Black Box ACL0802A User manual

APRIL 2002
ACL0802A
FREE tech support 24 hours a day, 7 days a week: Call 724-746-5500 or fax [phone].
Mailin address: Black Box Corporation, 1000 Park Dr., Lawrence, PA 15055-1018
World-Wide Web: www.blackbox.com • E-mail: in [email protected]
© Copyri ht 2002. Black Box Corporation. All ri hts reserved.
Customer Support In ormation:

1
THE SERVSWITCH™ FAMILY
Welcome to the ServSwitchTM Family!
Thank you for purchasing a BLACK BOX®ServSwitch™Brand KVM switch! We
appreciate your business, and we think you’ll appreciate the many ways that your
new ServSwitch keyboard/video/mouse switch will save you money, time, and
effort.
That’s because our ServSwitch family is all about breaking away from the
traditional, expensive model of computer management. You know, the one-size-
fits-all-even-if-it-doesn’t model that says, “One computer gets one user station, no
more, no less.” Why not a single user station (monitor, keyboard, and mouse) for
multiple computers—even computers of different platforms? Why not a pair of
user stations, each of which can control multiple computers? Why not multiple
user stations for the same computer?
With our ServSwitch products, there’s no reason why not. We carry a broad line
of robust solutions for all these applications. Do you have just two PCs, and need
an economical alternative to keeping two monitors, keyboards, and mice on your
desk? Or do you need to share dozens of computers, including a mix of IBM®PC,
RS/6000®, Apple®Macintosh®, Sun Microsystems®, and SGI®compatibles among
multiple users with different access levels? Does your switch have to sit solidly on a
worktable and use regular everyday cables? Or does it have to be mounted in an
equipment rack and use convenient many-to-one cables? No matter how large or
small your setup is, no matter how simple or how complex, we’re confident we
have a ServSwitch system that’s just right for you.
The ServSwitch™family from Black Box—the one-stop answer for all your KVM-
switching needs!
*
This manual will tell you all about your new ServSwitch™ Brand 8 x 2 Matrix
Video Switch, including how to install, operate, and troubleshoot it. For an
introduction to the Switch, see Chapter 2. The Switch product code covered in this
manual is:
ACL0802A

2
SERVSWITCH™ BRAND 8 X 2 MATRIX VIDEO SWITCH
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.
Shielded cables must be used with this equipment to maintain compliance with
radio-frequency energy-emission regulations and ensure a suitably high level of
immunity to electromagnetic disturbances.
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.

3
EU DECLARATION OF CONFORMITY
EUROPEAN UNION DECLARATION OF CONFORMITY
This equipment has been tested and found to comply with the limits for a class A
computing device in accordance with the specifications in the European standard
EN55022. These limits are designed to provide reasonable protection against
harmful interference. This equipment generates, uses, and can radiate radio
frequency energy and if not installed and used in accordance with the instructions
may cause harmful interference to radio or television reception. However, there is
no guarantee that harmful interference will not occur in a particular installation. If
this equipment does cause interference to radio or television reception, which can
be determined by turning the equipment on and off, the user is encouraged to
correct the interference with one or more of the following measures:
(a) Reorient or relocate the receiving antenna.
(b) Increase the separation between the equipment and the receiver.
(c) Connect the equipment to an outlet on a circuit different from that to which
the receiver is connected.
(d) Consult the supplier or an experienced radio/TV technician for help.
Shielded cables must be used with this equipment to maintain compliance with
radio-frequency energy-emission regulations and ensure a suitably high level of
immunity to electromagnetic disturbances.

4
SERVSWITCH™ BRAND 8 X 2 MATRIX VIDEO SWITCH
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
NOM STATEMENT, TRADEMARKS
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.
TRADEMARKS USED IN THIS MANUAL
BLACK BOX and the logo are registered trademarks, and ServSwitch is a
trademark, of Black Box Corporation.
Apple and Macintosh are registered trademarks of Apple Computer, Inc.
IBM and RS/6000 are registered trademarks of International Business Machines
Corporation.
Sun Microsystems is a registered trademark of Sun Microsystems, Inc. in the
United States and other countries.
Any other trademarks mentioned in this manual are acknowledged to be the property of the
trademark owners.

