Paradyne 7511 User manual

MODEL 7511
DUAL DSU
USER’S GUIDE
Document No. 7511-A2-GB20-00
June 1997

Printed on recycled paper
A 7511-A2-GB20-00
June 1997
Copyright 1997 Paradyne Corporation.
All rights reserved.
Printed in U.S.A.
Notice
This publication is protected by federal copyright law. No part of this publication may be copied or distributed,
transmitted, transcribed, stored in a retrieval system, or translated into any human or computer language in any form
or by any means, electronic, mechanical, magnetic, manual or otherwise, or disclosed to third parties without the
express written permission of Paradyne Corporation, 8545 126th Avenue North, P.O. Box 2826, Largo,
Florida 33779-2826.
Paradyne Corporation makes no representation or warranties with respect to the contents hereof and specifically
disclaims any implied warranties of merchantability or fitness for a particular purpose. Further, Paradyne Corporation
reserves the right to revise this publication and to make changes from time to time in the contents hereof without
obligation of Paradyne Corporation to notify any person of such revision or changes.
Changes and enhancements to the product and to the information herein will be documented and issued as a new
release to this manual.
Trademarks
All products and services mentioned herein are the trademarks, service marks, registered trademarks or registered
service marks of their respective owners.
Warranty, Sales, and Service Information
Contact your sales or service representative directly for any help needed. For additional information concerning
warranty, service, repair, spare parts, installation, documentation, or training, use one of the following methods:
Via the Internet: Visit the Paradyne World Wide Web site at http://www.paradyne.com
Via Telephone: Call our automated call system to receive current information via fax or to speak with a
company representative.
— Within the U.S.A., call 1-800-870-2221
— International, call 727-530-2340

i
7511-A2-GB20-00 June 1997
Contents
About This Guide
Document Purpose and Intended Audience iii. . . . . . . . . . . . . . . . . . . . . . . . .
Document Summary iii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Product-Related Documents iv. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1About the Dual DSU
Model 7511 Dual DSU Features 1-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DSU Configurations 1-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2Configuring and Installing the DSUs
Configuring the Dual DSU 2-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installing the Rear Connector Plate 2-7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installing the DSU Card 2-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installing the Network and DTE Cables 2-10. . . . . . . . . . . . . . . . . . . . . . . . . . . .
3Monitoring the DSUs
Selecting a DSU 3-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Front Panel LEDs 3-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Initialization 3-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
LED Groups 3-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Status LEDs 3-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Network LEDs 3-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DSU Selection LEDs 3-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Test 3-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Port 3-6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4Testing
Selecting a DSU 4-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Local Loopback 4-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CSU or External Network Loopback 4-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Digital Loopback (DL) and Remote Loopback (RL) 4-3. . . . . . . . . . . . . . . . . .
Ending an Active Test 4-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Contents
ii 7511-A2-GB20-00
June 1997
5Troubleshooting
Troubleshooting 5-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ACables and Pin Assignments
Overview A-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
RJ48T 50-Pin Network Interface Connector A-1. . . . . . . . . . . . . . . . . . . . . . . . .
Digital Network (DDS) Connector A-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
V.35 DTE Connector A-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
BTechnical Specifications
Glossary
Index

iii
7511-A2-GB20-00 June 1997
About This Guide
Document Purpose and Intended Audience
This guide contains information needed to set up, configure, and operate the
Model 7511 DSU and is intended for installers and operators.
Document Summary
Section Description
Chapter 1 About the Dual DSU. Describes the DSU features and
shows examples of typical configurations.
Chapter 2
Configuring and Installing the DSUs. Provides procedures
for setting up and installing the DSU card.
Chapter 3
Monitoring the DSUs. Describes monitoring details about
the LEDs, DSU status, and network statistics.
Chapter 4
Testing. Provides details about available tests and test
setup.
Chapter 5
Troubleshooting. Provides information on device
troubleshooting.
Appendix A
Cables and Pin Assignments. Contains connector and
interface details.
Appendix B
Technical Specifications. Contains physical and regulatory
specifications of the DSU.
Glossary Defines acronyms and terms used in this document.
Index Lists key terms, acronyms, concepts, and sections in
alphabetical order.

