Black Box V.35 User Manual

1

For sending sync or
async data.

2-wire, twisted-pair
operation.

Transmit speeds up to

38.4 or 128 kbps.

Distances up to

3.4 miles (5.5 km).

Full-duplex operation
using “echo
cancellation.”

Performs local analog
loopbacks and local
and remote digital
loopbacks.

Generates bit error
rate test patterns.

Isolation transformer
guards versus AC or
DC overvoltages.

T

he BLACK BOX®V.35 2-Wire

Short-Haul Modem provides a
simple way to send your data at
short distance over telco lines.
The modem operates full-duplex
synchronously over a single 2-wire
twisted pair, at selectable data
rates from 600 bps up to 128 kbps,
or asynchronously up to 38.4 kbps.

The short-haul modem
incorporates interface circuits
for the terminal or computer, an
adaptive echo-canceler, an
automatic adaptive equalizer, a
modulator, and a demodulator. The
adaptive equalizer provides noise
immunity and high performance
over low-quality lines.

The modem uses 2B1Q line
coding and provides an operating
range of up to 3.4 miles (5.5 km)
over 26 AWG twisted-pair wire—
no matter what data rate is used.

The modem also couples to the
telephone line through an isolation
transformer that protects against
AC or DC overvoltages.
The protection circuitry enables
the unit to survive even if DC is
connected to the line accidentally.

ASYNC/SYNC 2-WIRE SHORT HAUL MODEM

DIG

ANA

PWR

RTS

TD

RD

DCD

LOS

ERR

TEST

REM

PATT

RESET

Send sync or async data up to 3.4 miles (5.5 km)

over your existing 2-wire twisted-pair lines.

Key Features

V.35 2-WIRE SHORT-HAUL MODEM

Full-duplex operation uses
echo cancellation. You need only
to set one modem to be a master
and the other to be a slave.

Internal DIP-switch controls
enable you to configure the V.35
2-Wire Short-Haul Modem to suit
your application. To reconfigure
the modem for a different type
of operation, just reposition the
switches.

The short-haul modem also
features diagnostic capabilities,
including local analog loopback
and local and remote digital
loopback. An operator at either end
of the link can test both local and
remote short-haul modems as well
as the line itself. Control loopback
with either the unit’s front-panel
pushbuttons or signals passed
through the DTE (PC, data terminal)
interface. Pressing the front-panel
Pattern button causes the local
short-haul modem to send the
remote unit a continuous Bit Error
Rate Test (BERT) pattern. By
performing these end-to-end tests,
you can ensure link integrity and
quickly find out which components

of your short-haul modem system
are operating properly and which
aren’t.

For monitoring and
troubleshooting purposes, the
short-haul modem has eight front­panel LEDs that inform you of the
device’s operational status and
activity. At a glace, you can tell
whether the local and remote units
are in sync, when the RTS signal
from the DTE is high, when the
local unit is transmitting or
receiving data, when the modem
detects an error in the BERT
pattern, and more.

For your transmission line, we
highly recommend using twisted­pair cable capable of supporting
high data rates, especially
Category 3 grade or better. For
DTE-side cable runs, use straight­through-pinned cable that’s no
more than 25 feet (7.6 m) long with
an M/35 male connector for
plugging into the V.35 2-Wire
Short-Haul Modem.

NOTE: Must be used in pairs.

Black Box Corporation • 1000 Park Drive • Lawrence, PA 15055-1018 • Tech Support: 724-746-5500 • www.blackbox.com • e-mail: [e-mail]

© 2004. All rights reserved.

Black Box Corporation.

11/18/2004 #14072

2

Approvals: FCC Part 15 Subpart B

Class A, DOC Class/MDC classe
Al; CE (ME376AE-R2 version)

Clocking: Internal, external, receive

Data Format: 7 or 8 data bits; 1 or 2

stop bits; even, odd, or no parity
(user-selectable)

Speed (Maximum): 128 kbps

synchronous, 38.4 kbps
asynchronous

Diagnostics: V.54-compliant

loopback tests: local analog
loopback (switch- or signal­triggerable); local digital
loopback (switch-triggerable);
remote digital loopback (switch­or signal-triggerable)

Distance (Maximum): DTE side:

25 ft. (7.6 m);

Line side: 3.4 mi. (5.5 km) over

26 AWG wire

Operation: Line side: Full duplex

with echo cancellation

Protocols: DTE side: Sync or async;

Line side: 2B1Q encoding

Standard: T1: ANSI T1.601.1988

Transmission Level: Up to 14 dBm

MTBF: 75,500 hours

User Controls: (5) front-mounted:

(4) pushbuttons: DIG (local

digital loopback), ANA (local
analog loopback), REM
(remote digital loopback),
PATT (test pattern);

(1) Recessed RESET switch;

(6) internal: (1) 7-position DIP

switch for protocol, data
format, signaling options;
(1) rotary switch for data rate;
(4) jumpers for clock source,
loopback testing, ground
connection

Interface: 2-wire telco, ITU-TSS

(CCITT) V.35

Connectors: V.35: (1) M/34 F;

Line side: (1) RJ-45, (1) 3-screw

terminal block

Indicators: (8) front-mounted LEDs:

PWR (Power), RTS, TD, RD, DCD,
LOS (Loss Of Signal), ERR (Error),
TEST

Temperature Tolerance:

32 to 122˚F (0 to 50˚C)

Humidity Tolerance: Up to 90%,

noncondensing

Power: ME376A-R2:

103.5–131.5 VAC, 47–63 Hz;

ME376AE-R2: 207–253 VAC,

47–63 Hz

Size: 1.8"H x 7.7"W x 9.7"D

(4.6 x 19.6 x 24.6 cm); but the
unit’s pushbuttons protrude up to

0.1" (25 mm) from the front panel
and the connectors protrude up
to 0.8" (2 cm) from the rear panel

Weight: 3.1 lb. (1.4 kg)

Specifications

Ordering Information

ITEM CODE

V.35 2-Wire Short-Haul Modem

103.5–131.5-VAC...............................................ME376A-R2

207–253-VAC...................................................ME376AE-R2

NOTE: Must be used in pairs.

Y

ou may also need…

V.35 Interface Cable,

10-ft. (3-m) Male/Male ........................EYN450-0010-MM

GigaBase

®

350 350-MHz CAT5e Bulk Cable, 4-Pair, PVC,

1100-ft. (335.3-m) Boxed Reel, Blue........EYN851A-1100

Recognize any of these
situations?

• You wait more than 30
minutes to get through to a
vendor’s tech support.

• The so-called “tech” can’t
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• You don’t have a purchase
order number and the tech
refuses to help you.

• It’s 9 p. m. and you need help,
but your vendor’s tech
support line is closed.

According to a survey by Data
Communications magazine, 90%
of network managers surveyed
say that getting the technical
support they need is extremely

important when choosing a
vendor. But even though network
managers pay anywhere from 10
to 20% of their overall purchase
price for a basic service and
support contract, the technical
support and service they receive
falls far short of their
expectations—and certainly isn’t
worth what they paid.

At Black Box, we guarantee
the best value and the best
support. You can even consult our
Technical Support Experts before
you buy if you need help selecting
just the right component for your
application.

Don’t waste time and
money—call Black Box today.

Why Buy From Black Box? Exceptional
Value .Exceptional Tech Support.Period.