6
SERVSWITCH™ BRAND 8 X 2 MATRIX VIDEO SWITCH
Contents
Chapter Page
1. Specifications ............................................................................................. 7
2. Introduction ............................................................................................... 9
3. Installation and Configuration ............................................................... 11
4. Operation ................................................................................................. 15
4.1 The Switch’s LEDs ............................................................................ 15
4.2 Switching with the Keypads .............................................................. 15
4.3 Switching and Monitoring with Serial Devices ................................ 16
4.4 Blanking the Video Output and Performing a Keypad Self-Test ... 17
4.4.1 With the Keypads .................................................................... 17
4.4.2 With a Serial Device ................................................................ 17
5. Troubleshooting ...................................................................................... 18
5.1 Calling Black Box .............................................................................. 18
5.2 Shipping and Packaging ................................................................... 18
Appendix: Pinout of the Serial/Keypad Port ................................................ 19

7
CHAPTER 1: Specifications
1. Specifications
Compliance: CE; FCC Part 15 Subpart B Class A, IC Class/classe A
Standards: VGA, SVGA, XGA, or XGA-2 video
Interfaces: Video: Single or dual VGA;
Keypads: EIA/TIA RS-232 serial, pinned according to a
subset of TIA-574 (compatible with IBM PC serial
ports)
Supported
Video Types: RGBHV (VGA, SVGA, XGA, or XGA-2), RGBS, or
RGsB (“sync on green”) from one or two video heads
Resolution and
Refresh Rate: Up to 1600 x 1280 noninterlaced at up to 85 Hz on each
display
Video Coupling
and Bandwidth: DC to 265 MHz
Video Level: 0.7 volts peak-to-peak
Video Gain: 1-to-1 (buffered); for distances over 100 ft. (30 m), can
be set to proportionally apply higher gain to higher
signal frequencies
Maximum
Distance: Up to 300 ft. (90 m) of total cable length from any
attached CPU or other input device to any attached
monitor or other output device
User Controls: (2) 10-button switching keypads, (1) for each user, or
optional switching through attached serial devices;
Serially triggered on-screen menu for selecting normal or
tandem (dual-head) video switching;
(2) Rear-mounted 8-position DIP switches—(1) for each
user port—for distance compensation
Indicators: (16) Rear-mounted LEDs, (2) for each video-source port;
(10) LEDs on each keypad

8
SERVSWITCH™ BRAND 8 X 2 MATRIX VIDEO SWITCH
Connectors: Front-mounted: (8) HD15 female for video input;
Rear-mounted:
(2) HD15 female for video output, (1) for each user
port;
(2) DB9 female for keypad input, (1) for each user
port;
(1) 5-pin DIN female power inlet
Maximum
Altitude: 10,000 ft. (3048 m)
Temperature
Tolerance: Operating: 32 to 122˚F (0 to 50˚C);
Storage: –40 to +185˚F (–40 to +85˚C)
Humidity
Tolerance: Up to 95% noncondensing
Enclosure: Steel
MTBF: 300,000 hours (calculated estimate)
Power: From utility-power (mains) outlet, through included
detachable output cord and external universal power
supply:
Input: 100 to 240 VAC at 50 to 60 Hz (autosensing);
Output: +5 VDC at 1 A, +12 VDC at 0.5 A, and –12 VDC
at 0.5 A;
Consumption: 5 VA (5 watts) maximum
Size: 1.5"H x 12.1"W x 4.1"D (3.9 x 30.8 x 10.4 cm); mounting
ears protrude an additional 0.9" (2.3 cm) wide on each
side
Weight: Net:
Switch itself: 2.3 lb. (1 kg);
Keypads: 1 lb. (0.5 kg) each;
Power supply: 1.3 lb. (0.6 kg);
Shipping: 6.7 lb. (3 kg)

