Black Box MX515A, MX515AE 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

MX515A

MX515AE

Local Mux-6

Local Mux-6

POWER

RLB

LLB

TEST

LOCAL

REMOTE

SYNC

LOSS

3

LOCAL MUX-6

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 the Canadian
Department of Communications.

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 le ministère des Communications du Canada.

4

LOCAL MUX-6

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.

5

LOCAL MUX-6

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.

6

LOCAL MUX-6

TRADEMARKS

All applied-for and registered trademarks are the property of their respective
owners.

7

LOCAL MUX-6

Contents

1. Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

1.1 Sub-Channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

1.2 Main Channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

1.3 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9

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

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

2.2 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

2.3 Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11

3. Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14

3.1 Site Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14

3.2 Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14

3.3 Installation in 19" Racks . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

3.3.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

3.3.2 Installation of Unit . . . . . . . . . . . . . . . . . . . . . . . . . . .15

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

3.4.1 AC Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

3.4.2 Sub-Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

3.4.3 Main Channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

4. Operating Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

4.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

4.2 Controls and Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

4.3 Operating Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23

4.4 System Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24

4.5 Fault Isolation annd Troubleshooting . . . . . . . . . . . . . . . .25

8

LOCAL MUX-6

1. Specifications

1.1 Sub-Channels

Transmission Format—Asynchronous

Data Rate—Up to 19.2 kbps (refer to Table 2-1)

Distortion—Refer to Table 2-1

Interface—EIA RS-232-C/CCITT V.24

Connectors—(6) DB25 female

Number of Sub-channels—Up to twelve by attaching a channel doubler

to each of the connectors

Mode of Operation—Full duplex

1.2 Main Channel

Electrical Interface

Transmission Line—4-wire unconditioned telephone lines (two twisted pairs)

Operating Range—Maximum of 1.6 km (1 mile) on 22 AWG cable

Data Rate—1.2288 Mbps

Output Format—Balanced, transformer-isolated 6 Vp-p (on 100 Ω)

Input Resistance—100 Ω

Connector—Terminal block

9

LOCAL MUX-6

1.3 General

Diagnostics

Local digital loopback—Activated by pushbutton.

Remote digital loopback—Activated by pushbutton.

Switches/Indicators

Power Indicator (Green)—On when unit is powered.

Test Indicator (Yellow)—On when local or remote unit is performing

a loopback.

Local Sync Loss Indicator (Red)—On when synchronization is lost at local
unit.

Remote Sync Loss Indicator (Red)—On when synchronization is lost at
remote unit.

LLB Switch—When pressed, unit is performing local loopback.

RLB Switch—When pressed, unit is performing remote loopback.

Physical Description

Size—1.72"H (1U) x 13.3"W x 8.6"D (4.4 x 33.8 x 22 cm)

Weight—3.5 lb. (1.6 kg)

Environment

Temperature—32 to 122°F (0 to 50°C)

Humidity—Up to 90% non-condensing.

Power

Power Requirements—MX515A: 115 VAC, 60 Hz; MX515AE: 230 VAC, 50 Hz

10

LOCAL MUX-6

2. Introduction

2.1 General

The Local Mux-6 is a full-duplex time-division asynchronous multiplexor
enabling up to twelve async terminals to be multiplexed onto a single
channel. The Local Mux-6 is intended for use in manufacturing facilities,
building complexes, campuses, and other similar point-to-point applications.

2.2 Functional Description

The Local Mux-6 contains six sub-channels that can be expanded to twelve
through connection of channel-doubler cables. The number of channels
available (6/12) is set by a user-selectable strap.

When the unit is set for six channels, each channel can be used to transmit
full-duplex data end to end. When the unit is set for twelve channels, each
sub-channel can be used for either data or control-signal transmission,
according to the specific application. For example, six channels can be used
to transmit full-duplex data and six can be used to transmit control signals
end to end, or else the full twelve channels can be used to transmit full
duplex data end to end.

The Local Mux-6 comes with a 4-wire terminal block for transmission over
two twisted pairs.

Multiplexing is implemented using an over-sampling technique.
Each of the twelve channels is sampled at 78.6 kbps. Table 2-1
summarizes Local Mux-6 performance.

NOTE

Whenever possible (if the number of channels is less than or equal to 6),
we recommend that you operate the Local Mux-6 in the six-channel
mode, which results in less distortion.

11

LOCAL MUX-6

Table 2-1. Performance in Various Modes of Operation.

