Black Box ME447A, ME447AE, ME447C-232, ME447C-35, MED447C-530 User Manual

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: [e-mail]

MARCH 1997

ME447A

ME447AE

ME447C-232

ME447C-35

MED447C-530

LDM-144LR

LDM-144LR Card

LDM-144LR

PATT

REM

ANA

DIG

PWR

RTS

TD

RD

DCD

TEST

ERR

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LDM-144LR

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 B 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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LDM-144LR

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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LDM-144LR

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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LDM-144LR

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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LDM-144LR

Contents

Chapter Page

1. Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

1.1 Transmission Line. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

1.2 Digital Interface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

1.3 Diagnostics (V.54 Standard Compliant) . . . . . . . . . . . . . . . . . . . . . . 7

1.4 Timing Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

1.5 Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

1.6 Physical. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

1.7 Electrical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

1.8 Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

1.9 Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

2.1 General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

2.2 Physical Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

2.3 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

2.3.1 Encoder Modulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

2.3.2 Modulation Timing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

2.3.3 Selectable Level Transmit Amplifier . . . . . . . . . . . . . . . . . . . . 13

2.3.4 V.54 Diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

2.3.5 Test Pattern Generator and Receiver . . . . . . . . . . . . . . . . . . . 13

2.3.6 Selectable Carrier Detect Sensitivity . . . . . . . . . . . . . . . . . . . . 13

2.4 Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

3. Standalone Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

3.1 General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

3.2 Site Preparation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

3.3 Mechanical Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

3.4 Electrical Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

3.4.1 Power Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

3.4.2 Rear Panel Connectors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

3.4.3 DTE Interface Side . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

3.4.4 Strap Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

3.4.5 Installation of Internal Jumpers and Switches . . . . . . . . . . . . 19

3.4.6 Line Side . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

6

LDM-144LR

Contents (continued)

Chapter Page

4. Standalone Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

4.1 General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

4.2 Controls and Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

4.3 Operating Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

4.3.1 Powering On . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

4.3.2 Self Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

4.3.3 Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

4.3.4 Turning Off Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

4.4 Field Settings of Jumpers and Switches . . . . . . . . . . . . . . . . . . . . . . . 29

5. Tests and Diagnostics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

5.1 General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

5.2 V.54 Loop Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

5.2.1 Local Test—Local Analog Loopback (ANA) . . . . . . . . . . . . . 30

5.2.2 Remote Digital Loopback (REM) . . . . . . . . . . . . . . . . . . . . . . 32

5.2.3 Local Digital Loopback (DIG) . . . . . . . . . . . . . . . . . . . . . . . . . 33

6. Card Cage Version . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

6.1 RM110A Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

6.2 LDM-144LR Card Version . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

6.3 Power Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

6.3.1 AC Supply (110 or 230 VAC) . . . . . . . . . . . . . . . . . . . . . . . . . . 35

6.3.2 DC Supply (-48 VDC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

6.3.3 Power Supply with Redundancy. . . . . . . . . . . . . . . . . . . . . . . . 35

6.4 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

6.4.1 Electrical Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

6.4.2 Mechanical Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

6.5 Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Appendix A: IR-G.703 Co-Directional 64-kbps Interface . . . . . . . . . . . . . . . 38

Appendix B: RS-422 Interfacing Pinout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

Appendix C: Unit Case Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

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LDM-144LR

1. Specifications

1.1 Transmission Line

Line Type—Unloaded twisted pair 19 to 26 gauge; DC continuity is not

required

Range—Refer to Table 1-1

Level—0 dBm or -6 dBm (jumper-selectable)

Transmit Impedance—LOW or HIGH (jumper-selectable)

Receive Impedance—150 Ω or HIGH (jumper-selectable)

Return Loss—Greater than 15 dB

Carrier—RTS controlled (CNTRL) or permanently ON; in the X.21 mode,

the carrier is controlled by CONT signal (pins 3 and 10)

Modulation—Partial Response, Class IV (PR4)

1.2 Digital Interface

Type—When ordering, three options are available:

1. V.24/RS-232 via a DB25 female connector (ME447C-232)

2. V.35 via a 34-pin female connector (ME447AE-35, ME447C-35)

3. RS-530 via a DB25 female connector (ME447C-530)
The interfaces are modular and field-interchangeable.

Baud Rates—Selectable to 48, 56, 64, 72, 96, 112, 128, and 144 kbps;

48-128 kbps for V.24

RTS/CTS Delay—Jumper selectable: 8 or 70 ms

1.3 Diagnostics (V.54 Standard Compliant)

Digital Loopback—Local (DIG): activated by front-panel pushbutton,

Remote (REM): activated by front-panel pushbutton, or by control
signal from the digital interface.

