Black Box SHM-B Sync User manual

DECEMBER 1999
ME801A
ME801A-E
ME801-C
Short-Haul Modem-B Sync
(SHM-B 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]
SYNC SHORT HAUL MODEM
TD RD
NORMAL
LOOPBACK

1
FCC/IC 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 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.
TRADEMARKS USED IN THIS MANUAL
Any trademarks mentioned in this manual are acknowledged
to be the property of the trademark owners.

2
SHORT-HAUL MODEM-B SYNC (SHM-B SYNC)
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.

3
NOM STATEMENT
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.

4
SHORT-HAUL MODEM-B SYNC (SHM-B SYNC)
Contents
Chapter Page
1. Specifications ......................................................................... 5
2. Introduction .......................................................................... 8
3. Configuration ........................................................................ 9
4. Installation ........................................................................... 12
4.1 Installing Standalone Units ........................................ 12
4.2 Installing Card Units .................................................. 15
4.3 Initial Testing .............................................................. 18
5. Operation ............................................................................. 19
5.1 Normal Operation and LED Functions .................... 19
5.2 The RS-232 Signals, Flow Control, and
Synchronous Timing ............................................... 20
6. Troubleshooting .................................................................. 24
6.1 Loopback Mode .......................................................... 24
6.2 Common Problems ..................................................... 26
6.3 Calling Black Box ........................................................ 31
6.4 Shipping and Packaging ............................................. 32
Appendix A: Distances, Data Rates, and Cable Specifications .. 33
Appendix B: Block Diagram ........................................................ 34

5
CHAPTER 1: Specifications
1. Specifications
Compliance — FCC Part 15 Subpart J Class A,
IC Class/classe A
Interfaces — RS-232-C (DCE) to attached local device;
Proprietary balanced 4-wire to line
Protocol — Synchronous
Clock Source — Local internal (each SHM-B Sync unit
independently generates its own clock)
Operation — 4-wire full-duplex
Flow Control — Hardware (RTS and/or DTR), local only
(control signals are not passed across the
4-wire line—see Section 5.2); transparent
to software (X-ON/X-OFF, etc.)
Data Rate — 19,200, 9600, 4800, 2400, 1200, or 600 bps
(user-selectable)
Maximum
Distance — See the table in Appendix A
Loopback — Simultaneous local loopback to attached
RS-232 device and remote loopback to
remote SHM-B Sync (user-controllable)

6
SHORT-HAUL MODEM-B SYNC (SHM-B SYNC)
User Controls — (1) Front-mounted pushbutton to turn
loopback ON and OFF;
(6) Internal pairs of jumper posts for setting
the data rate;
(3) Internal pairs of jumper posts for setting
CTS delay
Indicators — (2)Front-mounted bicolor LEDs for transmit
status and receive status; these light green
for a “low” logic level (–3 to –25 V) or red
for a “high” logic level (+3 to +25 V)
Connectors — RS-232: (1) Rear-mounted DB25 female;
Line: (1) Internal 4-position screw-terminal
block
Leads/Signals
Supported — RS-232: Transmit Data (TD), Receive Data
(RD), Request to Send (RTS), Clear to
Send (CTS), Data Set Ready (DSR), Signal
Ground (SGND), Carrier Detect (CD),
Transmit Clock (TC), Receive Clock (RC),
and Data Terminal Ready (DTR)—
Pins 1 through 8, 15, 17, and 20
respectively;
Line: TX+, TX–, RX+, and RX–