No. of Max Electrical Distortion (%)

Sub-channels Data Rate

in use (Kbps)

6 19.2 12.5

6 38.4 —

12 19.2 25.0

2.3 Applications

The Local Mux-6 is used mainly for point-to-point configurations where
distances of up to several kilometers are involved. A typical application is
demonstrated in Figure 2-1, where a cluster of terminals is connected to a
host computer through a single link. Different configurations are available
using the 4-wire transmission media. The maximum data rate in a point-to­point configuration is 19.2 kbps for 12 data subchannels, 6 data subchannels,
or 6 data and 6 control subchannels.

12

LOCAL MUX-6

Figure 2-1. Typical Point-to-Point Installation.

For installations involving clusters of terminals distributed in several
locations, Local Mux-6 units may be installed in a ring-type configuration
(refer to Figure 2-2). At each site the unconnected channels must be
bypassed by shorting Pins 2 and 3 of the relevant sub-channel connector.

Local Mux-6

Local Mux-6

Async

Computer

13

LOCAL MUX-6

Table 2-2. Distortion.

Data Rate Distortion Number of

on Each per Node Nodes/Sites

Sub-Channel (%)

19.2 kbps 25.00 2

9.6 kbps 12.50 3

4.8 kbps 6.250 4

2.4 kbps 3.125 8

1.2 kbps 1.5625 16

Figure 2-2. Typical Ring Installation.

4

TERM

4

TERM

4

TERM

T

R

9

12

5

8

1

4

T

R

R

T

R

T

1

12

HOST

2WIRE

2WIRE

2WIRE

2WIRE

14

LOCAL MUX-6

3. Installation

3.1 Site Preparation

The Local Mux-6 must be installed within 5 feet (1.5 m) of a grounded AC
outlet.

3.2 Setup

1. Unscrew the two upper cover screws located at the back of the unit
(refer to Figure 3-3).

2. Slide the rear drawer out.

3. Locate the strap marked “select 6 or 12 channels” (indicated by an arrow
on the circuit board). For up to 6 channels with no control applications,
place the strap between the center pin, and the one marked “6.” For any
other applications, place the strap between the center pin and the one
marked “12” (refer to Figure 3-1).

4. Locate the strap marked GND. According to your requirements, set the
signal ground to be connected to shielding (chassis) ground or floating
(NC).

5. Replace the rear drawer.

6. Fasten the two upper cover screws at the back of the unit.

Figure 3-1. Strapping Diagram.

12

6

SELECT

6 OR 12

CHANNELS

GND

NC

15

LOCAL MUX-6

3.3 Installation in 19” Racks

3.3.1 G

ENERAL

The Local Mux-6 can be installed in a 19" rack. Its height is slightly less than
1U (1.75"), and the width is slightly less than the available mounting width.

WARNING

Disconnect the units from mains power while performing the following
procedures. If you don’t, you could be shocked!

3.3.2 I

NSTALLATION OF AUNIT

The rack adapter components for single-unit installation include two short
brackets. The brackets are fastened by means of screws to the side walls for
the case, as shown in Figure 3-2. The brackets are attached to the two side
walls of the unit.

1. To prepare the unit for rack installation, attach the two brackets to the
side walls of the unit. Each bracket is fastened by means of two screws
(with flatwashers), which are inserted into the two front holes on the
wide wall (nuts are already in place, on the inner side of the wall).

2. After attaching the brackets, the unit is ready for installation in the
19” rack. Fasten the brackets to the side rails of the 19" rack by means
of four screws—two per side.

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LOCAL MUX-6

Figure 3-2. Installation of a Unit in a 19" Rack.

3.4 Electrical Installation

In the following discussions, refer to Figure 3-3 (rear panel).

3.4.1 AC P

OWER

AC power is supplied to the Local Mux-6 through a 5 feet (1.5 m) cord
terminated by a grounded 3-wire plug. The AC cord is fused at the rear
panel AC power receptacle of the unit. A slow-blow fuse of 0.1A is required
for 230V operation, and a 0.2A fuse is required for 115V operation.

3.4.2 SUB-

CHANNELS

Six D-type 25-pin female connectors on the rear panel enable connection to
the unit. Detailed information about the signals present at these connectors
is given in Table 3-1. For twelve-channel operation, channel doublers (CD)
are required. Refer to Figure 3-4 for the pinout of the CD. For six-channel
operation, with full duplex data and end-to-end control signals on each
channel, refer to Figure 3-5 (DTR to DSR control signal) or to Figure 3-6
(RTS to DCD control signal).

17

LOCAL MUX-6

3.4.3 M

AINCHANNEL

A 5-screw terminal block is located at the rear panel, marked TX-A, TX-B,
CHASSIS GND, RX-A, RX-B for connecting transmit and receive wires and
the cable shield (if available). TX connectors at the local unit must be
connected to RX connectors at the opposite unit.

