Black Box AC505A User manual

2x1 Compact VGA Switch
Model AC505A
with
Push-button Switch Cord and Serial Control Port
March 2006
CUSTOME
R
SUPPORT
INFORMATION
Order toll-free in the U.S. 24 hours, 7 A.M. Monday to midnight Friday:
877-877-BBOX
FREE technical support, 24 hours a day, 7 days a week:
Call 724-746-5500 or fax [phone]
Mail order: Black Box Corporation, 1000 Park Drive, Lawrence, PA 15055
Web site: www.blackbox.com • E-mail: [email protected]
UMA1032, Rev 1.2

2x1 Compact VGA Switch
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TRADEMARKS USED IN THIS MANUAL
Black Box, and (logo) are trademarks of Black Box Corporation. IBM
is a registered trademark of International Business Machines Corporation.
Any other trademarks mentioned in this manual are acknowledged to be the
property of the trademark owners.
FEDERAL COMMUNICATIONS COMMISSION
RADIO FREQUENCY INTERFERENCE STATEMENT
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 designed 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 intended 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
or her 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.
EUROPEAN UNION DECLARATION OF CONFORMITY
This product complies with the requirements of the European EMC
directive 89/336/EEC

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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.

2x1 Compact VGA Switch
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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.
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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Contents
1. Introduction ..........................................................page 5
1.1 General ................................................................ page 5
1.2 Features ...............................................................page 6
2. Installation.............................................................page 6
3. Configuration and Operation ..............................page 8
3.1 Dip Switch Settings ............................................. page 8
3.2 More on Serial RS-232 Operation .....................page 11
3.3 Serial Control Codes .......................................... page 12
4. Troubleshooting ..................................................page 13
Contacting Black Box............................................page 14
Shipping & Packaging ........................................... page 15
5. Specifications.......................................................page 15

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1. Introduction
1.1 General
The Model AC505A is a versatile, compact, high
performance, solid-state, 2 input x 1 output, VGA video
switch that can operate at resolutions of up to 1600x1200.
The unit allows one monitor to be switched between two
video sources. The device is housed in a small RFI shielded
enclosure and is supplied with an universal power supply, a
push-button remote switch control cable, and a Serial (RS-
232) control cable for connecting to a PC or other serial
control device.
The switch terminates both video input signals and buffers
the output in order to protect signal integrity. The Model
AC505A can drive video cables to 150 feet or more
(depending on cable quality an resolution setting). The input
and output connectors are all HD15 Female (standard VGA
style).
1.2 Features
 Allows one monitor to be switched between two sources
 Can be controlled manually, via Serial port, or from TTL level
(or contact closure)
 Select input 1, input 2, or blank the output
 Auto mode automatically scans and selects the input with active
video (Inputs can also be prioritized)
 Infinite switching cycle life
 Can drive long cables
 Terminates both video input signals and buffers the output to
protect signal integrity
 Includes pushbutton and serial cables for control

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2. Installation
Your package should include two control cables, a power
supply, and the Video Switch unit itself. Please take
inventory of all items received and ensure that you have the
above items.
Connect INPUT 1 and INPUT 2 of the switch to your video
sources such as computer or notebook PC. You will require a
cable for each connection. It is highly recommended that you
use multi-coaxial high-resolution VGA cables for this
purpose. The cables would generally be male-to-male. Black
Box can provide cables from 3 feet to 100 feet or more;
please contact us for ordering information.
Connect the display device such as a monitor (or a video
projector) to the output of the Switch.
Set the dip switches according to the mode of operation that
best suites your application.
Connect the supplied AC power adapter to the Splitter, and
plug-in the push-button switch cord.
Please refer to figure 2.1 for installation block diagram.
Important Notice
Always use the unit with the provided power supply. Do
Not Substitute other DC Power Source. If you would like
to use a different power supply source, contact Black
Box first to confirm compatibility.

