Paradyne 7520 User manual

TM
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7520-A2-GN10-10 December 1998
Model 7520 DSU
Startup Instructions
Document Number 7520-A2-GN10-10
December 1998
Product Documentation on the World Wide Web
We provide complete product documentation online. This lets you search the
documentation for specific topics and print only what you need, reducing the
waste of surplus printing. It also helps us maintain competitive prices for our
products.
Complete documentation for this product is available at www.paradyne.com.
Select Service & Support → Technical Manuals → Subrate Digital Access
Devices.
Select the following document:
7520-A2-GB20
Model 7520 DSU User’s Guide
To request a paper copy of a Paradyne document:
Within the U.S.A., call 1-800-PARADYNE (1-800-727-2396)
Outside the U.S.A., call 1-727-530-8623
Package Checklist
Verify that your package contains the following:
A Model 7520 Single Port DSU
Power cord with power transformer
RJ48S modular cable for U.S. network access (14)
No DTE cables are provided. Additional cables may need to be ordered.

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December 1998
Cables and Equipment You May Need to Order
If connecting . . . Order a . . .
A VT100-compatible terminal
to the Terminal port Standard straight-through EIA-232 cable with DB25 plug connectors on both ends.
A PC to the Terminal port Standard straight-through EIA-232 cable with a DB25
plug connector on one end and a DB9 socket
connector on the other end.
An External Modem to the
Terminal port Standard crossover EIA-232 cable with DB25 plug connectors on both ends.
A DTE with a V.35 connector
to the 34-pin DTE port V.35 cable with an MS34 plug connector on one end and an MS34 socket connector on the other end.
A DTE with a DB25 connector
to the 25-pin DTE port Standard straight-through EIA-232 cable with DB25 plug connectors on both ends.
Contact your sales or service representative to order these cables. For details,
refer to Appendix C, Cables and Pin Assignments, in the User’s Guide.
Site Preparation
Before installation, read the Important Safety Instructions on page 15.
Make sure you have:
A dedicated, grounded ac outlet that is protected by a circuit breaker within
6 feet of the access unit.
A clean, well-lit, and ventilated site that is free from environmental extremes.
One to two feet of clearance for cable connections.
An operable network connection.
An asynchronous terminal or PC with terminal emulation software.

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7520-A2-GN10-10 December 1998
Installing Your DSU
97-15781
RJ48S
Jack
NETWORK
TERMINAL MANAGEMENT
POWER
D
T
E
DTE
EIA-232
Terminal
Connection
AC Adapter
Network
Connection
DTE
Connection
or V.35

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December 1998
Installing the Power Cord
CAUTION:
Use no power supply except the one provided with the DSU. Using the
wrong power supply can destroy the DSU.
Procedure
1. Insert the power plug into the POWER jack.
2. Plug the power transformer into an ac outlet.
D
T
E
TERMINAL DTE NETWORK
POWER
97-15782
Power
Jack
Connecting the Terminal Port to an Async Terminal
Procedure
1. Insert the 25-pin end of the EIA-232 cable into the TERMINAL port.
2. Insert the other end of the cable into the VT100-compatible terminal.
3. Press Return on the keyboard to display the Main Menu.
D
T
E
TERMINAL DTE NETWORK
POWER
97-15783
To Connect to a PC
or Async Terminal
Terminal
Port

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7520-A2-GN10-10 December 1998
NOTE:
Communications parameters on the Terminal port are 9.6 kbps, 8 bits per
character, one stop bit, and no parity.
Connecting to a DTE
Procedure
1. Insert one end of a 34-pin V.35 cable into the MS34 DTE port
– or –
insert one end of 25-pin EIA-232 cable into the DB25 DTE port.
2. Insert the other end of the cable into the appropriate connector on your DTE.
D
T
E
TERMINAL DTE NETWORK
POWER
97-15784
DTE
DTE Port
or
Connecting to the Network
Procedure
1. Insert the 8-pin connector on the RJ48S network cable into the NETWORK
jack.
2. Insert the other end of the cable into the RJ48S modular jack.
D
T
E
TERMINAL DTE NETWORK
POWER
97-15785
RJ48S
Jack
Network
Interface