Figure 3-3. Rear Panel.

CH 1/7 CH 2/8 CH 3/9

CH 4/10 CH 5/11 CH 6/12

MAIN CHANNEL

FUSE

~115V/O.2AS.B.

RX-B TX-BRX-A TX-A

m

18

LOCAL MUX-6

Table 3-1. Sub-Channel Connector Pin Assignment.

CCITT EIA Pin Signal Name Description
V.24 RS-232C No.

101 AA 1 Protective Ground Chassis ground. May be

isolated from signal
ground.

102 AB 7 Signal Ground Common signal and DC

power-supply ground.

103 BA 2 (14) Transmit Data Serial digital data from a

terminal or other source
into the Local Mux-6.

104 BB 3 (16) Receive Data Serial digital data output

from the Local Mux-6.

105 CA 4 (19) Request to Send A positive level to the

Local Mux-6 when data
transmission is desired.

106 CB 5 (13) Clear to Send A positive level from the

Local Mux-6 (if data
transmission is possible).

107 CC 6 (21) Data Set Ready A positive DC voltage

(+8V) from the Local
Mux-6 indicating the unit
is powered.

109 CF 8 (12) Receive Line A positive level from the

Signal Detector Local Mux-6 except when
(Carrier Detect) either a sync loss occurs

or remote loopback is
performed.

—— 9 +8 volts These signals are

10 -8 volts reserved for data-set

testing and for powering
miniature modems.

NOTE: Pin numbers in parentheses are for the secondary channel

available when using a channel-doubler cable.

19

LOCAL MUX-6

Figure 3-4. Connecting Channel Doubler to Local Mux-6 Sub-Channel.

1
2
3
4
5
6
8
15
17
20
24
7

14
16
19
13
21
12
11
18
25
23

1
2
3
4
5
6
8
15
17
20
24
7

14
16
19
13
21
12
11
18
25
23

1
2
3
4
5
6
8
15
17
20
24
7

1
2
3
4
5
6
8
15
17
20
24
7

Local Mux-6

Sub-Channel

Connector

Channel Doubler

Port A

Port B

Not used

Signal Ground

Not used

Protective Ground

Transmitted Data (TD)

Received Data (RD)

Request to Send (RTS)

Clear to Send (CTS)

Data Set Ready (DSR)

Received Line Signal Detector

Secondary TD

Secondary RD
Secondary RTS
Secondary CTS
Secondary DSR

Secondary RLSD

20

LOCAL MUX-6

Figure 3-5. DTR to DSR End-to-End Control Signal.

Figure 3-6. RTS to DCD End-to-End Control Signal.

1
2
3
4
5
6
8
7
14
16

1
2
3
4
5
6

7

8

1
2
3
4
5
6
8
7
14
16

1
2
3
4
5
6
8
7
14
16

1
2
3
4
5
6
8
20
7

1
2
3
4
5
6
8
7
14
16

Local Mux-6

Sub-Channel

Connector

Channel Doubler

Special

Cable 1

Protective Ground

Transmitted Data (TD)

Received Data (RD)

Request to Send (RTS)

Clear to Send (CTS)

Data Set Ready (DSR)

Received Line Signal Detector

Signal Ground

Secondary TD

Secondary RD

Local Mux-6

Sub-Channel

Connector

Channel Doubler

Special
Cable 2

Protective Ground

Transmitted Data (TD)

Received Data (RD)

Request to Send (RTS)

Clear to Send (CTS)

Data Set Ready (DSR)

Received Line Signal Detector

Signal Ground

Secondary TD

Secondary RD

21

LOCAL MUX-6

4. Operating Instructions

4.1 General

This chapter covers:

• A list of controls and indicators together with their functions.

• An operating procedure covering turning on the power,
operating instructions, and turning off the power.

• Information on strapping.

• A unit system test procedure for use by the operator and technician.

Installation procedures given in Chapter 3 must be completed and

checked before operating the Local Mux-6.

4.2 Controls and Indicators

Tables 4-1 and 4-2 list the function of the Local Mux-6 indicators
and switches. The Local Mux-6 front panel is shown in Figure 4-1.

Figure 4-1. Local Mux-6 Front Panel.

22

LOCAL MUX-6

Table 4-1. Local Mux-6 Indicators.

Item Indicator Function

1 Power Green LED lights when power is present.

2 Test Yellow LED lights when either local or remote

unit is performing a test.

