Paradyne Dual DSU 7511 User manual

TM
1
7511-A2-GN10-10 January 1999
Model 7511 Dual DSU
Startup Instructions
Document Number 7511-A2-GN10-10
January 1999
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:
7511-A2-GB20
Model 7511 Dual 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
Preparation
Make sure you have:
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.
Package Checklist
Verify that your package contains the following:
A Model 7511 DSU
A backplate bearing two 25-pin connectors
Two V.35 adapter cables

2 7511-A2-GN10-10
January 1999
Cables You May Need to Order
You will need cables to connect your Network Interface Module (NIM) to the
network and your 7511 DSUs to DTEs. For further information refer to the
documentation shipped with your NIM, and Appendix A,
Cables and Pin
Assignments,
in the User’s Guide.
Installing the Dual DSU
Before you install your DSU, read the Important Safety Instructions beginning on
page 13.
!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.
Configuring the DSUs
Procedure
To configure the Model 7511 Dual DSU:
1. Review Table 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.
2. Mark any options in the table that you wish to differ from the factory default.
3. Using Figure 1 and Table 1, verify that the switch settings of each DSU 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

3
7511-A2-GN10-10 January 1999
S1
97-15396
12345678
ON
12345678
ON
12345678
ON
12345678
ON
12345678
ON
S2
S3 S4
S5
Figure 1. Model 7511 Switch Locations
Table 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.

4 7511-A2-GN10-10
January 1999
Table 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.

5
7511-A2-GN10-10 January 1999
Table 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.

6 7511-A2-GN10-10
January 1999
Table 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.

7
7511-A2-GN10-10 January 1999
Table 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.

8 7511-A2-GN10-10
January 1999
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

9
7511-A2-GN10-10 January 1999
Installing the DSU Card
Procedure
To install the Model 7511 Dual DSU:
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.

10 7511-A2-GN10-10
January 1999
495-14797
3. Slide the circuit card into the slot and press until the connectors are seated
firmly into the back of the carrier.
4. If power is applied to the carrier:
— All LEDs on the card light up momentarily.
— The card completes its power-up self-test.
— The Alarm and OK LEDs are turned off or on depending on the test
results.
5. Press the faceplate latch to secure the circuit card.
6. Rotate the circuit pack lock into the closed position, and tighten the screw.
7. Return to the rear of the carrier and tighten the screw on the rear connector
plate.