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December 1998
Hardware Verification
Verify that the OK LED lights up.
Verify that the ALARM LED is off.
97-15786
NetworkSystem Port
CTS (106) OK ALARM TEST DM OOS OOF NS TXD (103) RXD (104) RTS (105) DTR (108)
7520 DSU
Verify that the User Interface Idle screen is displayed on the terminal or PC.
Press the Enter key. Verify that the Main Menu appears.
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main
Device Name: Model: 7520
MAIN MENU
Status
Test
Configuration
Control
––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––
Ctrl-a to access these functions Exit
If the DSU fails to respond as described, refer to Chapter 6, Messages and
Troubleshooting , in the User’s Guide.

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7520-A2-GN10-10 December 1998
Identifying the Device and System
Use the Device Name screen to determine the name that will be displayed at the
top of all ATI screens, and system information that will be displayed on the
Identity screen. To access the Device Name screen, follow this menu selection
sequence:
Main Menu → Control → Device Name
main/control/device name
Device Name: Node A Model: 7520
DEVICE NAME
Device Name: Node A Clear
System Name: ________________________________________ Clear
System Location: ________________________________________ Clear
System Contact: ________________________________________ Clear
––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––
Ctrl-a to access these functions, ESC for previous menu MainMenu Exit
Save
Î
Î
ÎÎ
ÎÎ
Fields on the Device Name screen are null until you enter values. Allowable
values are any printable ASCII character.
Saving Configuration Options
When changes are made to the configuration options, the changes must be
saved to take effect. Use the Save key or Save Configuration screen.
Procedure
To save configuration options changes:
1. Press Ctrl-a to switch to the screen function key area below the dotted line.
2. Select Save and press Enter. The Save Configuration To screen appears.
3. Select Current Configuration and press Enter. (Current Configuration is the
only option. The factory default configuration cannot be altered.)
Configuring the DSU
Configuration option settings determine how the DSU operates. Use the DSU’s
Configuration branch to display or change configuration option settings.
The DSU is shipped with factory settings in the Default Factory configuration
area. The defaults are shown in the configuration options tables.

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December 1998
Accessing and Displaying Configuration Options
To display the configuration options, you must first copy one configuration option
set into the edit area.
Procedure
To load a configuration option set into the configuration edit area:
1. Follow this menu selection sequence:
Main Menu → Configuration (Load Configuration From)
2. Select Current Configuration or Default Factory Configuration. Press Enter.
The selected configuration option set is loaded and the Configuration
Edit/Display menu screen appears.
Configuration
Edit/Display
• System
• Network
• Data Port
• Terminal Port
MAIN MENU
Status
Test
Configuration
Control
497-15239
Load
Configuration
From ...
System Options Menu
For System Options, refer to Table 1. To access the System Options screen,
follow this menu selection sequence:
Main Menu → Configuration (Load Configuration From) →
Configuration Edit/Display → System
Table 1. System Options (1 of 2)
Operating Mode
Possible Settings: DDS,LADS
Default Setting: DDS
Determines the unit’s operating mode. The choice depends on the DSU’s application.
DDS – Standard DDS network operation.
LADS – The Local Area Data Set operating mode requires that the local and remote
units are connected directly to each other. This is a point-to-point application; also
known as LDM.

