate for at least one
second, or the receiver has received OOS, OOF, idle, or loop
codes for about 20 U.I.

114 15 Transmit Clock - This output is supplied by the DCE as an

Out
externa l DTE ti ming source . It is gene rated from the intern al
data clock or the far end t ransmit data.

115 17 Receive Clock - This clock output is the timing for the RD

Out
and is always used to time the receive data. This clock is
alwa ys deri ved fr om the DDS r eceiv e data.

8 CHAPTER 2: INSTALLATION AND CONFIGURATION

Configuration This section describes the configuration of the Multi-Rate DDS

CSU/DSU. This unit is configured using DIP switches shown in
Figure 2-1.

On power up, the unit configures to the hardware settings of
option switches SW1 and SW2. Changes to these settings take
effect a fter resett ing t he unit by re movi ng and then re appl ying
power. The unit then cycles through its LEDs and reads the new
configuration.

Rate
(kbps)SW1-1SW1- 2SW1-3

RTS -to-CTS
Delay (ms)

2.4 B B B 8.0

4.8 A B B 4.0

9.6 B A B 2.0

19.2 A A B 1.0

28.0 B B A 0.8

38.4 ABA0.5

56.0 B A A 0.4

64.0 AAA0.3

V.54 Loop

Enabled

B

A

Channel

Data Inverted

Bit Rate

Data Normal

V.54 Disabled

* Asynchronous data

does not function at
28, 56, and 64 kbps.

Figure 2-1 Multi-Rate DDS CSU/DSU Configuration

Circuit Assurance On

Circuit Assurance Off

Bits SW2-2 SW2-3

8A B
9B B
10 A A
11 B A

CTS Forced On

RTS -t o- C T S De l a y ×2

867

CTS Normal

Synchronous Data Asynchronous Data*

RTS- to - CTS Delay Normal

Extended Range

(−2.5 to 2.3%)

not used

not used

not used

254313142

5867

Async

Word

Length

not used

not used

not used

Basic Range

(−2.5 to 1.0%)

The symbol indicates that the
switch point ed to doe s not fu nction
unless the opposite end of the arrow
is in the position shown. For
example, SW1-8 functions only
when SW1-7 is in the A position.

not used

not used

Configur ation 9

SW1 and SW2 are two 8 - position DIP switches located on the
side of the unit. These switches provide the following
configuration parameters.

Network Bit

Rate Select

Positions SW1 -1, SW1-2, and SW1-3 are used to set the
network bit rate. Refer to the table shown in the upper left of
Figure 2-1 to de termi ne the sw itch se tting s for a par ticula r bit
rate. RTS - to - CTS delays double when position SW1 - 8 is in the
B positi on.

V.54 Loop

Position SW1-4 is used to enable or disable V.54 loop operation.

Operation

A - Disabled B - Enabled

Data Polarity SW1- 5 is us ed to de termin e whe ther data bits ar e inver ted. In

the A position, marks equal pulses. In the B position, spaces
equal pulses. Receipt of OOF, OOS, idle, or loop codes forces
the DSU dat a to all marks (A position) or spaces (B position).

A - Norma l B - Inver ted

Circuit

Assurance

When SW1- 6 is in position B, the status of CF (receive line
signal det ector) and CA (request to send) controls the output CB
(clear to send). If either CA or CF is Off, CB is Off. If CA and
CF are On, CB is On.

A - Off B - On

CTS Control When SW 1 - 7 is in pos ition B, C TS is for ced On re gard less of

the RTS input status. In the A position, the delays are determined
by SW1- 8.

RTS -to-CTS

Delay

Synchronous/

Asynchronous

Data

A - CTS normal B - CTS forced On

When SW 1 -8 is in th e A posit ion, th e RTS - to -CT S dela y is as
shown in the table shown in the upper left of Figure 2-1. In the
B position, the delays double.

A - The normal Delay B - Twice the normal delay

When SW2-1 is in the A position, the unit operates in
Synchronous mode. This switch must be in position B for
switches SW 2 -2 and SW2 - 3 to function. When in position B,
the unit operates in Asynchronous mode. In Asynchronous mode,
data functions at 2.4, 4.8, 9.6, 19.2, and 38.4 kbps.

A - Synchronous B - Asynchronous

10 CHAPTER 2: INSTALLATION AND CONFIGURATION

Asynchronous

Word Length

Switches SW2-2 and SW2- 3 are set to match the number of bits
that make in each word of the asynchronous data. Refer to the
table shown in the upper right of Figure 2-1.

Signalling

Rate Range

Switch SW2-4 is set to match the ranges provided by the service
provider.

