Black Box NTU-1 User manual

CUSTOMER
SUPPORT
INFORMATION
Order toll-free in the U.S.: Call 877-877-BBOX (outside U.S. call 724-746-5500)
FREE technical support 24 hours a day, 7 days a week: Call 724-746-5500 or fax [phone]
Mailing address: Black Box Corporation, 1000 Park Drive, Lawrence, PA 15055-1018
Web site: www.blackbox.com • E-mail: [email protected]
DECEMBER 2000
IS200A-R2
NTU-1

1
FCC INFORMATION
FEDERAL COMMUNICATIONS COMMISSION
and INDUSTRY CANADA
RADIO FREQUENCY INTERFERENCE STATEMENTS
Class B Digital Device. This equipment has been tested and found to comply with
the limits for a Class B computing device pursuant to Part 15 of the FCC Rules.
These limits are designed to provide reasonable protection against harmful
interference in a residential installation. However, there is no guarantee that
interference will not occur in a particular installation. This equipment generates,
uses, and can radiate radio frequency energy, and, if not installed and used in
accordance with the instructions, may cause harmful interference to radio
communications. If this equipment does cause harmful interference to radio or
telephone reception, which can be determined by turning the equipment off and
on, the user is encouraged to try to correct the interference by one of the following
measures:
• Reorient or relocate the receiving antenna.
• Increase the separation between the equipment and receiver.
• Connect the equipment into an outlet on a circuit different from that to which
the receiver is connected.
• Consult an experienced radio/TV technician for help.
Caution:
Changes or modifications not expressly approved by the party
responsible for compliance could void the user’s authority to operate the
equipment.
To meet FCC requirements, shielded cables and power cords are required to
connect this device to a personal computer or other Class B certified device.
This digital apparatus does not exceed the Class B limits for radio noise emission from digital
apparatus set out in the Radio Interference Regulation of Industry Canada.
Le présent appareil numérique n’émet pas de bruits radioélectriques dépassant les limites
applicables aux appareils numériques de classe B prescrites dans le Règlement sur le brouillage
radioélectrique publié par Industrie Canada.

2
NTU-1
NORMAS OFICIALES MEXICANAS (NOM)
ELECTRICAL SAFETY STATEMENT
INSTRUCCIONES DE SEGURIDAD
1. Todas las instrucciones de seguridad y operación deberán ser leídas antes de
que el aparato eléctrico sea operado.
2. Las instrucciones de seguridad y operación deberán ser guardadas para
referencia futura.
3. Todas las advertencias en el aparato eléctrico y en sus instrucciones de
operación deben ser respetadas.
4. Todas las instrucciones de operación y uso deben ser seguidas.
5. El aparato eléctrico no deberá ser usado cerca del agua—por ejemplo, cerca
de la tina de baño, lavabo, sótano mojado o cerca de una alberca, etc..
6. El aparato eléctrico debe ser usado únicamente con carritos o pedestales que
sean recomendados por el fabricante.
7. El aparato eléctrico debe ser montado a la pared o al techo sólo como sea
recomendado por el fabricante.
8. Servicio—El usuario no debe intentar dar servicio al equipo eléctrico más allá
a lo descrito en las instrucciones de operación. Todo otro servicio deberá ser
referido a personal de servicio calificado.
9. El aparato eléctrico debe ser situado de tal manera que su posición no
interfiera su uso. La colocación del aparato eléctrico sobre una cama, sofá,
alfombra o superficie similar puede bloquea la ventilación, no se debe colocar
en libreros o gabinetes que impidan el flujo de aire por los orificios de
ventilación.
10. El equipo eléctrico deber ser situado fuera del alcance de fuentes de calor
como radiadores, registros de calor, estufas u otros aparatos (incluyendo
amplificadores) que producen calor.
11. El aparato eléctrico deberá ser connectado a una fuente de poder sólo del
tipo descrito en el instructivo de operación, o como se indique en el aparato.