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7520-A2-GN10-10 December 1998
Table 1. System Options (2 of 2)
DDS Line Rate (Kbps)
Possible Settings: 2.4, 4.8, 9.6, 19.2, 38.4, 56, 64CC
Default Setting: 9.6
Sets the line speed for the DDS line.
DDS Line Rate (Kbps) option appears when Operating Mode is set to DDS.
2.4 to 56 – 2.4 to 56 kbps line rate.
64CC – 64 kbps Clear Channel on a 72 kbps circuit.
LADS Timing
Possible Settings: Internal, External, Receive
Default Setting: Internal
Determines the timing source for the unit.
LADS Timing option appears when Operating Mode is set to LADS.
Internal – Timing derived from the unit’s local clock. Use this setting for the LADS
primary timing unit that establishes the timing for both point-to-point units.
External – Timing is derived from the external clock provided by the DTE connected to
the V.35 interface on circuit CT113 (pins U, W).
Receive – Timing is derived from the line receive signal unless the unit is running
diagnostic tests. During the tests, the timing source is the internal clock. This setting
should be used for a LADS secondary timing unit.
LADS Line Rate (Kbps)
Possible Settings: 2.4,4.8,9.6,19.2,38.4,56,64
Default Setting: 9.6
Sets the line operating rate for LADS operation.
LADS Line Rate (Kbps) option appears when Operating Mode is set to LADS.
2.4 to 64 – DSUs communicate at this line rate.
Test Timeout
Possible Settings: Enable,Disable
Default Setting: Disable
Allows user-initiated tests to end automatically.
Enable – User-initiated loopback and pattern tests end when test duration is reached.
Disable – Tests must be terminated manually from the Network Tests screen.
NOTE: Tests commanded by the DTE or network-initiated tests are not affected by
this test timeout.
Test Duration (min)
Possible Settings: 1–120
Default Setting: 10
Determines the number of minutes for a test to be active before automatically ending.
Test Duration (min) option appears when Test Timeout is enabled.
1 to 120 – Amount of time in minutes for a user-initiated test to run before terminating.

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December 1998
Network Interface Options Menu
For Network Interface Options, refer to Table 2. To access the Network Interface
Options screen, follow this menu selection sequence:
Main Menu → Configuration (Load Configuration From) →
Configuration Edit/Display → Network
Table 2. Network Interface Options
Network-initiated DSU Loopback (64K CC)
Possible Settings: Enable, Disable
Default Setting: Enable
Indicates whether the access unit responds to a DSU latching loopback sequence sent
by the network as specified by TR62310.
Network-initiated DSU Loopback (64K CC) option appears when Operating Mode
is set to DDS (see Table 1, System Options).
Enable – Responds to network-initiated commands to start and stop a latching DSU
loopback.
Disable – DSU will not respond to a DSU loopback initiated by the network.
Data Scrambling (64K CC)
Possible Settings: Enable, Disable
Default Setting: Disable
Determines whether data scrambling is used to suppress the possible simulation of
network-initiated DSU latching loopback commands by application data.
Data Scrambling (64K CC) option appears when Operating Mode is set to DDS
(see Table 1, System Options).
Enable – Enables data scrambling. The local and remote units must be set the same.
Disable – No data scrambling.
V.54 Initiated DSU Loopback
Possible Settings: Enable, Disable
Default Setting: Enable
When enabled, user data is looped back to the network when a V.54 Loop Up sequence
is received. The DSU loopback ends when a V.54 Loop Down sequence is detected.
Enable – DSU loopback can be initiated or terminated by a remote unit sending in-band
V.54 Loop 2 Up or Down sequences.
Disable – V.54 Loop 2 sequences are ignored.

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7520-A2-GN10-10 December 1998
Data Port Options Menu
For Data Port Options, refer to Table 3. To access the Data Port Options screen,
follow this menu selection sequence:
Main Menu → Configuration (Load Configuration From) →
Configuration Edit/Display → Data Port
Table 3. Data Port Options (1 of 3)
DTE Port
Possible Settings: EIA232, V.35
Default Setting: EIA232
Determines the active DTE interface.
EIA232 – The EIA-232 port is the active DTE interface. Use for rates up to and including
19.2 kbps, and distances up to 50 feet.
V.35 – The V.35 is the active DTE interface. Use for all rates and distances up to
1,000 feet.
All the following Data Port Options apply to the interface selected.
Invert Transmit Clock
Possible Settings: Enable, Disable
Default Setting: Disable
Determines whether the DSU clock provided on Interchange Circuit CT114, Transmit
Signal Element Timing DCE source (TXC), is phase inverted with respect to
Interchange Circuit CT103, Transmitted Data (TXD). The feature should be enabled
when data errors are occurring due to long cable lengths.
Enable – The DSU-supplied clock is phase inverted with respect to the transmitted data
TXD.
Disable – The clock supplied by the DSU on TXC is normal (i.e., not inverted).
Port (DTE) Initiated Loopbacks
Possible Settings: Disable,Local, Remote, Both
Default Setting: Disable
Specifies whether the DTE can initiate and terminate local and/or remote loopbacks.
The DTE loopback control is done through the Interchange Circuits specified by the
V.54 standard.
Disable – No local or remote loopbacks can be initiated by the DTE.
Local – A local loopback can be controlled by the DTE, via the Interchange Circuit LL
(CT141), as specified by V.54. The DTE port remains in loopback as along as LL
remains on. Aborting the loopback from the ATI has no effect.
Remote – A remote digital loopback can be controlled by the DTE, via Interchange
Circuit RL (CT140), as specified by V.54. The remote equipment must be able to detect
the in-band V.54 loopback sequence.
Both – Both the local and remote loopbacks can be controlled by the DTE.