About This Guide
iv 7511-A2-GB20-00
June 1997
Product-Related Documents
Document Number Document Title
3000-A2-GA31 COMSPHERE 3000 Series Carrier
Installation Manual
3000-A2-GZ47 Network Interface Cable, Network Interface Module
Installation
7511-A2-GN10 Model 7511 Dual DSU Startup Instructions
To order additional product documentation, refer to Warranty, Sales, and Service
Information
on page A at the beginning of this User’s Guide.

1-1
7511-A2-GB20-00 June 1997
About the Dual DSU 1
Model 7511 Dual DSU Features
The DSU provides an interface between the customer premises equipment (CPE)
and a Digital Data Service (DDS) network.
The DSU’s features and capabilities include:
Two DSUs on one card. Permits up to 32 DSUs in one 3000 Series carrier.
Easy Installation. Connects to your equipment using standard connectors
and cables.
Easy Configuration. Simple hardware strapping minimizes your
customization effort.
DDS Operation. Operates at 56 and 64 kbps CC (clear channel).
Local Area Data Set (LADS) Operation. Operates at 56 and 64 kbps
full-duplex as a limited-distance modem.
Diagnostics. Lets you diagnose device and network problems with digital
loopbacks and pattern tests.
Interoperability. Line-compatible with Model 3510, 3511, 3550, 3551, 3610,
3611, 3615, 3616, 7510, 7610 and 7612 DSUs on the DDS Primary Channel.
Reliability. The 7511 Dual DSU’s Mean Time Between Failures (MTBF) is
over 30 years.

About the Dual DSU
1-2 7511-A2-GB20-00
June 1997
DSU Configurations
As shown in the following illustration, each DSU can be used in a multipoint
network configuration across a DDS network.
DDS
Network
97-1550
0
DTE
DSU
DSU
DTE
DTE
Model 7511 DSU
in 3000 Series Carrier
DSUs can also be used for point-to-point DDS or frame relay applications.
Frame
Relay
Network
97-1536
2
DTE
DTE
DSU
DSU
DTE
DTE
Model 7511 DSU
in 3000 Series Carrier
DSUs can be connected back-to-back to act as Local Area Data Sets. Table B-2
in Appendix B shows the maximum distances for LADS applications.
97-15364
DSU
DTE
DSU
DTE
DTE
Model 7511 DSU
in 3000 Series Carrier
56 or 64 Kbps
DTE 56 or 64 Kbps

2-1
7511-A2-GB20-00 June 1997
Configuring and Installing
the DSUs 2
Configuring the Dual DSU
!HANDLING PRECAUTIONS FOR
STATIC-SENSITIVE DEVICES
The Model 7511 Dual DSU is designed to protect sensitive components
from damage due to electrostatic discharge (ESD) during normal
operation. When performing installation procedures, however, take
proper static control precautions to prevent damage to equipment. If
you are not sure of the proper static control precautions, contact your
nearest sales or service representative.
Procedure
To configure the Model 7511 Dual DSU:
1. Review Table 2-1 to determine the proper settings for your environment.
The first choice for each option (shown in boldface type) is the factory
default setting. If you choose the factory default value, you do not need to
change the position of the associated switch.
The factory default setting for all switches is Off.
2. Mark any options in the table that you wish to differ from the factory default.
3. Using Figure 2-1 and Table 2-1, verify that the switch settings for both DSUs
on the 7511 card match your selections.
Do not modify the settings of switches not listed in the table. Any switch
not designated for customer use should be in the Off position.
4. Where required, verify that the local and remote DSUs employ the same
options. For example, both the local and remote DSU must use the same
Line Rate and 64CC Data Scrambler settings.
496-15104

