Convergence test pattern showing the RGB crosses. In this case, the green signal can be seen out of line with the other two colours.

Video skew adjustment (X200AS models only)

The category 5, 5e and 6 cabling supported by the AdderView CATx consists of four pairs of wires per cable. Three of these pairs are used 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

 

1 2 3 4 5 6 7 8

 

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 and is particularly

 

 

 

apparent when using higher screen

 

 

 

resolutions and some types of category 5e

 

 

 

cables.

8

8

Data signal

To alleviate this situation, the Adder

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7

 

X200AS modules provide internal skew

6

6

Red

adjustment that can help to rectify the

3

3

video signal

 

 

 

situation. The skew adjustment works by

5

5

Green

delaying or advancing the timing of any

4

4

video signal

2

2

Blue

of the red, green or blue colour signals so

1

1

video signal

that they are all delivered to the monitor

at precisely the same time. For best results, the “skew” program supplied on the disk or downloadable from www.adder.com or www.adder.info is the most accurate way of setting skew as the red, green and blue lines are rendered exactly on the screen as single pixel wide lines. The skew.bmp test pattern can also be used but it is less accurate. Alternatively, you can create your own skew pattern using a standard image creation package, as detailed opposite.

To use skew adjustment

1Display a skew pattern on the appropriate computer. You can either use the supplied skew pattern or create your own:

Using the supplied skew pattern

iInsert the supplied Adder Installation CD-ROM into the CD player of the computer.

iiWithin 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 cable link.

Creating a skew test pattern

iRun any image creation/editing application, such as the Paint program supplied with Windows.

iiUsing the image application create three

stacked horizontal rectangles (one red, one green and one blue) that fill the width of the screen.

iiiDraw a vertical black line down across the coloured bars and then repeat this vertical line at intervals along the width of the coloured bars. These lines create breaks across the colours and give you more opportunities to view the horizontal position of each colour relative to the others.

2 On the keyboard connected to the X200AS, 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.

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Adder Technology manual Video skew adjustment X200AS models only, To use skew adjustment