7
CHAPTER 1: Specifications
Power — ME801A: From utility-power (mains) outlet
through wallmount transformer:
Input: 108 to 132 VAC, 60 Hz, at ~160 mA
(20 watts);
Output: 17 VAC CT at 700 mA;
ME801A-E: From utility-power (mains) outlet
through desktop transformer:
Input: 198 to 242 VAC, 50 or 60 Hz, at
~90 mA (20 watts);
Output: 17 VAC CT at 700 mA;
ME801-C: 17 VAC CT at 700 mA from rack’s
electrical-power bus
Surge Protection — Internal opto-isolators (effective up to
20 VDC) on transmit and receive lines
Temperature
Tolerance — 32 to 122˚F (0 to 50˚C)
Humidity
Tolerance — Up to 95% noncondensing
Enclosure — ME801A, ME801A-E: High-impact plastic
Size — ME801A, ME801A-E: 1.4"H x 4.3"W x 4.5"D
(3.6 x 10.9 x 11.5 cm);
ME801-C: 4"H x 0.5"W x 4.5"D
(10.2 x 1.3 x 11.5 cm)
Weight — ME801A, ME801A-E: 1.3 lb. (0.6 kg)
including power supply;
ME801-C: ~3 oz. (~85 g)

8
SHORT-HAUL MODEM-B SYNC (SHM-B SYNC)
2. Introduction
The Short-Haul Modem-B Sync (SHM-B Sync for short)
is a synchronous full-duplex 4-wire line driver and
receiver that makes it possible for two RS-232-C devices
to communicate across distances up to 5 miles (8 km), at
data rates up to 19,200 bps. In addition to its transmitter
and receiver circuits, the SHM-B Sync also features status
LEDs, a loopback switch, and support for RS-232 clock
and control signals.
The SHM-B Sync is designed to operate with 4-wire
cable. See Appendix A for optimum cable specifications
and supported distances/data rates.
The SHM-B Sync is also designed for maximum
operator safety. There are no voltages greater than
12 VDC or 17 VAC present on the unit’s circuit board.
Opto-isolation circuits protect both the transmit and
receive lines against voltage surges (up to 20 VDC) such
as those caused by lightning.
The SHM-B Sync is available in either a 120-VAC
(ME801A) or 220-VAC (ME801A-E) standalone version
or a card version (ME801-C) that will fit in our ME810
or RM007 card chassis.

9
CHAPTER 3: Configuration
3. Configuration
Before you install a pair of SHM-B Sync units, you
should set their configuration jumpers as necessary.
CAUTION!
If you have the card version, make very sure that the
SHM-B Sync card is not installed in a powered chassis
when you configure it. If you have the standalone version,
make sure that it is unplugged and is disconnected from
any other devices. No voltages greater than 17 VAC are
ever present on the board even when it is powered, but the
possibility of electric shock should always be avoided.
When you handle the SHM-B Sync’s circuit board, take
every reasonable precaution against damaging the board
with static electricity. At the very least, discharge yourself
by touching a fixed metal surface before handling the
board; if possible, stand on an anti-static mat and wear a
grounding strap or anti-static gloves.
There are two sets of jumper posts mounted on the
SHM-B Sync’s circuit board:
• Six pairs of posts are used to set the SHM-B Sync’s
data rate. They’re at the front of the left-hand side
of the board (the ones labeled “DATA-RATE
SELECTION” in Figure 3-1). The six possible data-
rate settings are 600, 1200, 2400, 4800, 9600, and
19,200 bps. The factory-default value is 9600 bps; if
your RS-232 equipment is using one of the other
data rates, set the jumpers in both units accordingly
by moving the jumper to the appropriate pair of

10
SHORT-HAUL MODEM-B SYNC (SHM-B SYNC)
posts. (The SHM-B Sync units must both be set
to the same data rate, which they will generate
internally; the attached devices must be set to
accept clock from them.)
• Three pairs of posts are used to set the SHM-B
Sync’s CTS delay. They’re at the rear of the right-
hand side of the board (the ones labeled “CTS-
DELAY SELECTION” in Figure 3-1). The CTS delay
is the amount of time that the SHM-B Sync waits
after detecting that the attached device has raised
RTS before it responds by raising CTS. The possible
settings are LONG (53 ms), SHORT (7 ms), or
NONE. Factory default is NONE, but if your RS-232
device needs to see a CTS delay in order to function
properly, move the jumper to the appropriate post
in that SHM-B Sync only.
Standalone units only: To open the unit’s case, push in on
either side of the top half of the case, close to the front
of the unit, then pry the top of the case away from the
bottom half. (If your hand is large enough, you can
squeeze both sides of the case’s top half toward each
other at the same time, then pry it upward.) The halves
of the case are hinged at the back, so the unit swings
open like a compact or a makeup case.

