Skew adjustment – Adder Technology ADDERLINK X2 User Manual
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Skew adjustment
The twisted pair cabling supported by the X2 Dual Access modules (category 5,
or higher) consists of four pairs of cables. Three of these pairs are used by the
modules to convey red, green and blue video
signals to the remote video monitor. 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 same time. 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.
In this situation, the X2 Dual Access modules
provide internal skew adjustment that can help
to rectify the situation. The skew adjustment
works by delaying or advancing the timing of any of the red, green or blue
colour signals so that they are all delivered to the monitor at precisely the same
time. For best results a test pattern is provided and this should be displayed
when using skew adjustment.
To use skew adjustment
1 Insert the supplied Adder Installation CD-ROM into the CD player of the
computer.
2 Within Windows, use the My Computer option (usually available as a
desktop icon or within the Start menu) to view the contents of the CD-ROM.
Double-click the
Skew entry to display the standard test pattern. If necessary
maximise the application window so that the image fills the screen.
The screen will show a series of fine red,
green and blue crosses which should all
be in line, vertically and horizontally. Skew
affects the horizontal placement of the
colours and using this pattern it is much
easier to discover which, if any, colours are
being adversely affected by the twisted pair
cable run.
3 Simultaneously, press the hotkeys (by
default,
and
) along
with
to enter configuration mode.
The three keyboard indicators (‘Num Lock’, ‘Caps
Lock’ and ‘Scroll Lock’) will now begin to flash in
sequence.
4 As appropriate, press either the R, G or B keyboard keys to select the
appropriate colour channel. Corresponding keyboard indicators
will flash rapidly to show which channel is currently selected
for adjustment: Num Lock for Red, Caps Lock for
Green and Scroll Lock for Blue.
Convergence test
pattern showing the
RGB crosses. In this
case, the green signal
can be seen out of
line with the other
two colours.
5 Press the and keys to retard or advance the timing of the selected
colour channel respectively. On screen you will see a change in the position
of the selected colour crosses in relation to the other two.
Num
Loc
k
Caps
Loc
k
Scrol
l
Loc
k
Num
Loc
k
Caps
Loc
k
Scrol
l
Loc
k
Num
Loc
k
Caps
Loc
k
Scrol
l
Loc
k
Advance
colour
timing
Retard
colour
timing
Restore
default
skew
settings
Exit image
controls
and save
settings
6 When the selected colour crosses are correctly positioned, press
to
exit that colour channel. The keyboard indicators will return to flashing in
sequence.
7 If required, repeat steps 4 to 6 to select and adjust any colour channel until
the vertical lines of the red, green and blue crosses are all aligned.
8 When all colours are correctly aligned, press
to exit configuration mode
and permanently save all settings.
Note: Once you have made a skew adjustment, it may be necessary to re-
adjust the image controls to attain an optimum screen image.
1 2 3 4 5 6 7 8
8
6
5
2
8
6
5
2
Data signal
Red
video signal
Green
video signal
Blue
video signal
7
3
4
1
7
3
4
1