9
CHAPTER 2: Introduction
2. Introduction
The ServSwitch™ Brand 8 x 2 Matrix Video Switch is an ideal tool for sharing
and/or switching between the output of as many as eight video sources (such as
PCs), in order to display or capture that output at two video destinations (such as
monitors). Once you attach all your devices, you can hook the Switch to the
included keypad for full manual switching control.
The Switch’s features include:
• With its large bandwidth, it can handle even very high resolutions and refresh
rates, up to 1600 x 1280 pixels at up to 85 Hz.
• It can switch the single video output of as many as eight devices and send it to
both monitors simultaneously, or it can switch the dual video output of as
many as four devices, sending one head’s signal to one monitor and the other
head’s signal to the other monitor.
• It includes two serial keypads, so it’s ready to do manual switching almost right
out of the box (you do have to attach the keypad to the Switch first). Or you
can attach one or both of the Switch’s keypad ports to a PC’s serial ports or to
some other serial device and perform switching and monitoring with serial
commands.
• Because it has a universal power supply, you can plug it in almost anywhere if
you have the right input cord. (And it’s small and light enough to take almost
anywhere!)
• It’s primarily designed to carry VGA/SVGA video, but it can handle separate
horizontal and vertical sync, composite sync, and sync on green, so with the
right kinds of cables or adapters it can accept all sorts of video from all sorts of
devices.
• All of its input and output signals are buffered, so you’ll get the sharpest
possible images.
• It can drive video signals as far as 300 ft. (90 m) end-to-end, so it’s ideal for use
in auditoriums, conference halls, and similar spaces.
• Its front-panel LEDs show you right away which video inputs are going to
which outputs.
• To top it off, it can be operated by pressing a single keypad button, so anybody
can use it without having to be extensively trained.

10
SERVSWITCH™ BRAND 8 X 2 MATRIX VIDEO SWITCH
The Switch comes with:
• (2) 10-button keypads
• (2) 6-ft. (1.8-m) DB9 male to DB9 female keypad cables
• Power supply
• This manual

11
CHAPTER 3: Installation and Configuration
3. Installation and Configuration
To set up your ServSwitch™ Brand 8 x 2 Matrix Video Switch system, take these
steps:
1.
Making sure that the Switch is powered off, find its input ports. (These are the
HD15 connectors on its front panel labeled “INPUT 1” through “INPUT 8.”)
Run cabling from these ports to the video-output ports of the PC CPUs or
other devices that will be providing the Switch’s video input.
If all of these input devices are transmitting VGA/SVGA/XGA-type video
signals on HD15 female connectors, you can use standard VGA video-
extension cables such as our product code EVNPS05-MM. Keep in mind that
the length of any of these cables plus the length of any of your monitor/
output cables (see step 2) should not be more more than 300 ft. (90 m).
(You’ll configure the Switch for the length of your cables in step 3.)
If any of your input devices transmit some other type of video signal
and/or use some other type of video connector, you might need special
cables or adapters; call Black Box Technical Support.
If you are attaching single-head video-source devices, attach as many as
eight of them in any order to any of the input ports. But if you are attaching
dual-head devices, you can only attach up to four of them, and you need to
connect the left heads to input ports #1 through 4 and the right heads to the
corresponding input ports #5 through 8. (If the left video from a device goes
into INPUT 6, the right video from that device must go into INPUT 10, etc.)
Figure 3-1. The Switch’s rear-panel components.
2. The Switch’s output ports are the two HD15 female connectors labeled
“OUT A” and “OUT B” on the Switch’s rear panel. If both of your output
devices are standard VGA or multisync monitors with HD15 male connectors
on their video cables, you can plug them directly into these ports (if they’ll be
placed nearby) or run video-extension cables to them such as our product
code EVNPS05-MF (if they’ll be some distance away). Keep in mind that the
length of any of these cables plus the length of any of your CPU/input cables
(see step 1) should not be more more than 300 ft. (90 m). (You’ll configure
the Switch for the length of your cables in step 3.)