11
CHAPTER 3: Configuration
Figure 3-1. The SHM-B Sync’s circuit board. (Standalone board shown;
card version will not have power-line connection.)
RX+ RX– TX+ TX–
• • 600
• • 1200
• • 2400
• • 4800
• • 9600
• • 19200
• • LONG
• • SHORT
• • NONE
TRANSMISSION-
LINE CONNECTION
DATA-RATE
SELECTION
16-VAC
POWER
LINE
4-WIRE (2-PAIR) TWISTED-PAIR
COMMUNICATIONS LINE
TX RX
INDICATORS
LOOPBACK
SWITCH
CTS-DELAY
SELECTION
J1: RS-232
CONNECTOR

12
SHORT-HAUL MODEM-B SYNC (SHM-B SYNC)
4. Installation
4.1 Installing Standalone Units
Take these steps to install a pair of standalone SHM-B
Sync units (ME801A or ME801A-E):
1. Open the case of one of the SHM-B Sync units.
Refer to Chapter 3 for how to do this (and for
precautions you should take when you do).
2. Feed the 4-wire twisted-pair cable that will run
between your SHM-B Sync units through the
appropriate hole in the back of the case (refer to
Figure 3-1 on the previous page). Refer to
Appendix A for maximum-length guidelines for
this cable.
3. Take the end of this cable and remove the outer
jacket and insulation from the last half-inch
(1.3 cm) or so of it, exposing the ends of the four
individual wires. Strip the insulation from the last
1⁄8to 3⁄16 of an inch (0.3 to 0.5 cm) of each wire.

13
CHAPTER 4: Installation
4. Thread the bare ends of the four wires into the
four screw terminals on the SHM-B Sync’s board
marked RX+, RX–, TX+, and TX–. Refer to
Figure 3-1 on page 11 for the location of these
terminals. Bear in mind as you do this that the
wires must run from TX+ in one SHM-B Sync
to RX+ in the other, and from TX– to RX–, RX+
to TX+, and RX– to TX–, as shown in Figure 4-1
below.
Figure 4-1. Cable wiring between SHM-B Sync units.
5. Wrap the nylon cable tie provided with the SHM-B
Sync around the four wires, threading it through
the two holes in the circuit board just behind the
terminal block. Pull it tight to secure the wires in
place against the board. Remove the excess nylon
tie with a pair of scissors or wire cutters.
6. Close the unit’s case.
RX+
RX–
TX+
TX–
TX+
TX–
RX+
RX–
SHM #1 SHM #2

14
SHORT-HAUL MODEM-B SYNC (SHM-B SYNC)
7. Plug one end of an RS-232 cable into the DB25
female connector on the rear of the unit. Avoid
running this cable farther than 50 ft. (15.2 m).
Refer to Section 5.2 for information about
supported RS-232 signals and about how this cable
should be pinned.
8. Plug the other end of the RS-232 cable into a
powered-down device whose serial communication
you want to extend.
9. Repeat steps 1 through 8 with the remote site’s
SHM-B Sync unit.
10. Plug in both SHM-B Sync units and power up the
attached RS-232 devices. Your SHM-B Sync system
should begin operating right away. If the LEDs on
the units’ front panels light up, go on to
Section 4.3. If not, refer to the first item in
Section 6.2.