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LDM-144LR

Analog Loopback—Local (ANA): activated by front-panel pushbutton or

by control signal from the digital interface

Pattern—Test pattern (PATT): activated by a manual switch. The received

pattern is compared to the transmitted pattern; if unequal, ERR LED
flashes.

NOTE

The X.21 and G.703 interfaces do not support the activation of Digital and
Analog loopbacks via the interface connector.

1.4 Timing Elements

Receive Clock—Derived from the Receive signal

Transmit Clock—Derived from one of three alternative sources:

1. External oscillator

2. External from the DTE

3. Loop clock derived from the receive signal

NOTE

When the X.21 interface is set to EXT CLK, the modem receives clocking
signals from the digital side using unassigned pins of the X.21 interface.

1.5 Indicators

TD (yellow)—Transmit Data

RD (yellow)—Receive Data

RTS (yellow)—Request to Send

DCD (yellow)—Data Carrier Detect

TEST (red)—Test

PWR (green)—Power

ERR (yellow)—Error

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LDM-144LR

1.6 Physical

Size—ME447AE: 1.75"H x 8.6"W x 10.6"D (4.4 x 21.5 x 26.5 cm);

ME447C: 0.9"H x 6.2"W x 9"D (2.5 x 15.7 x 23 cm)

Weight—ME447AE: 2.6 lb. (1.2 kg); ME447C: 10 oz. (0.36 kg)

1.7 Electrical

Power Supply—100 VAC, 115 VAC, or 230 VAC (±10%, 47 to 63 Hz,

5 watts), -48 VDC (±10%)

1.8 Protection

AC/DC overvoltage protection circuits are connected in-line,
preceding the transformer, to the transmit and receive lines.

1.9 Environment

Temperature—32 to 122°F (0 to 50°C)

Humidity—Up to 90%, non-condensing

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LDM-144LR

2. Introduction

2.1 General

The LDM-144LR is a short-range modem for synchronous transmission, full
or half duplex, over unconditioned lines. The LDM-144LR has a range of up
to 26.5 km (16.5 miles) and operates at selectable data rates from 48 kbps to
144 kbps.

The modem uses a unique modulation technique named Partial Response,

Class IV (PR4) in order to:

• Provide background noise immunity

• Eliminate normal line distortion

• Enable efficient transmission and reception of serial data over a twisted
pair cable

• Provide extended range

The LDM-144LR is coupled to the line through isolation transformers,
which in conjunction with protective circuitry, safeguard against AC or DC
overvoltages. The protective circuitry enables operation even when DC is
connected to the line.

The LDM-144LR transmit timing is internally provided, or externally
derived either from the data terminal or from the receive signal. The receive
timing is always regenerated from the receive signal.

The LDM-144LR features V.54 diagnostic capabilities for performing local
analog loopbacks and local and remote digital loopbacks. In the digital
loopback mode, the operator at either end of the line may test both modems
and the line. The loopback is controlled either by the front-panel
pushbuttons or through the DTE interface. Three DTE digital interface
options are available:

• RS-232/V.24 (up to 128 kbps)

• V.35

• RS-530

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LDM-144LR

An RS-422/V.36 terminal can be connected through the RS-530 interface
using an adaptive cable, as detailed in Appendix B.

The LDM-144LR incorporates a built-in Bit Error Rate Tester (BERT). The
internal BERT enables complete testing of both modems and the line without
external test equipment. A CCITT/V.52, 511-bit pseudo-random test pattern
is generated through a front-panel switch for testing end-to-end connectivity.
When a bit error is encountered, the ERR indicator flashes.

2.2 Physical Description

The LDM-144LR is available as a standalone unit (LDM-144LR), or as a rack­mounted unit (LDM-144LR Card) within a 19" rack. A 19" rack can carry up
to 14 cards and provides DB25 connectivity to digital interfaces. Optional
V.35 and X.21 interface adapters are available.

2.3 Functional Description

This section contains the functional descriptions of the LDM-144LR circuit
blocks, primarily those circuits that are required to set the correct
configuration of the modem. For the block diagram, see Figure 2-1.