12
SERVSWITCH™ BRAND 8 X 2 MATRIX VIDEO SWITCH
If either of your output devices are designed to receive a non-VGA video
signal and/or use a different type of video connector, you might need special
cables or adapters; call Black Box Technical Support.
3. For each of the two outputs there is an 8-position DIP switch on the Matrix
Video Switch’s rear panel—labeled “GAIN A” for “OUT A” and “GAIN B” for
“OUT B”—that you can use to control the gain applied to the corresponding
input signals. For each of the eight inputs, calculate the total lengths of the
video cables from the source to each of the two destinations (the devices
attached to OUT A and OUT B). Then set the corresponding switch position
(“1” for input 1 through “8” for input 8 on either GAIN A for OUT A or
GAIN B for OUT B): Move it DOWN if the total length is 100 ft. (30 m) or
less, or UP if the total length is over 100 ft. (30 m). (In the UP setting, extra
compensation is added to the signal to make up for the high-frequency losses
typical of longer cabling.)
4. Plug the output cord of the Switch’s power supply into the Switch’s 5-pin DIN
female power inlet. Plug one end of the power supply’s input cord into the
transformer’s IEC 320 male inlet; plug the other end of the input cord into a
working AC outlet.
The Switch should power up automatically in its factory-default state (it
has no ON/OFF switch): If you’re running single-head video, both of the
Switch’s outputs will be set to display input #1 (even though there’s no video
present yet). If you’re running dual-head video, output #1 will display
input #1 and output #2 will display input #5 (inputs #1 and #5 should be from
the same source, even though there’s no video present yet). After subsequent
power-ups, the Switch will display whichever inputs were selected by the
outputs when power was most recently removed.
5. Plug in and turn on all devices attached to the switch. If the Switch displays
what it should at its output monitors, you can proceed to the following steps.
If it doesn’t, check the rear-panel LEDs to make sure the Switch is ON; check
your devices and make sure they’re ON; and check your input and output
cabling and make sure it’s all properly connected. If everything seems like it
should work but the system still doesn’t display video correctly, call Black Box
Technical Support.
6. Serial control and/or dual-head video only: Attach the male end of a DB9 male-to-
female serial cable such as EDN12H-MF to either of the DB9 female
connectors labeled “KEYPAD A” and “KEYPAD B” on the Switch’s rear panel.
(Refer to the Appendix for the pinout of these connectors.) Attach the
female end of this cable to the serial port on a terminal, a PC running a
terminal emulator such as HyperTerminal™, or some other RS-232 device

13
CHAPTER 3: Installation and Configuration
that can output ASCII characters. (Configure this port or device to transmit at
9600 bps, 8 data bits, no parity, and 1 stop bit.)
7. Dual-head video only: Type an uppercase “P” on the PC’s or terminal’s
keyboard or send an uppercase “P” from the device to the Switch. The Switch
will send this menu text to appear on screen:
Select Switching Mode
N = Normal
T = Tandem (used for dual-head displays)
Type an uppercase “T” on the PC’s or terminal’s keyboard or send an
uppercase “T” from the device to the Switch; the Switch will respond with the
string “Tandem mode selected.” The Switch will stay in tandem (dual-video)
mode until you repeat this step and select “N” instead, at which point the
Switch will respond “Normal mode selected” and go back to normal (single-
video) mode. If you type in any other character than “T” or “N,” the Switch
will default to normal mode.
If you will be controlling the Switch with a keypad only, disconnect the
serial cable. If you’ll be controlling the Switch with both a keypad and a serial
device simultaneously, move the serial cable to “KEYPAD B” if it isn’t already
attached to that port. If you’ll be controlling the Switch with a serial device
only, you can leave the serial cable where it is.
8. Keypad control only: Run the included 6-ft. (1.8-m) DB9 cable(s) from the
keypad(s) you’re using (also included) to the DB9 female connectors labeled
“KEYPAD” on the Switch’s rear panel. If you’re running dual-head video,
you’ll only need one keypad, and you should connect it to “KEYPAD A.” If
you’re using both keypads, connect one to “KEYPAD A” and one to
“KEYPAD B.” If you’re using one keypad and one serial-device connection in
a single-head video system, it doesn’t matter which “KEYPAD” port the keypad
and device are connected to.
If you have an attached monitor placed father than 6-ft. (1.8 m) from the
Switch, you can use DB9 male to DB9 female extension cable such as
EDN12H-MF to run just as far to the corresponding keypad, up to the
maximum of 300 ft. (90 m).
9. Test the Switch’s keypad- and/or serial-switching features and make sure they
work properly. If they don’t, check your keypad and/or serial cabling and
make sure it’s properly connected. If everything seems like it should work but
the system still doesn’t switch correctly, call Black Box Technical Support.
Your Matrix Video Switch system is now fully installed, as shown in Figure 3-2 on
the next page. The system should be ready for continuous operation.

