Black Box ClassWork Plus 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: [email protected]
JUNE 2001
AC817A
AC817AE
ClassWork Plus Line Multiplier

1
FCC INFORMATION
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 la classe A prescrites dans le Règlement sur le
brouillage radioélectrique publié par Industrie Canada.

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CLASSWORK PLUS LINE MULTIPLIER
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.

3
NOM STATEMENT
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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CLASSWORK PLUS LINE MULTIPLIER
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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CONTENTS
Contents
Chapter Page
1. Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.1 Designing a ClassWork Plus Classroom Using the Line Multiplier . . 7
2.2 What the Package Includes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3. Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.1 Before Installing the Line Multiplier . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.2 Connecting the System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.3 Connecting the Line Multiplier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.4 Connecting Branch 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.5 Connecting Branch 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.6 Connecting Branch 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.7 Connecting Branch 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.8 Connecting the Terminators. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
3.9 Connecting the Power Supply. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
3.10 Setting the DIP Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
4. Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

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CLASSWORK PLUS LINE MULTIPLIER
1. Specifications
Input
Signal:Input: R, G, B video signals, 200 MHz, 1.6 Vpp
Sync:Input: H, V, TTL
Sync Range:Horizontal: Up to 100 kHz; Vertical: Up to 100
Output
Video Gain:Output: R, G, B video signals 200 MHz, 1.6 Vpp
Sync: TTL
General
Bandwidth: 200 MHz
Internal Jumpers: Cancel keyboard; Mouse driver
Connectors:Input: (2) DB25 female; Output: (4) DB25 female
Power: AC817A: Input: 115 VAC; Output: 9 VAC; AC817AE: Input: 230 VAC
Size: 6.1" x 3.5" x 4.5" (15.5 x 8.9 x 11.4 cm)
Weight: 1.2 lb. (0.5 kg)

7
CHAPTER 2: Introduction
2. Introduction
The standard ClassWork Plus classroom consists of one long bus used to transmit
and receive signals. The Line Multiplier allows you to create up to five smaller
buses (or branches) within one classroom. These smaller buses provide stronger
signals to all CPUs in the classroom.
2.1 Designing a ClassWork Plus Classroom Using the Line Multiplier
The following example will explain how to set up a ClassWork Plus classroom of 30
students using one Line Multiplier (see Figure 2-1).
Figure 2-1. Typical ClassWork Plus classroom with 30 students connected to
one Line Multiplier.
In this example, six Student Interface Units (SIUs) are connected directly to the
Teacher Interface Unit (TIU). Student Number 6 is then connected to the System
In port of the Line Multiplier. Six more SIUs are connected to each Branch port of
the Line Multiplier (Branch 1, Branch 2, Branch 3, and Branch 4). A Terminator
(see Section 3.8 for more information) is then connected to the System Out port
of the Line Multiplier, and to the last SIU in each of the branches.
CPU 6
CPU 7 CPU 8 CPU 9 CPU 10 CPU 11 CPU 12
CPU 13 CPU 14 CPU 15 CPU 16 CPU 17 CPU 18
CPU 19 CPU 20 CPU 21 CPU 22 CPU 23 CPU 24
CPU 25 CPU 26 CPU 27 CPU 28 CPU 29 CPU 30
CPU 5 CPU 4 CPU 3 CPU 2 CPU 1
Instructor
Line
Multiplier

8
CLASSWORK PLUS LINE MULTIPLIER
2.2 What the Package Includes
Your package should include the following items.
• ClassWork Plus Line Multiplier
• (1) 6.6-ft. (2-m) System cable
• (1) Power supply (110-VAC for AC817A, 220-VAC for AC817AE)
• (4) DB25 terminators
• This users’ manual
If anything is missing or damaged, please call Black Box at 724-746-5500.

