Black Box ACU5110A, ACU5114A, ACU5112A, ACU5122A, ACU5142A Specifications

1

Get maximum
bandwidth and
distances over CAT5,
CAT5e, or CAT6 cable
with this KVM
ServSwitch™.

Skew compensation
reduces color drift and
keeps images sharp.

Kits include a local
and a remote module.

56-kbps RS-232 serial
transmission is
transparent.

Provides 1600 x 1200
resolution at 656.1 feet
(200 m) or 1280 x 1024
resolution at 984.2 feet
(300 m).

E

xtend the distance between

KVM devices using the
ServSwitch Wizard™ Extender Kit
with Skew Compensation.

Over long runs of CAT5,
CAT5e, or CAT6 cable, color drift
can be a problem. Since the four
wires in a typical cable can be of
different lengths, the color signals
transmitted on each wire won’t
arrive at their destination at the
same time. This results in colored
shadows in the image on a video
screen, also known as delay
skew.

At distances above 492.1 feet
(150 m), skew compensation is
definitely needed with at least
300 MHz of de-skew circuitry. The
skew compensator uses
impedance-controlled circuit
board tracks to achieve very high
bandwidths and does not suffer
from any bandwidth limiting
problems.

Get clear, crisp video resolution at

distances up to 984.2 feet (300 m).

Key Features

SERVSWITCH WIZARD EXTENDER KITS

WITH SKEW COMPENSATION

The ServSwitch Wizard
Extender Kits with Skew
Compensation eliminate delay
skew for clean, crisp video
images. Maximum resolutions of
1600 x 1200 at 60 Hz support
distances of 656.1 feet (200 m).
Reach longer distances (984.2 feet
[300 m]) at 1280 x 1024 resolution
and 60 Hz.

The ServSwitch kit supports
high-fidelity audio, serial mouse
support, and dual and quad multi­head support.

And it works with graphic
adapter cards that use Display
Data Channel (DDC) information
for proper operation. The
ServSwitch Wizard kit transmits
an attached monitor’s DDC
information to a remote module.

Five models are available. The
ACU5110A extends PS/2 keyboard
and mouse signals, transparent
serial signals, and the analog VGA

signal over a single CAT5, CAT5e,
or CAT6 cable up to 984.2 feet
(300 m).

The ACU5114A functions in the
same way as the ACU5110A, but
either the local or the remote user
can operate the PC.

The ACU5112A transmits serial
signals, KVM signals, and
bidirectional stereo audio signals.
With this model, you can use
speakers, headsets, and
microphones at your workstation.

For applications that include
multihead graphics cards, choose
the ACU5122A or ACU5142A.

Rackmount the cards for neat
installation and easy access.

The ServSwitch kit also
provides increased tolerance of
common-mode ground noise. It’s
unlikely to be affected by indus­trial motor startups or fluorescent
lights being switched on and off.

Black Box Corporation • 1000 Park Drive • Lawrence, PA 15055-1018 • Tech Support: 724-746-5500 • www.blackbox.com • e-mail: [e-mail]

© 2006. All rights reserved.

Black Box Corporation.

1/23/2006 #12465

2

UTP cable is often used with
video or KVM extenders to extend
the reach of a video signal. It’s
popular for this application
because it’s lightweight, easy to
handle, and inexpensive. But
when you transmit video over
long stretches of twisted-pair
cable, you sometimes run into a
phenomenon called color drift or
color split.

Color drift shows up as that
annoying colored shadow you
occasionally see around objects
on a video screen. It sometimes
happens with UTP cable because
the pairs of wire in the cable are
twisted at slightly different rates
to reduce crosstalk between
pairs. Because of these
differences between wire pairs,
video signals for different colors
often travel different distances

before they reach the remote
receiver. When one color signal
arrives behind the others because
its wire is longer, you get that red,
green, or blue shadow around the
objects on your video screen.

UTP cable varies widely by
manufacturer, so before installing
video extenders, it’s difficult to
determine whether or not you’re
going to have a color drift
problem. You’re more likely to
experience color drift with higher
grades (CAT5e or CAT6) of cable,

There are two prominent
CAT5e and CAT6 cable
constructions on the market. The
first is referred to as “2 + 2,“
where two of the four pairs are of
similar electrical length, and the
other two pairs are of different
lengths. The second cable
construction is known as “3 + 1,“
where three pairs are of similar
electrical length.

If you encounter delay skew
when using the 2 + 2 type of cable
construction, a delay line will be
required because it is impossible
to find three cable pairs that
closely match for RGB. If delay
skew is encountered with a 3 + 1
cable construction, it can often be
eliminated (if not greatly reduced)
by using the three similar cable
pairs to send RGB signals.

The preferred way to
determine which cable
construction you have is to
measure a 300-foot (91.4-m) run
with a cable scanner. Otherwise,
you can strip back 3 inches
(7.6 cm) of the cable sheath and
look at how pairs are twisted.
If you have a 2 + 2 cable, the two
pairs of similar length will be more

Black Box Explains: Skew Compensation

on longer cable runs, and on high­resolution screens.

If you experience color drift,
there are several possible
solutions. You can use a shorter
length of cable, switch from
CAT5e or CAT6 cable to CAT5
cable, use a lower screen
resolution, or use a video skew
compensator.

A video skew compensator
removes color drift by delaying
some color signals to compensate
for differences in wire pairs.

Black Box Explains: Cable Construction and Delay Skew

tightly twisted than the other two
pairs. If you have a 3 + 1 cable, the
three pairs of similar length will be
more tightly twisted than the
fourth. The three similar pairs can
then be “pair swapped“ onto the
RJ-45 pins that carry RGB signals
and the fourth can be used for
data.

Local unit

Remote unit

Power

Keyboard

Mouse

Monitor

Serial port
on monitor

ServSwitch Wizard Extender Kit with

Skew Compensation, Serial, Single-

Access (ACU5110A)

CATx cable up to

984.2 feet (300 m)

CPU

Typical Application