14
SERVSWITCH™ BRAND 8 X 2 MATRIX VIDEO SWITCH
Figure 3-2. A fully installed single-head Switch system using keypad
switching.
HD15
HD15
HD15
ServSwitch Brand
8 x 2 Matrix Video
Switch
DB9
DB9 (incl ded)
HD15
•
•
•
CPUs
•
•
•
Monitor B
Keypad B
Power s pply
Keypad cable
Keypad
cable
(incl ded)
Video-extension
cables s ch as
EVNPS05-MM
Up to 300 ft. (90 m)
Monitor A
Keypad A
AC
o tlet

15
CHAPTER 4: Operation
4. Operation
4.1 The Switch’s LEDs
The LEDs on the ServSwitch™ Brand 8 x 2 Matrix Video Switch’s rear panel,
shown in Figure 3-1 at the start of Chapter 3, indicate which of the Switch’s outputs
are displaying the video from which inputs, and which outputs have been blanked
and aren’t showing anything (see Section 4.3).
There are two rows of eight LEDs, labeled “Channel” and “1” through “8.” The
top row shows which input is selected for “OUT A,” while the bottom row shows
which input is selected for “OUT B.” If no LEDs are lit in an output port’s row, the
output has been blanked and the keypad is in test mode (see Section 4.3)
4.2 Switching with the Keypads
In a single-head video system: To switch your output port’s monitor or other
destination device to display a given input, press the number of that input on your
keypad. For example, to display the video from a CPU attached to INPUT 8, press
the “8” button. The LED next to that button will light (and will stay lit until a
different port is selected).
In a dual-head video system: To switch the output-port monitors or other pair of
destination devices to display a given pair of inputs, press the number of the lower-
numbered input on your keypad (which must be connected to the Switch’s
“KEYPAD A” port). For example, to display the video from a CPU attached to
INPUT 3 and INPUT 7, press the “3” button. The LED next to that button will
light (and will stay lit until a different port is selected). Buttons #5 through #8 have
no function.
In either single- or dual-head systems: Buttons 9 and 10 on the keypad have no
switching function; pressing them will have no effect unless you press both at the
same time, which will blank the output and trigger the keypad’s self-test function
(see Section 4.4).
If you use both a keypad and a serial device (see Section 4.3) to control the
Switch, keep in mind that the serial device can switch both outputs, so your display
might sometimes switch to a different input without your pressing any buttons on
the keypad. If this happens, you can check the keypad’s LEDs to see which input is
now being displayed.

16
SERVSWITCH™ BRAND 8 X 2 MATRIX VIDEO SWITCH
4.3 Switching and Monitoring with Serial Devices
You can send the Switch ASCII commands to switch input channels using a
terminal, a PC running a terminal emulator, or some other RS-232 device that can
output ASCII characters. If you’re using a PC or other device that can receive
ASCII input, you can also monitor the switching state of either of the Switch’s
outputs. (Configure the device to transmit and/or receive at 9600 bps, 8 data bits,
no parity, and 1 stop bit. The ASCII letters in these commands must be entered in
uppercase.)
In a single-head video system: To switch either output port’s monitor or other
destination device to display a given input, send the ASCII string “OyIx” followed
by a carriage return, where xis the number of the input port and yis the number
of the output port. (If xis zero, output yis blanked and goes into self-test mode—
see Section 4.4.) For example, to switch output #2 to input #6, send “O2I6
[Enter]”.
In a dual-head video system: To switch the output-port monitors or other pair of
destination devices to display a given pair of inputs, send the ASCII string “Ix”
followed by a carriage return, where xis the number of the lower-numbered input
port. (If xis zero, the outputs are blanked—see Section 4.4.) For example, to
display the video from a CPU attached to INPUT 3 and INPUT 7, send “I3
[Enter]”. (If you are also using a keypad, the keypad should be attached to
“KEYPAD A” and the serial device should be attached to “KEYPAD B”.)
In either single- or dual-head systems: When the switching action is complete, the
Switch will send a copy of the command string, including the carriage return, out
of both KEYPAD ports. (Attached serial devices must be able to either ignore such
strings or react appropriately to them. Any attached keypad will change the state of
its LEDs if a command string affects its output, and will ignore all command strings
that affect only the other output.)
To query the current switching state of either output (particularly at power-up,
which is normally the only time when the output state won’t be certain), send the
ASCII string “Oy?” followed by a carriage return, where yis the number of the
output port. The Switch will respond with the string “OyIx[Enter]”, just like the
switching command. In a dual-head video system, “O1?” and “O2?” will return the
numbers of the input-port pair: “O1?” will return the number of the lower-
numbered input port (for example, “O1I4 [Enter]”) and “O2?” will return the
number of the higher-numbered input port (for example, “O2I8 [Enter]”).