Configuring and Installing the DSUs
2-2 7511-A2-GB20-00
June 1997
S1
97-15396
12345678
ON
12345678
ON
12345678
ON
12345678
ON
12345678
ON
S2
S3 S4
S5
Figure 2-1. Model 7511 Switch Locations
Table 2-1. Configuration Options (1 of 5)
Switch Options and Usage Default in Bold
Line Rate
S1-1 (DSU A)
S3-1 (DSU B)
S1 S2
S3 S4
DSU A
DSU B
ON ON
ON ON
DDS or LADS line rate.
Off 56 kbps
The line rate is 56 kbps.
ON 64 kbps
LADS: The line rate is 64 kbps.
DDS: The line rate is 64 kbps clear channel.

Configuring and Installing the DSUs
2-3
7511-A2-GB20-00 June 1997
Table 2-1. Configuration Options (2 of 5)
Switch Options and Usage Default in Bold
TX Timing Source
S1-2 & S1-3 (DSU A)
S3-2 & S3-3 (DSU B)
S1 S2
S3 S4
DSU A
DSU B
ON ON
ON ON
The timing source for the DSU.
Off Off DDS
For DDS, both switches must be Off.
For LADS:
Off ON Receive
Receive means timing is derived from the line receive signal.
ON Off Internal
Internal means timing is provided by the unit’s internal clock.
ON ON External
External means timing is provided by the DTE.
Ten-Minute Test
Abort Timer
S1-4 (DSU A)
S3-4 (DSU B)
S1 S2
S3 S4
DSU A
DSU B
ON ON
ON ON
Determines whether user-initiated tests automatically terminate after
10 minutes.
Off Enable
Tests terminate automatically after 10 minutes.
ON Disable
Tests run indefinitely.
Network-Initiated
DSU Loopback
S1-5 (DSU A)
S3-5 (DSU B)
S1 S2
S3 S4
DSU A
DSU B
ON ON
ON ON
Determines whether the DSU responds to DSU latching loopback start
and stop sequences sent by the network. This option is applicable only
if the DDS line rate is 64 kbps clear channel.
Off Enable
The DSU responds to loopback sequences.
ON Disable
The DSU ignores loopback sequences.

Configuring and Installing the DSUs
2-4 7511-A2-GB20-00
June 1997
Table 2-1. Configuration Options (3 of 5)
Switch Options and Usage Default in Bold
64CC Data Scrambler
S1-6 (DSU A)
S3-6 (DSU B)
S1 S2
S3 S4
DSU A
DSU B
ON ON
ON ON
Determines whether the DSU scrambles data to minimize the possibility
of the remote DSU falsely recognizing a loopback command.
Off Disable
Data scrambling is disabled.
ON Enable
Data scrambling is enabled.
V.54 Sequence
Detection
S1-7 (DSU A)
S3-7 (DSU B)
S1 S2
S3 S4
DSU A
DSU B
ON ON
ON ON
Determines whether the DSU responds to V.54 Loop Up and Loop
Down sequences from the remote DSU.
Off Disable
V.54 loop sequences are ignored.
ON Enable
The DSU responds to V.54 loop sequences.
Invert
TX Clock
S1-8 (DSU A)
S3-8 (DSU B)
S1 S2
S3 S4
DSU A
DSU B
ON ON
ON ON
Determines whether the DSU clock provided on interchange circuit
CT114 (TXC) is phase-inverted with respect to interchange circuit
CT103 (TXD). This can reduce errors encountered due to excessive
cable lengths.
Off Normal
TXC is not inverted.
ON Invert
TXC is inverted with respect to TXD.