3
NOM STATEMENT
12. Precaución debe ser tomada de tal manera que la tierra fisica y la polarización
del equipo no sea eliminada.
13. Los cables de la fuente de poder deben ser guiados de tal manera que no
sean pisados ni pellizcados por objetos colocados sobre o contra ellos,
poniendo particular atención a los contactos y receptáculos donde salen del
aparato.
14. El equipo eléctrico debe ser limpiado únicamente de acuerdo a las
recomendaciones del fabricante.
15. En caso de existir, una antena externa deberá ser localizada lejos de las lineas
de energia.
16. El cable de corriente deberá ser desconectado del cuando el equipo no sea
usado por un largo periodo de tiempo.
17. Cuidado debe ser tomado de tal manera que objectos liquidos no sean
derramados sobre la cubierta u orificios de ventilación.
18. Servicio por personal calificado deberá ser provisto cuando:
A: El cable de poder o el contacto ha sido dañado; u
B: Objectos han caído o líquido ha sido derramado dentro del aparato; o
C: El aparato ha sido expuesto a la lluvia; o
D: El aparato parece no operar normalmente o muestra un cambio en su
desempeño; o
E: El aparato ha sido tirado o su cubierta ha sido dañada.

4
NTU-1
TRADEMARKS USED IN THIS MANUAL
Any trademarks mentioned in this manual are acknowledged to be the property of the
trademark owners.

5
CONTENTS
Contents
Chapter Page
1. Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.1 Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.2 What the Package Includes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.3.1 ISDN Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.3.2 Compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3. Installation and Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.1 Preparing the Site . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.2 Wall Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.3 DIP-Switch Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.4 ISDN and Terminal Hookup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.5 Wallmount Transformer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.6 Remote Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.7 Signal Power. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.8 Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.9 LEDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4. Connector Pinouts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.1 NTU-1 to ISDN U Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.2 NTU-1 to Terminal Endpoint Equipment. . . . . . . . . . . . . . . . . . . . . 14
5. Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5.1 Calling Black Box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5.2 Shipping and Packaging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Appendix. Wallmount Template . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

6
NTU-1
1. Specifications
Maximum Operating Distance—18,000 ft. (5486 m)
U Interface Coding—2B1Q
Operating Temperature—32 to 122°F (0 to 50°C)
Humidity—Up to 95% noncondensing
Power Consumption—5 watts maximum
Wallmount Transformer Output—34 VAC
Size—1.5"H x 6.3"W x 5.1"D (3.8 x 16 x 13 cm)
Weight—2.5 lb. (1.1 kg) with transformer

7
CHAPTER 2: Introduction
2. Introduction
2.1 Description
The Network Termination Device (NTU-1) is designed for the ISDN basic rate
communication system. It installs between the Central Office U interface, and the
customer premise S or T interface. It effectively converts the central office 2-wire
echo-canceled 2B1Q code to a customer premise 4-wire alternate space inversion
code (see Figure 2-1). Both point-to-point and multipoint configurations are
supported.
Figure 2-1. Typical ISDN interface arrangements.
The NTU-1 can reside on a desk or be wall mounted. Six light-emitting diodes
(LEDs) show unit status. The rear panel houses the power jack, two jacks for either
an S or T interface to the customer premise equipment, one U jack for connection
to the central office, and one 4-position DIP switch for terminating resistor
selection. Power is supplied by the wall transformer, which also provides power to
the associated terminal devices via the S/T jacks.
2.2 What the Package Includes
Your package should include the following items. If anything is missing or
damaged, contact Black Box Technical Support at 724-746-5500.
• Network Termination Unit (NTU-1)
• U interface cable
Customer Premise
Equipment Central Office
Terminal
Adapter
NT2
NTU-1
2-wire
2B1Q Code
S Interface
T Interface
U
Interface
ISDN
2B+D
and/or 4-wire
ASI Code
LAN
WAN
PBX
Fax
PCs