A - Basic (−2.5 to 1.0%) B - Basic (−2.5 t o 2.3 %)

Not Used Switches S2-5, S2- 6, S2 -7, and S2- 8 are not used.

ESTING

T

3

Introduction This chapter describes the diagnostic and test features of the

Verilink Multi-Rate DDS CSU/DSU. The unit is controlled
manually using DIP switches (the DIP switches are discussed on
page 8). The indicators are described below.

Indicators The unit indicators show major alarm conditions, power, and

loop status.

Network This three- color indicator shows the receiver’s operating status.

Green indicates a signal at the receiver (either customer data or
zero suppression). Amber indicates signal is present, but received
data is id le or ou t of ser vice. Re d indic ates an insuff icient si gnal
for the receiver to operate properly.

Tx Data This three- color indicator shows the status of the transmitted

data. Green indi cates marks. Red indicates spaces. Amber
indicates alternate marks and spaces.

Rx Data This three- color indicator shows the status of the received data.

Green indicates marks. Red indicates spaces. Amber indicates
alternate marks and spaces.

Loop Test This indicator show the loop status of the unit. Amber indicates

the unit i s in loop mode. When the indicator is Off, the unit i s
not in loopback.

Loopbacks This section describes loops that can be initi ated on the

Multi-Rate DDS CSU/DSU.

Channel

Loop

This loop (shown in Figure 3-1) is activated by the reversal of
the simplex, 20 mA sealing current. This is a unidirectional loop
that ign ores th e DSU tr ansm it data and retra nsmi ts the re ceive d
DDS data. Receive data is unaffected and circuit CF is forced
Off.

DTE

Figure 3-1 Chann el Loop (M andat ory Loop )

NET

12 CHAPTER 3: TESTING

Data

Set

Loop

(Non-latching)

V.54

Channel

Loop

This loop (shown in Figure 3-2) is activated by the receipt of at
least four consecutive loop commands and remains looped as
long as eac h th ird p atte rn b yte is th e lo op co mma nd. It retu rns to
normal operation after at least four pattern bytes that are not the
loop command. This is a unidirectional loop that retransmits the
DSU received data on the DSU transmit data. Receive data is
unaffected and circuit CF is Off.

DTE

Figure3-2 Remote Channel Loop (V.54) and Data Set Loop

NET

This loop i s activated by the receipt of the V.54 loop command.
This loop is unidirectional and returns the DSU receive data to
the DSU tr ansm it data , and sub seque ntly the DDS tran smit data.
Receive data is unaffected.

Five-Year Har dwa re Limited Warranty

I. Limited Warranty. Subject to the limitations and disclaimers set forth in this Hardware Limited Warranty, Verilink warrants to the original pur-

chaser (“Buyer”) that the Verilink equipment and compon ent parts (“Goods”) purchased by Buyer shall be free from defects in material and
workmanship under normal use and service for a period of five years from the date of shipment of the Goods to Buyer (“Limited Warranty”).
Verilink’s so le obligation and Buyer’s sole remedy under t his Limited Warranty shall be to re pair or replace any Verilink Good s t ha t Verilink
determines to be so defective. Any claim by Buyer under this Limited Warranty must be presented to Verilink in writing within five years and
fifteen (15) days of the date of shipment of the Goods to Buyer, as evidenced by Verilink’s packing slip or similar shipment documentation from
a Verilink authorized reseller. Any replacement Goods may be new or reconditioned. Verilink reserves the right to substitute equiva lent Goods
for defective Goods, in its sole discretion. As long as Verilink either so repairs or replaces the Goods, this Limited Wa rranty will not be found
to have failed its es s ential purpose. If th e defect has been caused by accident, misuse or abnormal operating conditions (including lightning
damage) occur r ing after delivery to Buyer, repairs and/or replacement wil l be made at Buyer’s expense. In su ch event, an estimate of cost will
be submitted to Buyer before repair work is started. The Limited W arranty will continue to apply to replaced or repaired Goods for whichever
is longe r: the 90-day period a fter the shipme nt of such Goods to Buyer or the remainder of the original Limited Warranty period.

II. EXCLUSION OF IMPLIED WARRANTIES OR OTHER REPRESENTATION

OUT ANY WARRANTY OR GUARANTEE OF ANY KIND OTHER THAN THE LIMITED WARRANTY SET FORTH ABOVE, WHICH
IS MADE EXPRESSLY IN LIEU OF ALL OTHER WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AND VERILINK HEREBY
DISCLAIMS ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, NONINFRINGE­MENT, AND ALL OTHER IMPLIED WARRANTIES ON THE PART OF VERILINK. VERILINK DOES NOT WARRANT THAT THE
BUYER'S USE OF THE GOODS WILL BE UNINTERRUPTED, SECURE, OR ERROR-FREE. Buyer agrees that no oral or written repre­sentation, advice, advertisement or other statement by Verilink, its reseller, agent, employee, or representative constitutes any warranty, guaran­tee or modification of the foregoing disclaimer and Lim ited Warranty, and Buyer ackno w ledges that no pe rson, including resellers, agents,
employees , or r e pr esentatives of Verilink, is authorized to assume for Verilink any other liability on its be half except as set forth in this para­graph.