17
CHAPTER 4: Operation
If you use both a keypad (see Section 4.2) and a serial device to control the
Switch, keep in mind that the keypad can switch its own output independently of
the serial device, and the serial device can switch both outputs independently of the
keypad. If the serial device switches the keypad’s output, the state of the keypad’s
LEDs will change to reflect the switch.
4.4 Blanking the Video Output and Performing a Keypad Self-Test
4.4.1 W ITH THE K EYPADS
Pressing both the 9 and 10 buttons simultaneously on one of the Switch’s keypads
will blank the video output controlled by that keypad (the monitor will go dark). It
will also cause that keypad to go into self-test mode and light all of its LEDs.
If you see that any of a keypad’s LEDs don’t light while it’s in self-test mode,
consider contacting Black Box to arrange for the keypad to be repaired or
returned. (A dark LED probably just means that the LED is defective, but there’s a
slim chance that something more serious might be wrong.)
To exit test mode and restore video output, press any of the buttons 1 through 8
to select the corresponding channel.
4.4.2 W ITH A S ERIAL D EVICE
To blank either output using a serial-control device, send one of the following
command strings to either of the Switch’s KEYPAD ports:
•Single-head video: Send “O1I0 [Enter]” (uppercase letter O, number one,
uppercase letter I, number zero, carriage return) to blank output #1.
Send “O2I0 [Enter]” (uppercase letter O, number two, uppercase letter I,
number zero, carriage return) to blank output #2.
•Dual-head video: Send “I0 [Enter]” (uppercase letter I, number zero, carriage
return) to blank both outputs.
After the Switch receives the command and blanks the designated monitor, it
will send a copy of the command string, including the carriage return, out of both
KEYPAD ports. (Attached serial-control devices must be able to either ignore such
strings or react appropriately to them. Any attached keypad that receives such a
string will go into self-test mode and light all of its LEDs if the string affects its
output; it will ignore the string otherwise.)
Refer to Section 4.4.1 if you see that any of a keypad’s LEDs don’t light while it’s
in self-test mode. To exit test mode and restore video output, send a switching
command (see Section 4.3) to select channel 1 through 8.

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SERVSWITCH™ BRAND 8 X 2 MATRIX VIDEO SWITCH
5. Troubleshooting
5.1 Calling Black Box
If you determine that your ServSwitch™ Brand 8 x 2 Matrix Video Switch is
malfunctioning, do not attempt to alter or repair it. It contains no user-serviceable
parts. Contact Black Box Technical Support at 724-746-5500.
Before you do, make a record of the history of the problem. We will be able to
provide more efficient and accurate assistance if you have a complete description,
including:
• the nature and duration of the problem;
• when the problem occurs;
• the components involved in the problem—that is, what types of computers or
other video sources; what types, makes, and models of monitors or other video
destinations; etc.;
• any particular application that, when used, appears to create the problem or
make it worse; and
• the results of any testing you’ve already done.
5.2 Shipping and Packaging
If you need to transport or ship your ServSwitch Brand 8 x 2 Matrix Video Switch:
• Package it carefully. We recommend that you use the original container.
• Before you ship the Switch back to Black Box for repair or return, contact us
to get a Return Authorization (RA) number.

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APPENDIX: Pinout of the Serial/Keypad Port
Appendix:
Pinout of the Serial/Keypad Port
The “KEYPAD A” and “KEYPAD B” ports on the rear panel of the ServSwitch™
Brand 8 x 2 Matrix Video Switch are RS-232 serial ports that use a subset of the
TIA-574 pinout on DB9 female connectors:
Pin Direction Signal
1 (reserved) (used by keypad, do not connect to other devices)
2 output from Switch Transmit Data (TD)
3 input to Switch Receive Data (RD)
input to Switch Data Set Ready (DSR), signal level must be high in
order for the Switch to transmit
5 common Signal Ground (SGND)
6 output from Switch Data Terminal Ready (DTR), high signal indicates
that the Switch is ready to receive
7, 8 (no connection) (none)
9 (reserved) (used by keypad, do not connect to other devices)