Black Box ME800A-R2 User manual

AUGUST 2000
ME800A
ME800A-R2
ME805-C
ME805-C-R2
ME810
Short-Haul Modem B
(SHM-B Async)
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]
ASYNC SHORT HAUL MODEM
TD RD
NORMAL
LOOPBACK

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SHM-B ASYNC
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 J 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 classe A prescrites dans le Règlement sur le
brouillage radioélectrique publié par Industrie Canada.

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SHM-B ASYNC
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.

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SHM-B ASYNC
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.
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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SHM-B ASYNC
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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SHM-B ASYNC
1. Specifications
Transmission —
Data Rate (bps) Distance (miles/km)
19,200 1/1.6
9600 2/3.2
4800 3/4.8
2400 4/6.4
NOTE:The above specifications are valid for 24- or 26-AWG unshielded
twisted-pair telephone cable insulated by polyethylene with a
mutual capacitance of 0.083 µf/mile. Shielded twisted-pair cable
will reduce the distance to one-third of the table value, due to the
additional capacitance contributed by the cable’s shielding. Actual
distances may vary depending on your specific operating
equipment and the cable you use.
Protocol — Asynchronous
Operation — 4-wire, full duplex, point-to-point
Line Interface — Balanced current loop; Receive lines
are protected through optical isolators rated at 1500
volts
Equipment Interface — EIA-232/CCITT V.24 interface
with a hardware handshake (selected through use of an
internal strap). Carrier Detect (CD) true (high)
indicates operating short-haul modem at the remote

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SHM-B ASYNC
end of the loop. Interface is switch-selectable for
DTE/DCE configuration (pins 2 and 3 are reversed)
Connectors — (1) DB25 female, (1) 5-screw terminal
block
Diagnostics — Loopbacks provided by a front-panel
switch: Analog loopback on a 4-wire loop and digital
loopback on equipment interface (EIA-232)
Status Indication — Two bi-color LEDs indicate the
status of the transmitter and receiver. A green light
indicates a “low” logic level (-3 to -25V) on the EIA-232
interface; a red light indicates a “high” logic level (+3 to
+25V).
Operating Temperature — 32 to 112°F (0 to 50°C)
Humidity — 95%maximum, noncondensing
Enclosure — Standalone: High-impact plastic;
Rackmount: Aluminum alloy
Power — Power is supplied by a wall-mounted power
transformer. No more than 16 Vrms is present in unit.

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SHM-B ASYNC
Primary: 115 VAC ±10%, 60 Hz, 5 watts (12 watts max.);
Primary: 230 VAC ±10%, 50/60 Hz; Secondary: 17 VAC,
700 mA
Size — Standalone: 1.4"H x 4.25"W x 4.5"D (3.8 x 10.9 x
11.7 cm); Rackmount: 5.25"H x 17"W x 9"D (13 x 43 x
23 cm)
Weight — Standalone: 1.3 lb. (0.6 kg), including
transformer; Rackmount: 3.7 lb. (1.7 kg), including
transformer

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SHM-B ASYNC
2. Introduction
The Short-Haul Modem Model B Async (SHM-B Async)
is an asynchronous full-duplex 4-wire line
driver/receiver which allows two EIA-232 devices to
communicate at distances of up to 4 miles and at data
speeds of up to 19,200 bps. In addition to the
transmitter and receiver circuits, the SHM-B Async
includes EIA-232 control line interfaces, status monitor
LEDs, and a loopback switch. The SHM-B is available in
both a standalone version (ME800A) and a rackmount
version (ME805-C). Models ME800A-R2 and ME805-C-
R2 include cables.
The SHM-B is designed to operate over a 4-wire metallic
circuit. Optimum performance is obtained with twisted-
pair cable (see specifications). Most types of twisted-pair
cable may be used, often with little or no performance
degradation.
The SHM-B Async is designed for maximum operator
safety. There are no voltages greater than 12 VDC or 16
VAC present on the circuit board of the unit. The
Receive lines are protected from potential ground
differences through optical isolators rated at 1500 volts.

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SHM-B ASYNC
3. Installation
Installation involves three basic steps: four-wire
connections; EIA-232 connection; switch settings.
3.1 Four-Wire Connections
Figure 1 shows the location of the terminal block on the
circuit board. Refer to Figure 2 to make the proper
connections between two SHM-B units.
NOTE: Transmit + (TX+) on one modem is wired
to Receive + (RX+) on the other modem; Transmit -
(TX-) is wired to Receive - (RX-). A ground
connection is optional.
1. If the unit is assembled, separate the top and
bottom panels at the front of the unit.
2. Push the rear connector to force out the front
panel and printed circuit board.
3. Route the four-wire cable through the open hole in
the rear panel of the enclosure.
4. Strip each of the four wires about 1⁄8".