Configuring and Installing the DSUs
2-5
7511-A2-GB20-00 June 1997
Table 2-1. Configuration Options (4 of 5)
Switch Options and Usage Default in Bold
CTS
S2-1 & S2-2 (DSU A)
S4-1 & S4-2 (DSU B)
S1 S2
S3 S4
DSU A
DSU B
ON ON
ON ON
Determines the operation of interchange circuit CT106, Clear to Send
(CTS).
Off Off Standard
CTS follows RTS with a fixed delay except when an alarm is detected
or a test is active, when CTS is turned off.
Off ON Circuit Assurance
Same as standard, but CTS is also turned off when Carrier Mode Idle
codes are received.
ON Off Follow RTS
CTS follows RTS without delay, regardless of alarms and tests.
ON ON Forced On
CTS is forced on after a successful self-test.
RTS
S2-3 (DSU A)
S4-3 (DSU B)
S1 S2
S3 S4
DSU A
DSU B
ON ON
ON ON
Determines the operation of interchange circuit CT105, Request to
Send (RTS).
Off Constant
The internal RTS is forced on and the DSU is in a constant data mode.
The transmitted signal is either Data Mode Idle codes or DTE data.
ON Switched
RTS is monitored, and Carrier Mode Idle codes are transmitted when
RTS is off.
LSD
S2-4 (DSU A)
S4-4 (DSU B)
S1 S2
S3 S4
DSU A
DSU B
ON ON
ON ON
Determines the operation of interchange circuit CT109, Line Signal
Detect (LSD).
Off Standard
LSD is on when the receive line is in data mode, and off when an alarm
is detected or Carrier Mode Idle codes are received.
ON Forced On
LSD is forced on after a successful self-test.

Configuring and Installing the DSUs
2-6 7511-A2-GB20-00
June 1997
Table 2-1. Configuration Options (5 of 5)
Switch Options and Usage Default in Bold
DSR
S2-5 (DSU A)
S4-5 (DSU B)
S1 S2
S3 S4
DSU A
DSU B
ON ON
ON ON
Determines the operation of interchange circuit CT107, Data Set Ready
(DSR).
Off Standard
DSR is always on, except when an alarm is detected or a test is active.
ON Forced On
DSR is forced on after a successful self-test.
511 Test
Pattern
Generation
and
Monitoring
S2-6 (DSU A)
S4-6 (DSU B)
S1 S2
S3 S4
DSU A
DSU B
ON ON
ON ON
Determines whether the DSU will generate and monitor a 511 test
pattern in remote loopback tests.
Off Enable
A 511 pattern is generated and monitored during the remote loopback
test.
ON Disable
A 511 pattern is not generated. External test equipment is required to
perform a Bit Error Rate test.
CT141
S5-1 (DSU A)
S5-3 (DSU B)
S5
DSU A
DSU B
ON Determines whether a local digital loopback can be controlled by the
DTE using interchange circuit CT141, Local Loopback (LL). If enabled,
the DTE port remains in loopback while LL is on.
Off Disable
The DSU will not initiate the loopback on command from the DTE.
ON Enable
The DSU initiates the loopback.
CT140
S5-2 (DSU A)
S5-4 (DSU B)
S5
DSU A
DSU B
ON
Determines whether a remote digital loopback can be controlled by the
DTE using interchange circuit CT140, Remote Loopback (RL). If
enabled, the remote DSU must be able to detect the in-band V.54
loopback sequence.
Off Disable
The DSU will not initiate the loopback on command from the DTE.
ON Enable
The DSU initiates the loopback.

Configuring and Installing the DSUs
2-7
7511-A2-GB20-00 June 1997
Installing the Rear Connector Plate
Procedure
To install the rear connector plate:
1. At the rear of the carrier, place the tab on the connector plate in its slot in the
carrier’s backplane. The connector plate must use the same slot position
intended for the DSU card.
2. Loosely fasten the screw, allowing for a slight adjustment when installing the
DSU card.
97-15484
V.35 V.35
25-Pin
DTE Connectors
P21

Configuring and Installing the DSUs
2-8 7511-A2-GB20-00
June 1997
Installing the DSU Card
Procedure
To install the DSU card:
1. Using a Phillips screwdriver, loosen the screw holding the circuit pack lock.
Rotate the lock to the open position and open the latch.
Circuit
Card
Guides
Circuit
Pack
Lock
Latch
Open
(Unlocked)
Closed
(Locked)
495-14813
2. At the front of the carrier, hold the circuit card vertically with the latch on its
faceplate in the open position. Then insert the circuit card into the top and
bottom circuit card guides.