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Plug-and-Play
DDC (Direct Data Channel) is a standard by which a
compatible monitor sends its identification and other
parameters to a PnP operating system such as Windows
XP etc. The AC505A does not switch the PNP signal lines
to the PC. This means that, in some instances, you may
have to select a new monitor or video settings on your PC.
Also notice that most Notebook PC's have a special
function key to activate the external video output
connector
AC505A
Pushbutton
Switch Cord
- OR -
RS-232 Device
- OR -
TTL Level
- OR -
Automatic
Figure 2.1

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3. Configuration & Operation
3.1 Dip Switch Settings
The Model AC505A provides a convenient dip switch for
setting the desired mode of operation. It is recommended to
set the jumper prior to applying power to the unit, however
the device does monitor the dip switch settings when on and
changes mode of operation as needed.
Normal (all switches off – levers up)
This is the default mode setting for the switch. In this mode
the unit is controlled from the push-button switch cord. The
switch at the end of the cable is momentary and it has a built-
in LED. The LED is used to indicate which input is selected.
Solid on means Input 1, blinking means Input 2 (when
blanking mode is enabled, LED off means blanked output).
Every time you press the button the output switches from the
current input to the other input. When blank mode is on,
double clicking the button will blank the output screen.
Figure 3.1

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Auto
If selected, causes the switch to select the input with active
video automatically. The presence of video is determined by
examining the V.Sync signal of the input connectors.
In Auto mode you don’t need to have the pushbutton cord
plugged in. However, if a push button cord is plugged-in, the
button itself cannot be used for switching, but the LED either
stays on or blinks to indicate which input is selected.
Additionally, it is possible to blank the output in auto mode
using the push-button switch (see below)
Auto Mode with Priority: There are two modes of operation
for the Auto-detection of video. In the default mode (with dip
switches as shown above – TTL switch in off position) no
priority is assigned to either input. Once the switch finds a
video at one of the inputs it selects it and stops scanning until
the currently selected input's video is absent, then the switch
will start scanning again.
If the TTL dip switch is down (on) at the same time as Auto,
then priority is given to input #1. This means that at any time
video is present at input #1 the VS-2 will automatically select
it, regardless of what is happening at input #2. For example if
the Switch is showing an image from input #2 and you plug
in a video signal to input #1, the switch will select #1 right
away.
Auto Mode with Blanking:. If the blanking dip switch is on
(down) at the same time as Auto then double clicking the
pushbutton will cause the output video to blank out. Click the
button again to restore the output.

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Blank
If enabled, then double clicking the pushbutton will cause the
output to go blank. If dip switch is off, then the double click
feature is not there and if the user presses the button in quick
succession, all that the switch will do is to switch between the
inputs quickly!
TTL
In this mode the selection of input is determined by an
external contact closure or TTL signal. The customer should
provide his or her own cable. The signal is to be asserted
between the tip and ground of the 3.5mm mini-plug. A high
(or open input) selects input #1 and a low (or short to ground)
will select input #2. The center ring of the connector can be
used to light an external LED for indication of the selected
channel if desired. Simply tie the ring to the anode of the Led
with the cathode tied to ground.
RS-232
This position is to allow the switch to be controlled via a
Serial device. The same CTRL connector is used to attach the
device to the serial port via a supplied cable. The unit
operates at 1200 baud (adequate since only single ASCII
characters are used to command the switching, and the lower
baud rate eliminates cable length, shielding and noise issues).
From the serial port you have full control over the operation
of the switch (e.g. select input 1, input 2, blank the output,
un-blank the output, or place the switch in and out of auto-
mode).

