Black Box High Speed SHM-B Async User manual

JANUARY 1995
ME802A
ME802AE
ME802C
High Speed SHM-B Async
High Speed SHM-B Async Card
CUSTOMER SUPPORT INFORMATION
Order toll-free in the U.S. 24 hours, 7 A.M. Monday to midnight Friday: 877-877-BBOX
FREE technical support, 24 hours a day, 7 days a week: Call 724-746-5500 or fax [phone]
Mail order: Black Box Corporation, 1000 Park Drive, Lawrence, PA 15055-1018
Web site: www.blackbox.com • E-mail: [email protected]
HIGH SPEED SHM-B ASYNC
RD
TD
NORMAL
DLB

HIGH SPEED SHM-B ASYNC AND CARD
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 specifi-
cations 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.

HIGH SPEED SHM-B ASYNC AND CARD
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
UL is a registered trademark of Underwriters
Laboratories Incorporated.
Any other trademarks mentioned in this manual are acknowledged to be the property
of the trademark owners.

HIGH SPEED SHM-B ASYNC AND CARD
Contents
Chapter Page
1. Specifications .........................................................1
2. Introduction...........................................................4
3. Installation .............................................................5
3.1 Four-Wire Connections...............................5
3.2 EIA-232 Connection ....................................7
3.3 Jumper Settings ...........................................9
3.4 Flow Control ................................................9
3.5 ME800 Compatibility.................................11
4. Operation.............................................................12
5. Rackmount Installation.......................................15
6. Troubleshooting ..................................................17

1
CHAPTER 1: Specifications
1. Specifications
Transmission —
Data Rate (bps) Max. Distance (miles)
115,200 1.5
56,000 1.7
19,200 2
2,400 4
NOTE: The transmission specifications are for 24-AWG unshielded
twisted-pair cable with a mutual capacitance of no more than
15 pF/ft. Shielded twisted-pair cable will reduce the distance to
one-third of the table value, because of 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 2500 volts.

2
HIGH SPEED SHM-B ASYNC AND CARD
Equipment Interface — EIA-232/CCITT V.24
interface with hardware-handshake support. Carrier
Detect (CD) true (high) indicates that the short-haul
modem at the remote end of the loop is on and
active. Interface is jumper selectable for DTE/DCE
configuration.
Connectors — (1) DB25 female, (1) 4-screw terminal
block
Diagnostics — Loopbacks provided by a front-panel
switch: Analog loopback on the 4-wire loop and
digital loopback on equipment interface
(EIA-232).
Status Indication — Two light-emitting diodes
(LEDs) indicate the status of the transmitter and
receiver. When the LED is on, it indicates a “high”
logic level is present on the appropriate RS-232 lead.
Enclosure — Mild steel
Compliance — FCC Class A, Subpart J of Part 15;
CSA; UL®
Order Information — ME802A: 115-VAC stand-
alone unit; ME802AE: 230-VAC standalone unit;
ME802C: Rackmount card unit; RM007: 8-card
desktop rack; ME810: 16-card rack for 19" cabinets

3
CHAPTER 1: Specifications
Temperature
Operating — 32 to 140°F (0 to 60°C)
Storage — -4 to 158°F (-20 to 70°C)
Humidity — 0 to 95% max., noncondensing
Power — ME802A, primary: 115 VAC ±10%,
60 Hz;
ME802AE, primary: 230 VAC ±10%,
50/60 Hz; Both, secondary: 17 VAC, 5 watts
Size — ME802A, ME802AE: 1.5"H x 4.4"W x 4.1"D
(3.8 x 11.2 x 10.4 cm);
ME802C: 0.9"H x 3.9"W x 4.5"D (2.3 x 9.9 x 11.4 cm)
Weight — ME802A, ME802AE: 2 lb. (0.9 kg),
including transformer;
ME802C: 0.5 lb. (0.2 kg)

4
HIGH SPEED SHM-B ASYNC AND CARD
The High Speed SHM-B Async is an asynchronous
full-duplex 4-wire line driver/receiver. With a pair of
these devices, two EIA-232 devices can com-municate
at distances of up to 4 miles (6.4 km) and at data
speeds of up to 115.2 Kbps. In addition to the
transmitter and receiver circuits, the High Speed
SHM-B Async includes EIA-232 control-line
interfaces, status monitor LEDs, and a loopback
switch. The High Speed SHM-B Async is available in
both a standalone version (ME802A or ME802AE)
and a rackmount card version (ME802C).
The High Speed SHM-B Async is designed to operate
over a 4-wire metallic circuit. The best performance
is obtained with twisted-pair cable (see Chapter 1).
Most types of twisted-pair cable may be used;
however, to achieve maximum performance, we
recommend Level 4 or Level 5 UTP cable.
The High Speed SHM-B Async is designed for
maximum operator safety. There are no voltages
greater than ±9 VDC or 17 VAC present on the
circuit board of the unit. The Receive lines are
protected from potential ground differences
through optical isolators rated at 2500 volts.
2. Introduction