Configuring and Installing the DSUs
2-9
7511-A2-GB20-00 June 1997
495-1479
7
3. Slide the circuit card into the slot and press until the connectors are seated
firmly into the back of the carrier.
4. Press the faceplate latch to secure the circuit card.
5. Rotate the circuit pack lock into the closed position, and tighten the screw.
6. If power is applied to the carrier:
— All LEDs momentarily light up, then the OK and Test LEDs remain on
during a self-test.
— If the hardware passes the self-test, the Test LED turns off and the OK
LED remains on.
7. Return to the rear of the carrier and tighten the screw on the rear connector
plate.

Configuring and Installing the DSUs
2-10 7511-A2-GB20-00
June 1997
Installing the Network and DTE Cables
Procedure
To install the cables:
1. Note the location of the 7511 Dual DSU circuit cards in the carrier (slots 1–8,
slots 9–16, or all slots).
2. Connect network cables to the appropriate Network Interface Module (NIM)
and backplane connector according to the following table.
Facing the rear of the carrier, connect a 50-pin network cable to . . .
The NIM on the left side for DSU As on
7511 cards in slots 9–16. The NIM on the right side for DSU As on 7511 cards in slots 1–8.
Connector P22 for DSU Bs on 7511
cards in slots 9–16. Connector P21 for DSU Bs of 7511 cards in slots 1–8.
3. Connect a DTE cable to each of the V.35 connectors on the rear connector
plates. Connect the other end of each cable to its respective DTE interface.
The top V.35 connector of each rear connector plate is for DSU A on the 7511
card in that slot. The bottom V.35 connector is for DSU B.
97-15548
P26 P25
P22 P21
Slots 1  8
DSU A
Slots 9  16
DSU B
DSU A
DSU B
DSU A
DSU B
DSU A
DSU B
RJ48T RJ48T

3-1
7511-A2-GB20-00 June 1997
Monitoring the DSUs 3
Selecting a DSU
The 7511 comprises two DSUs, designated DSU A and DSU B. The DSU A and
DSU B LEDs designate which DSU is selected. To select the other DSU for
monitoring or testing, press the A/B switch on the faceplate.
Front Panel LEDs
The network activity and the status of the DSUs are reflected in the faceplate’s
light-emitting diodes (LEDs).
Initialization
When the card first receives power, a self-test begins and the LEDs exhibit the
following behavior:
1. All LEDs except A Alarm and B Alarm are initialized to off.
2. All LEDS turn on momentarily.
3. All LEDs turn off momentarily.
4. The Alarm and OK LEDs are turned off or on depending on the test results.
LED Groups
The LEDs can be divided into five logical groups:
Status
Network
DSU selection
Test
Port

Red
Green
Yellow
97-15357
LL
DL
RL
TXD
RXD
RTS
CTS
DTR
OK
Alrm
Alrm
NS
OOS
DSU
Status
7511
103
104
105
106
108
A
B
A
B
DSU
A/B
DSU
Test
Mode
OK:
ON – The 7511 is operational.
OFF – The 7511 is performing a power-on self-test (POST)
or has detected a system failure.
DSU A Alarm:
ON – One of the following occurred: POST Failure, No DDS
Signal, Out of Service, Out of Frame, crossed-pair
detected, or bit errors detected during loopback test.
OFF – No alarm condition has been detected on DSU A.
DSU B Alarm:
ON – One of the following occurred: POST Failure, No DDS
Signal, Out of Service, Out of Frame, crossed-pair
detected, or bit errors detected during loopback test.
OFF – No alarm condition has been detected on DSU B.
Monitoring the DSUs
3-2 7511-A2-GB20-00
June 1997
Status LEDs
The status LEDs show the general state of the 7511 card and its DSUs.