9
CHAPTER 3: Installation
3. Installation
3.1 Before Installing the Line Multiplier
Turn OFF all CPUs before installing the Line Multiplier.
3.2 Connecting the System
Figures 3-1 and 3-2 show the front and rear panels of the ClassWork Plus Line
Multiplier. Figure 3-3 shows a diagram of the ClassWork Plus system. Refer to these
diagrams when connecting the various cables.
Figure 3-1. The ClassWork Plus Line Multiplier’s front panel.
Figure 3-2. The ClassWork Plus Line Multiplier’s rear panel.

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CLASSWORK PLUS LINE MULTIPLIER
Figure 3-3. The ClassWork Plus Line Multiplier system.
Line
Multiplier
Instructor
CPU 6 CPU 5 CPU 4 CPU 3 CPU 2 CPU 1
CPU 7 CPU 8 CPU 9 CPU 10 CPU 11 CPU 12
CPU 13 CPU 14 CPU 15 CPU 16 CPU 17 CPU 18
CPU 19 CPU 20 CPU 21 CPU 22 CPU 23 CPU 24
CPU 25 CPU 26 CPU 27 CPU 28 CPU 29 CPU 30

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CHAPTER 3: Installation
3.3 Connecting the Line Multiplier
To connect the Line Multiplier to the ClassWork Plus system: Connect the DB25
male connector from the System cable (see Figure 3-4) to the System In port of the
Line Multiplier.
Figure 3-4. System cable.
Figure 3-5. System In port connection.
System Cable DB25
DB25
Line Multiplier Unit
System In port
System Cable
to CPU 6

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CLASSWORK PLUS LINE MULTIPLIER
3.4 Connecting Branch 1
The System cable from Student Interface Unit (SIU) 7 is used to connect Branch 1
to the Line Multiplier (see Figure 3-6). To connect this cable:
1. Connect the DB25 male connector of the System cable (see Figure 3-4) to the
Branch 1 port of the Line Multiplier.
2. Connect the other DB25 male connector of the System cable to the System
port of SIU 7 in Branch 1.
Figure 3-6. System In port connection.
3.5 Connecting Branch 2
The System cable from Student Interface Unit (SIU) 13 is used to connect Branch
2 to the Line Multiplier (see Figure 3-7). To connect this cable:
1. Connect the DB25 male connector of the System cable (see Figure 3-4) to the
Branch 2 port of the Line Multiplier.
2. Connect the other DB25 male connector of the System cable to the System
port of SIU 13 in Branch 2.
Figure 3-7. System In port connection.
Branch 1 port
System Cable
SIU 7
System port
Line Multiplier Unit
Branch 2 port
System Cable
SIU 13
System port
Line Multiplier Unit

13
CHAPTER 3: Installation
3.6 Connecting Branch 3
The System cable from Student Interface Unit (SIU) 19 is used to connect Branch
3 to the Line Multiplier (see Figure 3-8). To connect this cable:
1. Connect the DB25 male connector of the System cable (see Figure 3-4) to the
Branch 3 port of the Line Multiplier.
2. Connect the other DB25 male connector of the System cable to the System
port of the SIU 19 in Branch 3.
Figure 3-8. System In port connection.
3.7 Connecting Branch 4
The System cable from Student Interface Unit (SIU) 25 is used to connect Branch
4 to the Line Multiplier (see Figure 3-9). To connect this cable:
1. Connect the DB25 male connector of the System cable (see Figure 3-4) to the
Branch 4 port of the Line Multiplier Unit.
2. Connect the other DB25 male connector of the System cable to the System
port of SIU 25 in Branch 4.
Figure 3-9. System In port connection.
Branch 3 port
System Cable
SIU 19
System port
Line Multiplier Unit
Branch 4 port
SIU 25
System port
Line Multiplier Unit

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CLASSWORK PLUS LINE MULTIPLIER
3.8 Connecting the Terminators
Terminators are connected to the System ports of the last Student Interface Unit
(SIU) in each branch, and to the System Out port of the Line Multiplier.
Figure 3-10. Terminator.
3.9 Connecting the Power Supply
Insert the power-supply plug into the 9-VAC power port on the rear of the
ClassWork Plus Line Multiplier, and plug the cord into a wall socket.
Figure 3-11. Power supply connector.
After making the connection described in Sections 3.2 through 3.9, the ClassWork
Plus Line Multiplier will operate.
DB25 male
Power
Supply
Line
Multiplier
Unit
To Wall Socket
)=