5
CHAPTER 3: Installation
3. Installation
Installation involves three steps: four-wire
connections, EIA-232 connection, and jumper
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 High Speed
SHM-B Async units.
NOTE: Transmit + (TX+) on one modem is wired to Receive + (RX+) on
the other modem; Transmit - (TX-) is wired to Receive - (RX-).
1.Insert the wires into the terminal strip; tighten the
screw terminals.
2.After you have made all four connections, wrap the
nylon cable tie (included) around the wires. Pull the
tie tight around the wires to secure them to the
printed circuit board. Trim the excess nylon tie with
wire cutters or scissors.

6
HIGH SPEED SHM-B ASYNC AND CARD
Figure 1. High Speed SHM-B Async board:
locations of jumpers and 4-screw terminal block.
J1 RS-232 CONNECTOR
DCE
LOOPBACK SWITCH
RX+
RX- TX+
TX-
DTE
XW1A
XW1B
A B C
W2
A B C
W4
A B C
W3

7
CHAPTER 3: Installation
Figure 2. Wiring diagram for two High Speed
SHM-B Async units.
3.2 EIA-232 Connection
Connect the High Speed SHM-B Async to your
computer or terminal with a standard EIA-232 cable
and DB25 connectors. Refer to your equipment’s
installation manual if you need information on the
exact EIA-232 signals required for your equipment.
Often, it is best to use only the Transmit Data (TD),
TX+
TX-
RX+
RX-
RX+
RX-
TX+
TX-
SHM #1 SHM #2

8
HIGH SPEED SHM-B ASYNC AND CARD
Receive Data (RD), and ground lines if your
equipment does not require the use of the control
signals Request to Send (RTS), Clear to Send (CTS),
Data Set Ready (DSR), etc. The High Speed SHM-B
Async generates levels for the control signals if you
need to use them. The table below shows the pin
connections on the High Speed SHM-B Async.
Table 1. EIA-232 Pin Connections
ME802 ME802
Pin Signal configured configured
No. Name as DCE as DTE
1 Protective Ground earth ground earth ground
2 Transmit Data input output
3 Receive Data output input
4 Request to Send input output*
5 Clear to Send output* input
6 Data Set Ready output* input
7 Signal Ground signal ground signal ground
8 Carrier Detect output N/C
20 Data Terminal Ready input output
* Always high

9
CHAPTER 3: Installation
3.3 Jumper Settings
Refer to Figure 1 on page 6. Shunt W1 is used to
select DTE/DCE operation. This eliminates the need
to use a crossover cable when connecting to your
data-communications equipment.
If you connect the High Speed SHM-B Async to your
equipment using a straight-through cable, then W1
must be set to the opposite of your device’s
configuration. For example, if your device is
configured as DTE, select DCE via W1.
If you use a crossover cable to connect the High
Speed SHM-B Async to your equipment, then the
setting for W1 will be identical to your equipment’s
setting. Refer to your equipment’s manual for
information concerning its DTE/DCE setting.
3.4 Flow Control
H ARDWARE H ANDSHAKING
(J UMPER W2 IN THE A-B [E NABLED ] P OSITION )
When the High Speed SHM-B Async is set for DCE
operation (shunt jumper in the W1B position), DTR
or RTS asserted true (high) from the attached RS-
232 device activates the High Speed SHM-B Async
driver circuit. When the High Speed SHM-B Async
is set for DTE operation, CTS or DSR from the
attached RS-232 device activates the driver circuit

10
HIGH SPEED SHM-B ASYNC AND CARD
on the High Speed SHM-B Async. The High Speed
SHM-B Async at the remote end of the line will sense
this and raise its CD lead (pin 8) when it is
configured as a DCE device.
If the remote High Speed SHM-B Async is
configured as a DTE device, it raises its DTR lead
(pin 20) when it senses an active driver circuit on
the High Speed SHM-B Async at the other end of
the line.
X-ON/X-OFF M ODE (J
UMPER W2 IN THE B-C [D ISABLED ]
P
OSITION )
If X-ON/X-OFF characters are used for handshaking
control, rather than hardware logic levels, move
jumper W2 to the B-C or Disabled position.
Typically, units that use software X-ON/X-OFF flow
control do not want RTS to affect DCD on the
remote High Speed SHM-B Async. Moving jumper
W2 to the B-C position disables the RTS/DCD
relationship. The only thing that will force DCD low
with the jumper in the Disabled position is the
absence of power at either High Speed SHM-B
Async, or a broken twisted-pair wire.

