Specifications

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installation
operation
rter
inormation
14
What is skew and why is compensation needed?
The twisted pair cabling supported by the X-USBPRO modules consists of four
pairs of wires per cable, three of which are used to convey red, green and blue
video signals to the remote video display. Due to the slight difference in twist rate
between these three pairs, the red, green and blue video signals may not arrive
at precisely the correct times. This is visible as separate colour shadows on high
contrast screen images. This effect is particularly apparent when using higher
screen resolutions and some types of category 5e cables.
The video compensation system within the remote module allows you to delay
or advance the timing of any of the colour signals so that they all arrive at the
display at the correct times.
Take a close look at a locally connected display. From left to right, groups of
pixels are usually arranged in the order: R / G / B and the signals must arrive in
the correct order to obtain the optimum screen image. The Adder skewtest.exe
pattern (on the supplied CD-ROM) in particular helps to highlight the pixel
layout by showing very narrow horizontal and vertical lines.
Test images while compensating
For best results while adjusting video compensation, arrange a combination of
elements on the remote display. We suggest the following:
• Roughlyhalfofthescreentodisplay
standard operating system colour icons
on a mid-green wallpaper.
• AquarterscreenoftheAdder
skewtest.exe pattern (available on the
supplied CD-ROM).
• Aquarterscreenofstandardblacktext
on a white background.
Note: You need to set all of the above BEFORE entering video compensation
mode because the USB keyboard will be isolated from the computer.
Video compensation
The X-USBPRO modules include a video compensation system that allows you to
get the best results from your remote video display(s). Using this special mode
you can configure:
• Cable type - Select the type of link cable used.
• Cable length - Enter the length of the link cable.
• Video gain - Alter the signal gain for the image.
• Colour skew - Adjust the timing of each colour to fine tune the image.
• Expert mode - Please contact Adder technical support for details.
This flash sequence
indicates that you
are at Standby level
Num
Lock
Caps
Lock
Scroll
Lock
The indicators on the keyboard linked to the
remote unit will begin to flash in sequence.
Also, the green indicator adjacent to the CATx
link socket will flash.
Note: During video compensation mode, the
keyboard and any other connected USB devices
will be temporarily isolated from the computer.
1
ON
2
You are now at the standby level within video compensation mode.
From standby, you can choose which adjustments to make. Generally you
should set the cable type and cable length options first. Then, if necessary,
use the video gain and colour skew adjustments to fine tune the remote
video image.
Please see the next page for details about each adjustment >>>
When your adjustments are complete, return the unit to normal operation
as described below:
To exit video compensation mode (return to normal operation)
1 Ensure that you are at standby level by exiting from any adjustment options.
2 On the remote unit, return the miniature switch 1 to its OFF position.
All USB devices will be reconnected to the computer and normal operation
will continue.
The
skewtest.exe
test pattern
showing its RGB
crosses. In this case,
the green signal can be
seen out of line with the
other two colours.
To enter video compensation mode
1 Ensure that the two X-USBPRO units are connected to the computer and
powered on. A USB keyboard must be connected to the remote unit.
2 Arrange your test images on the remote screen. Please refer to the section
‘Test images while compensating’ shown bottom left.
3 On the remote unit, click the miniature switch 1
to its ON position.