3 Local Sync Loss Red LED lights when synchronization is lost at

the local unit.

4 Remote Sync Loss Red LED lights when synchronization is lost at

the remote unit.

Table 4-2. Local Mux-6 Switches.

Item Switch Function

5 LLB When pressed (pushed in) the unit performs

local loopback.

6 RLB When pressed (pushed in) the unit performs

remote loopback.

23

LOCAL MUX-6

4.3 Operating Procedure

WARNING

BEFORE SWITCHING ON THIS INSTRUMENT, the protective earth
terminals of this instrument must be connected to the protective
conductor of the (mains) power cord. The mains plug shall only be
inserted in a socket outlet provided with a protective earth contact. Do
NOT use an extension cord (power cable) without a protective conductor
(grounding).

Make sure that only fuses with the required rated current are used for
replacement. The use of repaired fuses and the short-circuiting of fuse
holders must be avoided.

Whenever it is likely that the protection offered by fuses has been
impaired, the instrument must be made inoperative and secured against
any unintended operation.

Turning On the Power

Apply AC power by connecting the AC power cord to an acceptable AC
source. If the power indicator lights, then the Local Mux-6 is powered.
If the local and remote Local Mux-6 units are in operation and properly
connected via the main channel, no other indicator should be ON. If any
other indicators light, refer to Section 4.5 for troubleshooting information.

Operation

The Local Mux-6 operates entirely unattended except when performing
system tests.

Turning Off the Power

To turn off Local Mux-6, simply remove the AC power cord from the AC
source.

Operational Field Strapping Changes

If you need to reconfigure the Local Mux-6 for twelve-channel mode
or six-channel mode, follow the appropriate set-up procedure described
in Section 3-2.

24

LOCAL MUX-6

4.4 System Tests

Two system tests are available in the Local Mux-6: local loopback and remote
loopback.

Local Loopback

When performing local loopback, the data from the local transmitter is
looped back to the local receiver at the digital level, thus checking all local
digital circuitry for proper operation. This test is activated by pressing the
LLB push-button on the front panel. If the local unit is operating properly,
the yellow TEST indicator should light, and all other indicators should be
OFF.

If the local and remote units are properly connected via the main channel,
the local transmitter analog interface and both the remote analog and digital
receiver sections are checked. The yellow TEST indicator on the remote unit
should also be lit if the units are properly connected.

Remote Loopback

Remote loopback loops back data from the remote receiver to the remote
transmitter, thus checking:

• All local digital circuitry

• Both local and remote analog interfaces

• Main channel link

• Remote digital receiver section.

This test is performed by pressing the RLB push-button on the front panel.
If both local and remote units operate properly, the yellow TEST indicators
should be lit at both units and all other indicators should be OFF.

NOTE

When either the local or the remote loopback test is performed, the
following signals at the remote unit sub-channels are set to OFF
(negative voltage) condition: Received Data (Circuit 104), Clear to Send
(Circuit 106), Receive Line Signal Detector (Circuit 109)

25

LOCAL MUX-6

4.5 Fault Isolation and Troubleshooting

The symptoms and corresponding procedures listed in Table 4-3 enable
the user to identify, isolate, and correct faults in accordance with the
knowledgeable tools and replacement parts available.

WARNING

These service instructions are for use by qualified personnel only.
To avoid electric shock, do not perform any servicing other than that
contained in the operating instructions unless you are qualified to do so.

Table 4-3. Fault Isolation and Troubleshooting.

Symptom Action

All front-panel indicators are OFF. (a) Check that power is supplied to the unit.

(b) Check the fuse inside the AC receptacle
on the rear panel and replace it with a new
one.
(c) Replace unit. The fault is probably in the
unit’s power-supply circuits.

Red LOCAL SYNC LOSS is ON (a) Perform LLB. Yellow TEST indicator

should light and LOCAL SYNC LOSS
should go OFF. If not, replace the local unit.
Otherwise, proceed to step (b).
(b) Perform local RLB. Yellow TEST
indicator should light and LOCAL SYNC
LOSS should go OFF. In that case, replace
the remote unit. Otherwise, proceed to
step (c).
(c) Perform steps (a) and (b) at the remote
site. If the fault is still not located, replace
both units one at a time. If the problem
remains, the main-channel link between
the units is probably defective and should
be checked.

Red REMOTE SYNC LOSS is ON Perform all the tests as in the case of

LOCAL SYNC LOSS, starting at the remote
site.

1000 Park Drive • Lawrence, PA 15055-1018 • 724-746-5500 • Fax [phone]

© Copyright 1997. Black Box Corporation. All rights reserved.