Black Box ME243A-F 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 1997
ME243A-F
V.35 Sync Modem Eliminator
V.35 Sync
Modem Eliminator

1
FCC AND DOC/MDC RFI STATEMENTS
FEDERAL COMMUNICATIONS COMMISSION
AND
INDUSTRY CANADA
RADIO FREQUENCY INTERFERENCE STATEMENTS
This equipment generates, uses, and can radiate radio-frequency energy, and if not
installed and used properly, that is, in strict accordance with the manufacturer’s
instructions, may cause interference to radio communication. It has been tested
and found to comply with the limits for a Class A computing device in accordance
with the specifications in Subpart B of Part 15 of FCC rules, which are designed to
provide reasonable protection against such interference when the equipment is
operated in a commercial environment. Operation of this equipment in a
residential area is likely to cause interference, in which case the user at his own
expense will be required to take whatever measures may be necessary to correct
the interference.
Changes or modifications not expressly approved by the party responsible
for compliance could void the user’s authority to operate the equipment.
This digital apparatus does not exceed the Class A 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 la classe A prescrites dans le Règlement sur le
brouillage radioélectrique publié par Industrie Canada.
TRADEMARKS USED IN THIS MANUAL
Any trademarks mentioned in this manual are acknowledged to be the property of the
trademark owners.

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V.35 SYNC MODEM ELIMINATOR
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.

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V.35 SYNC MODEM ELIMINATOR
Contents
Chapter Page
1. Specifications ............................................................................................. 5
2. Introduction ............................................................................................... 7
3 Configuration ............................................................................................. 8
3.1 Opening the Housing ......................................................................... 8
3.1.1 Opening the Middle Section .................................................... 9
3.1.2 Opening the Top of the Port-B End ...................................... 10
3.2 Setting the DIP Switch ...................................................................... 11
3.3 Setting the Jumpers .......................................................................... 13
3.4 Reclosing the Housing ...................................................................... 15
3.4.1 Closing the Top of the Port-B End ........................................ 15
3.4.2 Closing the Middle Section .................................................... 15
4. Installation and Operation ...................................................................... 16
5. Troubleshooting ...................................................................................... 18
5.1 Calling Black Box .............................................................................. 18
5.2 Shipping and Packaging ................................................................... 18
Appendix: Block Diagram .............................................................................. 19

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CHAPTER 1: Specifications
1. Specifications
Compliance — CE; FCC Part 15 Class A, DOC Class/MDC classe A
Interface — Serial ITU-TSS V.35
Protocol — Synchronous
Clock Source — Either internal for both ports or external for
Port A and recovered for Port B(user-selectable)
Flow Control — Transparent to software flow control; does not
support hardware flow control, but emulates RTS-to-
CTS delay of 0, 7, or 53 ms ±15% (user-selectable)
Operation — Point-to-point
Data Rate — 32, 48, 56, 64, 72, 112, 128, or 144 kbps (user-
selectable)
Maximum Distance — 300 ft. (91.4 m) from one attached DTE to the other
User Controls — (4) Internal:
(1) Four-position DIP switch for data rate;
(3) Jumpers for RTS/CTS delay, carrier control,
and clock source
Indicators — None
Connectors — (2) End-mounted M/34 (“34-pin M-block”) female
MTBF — 144,600 hours

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V.35 SYNC MODEM ELIMINATOR
Maximum Altitude — 10,000 ft. (3048 m)
Temperature
Tolerance — 32 to 122˚F (0 to 50˚C)
Humidity
Tolerance — 5 to 95% noncondensing
Power — From the V.35 Interface on both ports: 5 VDC,
6 mA drawn from each port’s RTS and DTR
signals (Pins C and H); maximum total
consumption approximately 120 mW
Size — 0.8"H x 2"W x 3"D (2 x 5.1 x 7.6 mm)
Weight — 3.3 oz. (95 g, 0.2 lb., 0.1 kg)

7
CHAPTER 2: Introduction
2. Introduction
With our V.35 Synchronous Modem Eliminator (SME), two synchronous
hosts that are not farther apart than 300 ft. (91.4 m) can communicate with
each other for a fraction of the cost of a pair of high-speed modems. The V.35
SME supports synchronous data rates of 32, 48, 56, 64, 72, 112, 128, and 144
kbps, and can be configured to emulate dialup or leased-line service. Timing
can be set for internal or external clock, and all necessary data, clocking, and
control signals are supported.
The V.35 SME implements the V.35 electrical interface on two standard
M/34 (“34-pin M-block”) female connectors. The unit draws its power directly
from the Request to Send (RTS) and Data Terminal Ready (DTR) signal leads
(Pins C and H) on both ports, so no AC power or batteries are required.
You can configure the V.35 SME’s behavior in several other ways. For
example, you can set it to keep carrier constantly ON or to have carrier follow
RTS; you can also set it to immediately respond to RTS with CTS or to
emulate an RTS-to-CTS delay of 7 or 53 ms.

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V.35 SYNC MODEM ELIMINATOR
3. Configuration
The V.35 Synchonous Modem Eliminator has seven internal user controls—
one four-position DIP switch and six jumpers—with which you can configure
the unit for a wide range of applications. This chapter tells you how to open,
set, and reclose the V.35 SME, and describes all of the unit’s possible
configuration settings (including its factory defaults).
3.1 Opening the Housing
Before you go any farther, answer these questions:
First, will your devices be using the V.35 SME’s internal clock, and do you
want carrier constantly ON and an RTS-to-CTS delay of 7 ms (the factory-
default settings for these options)? If not, you will need to open both the
middle portion and the top of the Port-B end of the unit’s housing: Skip
ahead and follow the directions in Sections 3.1.1 and 3.1.2.
Second, will your devices be communicating through the V.35 SME at
32 kbps (the factory-default data rate)? If not, you will need to open just the
middle portion of the unit’s housing: Skip ahead and follow the directions in
Section 3.1.1 only (do not do Section 3.1.2).
If you are satisfied with all of the factory-default settings, you don’t need to
configure the unit at all; skip ahead to Chapter 4.

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CHAPTER 3: Configuration
3.1.1 O PENING THE
M IDDLE S ECTION
Carefully insert a screwdriver, knife, or other tool with a very thin flat blade
into the seam along the side of the middle part of the V.35 SME’s housing
(the section with the model- and lot-number stickers). Gently twist the tool
until the all-plastic top and bottom panels of this housing section begin to
pop apart. (You will probably hear a snapping noise; this is normal.) If they
don’t come all the way off, carefully pry them the rest of the way off with your
fingers. See Figure 3-1 below.
Figure 3-1. Removing the middle section.