2x1 Compact VGA Switch
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----------------------
M E N U
----------------------
1 = #1 Input
2 = #2 Input
a = Auto mode
b
= Blank
u = Un-blank
----------------------
3.2 More on Serial (RS-232) operation
Approximately one second
after power-up, the AC505A
will output a menu on the
serial port. To view the menu
you need an ASCII serial
terminal or terminal emulator
software. An example is
Windows® Hyper-terminal®
(generally found in Accessories\Communication folder).
Hyper-terminal Configuration
 Connect Direct to COM1 or
COM2
 Configure for 1200 Baud, 8
bits, No Parity, 1 Stop bit, No
flow control
Figure 3.2

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3.3 Serial Control Codes (1 byte commands)
Ascii 1 (or Hex31)
Selects input #1 (immediately
and unconditionally). The device
will respond with:
In #1 Selected
Ascii 2 (or Hex32)
Selects input #2 (immediately
and unconditionally). The device
will respond with:
In #2 Selected
Ascii a (or Hex61)
Enters Auto Mode. The device
will respond with:
Auto Mode.
In auto mode the device
automatically switches to the video input source that is
active. "Active" means that video signal has sync signal, it
does not mean that there is a non-static screen! If both
inputs are active, then the AC505A stays on the currently
selected video until the video signal ceases, then it will
switch to the other channel if there is good video present
there.
Ascii b (or Hex62)
Blanks the output. The device will respond with:
Blanked output
Switching Details
When switching from one
input to another, the
AC505A blanks the
output, switches the input,
waits 25 milliseconds, and
un-blanks the output.
This is done in order to
reduce or eliminate the
undesired "flash of junk"
on screen when the
monitor is re-
synchronizing from one
input to the other. Most
monitors take some
additional time to
synchronize to the new
input and therefore the
blanking time may be
longer than 25 ms

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When output is blanked, only the color intensities of the
output are reduced to zero, the box still operates in normal
fashion and sync signals are still routed to the output.
Ascii u (or Hex75)
Un-blanks the output. The device will respond with:
Unblanked output
4. Troubleshooting
1. Fuzzy, blurry, or ghosting image
Make sure that you are using the power supply adapter that
came with the unit. The VGA cables must be of high quality
multi-coaxial construction. If you are using long video cables
in excess of 100 feet, the losses in the cable could be a
contributing factor, in which case, first reduce the refresh rate
to 60 HZ and if that is not enough, you may have to reduce
the resolution of the incoming video signal.
2. The PC does not recognize a Plug-and-Play monitor
If the PC’s Operating System is setup to detect a plug-and-
play monitor (usually in Display Properties Advanced
Settings), it may have trouble finding a monitor. If the PC
does not produce an image due to this, disable the plug-and-
play monitor detection in the PC’s operating system Display
Properties.
3. Substituting power supplies
The AC505A relies on the power adapter that it comes with.
Do not substitute any other power supply or DC power
source.

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Contacting Black Box
If you determine that your extender is malfunctioning, do not
attempt to repair the unit. Contact Black Box Tech. 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.
Shipping and Packaging
If you need to transport or ship your extender:
• Package it carefully. We recommend that you use the original
container.
• Before you ship the units back to Black Box Corporation for repair
or return, contact us to get a Return Authorization (RA) number.

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5. Specifications
Video Types VGA through UXGA, RGBHV
Resolution Up to 1600 x 1200 at up to 85 Hz
Bandwidth DC to 250 MHz
Max. Distance Up to 150 ft. (50 m)
Connectors HD15 female for input and both outputs; 3.5 mm Serial
Interfaces Standard Analog VGA; EIA/TIA RS-232 Serial
Compliance CE; FCC Part 15 Subpart B Class A, IC Class
Max. Altitude 10,000 ft. (3048 m)
Temperature Operating: 32 to 122°F (0 to 50°C);
Storage: –40 to +185°F (–40 to +85°C)
Humidity Up to 95% non-condensing
Enclosure Steel
MTBF 90,000 hours (calculated estimate)
Power From utility-power (mains) outlet, through included
external universal power supply. Input Voltage: 100~240
vAC, 50~60 Hz. Output Voltage: 6v DC regulated
Center-Positive. Power Consumption: 3 watts Max
Size 1.25” H x 2.75”W x 4.25” L (32 x 70 x 108 mm)
Weight 1.5 lbs. or 0.7 Kg (shipping)

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© Copyright 2006. Black Box Corporation..
All rights reserved.
1000 Park Drive Lawrence, PA 15055-1018 724-746-5500 Fax [phone]