Black Box Time-Division Multiplexor User manual

OCTOBER 1999
MX560A
Time-Division Multiplexor
PWR
Time Division Multiplexor
SYNC
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]

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TIME-DIVISION MULTIPLEXOR
FEDERAL COMMUNICATIONS COMMISSION
AND
CANADIAN DEPARTMENT OF COMMUNICATIONS
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 la classe A prescrites dans le Règlement sur le
brouillage radioélectrique publié par Industrie Canada.

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TIME-DIVISION MULTIPLEXOR
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.

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TIME-DIVISION MULTIPLEXOR
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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TIME-DIVISION MULTIPLEXOR
TRADEMARKS
UL®is a registered trademark of Underwriters Laboratories Incorporated.
The trademarks mentioned in this manual are the sole property of their owners.

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TIME-DIVISION MULTIPLEXOR
Contents
1. Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3. Setup and Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.1 Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.2 Character Length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.3 Stop-Bit Reduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.4 Channel 1 Sync/Async . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.5 Equipment Grounding. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.6 Factory Straps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.7 Board Layout and Jumper Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

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TIME-DIVISION MULTIPLEXOR
1. Specifications
Applications—RS-232 sync or async 2 sub-channel multiplexor
Capacity—(2) sync or (1) sync and (1) async RS-232 terminals, (1) sync RS-232
modem
Data Format—Data coding: synchronous or asynchronous
Data Rates—Async 600 bps to 19.2 kbps or sync up to 19.2 kbps with 38.4 kbps
composite
Data Interface—EIA RS-232C
Connectors—(3) DB25 female
Enclosure—Aluminum
Approvals—FCC Class A, UL®, CSA
Operating Temperature—32 to 122°F (0 to 50°C)
Relative Humidity—Up to 90% noncondensing
Altitude—Up to 10,000 feet (3048 m)
Power Requirements—110- or 220-VAC, 47-63 Hz, 5 W external wallmount
transformer
Size—2"H x 8.3"W x 6.1"D (5.1 x 21.1 x 15.5 cm)
Weight—2.25 lb. (1 kg)

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TIME-DIVISION MULTIPLEXOR
2. Introduction
The Time-Division Multiplexor is a full-duplex, RS-232, 2-channel, time-division
multiplexor with an independent switch-selectable V.14/V.22-compliant
asynchronous-to-synchronous interface adapter on sub-channel 1. The composite
channel is designed to interface directly with a high-speed synchronous modem via
a straight-through cable. The unit operates by sequentially selecting a bit of data
from the sub-channel and then multiplexing it onto the composite channel. Each
sub-channel can operate at 1⁄2the composite channel rate. Standard DB25 female
connectors are provided on all sub-channels as well as the composite channel.
Power is provided by an external transformer connected through J1 (Power) on
the rear of the mutliplexor. The external power transformer is UL and CSA
approved.
Front-panel LEDs include SYNC and Power. When two TDMs are in sync with
each other and data transmission is possible, the SYNC LED should be lit. The
Power LED should be on at all times.
Three DB25 female connectors are provided for connecting the modem on the
composite port (J2) and two terminals. Channel 1 (J3) can be used for
synchronous or asynchronous operation. Channel 2 (J4) can be operated only as a
synchronous channel. Channel 1 must be used as either sync or async on both ends
of the circuit for the multiplexor to function properly.
Figure 2-1. Typical Application.
Async
Terminal
Sync
Terminal
Time-Division
Multiplexor
Time-Division
Multiplexor
Modem Modem
Host
Processor

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TIME-DIVISION MULTIPLEXOR
3. Setup and Installation
3.1 Installation
Set switches to match the required configurations as described in Sections 3.2
through 3.5. The cabling between each device and the Time-Division Multiplexor
must be terminated with male connectors. Character length and stop-bit reduction
only apply to channel 1 when it is selected for asynchronous operation.
3.2 Character Length
SW1 positions 1 and 2 select the character length. The character length includes
the start, stop, and any parity bits. 10-bit length is 1 start bit, 8 data bits, and 1 stop
bit. Figure 3-1 outlines all the available character bit lengths available.
3.3 Stop-Bit Reduction
SW1 position 3 selects the percentage of stop-bit reduction to occur when the sync
rate is faster than the async rate. Setting SW1 position 3 to ON will select 25% stop-
bit reduction. Setting SW1 position 3 to OFF will select 12.5% stop-bit reduction.
3.4 Channel 1 Sync/Async
SW1 position 5 selects channel 1 as a sync or async channel. This selection must be
the same on both ends of the circuit for the units to operate correctly. Setting SW1
position 5 to ON will select asynchronous operation on channel 1. Setting SW1
position 5 to OFF will select synchronous operation on channel 1.
3.5 Equipment Grounding
SW1 position 6 connects Pin #1 (Chassis Ground) to Pin #7 (Signal Ground).
3.6 Factory Straps
SW1 position 4 is not used. It must be in the OFF position. Jumpers JP1 through
JP3 must be installed for proper operation.

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TIME-DIVISION MULTIPLEXOR
3.7 Board Layout and Jumper Settings
Figure 3-1. Board Layout.
Power
Connector
J1
JP3
JP2 JP1
Power Sync
Factory Test
Jumpers
MUST BE IN
Character
Length
ON OFF
{
25% Stop Bit Reduction = ON/12.5% Stop Bit Reduction = OFF
Factory Test, MUST BE OFF
Chan 1 Async = ON/Chan 1 Sync = OFF
Signal Ground Connected to Chassis Ground = ON
J2 J3 J4
Composite
(Modem)
Channel 1
(Terminal)
Character Length — SW1
1 2 Length
OFF OFF 10 Bits
ON OFF 11 Bits
OFF ON 8 Bits
ON ON 9 Bits
Channel 2
(Terminal)
1 2 3 4 5 6