8
NTU-1
• Power supply
• This users’ manual
2.3 Features
• Mounts on a wall or desktop
• Point-to-point or multipoint configuration
• Built-in surge protection
• All options and connections are accessible via the rear panel
• Up to 18,000 feet (5486 m) operating distance
• 2B1Q to alternate space inversion interface coding
• Standard RJ-45 jacks on all interfaces
• Wall transformer and U interface cable included
• Automatic remote (backup) power pickup
2.3.1 ISDN F EATURES
• Loss of power notification
• Embedded operations channel 2B+D loopback
• Integral metallic termination circuit (sealing current)
• Warm start activation
• Remote activated quiet mode and insertion loss tests in maintenance modes
2.3.2 C OMPLIANCE
Complies with these standards:
• ANSI T1.601-1992 network side
• ANSI T1.605

9
CHAPTER 3: Installation and Operation
3. Installation and Operation
3.1 Preparing the Site
The installation area should be free from extreme temperatures, humidity, shock,
and vibration. Allow sufficient space for cable clearance. For wallmount
applications, a template is provided to help locate the retaining screw holes (see
Appendix).
CAUTION
For wallmount applications, position the NTU-1 with connectors and
cables exiting downward. Make sure that the LEDs are visible during
operation.
3.2 Wall Mounting
Using the template found on the last page of this manual, mark the wall and insert
three number 6 pan-head type screws. Allow the screw heads to protrude 1⁄10 ". After
inserting all three screws, position the NTU-1 in place by engaging the screw heads
and sliding it to the right until it’s secure. You might have to adjust the screws for a
snug fit.
NOTE
On some installations, it may be easier to make connections or position
DIP switches before wall mounting.

10
NTU-1
3.3 DIP-Switch Options
When you install the NTU-1, you must set the terminating resistors to match the
applications shown in Figure 3-1.
Figure 3-1. Examples using terminating resistor settings.
DIP-switch S1 positions 1 and 4 control the resistors. S1-1 selects the transmit
resistor and S1-4 selects the receive resistor. The ON (down) position puts the
terminating resistors in the circuit. You can access the switch from the rear panel.
It is numbered and labeled (see Figure 3-2). The NTU-1 is shipped with all
positions switched ON (S1 positions 2 and 3 are not used).
100 ohms
IN
Up to 1 km
Up to 1 km
Point-to-Point Connection
Passive Bus
Connection
100 ohms
IN
100 ohms
OUT
NTU-1
Terminal
Eliminator
Terminal
Equipment
Terminal
Equipment
NTU-1
NTU-1
100 ohms OUT
on unit with
shortest cable
100 ohms IN
on unit with
longest cable
If cable length is
equal, 100 ohms IN
on either unit
100 ohms
IN
100 ohms
IN
100 ohms
IN
Example #1
Example #3
Example #2

11
CHAPTER 3: Installation and Operation
Figure 3-2. DIP-switch location.
The factory setting should work for most installations. S/T interface links that have
unusual characteristics may experience improved performance by putting resistors
in or out of the circuit. The units on the opposite end of the S/T line also have
terminating resistors that you must consider. As a general rule, the units at either
end have the resistance in while add-on nodes have the resistance out. Table 3-1
shows the switch settings.
Table 3-1. DIP-switch functions
DIP-Switch Transmit Resistor Receive Resistor
Position
OFF ON*
S1-1 100 ohms out 100 ohms in
S1-4 OFF ON*
100 100
ohms out ohms in
*Default setting.
NOTES
ON=Down and OFF=up. Set both resistors the same, either both ON or
both OFF.
S1-2 and S1-3 are not used.

12
NTU-1
3.4 ISDN and Terminal Hookup
Connecting the NTU-1 is simple and straightforward. The supplied U cable inserts
into the U jack on the NTU-1. The opposite end connects to the ISDN wall jack.
Similar cables are used to connect the S/T jacks to the designated terminal
endpoint equipment.
3.5 Wallmount Transformer
The NTU-1 is normally powered from the wallmount transformer. The transformer
and power-supply circuitry provides 5 watts for up to two terminal devices
connected to the S/T interface. Connect the transformer barrel connector to the
power jack on the rear panel. Plug the transformer into a standard 120-VAC wall
socket.
3.6 Remote Power
The NTU-1 can receive remote (backup) power over the U interface connector.
The input must be nominally 48 VDC and 5 watts minimum. Both local and
backup power is routed to the S/T interface connectors to power the associated
terminal equipment. Pins 7 and 8 on the U interface provide remote power to both
S/T jacks and the NTU-1.
NOTE
Remote power must be provided to the wall jack U connection by the
site facilities.
3.7 Signal Power
The NTU-1 routes local and remote power to the signal leads of the S/T interface.
For phantom powering applications, S/T interface connector pins 4 and 5
(transmit) are the negative power leads and pins 3 and 6 (receive) are the positive
power leads.
3.8 Operation
After installation and configuration, the NTU-1 operates automatically and
unattended.