15
CHAPTER 3: Installation
3.10 Setting the DIP Switches
Each branch of the ClassWork Plus Line Multiplier contains two DIP switches. You
must set these DIP switches to the Student Number of the first and last student in
each branch. Take a look at Figure 3-12. Tables 3-1 and 3-2 show you how to set the
DIP switches for this application.
Figure 3-12. Typical ClassWork Plus classroom with 30 students connected
to one Line Multiplier.
Table 3-1 indicates how to set the Line Multiplier DIP switches in the example
shown in Figure 3-12.
Table 3-1. Setting the DIP switches.
DIP-Switch Number DIP-Switch Setting
Switch 1 7
Switch 2 12
Switch 3 13
Switch 4 18
Switch 5 19
Switch 6 24
Switch 7 25
Switch 8 30
Line
Multiplier
Instructor
CPU 6 CPU 5 CPU 4 CPU 4 CPU 2 CPU 1
CPU 7 CPU 8 CPU 9 CPU 10 CPU 11 CPU 12
CPU 13 CPU 14 CPU 15 CPU 16 CPU 17 CPU 18
CPU 19 CPU 20 CPU 21 CPU 22 CPU 23 CPU 24
CPU 25 CPU 26 CPU 27 CPU 28 CPU 29 CPU 30

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CLASSWORK PLUS LINE MULTIPLIER
NOTE
All of the Line Multiplier’s unused branches must have their DIP
switches set to that of a Virtual Branch (student station numbers that do
not exist in the system).
If your system consists of 16 student stations (8 student stations
connected to Branch #1 and 8 student stations connected to Branch #2),
then the DIP switches on Branch #3 and Branch #4 should be set to
17/18 and 19/20 consecutively.
Table 3-2 shows how to set the Student Number.
Table 3-2. Setting the Student Number.
Student No. Switch Number
12345678
0 00000000
1 10000000
2 01000000
3 11000000
4 00100000
5 10100000
6 01100000
7 11100000
8 00010000
9 10010000
10 01010000
11 11010000
12 00110000
13 10110000
14 01110000
15 11110000
16 00001000
17 10001000
18 01001000
19 11001000
20 00101000
21 10101000
22 01101000
23 11101000

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CHAPTER 3: Installation
Table 3-2 (continued). Setting the Student Number.
Student No. Switch Number
12345678
24 00011000
25 10011000
26 01011000
27 11011000
28 00111000
29 10111000
30 01111000
31 11111000
32 00000100
33 10000100
34 01000100
35 11000100
36 00100100
37 10100100
38 01100100
39 11100100
40 00010100
41 10010100
42 01010100
43 11010100
44 00110100
45 10110100
46 01110100
47 11110100
48 00001100
49 10001100
50 01001100
51 11001100
52 00101100
53 10101100
54 01101100
55 11101100
56 00011100

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CLASSWORK PLUS LINE MULTIPLIER
Table 3-2 (continued). Setting the Student Number.
Student No. Switch Number
12345678
57 10011100
58 01011100
59 11011100
60 00111100
61 10111100
62 01111100
63 11111100
0=OFF, 1=ON

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CHAPTER 4: Operation
4. Operation
To operate the ClassWork Plus Line Multiplier:
1. Turn on all CPUs.
2. Turn on the Power switch on the rear of the ClassWork Plus Line Multiplier.
LED Indicators
The ClassWork Plus Line Multiplier’s front panel contains three LED indicators for
each branch. Figure 4-1 shows a diagram of the front panel. Table 4-1 explains the
LEDs.
Figure 4-1. The ClassWork Plus Line Multiplier’s front panel.
Branch Status
Function Status
Branch Power