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LDM-144LR

Figure 2-1. LDM-144LR Block Diagram.

2.3.1 E

NCODER

M

ODULATOR

The Encoder Modulator receives data from the DTE and modulates it by
means of the partial-response modulation technique. The Encoder
Modulator can operate in one of the following modes:

• 4-wire full-duplex

• 4-wire half-duplex

2.3.2 M

ODULATION

T

IMING

This circuit supplies the transmit clock to the Encoder Modulator. Three
clock sources are available:

• The modem’s internal crystal oscillator, INT

• The DTE clock, EXT

• The receive signal recovered clock, RCV

Setting the transmit clock jumper (J1) determines the timing mode of the
LDM-144LR.

CTS

Delay

OSC

Power

Supply

Modulation

Timing

REM

COMMAND

GENERATOR

RTS

BERT

ERROR

Encoder

Modulation

REM

COMMAND

GENERATOR

V.5 4

Diagnostics

PATT

REM

RTS
CTS

TXC
EXT
CLK

TXD

REM

ANA

RXD

TXD

TXD

CNT/ON

DIG

Encoder

Modulation

Transmit

Filter

Selectable Level

Transmit Filter

Loopback

Timing

RLB

Command

Decoder

Decoder

Timing

Recovery

Carrier

Detect

DATA
RATE

Automatic

Equalizer

ANA

TX

TX

Selectable Level
Receiv Amplifier

DIG

LPBK

5

6

7

3

2

1

4

0

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LDM-144LR

2.3.3 S

ELECTABLE

L

EVELTRANSMITAMPLIFIER

Two options are available for the transmit signal level: 0 and -6 dBm. The
transmit signal level is controlled by the XMT LEVEL jumper (J11). Receive
signal gain is controlled by the RCV LVL jumper (J9) and has two selectable
options: 0 and -6 dBm.

2.3.4 V.54 D

IAGNOSTICS

V.54 loops are activated either by the manual front panel push-buttons or
through the DTE interface. The push-button controlled loopbacks can be
enabled or disabled by the SWITCH jumper (J2), while the DTE controlled
remote and analog loopbacks are enabled and disabled by the RLB (J6) and
the ALB (J5) jumpers respectively. When the LDM-144LR is used as a tail-end
to a digital network, the V.54 DLY jumper (J7) in the modem closest to the
network is set to ON to prevent other equipment from receiving the V.54 data
sequence and inducing it into the loop.

2.3.5 T

EST

P

ATTERNGENERATOR ANDRECEIVER

The Test Pattern Generator enables easy and quick testing of the local
modem and the communication link. When the PATT pushbutton on the
front panel is activated, the circuit sends a standard 511-bit pseudo-random
pattern and checks its response. If errors are detected, the ERR indicator
remains ON or blinks.

The test can be carried out in local analog loopback, in remote digital
loopback, or in normal point-to-point operation opposite a remote LDM­144LR. For the latest test to take place, press the PATT pushbutton on the
remote unit or connect a Bit Error Rate Tester BERT, which generates and
receives a standard pseudo-random 511-bit pattern.

2.3.6 S

ELECTABLECARRIERDETECTSENSITIVITY

Carrier Detect Sensitivity is controlled by the CD SENS jumper (J4). Setting
J4 to LOW will activate DCD over short ranges. Setting J4 to HIGH will
activate DCD up to the ranges in Table 2-1.

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LDM-144LR

Table 2-1. Typical Range.

Data Rate 19AWG (0.9 mm) 22 AWG (0.6 mm) 24 AWG (0.5 mm) 26 AWG (0.4 mm)

(kbps) km miles km miles km miles km miles

48 26.4 16.5 16 10 11 6.8 8 5

56 25.2 15.7 15.2 9.5 10.5 6.5 7.5 4.5

64 24 15 14.5 9 10 6.2 7.3 4.7

72 21.6 14.6 13 8.1 9 7 7 4.6

96 20.4 14.2 12.3 7.7 8.5 5.3 6.8 4.5

112 19.2 12 11.5 7.2 8 4.9 5.7 3.4

128 18 11.2 10.8 6.8 7.5 4.7 5 3.3

144 16.8 10.5 10.1 6.4 7 4.3 4.8 3.2

2.4 Applications

Figures 2-2 and 2-3 illustrate the LDM-144LR in a variety of configurations,
each suitable for a particular application.