13
CHAPTER 3: Installation and Operation
3.9 LEDs
The LEDs display certain operating functions and will indicate if malfunctions are
occurring.
• LP (Local Power): ON indicates that the wallmount transformer is plugged in
and 120 VAC is present.
• RP (Remote Power): ON indicates that the remote power source is connected
and functional.
• RPR (Remote Power Reversed): ON indicates that the remote power source is
connected but polarity is reversed. This must be corrected by the site facilities.
• LB (Loopback): ON indicates that the ISDN switch has sent a 2B+D loopback
command to the NTU-1.
• SC (Sealing Current): ON indicates the presence of the metallic termination
test voltage from the ISDN switch.
• ACT (Activity: ON indicates that a link-up between the terminal equipment
and ISDN central office via the NTU-1 has been achieved and transmission can
take place.
If a disruption occurs between the U interface and the ISDN switch, the LED
flickers (8 Hz).
If a disruption occurs between the S/T interface and the terminal equipment,
the LED blinks once per second (1 Hz). If the LED flashes slowly, the S/T
device may not be plugged in.
If a disconnect occurs on both interfaces, the LED goes out.

14
NTU-1
4. Connector Pinouts
The NTU-1 connects to the central office (CO) and customer premise equipment
(CPE) with standard 8-pin RJ-45 modular connectors. All connections are on the
rear panel and are labeled.
4.1 NTU-1 to ISDN U Interface
The U jack connects the NTU-1 to the ISDN. Pin functions are shown in Table 4-1.
Table 4-1. Pin functions for U jack
Pin Function
1 Not used
2 Not used
3 Not used
4 Transmit to/Receive from ISDN network
5 Transmit to/Receive from ISDN network
6 Not used
7 Remote power source (-)
8 Remote power source (+)
4.2 NTU-1 to Terminal Endpoint Equipment
The S/T jacks connect the NTU-1 to the terminal equipment. Either jack can be
an S interface or a T interface. Pin functions are shown in Table 4-2.
Table 4-2. Pin functions for S/T jacks
Pin Function
1 Not used
2 Not used
3 Receive + from terminal equipment
4 Transmit + to terminal equipment
5 Transmit - to terminal equipment
6 Receive - from terminal equipment
7 Terminal equipment power (-)
8 Terminal equipment power (+)

15
5. Troubleshooting
5.1 Calling Black Box
If you determine that your NTU-1 is malfunctioning, do not attempt to alter or
repair the unit. It contains no user-serviceable parts. Contact Black Box at 724-746-
5500.
Before you do, make a record of the history of the problem. We will be able to
provide more efficient and accurate assistance if you have a complete description,
including:
• the nature and duration of the problem.
• when the problem occurs.
• the components involved in the problem.
• any particular application that, when used, appears to create the problem or
make it worse.
5.2 Shipping and Packaging
If you need to transport or ship your NTU-1:
• Package it carefully. We recommend that you use the original container.
• If you are shipping the NTU-1 for repair, make sure you include everything
that came in the original package. Before you ship, contact Black Box to get a
Return Authorization (RA) number.
CHAPTER 5: Troubleshooting

16
NTU-1
Appendix. Wallmount Template
Use this template to mount the NTU-1 on the wall.

1000 Park Drive • Lawrence, PA 15055-1018 • 724-746-5500 • Fax [phone]
© Copyright 2000. Black Box Corporation. All rights reserved.