15
CHAPTER 4: Installation
4.2 Installing Card Units
Take these steps to install a set of SHM-B Sync cards
(ME801-C):
1. Remove the front panel of the powered-down
ME810 or RM007 card chassis in which you’ll
be installing a SHM-B Sync card. If you’re unsure
how to do this, refer to the chassis’ manual.
2. Feed both (a) the 4-wire twisted-pair cable that will
run between your SHM-B Sync units and (b) the
RS-232 cable that will run from the SHM-B Sync to
the attached device through the back of a vacant
slot in the card chassis. Refer to Appendix A for
maximum-length guidelines for the 4-wire cable.
3. Take the end of the 4-wire cable and remove the
outer jacket and insulation from the last half-inch
(1.3 cm) or so of it, exposing the ends of the four
individual wires. Strip the insulation from the last
1⁄8to 3⁄16 of an inch (0.3 to 0.5 cm) of each wire.
4. Thread the bare ends of the four wires into the
four screw terminals on the SHM-B Sync’s board
marked RX+, RX–, TX+, and TX–. Refer to
Figure 3-1 on page 11 for the location of these
terminals. Bear in mind as you do this that the

16
SHORT-HAUL MODEM-B SYNC (SHM-B SYNC)
wires must run from TX+ in one SHM-B Sync to
RX+ in the other, and from TX– to RX–, RX+ to
TX+, and RX– to TX–, as shown in Figure 4-1 on
page 14.
5. Wrap the nylon cable tie provided with the SHM-B
Sync around the four wires, threading it through
the two holes in the circuit board just behind the
terminal block. Pull it tight to secure the wires in
place against the board. Remove the excess nylon
tie with a pair of scissors or wire cutters.
6. Plug one end of an RS-232 cable into the DB25
female connector on the back of the card. Avoid
running this cable farther than 50 ft. (15.2 m).
Refer to Section 5.2 for information about
supported RS-232 signals and about how this cable
should be pinned.
7. Slide the card into the front of the chosen vacant
slot in the card chassis: Slide it carefully along the
grooved tracks at the top and bottom of the slot
until it reaches the three “power pins” at the back
of the chassis. Make sure that the card’s three
power sockets have mated with these pins before
applying force to fully seat the card; otherwise,
when you push the card into the back of the
chassis, you might damage the card and the chassis.

17
CHAPTER 4: Installation
8. Plug the other end of the RS-232 cable into a
powered-down device whose serial communication
you want to extend.
9. Repeat steps 1 through 8 with the remote site’s
SHM-B Sync card.
10. Plug in both chassis and power up the RS-232
devices attached to each card. Your SHM-B Sync
system should begin operating right away. If the
LEDs on the cards’ front panels light up, do the
tests described in Section 4.3. If not, refer to the
first item in Section 6.2.
11. Repeat steps 1 through 10 for any other
communicating pairs of SHM-B Sync cards
you want to install in this pair of card chassis.
12. If all of your cards and attached devices seem to be
operating correctly, put the front panels of both
card chassis back on.

18
SHORT-HAUL MODEM-B SYNC (SHM-B SYNC)
4.3 Initial Testing
When you have installed and powered up a pair of
SHM-B Sync units and the attached RS-232 devices, test
your system by sending data from one RS-232 device to
the other (and vice versa if the link is meant to be
bidirectional). If this works, go on to Section 5.1. If it
doesn’t, perform loopback testing as described in
Section 6.1 and refer to the problem descriptions in
Section 6.2 as necessary.

19
CHAPTER 5: Operation
5. Operation
5.1 Normal Operation and LED Functions
While the SHM-B Sync and its attached devices are
plugged in and the atached devices are plugged in
and turned on, the system should operate continuously
without requiring human intervention. You can,
however, monitor the unit’s status at any time by looking
at the LEDs marked “TD” and “RD” on the unit’s front
panel. These will indicate the logic status of the
transmitter and recceiver circuitry, respectively: They
will light green for a “high” logic level or red for a “low”
logic level, and will flicker as data is transmitted and
received. (These LEDs respond to the actual transmitted
and received signals, not the TD and RD lines of the
RS-232 interface.)
Refer to the next section for a description of how the
RS-232 interface operates, and to Appendix B for a block
diagram of how the SHM-B Sync works at a circuit level.
If you ever have difficulty, you can do loopback testing
as described in the next section and/or refer to the
problem descriptions in Section 6.1.