III. LIMITATION ON LIABILITY

LIABLE FOR SPECIAL, CONSEQUENTIAL, EXEMPLARY, INCIDENTAL, OR PUNITIVE DAMAGES (INCLUDING, WITHOUT
LIMITATION, DAMAGES FOR LOSS OF PROFITS, BUSINESS INTERRUPTION, DATA LOSS, DAMAGE TO EQUIPMENT, OR THE
LIKE), REGARDLESS OF WHETHER THE CLAIM IS BASED ON BREACH OF W ARRANTY, BREACH OF CONTRACT, STRICT
LIABILITY, OR OTHER LEGAL THEORY, EVEN IF VERILINK OR ITS AGENT WAS ADVISED OF THE POSSIBILITY OF SUCH
DAMAGES. IN NO EVENT WILL VERILINK’S LIABILITY TO BUYER OR ANY SUCCESSOR TO BUYER EXCEED THE PRICE
PAID FOR THE APPLICABLE GOODS.

IV. LIMITED WARRANTY CONDITIONS

outside Verilink’s factory, unless Verilink specifically authorized such repairs or alterations; (ii) in the event parts not made or recommended by
Verilink are used by Buyer in the Goods; or ( ii i) if the Goods are used by Buyer ot her than in the manner intended by Verilink or other than in
conformance with operating instructions and specifications provided by Verilink.

V. MODIFICATIONS BY VERILINK

hereby, as mutually agreed upon by Verilink and Buyer, shall not be deemed to constitute a breach of the Limited Warranty. Verilink also
reserves the right to discontinue Goods and change specifications for Goods without notice, pr ovided such changes do not adversely affect the
performance of the Goods manufactured by Verilink or do not reduce perfor mance below any applicable contr act specifications between Ver­ilink and the Buyer. Verilink also reserves the right to make product improvements without incurring any obligations or liability to make the
same changes in Goods previously manufactured or purchased . Non-pay ment of any invoice r e ndered within the stated payment terms automat­ically suspends the application of, but not the running of, the Limited Warranty for the duration of the non-payment.

. IN NO EVENT SHALL VERILINK, ITS OFFICERS, DIRECTORS, EMPLOYEES, OR SUPPLIERS BE

. The Limited W arranty shall be void (i) with respect to any Goods that have been repaired or altered

. Minor deviations from specifications that do not materially affect performance of the Goods covered

. THE GOODS ARE SOLD BY VERILINK “AS IS” WITH-

VI. AMENDMENT OF WARRANTY TERMS

time to time in its sole discretion. The terms and conditions in effect at the time of purchase will apply to such Goods.

VII. RETURN OF GOODS

packaged to t he bes t commercial standard for electronic equipmen t. Verilink will pay shipping charges for delivery on retu rn. The Buyer is
responsible for mode and cost of shipment to Verilink. The Buyer must have a Return Material Authorization (RMA) number marked on the
shipping package. Products sent to Verilink without RMA numbers will be returned to the sender, unopened, at the sender’s expense. A product
sent directly to Verilink for repair must first be assigned an RMA number. The Buyer may obtain an RMA number by calling the Verilink Cus­tomer Service Center at 1.800.926.0085, extension 2282 or 2322 . Whe n calling Verilink for an RMA, the Buyer should have the followin g
information available:

• Model number and serial number for each unit

• Reason for return and symptoms of problem

• Purchase order number to cover charges for out-of-warranty items

• Name and phone number of person to cont act if Verilink has questions about the unit (s).

A return addres s will be provi d ed at the time t he RMA number is is sued. Th e standar d deliver y metho d for retur n shipme nt s is Stan dar d Ground
for domestic returns and International Economy for international returns (unless otherwise specified).

VIII. GOVERNING LAW

sions. The provisions of the UN Convention on Contracts for the International Sale of Goods shall not apply.

. If for any reason the Buyer must return a Verilink product, it must be returned to the factory, shipping prepaid, and

. This Agreement is governed by the la ws of the State of Ala bama, U.S.A., without reference t o its conflicts of law provi-

. These te r m s and co nditions of this Hardwa r e Li m ited Warranty ma y be r ev i sed by Ve r i link from