12 7520-A2-GN10-10
December 1998
Table 3. Data Port Options (2 of 3)
Bilateral Loopback
Possible Settings: Enable, Disable
Default Setting: Disable
If enabled, when a DSU loopback is initiated, a local DTE loopback is also automatically
initiated. A Bilateral Loopback can be started by the ATI or by detection of a V.54 Loop 2
Up sequence.
Enable – When Bilateral Loopback is enabled, running a DSU loopback also
automatically starts a local loopback. The local loopback ends when the DSU loopback
terminates.
Disable – Running a DSU loopback does not start a local loopback.
Carrier Control by RTS
Possible Settings: Constant, Switched
Default Setting: Constant
Simulates Constant or Switched Carrier operation.
Constant – The internal RTS is forced on and the DSU is in a constant Data Mode on
the transmit line. The external RTS lead is ignored. The actual signal on the line is either
all ones (DMI) or DTE transmitted data.
Switched – RTS is monitored and CMI codes are transmitted when RTS is off.
CTS Control
Possible Settings: Standard,Follow RTS, Forced On, Circuit Assurance,
Short Delay, Medium Delay, Long Delay
Default Setting: Standard
Specifies the operation of the Interchange Circuit CT106, Clear to Send (CTS), which is
an output from the DSU.
Standard – CTS follows the internal RTS with a fixed delay, except that CTS will be off
when a network interface related alarm is detected or a test is active. The active test
may be initiated locally, remotely, or by the network.
Follow RTS – CTS follows the external RTS lead without delay, regardless of alarms
and tests.
Forced On – CTS is always forced on after the unit is powered up with a successful
self-test.
Circuit Assurance – With circuit assurance, CTS operates the same as the Standard
option, except that CTS will also be deasserted when CMI codes are being received.
Short Delay – CTS operates as described for the Standard option except that a 50 ms
delay is inserted before CTS is turned on and after RTS is turned on.
Medium Delay – CTS operates as described for the Standard option except that a
150 ms delay is inserted before CTS is turned on and after RTS is turned on.
Long Delay – CTS operates as described for the Standard option except that a 500 ms
delay is inserted before CTS is turned on and after RTS is turned on.

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7520-A2-GN10-10 December 1998
Table 3. Data Port Options (3 of 3)
RLSD Control
Possible Settings: Standard,Forced On
Default Setting: Standard
Specifies the operation of the Interchange Circuit CT109, Received Line Signal Detector
(RLSD or CD), which is an output from the DSU.
Standard – RLSD is asserted when Data Mode is on the receive line. RLSD deasserts
when a DDS facility alarm is detected or the DSU is receiving CMI codes.
Forced On – RLSD is forced on after the unit is powered up with a successful self-test.
DSR Control
Possible Settings: Standard,Forced On, On During Test
Default Setting: Standard
Specifies the operation of the Interchange Circuit CT107, Data Set Ready (DSR), which
is an output from the DSU.
Standard – DSR is always asserted, except when a DDS facility alarm is reported or
the DSU is in Test mode.
Forced On – DSR is forced on after the unit is powered up with a successful self-test.
On During Test – DSU operates the same as the Standard option, except that DSR
remains asserted when the DSU is in Test mode to allow the DTE to send test patterns.
Monitor DTR
Possible Settings: Enable, Disable
Default Setting: Enable
Indicates to the DSU whether to monitor the Interchange Circuit CT108, Data Terminal
Ready (DTR), from the DTE.
Enable – The DSU monitors the state of DTR on the DTE port and displays it on the
System and Test Status screen.
Disable – DTR is not monitored by the DSU. Use when a DTE does not provide the
DTR lead at the interface.