11
CHAPTER 3: Installation
3.5 ME800 Compatibility
The High Speed SHM-B Async can be configured
to operate properly with ME800 SHM-B Async units.
Jumpers W3 and W4 when set in the A-B positions
allow the High Speed SHM-B Async to operate at
maximum speeds and distances. When jumpers W3
and W4 are set in the B-C positions, the output signal
of the High Speed SHM-B Async is reduced to be
compatible with the ME800 SHM-B Async. If the
Jumpers W3 and W4 are not placed in the B-C posi-
tion and an ME800 unit is attached, the receive
circuitry on the ME800 may be damaged.

12
HIGH SPEED SHM-B ASYNC AND CARD
After configuring the High Speed SHM-B Async for
your application, connect it to your equipment, then
plug the power transformer into its power source.
Check the operation of the High Speed SHM-B
Async at both ends of the loop by pressing the
front-panel LOOPBACK switch.
Press the LOOPBACK switch at the “local” High
Speed SHM-B Async to check the connections to
the attached RS-232 device. If a CRT terminal is
connected to the High Speed SHM-B Async, typing
characters on the keyboard should result in the same
characters appearing on the CRT screen. If no
characters appear, check your EIA-232 connections
and the setting of the DTE/DCE jumper W1.
Once you have checked the connection to the
attached RS-232 device, release the LOOPBACK
switch on the “local” High Speed SHM-B Async and
press the LOOPBACK switch on the “remote” High
Speed SHM-B Async. If a CRT terminal is connected
to the “local” High Speed SHM-B Async, typing
characters on the keyboard should result in the
same characters appearing on the CRT screen. If no
4. Operation

13
CHAPTER 4: Operation
characters appear, check the 4 wire connections
between the two High Speed SHM-B Async units for
improper polarity or broken wires. See Figure 3 for
an illustration of the loopback mode.
When the loopback tests are completed, return both
High Speed SHM-B Async units to normal mode.
Data transmission between the two modems should
now be possible.
If you have problems communicating between the two
High Speed SHM-B Async units, refer to Chapter 6 to
help diagnose the problem.
Figure 3. Activating the LOOPBACK switch.
TD
(RS-232)
RD
TX-
RX-
TX+
RX+
RD
(RS-232)
TD
RX-
TX-
RX+
TX+
TD
(RS-232)
RD
TX-
RX-
TX+
RX+
RX-
TX-
RX+
TX+
TD
(RS-232)
RD
TX-
RX-
TX+
RX+
TD
(RS-232)
RD
TX-
RX-
TX+
RX+
RD
(RS-232)
TD
SHM #1 in NORMAL mode. SHM #2 in NORMAL mode.
SHM #1 in LOOPBACK mode. SHM #2 in NORMAL mode.

14
HIGH SPEED SHM-B ASYNC AND CARD
The TD and RD LEDs on the front panel of your
High Speed SHM-B Async indicate the status of the
High Speed SHM-B Async transmitter and receiver,
respectively. The TD LED will light when data is
transmitted out of the RS-232 port on the High
Speed SHM-B Asyn; the RD LED will light when data
is received.

15
CHAPTER 5: Rackmount Installation
The High Speed SHM-B Async Card (ME802C) is
a rackmount unit that installs in a standard 19-inch
(48.3-cm) panel rack. (You can use the SHM-B Rack
[ME810], which can hold up to 16 cards.) The SHM-
B Async rack will occupy 5.25 inches (13.3 cm) of
vertical rack space, and is 9 inches (22.8 cm) deep.
To install the SHM-B Rack, first remove the acrylic
front panel by pulling out the six plunger latches on
the front of the panel, then pulling on opposite-side
plungers to loosen and remove the panel.
Locate the four 10/32 Phillips-head screws that were
shipped with the SHM-B Rack. Use these screws to
fasten the SHM-B Rack to your rack cabinet.
CAUTION
Do not attempt to use screws that are not countersunk,
since this will result in damage to the plastic front panel
when it is installed.
Wire each SHM-B board according to Figures 1 and
2. It is easiest to first feed all of the wires and cables
through the rack. Then you can make the necessary
circuit-board connections with the circuit boards
5. Rackmount Installation

16
HIGH SPEED SHM-B ASYNC AND CARD
positioned in front of the rack; this allows for the
easiest access to the terminals, switches, etc.
After a High Speed SHM-B Async Card is wired, it
can then be inserted into an open slot in the SHM-B
rack. Be certain that the circuit board has mated with
the power pins on the SHM-B rack before applying
force to fully seat the board; otherwise you may
damage the board and power pins.
When all boards have been wired and plugged into
the rack, plug the wall transformer into its power
source. You should be able to communicate as
described in Chapter 4. When all channels are
operating, attach the SHM-B Rack front panel by first
aligning the plunger latches with their respective
holes in the rack. Press on the top and bottom of the
panel to properly seat it, then firmly press in all six of
the plunger latches to retrain the panel.