14 7520-A2-GN10-10
December 1998
Terminal Port Options
For Terminal Port options, refer to Table 4. To access the Terminal Port Options
screen, follow this menu selection sequence:
Main Menu → Configuration (Load Configuration From) →
Configuration Edit/Display → Terminal Port
Table 4. Terminal Port Options
Monitor DTR
Possible Settings: Enable, Disable
Default Setting: Enable
Specifies monitoring of the Data Terminal Ready (DTR) control lead.
Enable – Standard operation of the DTR control lead.
Disable – DTR is ignored. Some external device connections may require this setting.
Inactivity Timeout
Possible Settings: Enable, Disable
Default Setting: Disable
Provides automatic logoff of an ATI session through the Terminal Port. When the
session is closed, User Interface Idle appears on the screen and the unit toggles the
Terminal port DSR lead.
Enable – The ATI session terminates automatically after the Disconnect Time set in the
next option. When the session was occurring over an external modem connected to the
Terminal port, the modem will interpret the DSR toggle as DTR being dropped and
disconnect.
Disable – An ATI session through the Terminal port will remain active indefinitely.
Disconnect Time(minutes)
Possible Settings: range 1 – 60
Default Setting: 5
Number of minutes of inactivity before the ATI session terminates automatically.
Timeout is based on no keyboard activity.
Disconnect Time(minutes) option appears when Inactivity Timeout is enabled.
1 to 60 – The ATI user session is closed after the selected number of minutes.

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7520-A2-GN10-10 December 1998
Important Safety Instructions
1. Read and follow all warning notices and instructions marked on the product
or included in the manual.
2. Slots and openings in the cabinet are provided for ventilation. To ensure
reliable operation of the product and to protect it from overheating, these
slots and openings must not be blocked or covered.
3. Do not allow anything to rest on the power cord and do not locate the product
where persons will walk on the power cord.
4. Do not attempt to service this product yourself, as opening or removing
covers may expose you to dangerous high voltage points or other risks. Refer
all servicing to qualified service personnel.
5. General purpose cables are provided with this product. Special cables, which
may be required by the regulatory inspection authority for the installation site,
are the responsibility of the customer.
6. When installed in the final configuration, the product must comply with the
applicable Safety Standards and regulatory requirements of the country in
which it is installed. If necessary, consult with the appropriate regulatory
agencies and inspection authorities to ensure compliance.
7. Input power to this product must be provided by one of the following: (1) a UL
Listed/CSA certified power source with a Class 2 or Limited Power Source
(LPS) output for use in North America, or (2) a certified power source with a
Safety Extra Low Voltage (SELV) output for use in the country of installation.
8. A rare phenomenon can create a voltage potential between the earth
grounds of two or more buildings. If products installed in separate buildings
are interconnected, the voltage potential may cause a hazardous condition.
Consult a qualified electrical consultant to determine whether or not this
phenomenon exists and, if necessary, implement corrective action prior to
interconnecting the products.
9. In addition, if the equipment is to be used with telecommunications circuits,
take the following precautions:
— Never install telephone wiring during a lightning storm.
— Never install telephone jacks in wet locations unless the jack is
specifically designed for wet locations.
— Never touch uninsulated telephone wires or terminals unless the
telephone line has been disconnected at the network interface.
— Use caution when installing or modifying telephone lines.
— Avoid using a telephone (other than a cordless type) during an electrical
storm. There may be a remote risk of electric shock from lightning.
— Do not use the telephone to report a gas leak in the vicinity of the leak.

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December 1998
Notices
!WARNING:
This equipment has been tested and found to comply with the limits for
a Class A digital device, pursuant to Part 15 of the FCC rules. These
limits are designed to provide reasonable protection against harmful
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 will be
required to correct the interference at his own expense.
The authority to operate this equipment is conditioned by the
requirements that no modifications will be made to the equipment
unless the changes or modifications are expressly approved by
Paradyne Corporation.
!WARNING:
To Users of Digital Apparatus in Canada:
This Class A digital apparatus meets all requirements of the Canadian
interference-causing equipment regulations.
Cet appareil numérique de la classe A respecte toutes les exigences du
règlement sur le matérial brouilleur du Canada.
Government Requirements
Certain governments require that instructions pertaining to connection to the
telephone network be included in the installation and operation manual. Specific
instructions are listed in the following sections.
Notice to Users of the Telephone Network in the United States
This equipment complies with Part 68 of the FCC rules. On the bottom of the
equipment is a label that contains, among other information, the FCC registration
number for this equipment. If requested, please provide this information to your
telephone company.
If your DSU causes harm to the telephone network, the telephone company may
discontinue your service temporarily. If possible, they will notify you in advance.
But if advance notice is not practical, you will be notified as soon as possible. You
will be advised of your right to file a complaint with the FCC.
Your telephone company may make changes in facilities, equipment, operations,
or procedures that could affect the proper operation of your equipment. If so, you
will be given advance notice so as to give you an opportunity to maintain
uninterrupted service.

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7520-A2-GN10-10 December 1998
No repairs may be performed by the user. Should you experience difficulty with
this equipment, refer to
Warranty, Sales, and Service Information on page 18.
For Digital Data Service (DDS) installations, inform the local telephone company
of the appropriate facility interface code for the service you desire.
DDS Facility
Interface Code Data Rate (kbps)
04DU5-24 2.4
04DU5-48 4.8
04DU5-96 9.6
04DU5-19 19.2
04DU5-38 38.4
04DU5-56 56
04DU5-64 64
The DDS Service Order Number is 6.0Y. The jack configuration required is
RJ48S.
After the telephone company has installed the requested service and jack, you
can connect the DSU with the cable provided. An FCC-compliant telephone cord
and modular plug are provided with this equipment. This equipment is designed
to be connected to the telephone network or premises wiring using a compatible
modular jack that is Part 68 compliant.
Canada
Notice to Users of the Canadian Telephone Network
The Industry Canada label identifies certified equipment. This certification means
that the equipment meets telecommunications network protective, operational
and safety requirements as prescribed in the appropriate Terminal Equipment
Technical Requirements document(s). The Department 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. 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 coordinated by a representative
designated 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 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 precaution may be particularly
important in rural areas.

18 7520-A2-GN10-10
December 1998
CAUTION:
Users should not attempt to make such connections themselves, but
should contact the appropriate electric inspection authority, or
electrician, as appropriate.
The Ringer Equivalence Number (REN) assigned to each terminal device
provides an indication of the maximum number of terminals allowed to be
connected to a telephone interface. The termination on an interface may consist
of any combination of devices subject only to the requirement that the sum of the
Ringer Equivalence Numbers of all the devices does not exceed 5.
If your equipment is in need of repair, refer to the procedures described in the
next section.
Warranty, Sales, and Service Information
Contact your local sales representative, service representative, or distributor
directly for any help needed. For additional information concerning warranty,
sales, service, repair, installation, documentation, training, distributor locations, or
Paradyne worldwide office locations, use one of the following methods:
HVia the Internet:
Visit the Paradyne World Wide Web site at
http://www.paradyne.com
HVia 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
— Outside the U.S.A., call 1-727-530-2340
Document Feedback
We welcome your comments and suggestions about this document. Please mail
them to Technical Publications, Paradyne Corporation, 8545 126th Ave. N.,
Largo, FL 33773, or send e-mail to [email protected]. Include the
number and title of this document in your correspondence. Please include your
name and phone number if you are willing to provide additional clarification.

*7520–A2–GN10–10*
Copyright E1998 Paradyne Corporation