IHSE USA R434-91 Series SDLink Rackmount Hubs - Manual (Page 26)

24 CATx KVM Extender Range
4. Remote Unit Configuration & Operation
Cat5/5e/6 cables are specifically designed for networking applications and not
for transmitting analog video. Your CATx KVM extender includes, and
requires, advanced technology to enable its use at high screen resolutions. This
section describes how to optimize the video signal, configure the Extender
system and operate the Remote Unit.
For details about flash upgrading and external configuration see Appendix C:
Remote Unit: Flash Upgrading & External Configuration, page 50.
For information about serial/audio port operation, see Appendix E:
Audio/Serial Ports: Operation & Multi-Port Configuration, page 54.
Video Configuration Overview
To get the best out of your extender system it is essential that you configure it
correctly and tune the video signal. Tuning is necessary because of distortions
that occur in a video signal when it is transmitted over lengthy CATx cables.
Generally, you only need to carry out this procedure after installation.
The system stores settings in an EEPROM in the Remote Unit and restores
them whenever the unit is powered up.
When you have installed your extender system, run an application that requires
a high screen resolution. Examine the video image on the remote console’s
monitor. You may see some of the following distortion effects:
Smearing: black smearing at the right-hand edge of large
horizontal objects such as title bars and characters. To
correct this smearing requires adjustment of LF
equalization.
Loss of Sharpness: Loss of high frequency (HF) signals
causes blurring and lack of detail. To correct this requires
adjustment of HF equalization.
Color Separation or Skew: This arises because of timing
differences in the reception of signals for the individual
colors. Each color in the RGB (Red, Green, Blue) video
signal is sent down a separate pair of wires in the
Interconnect cable.
On many cables, the twist rates differ and this leads to each color arriving at a
slightly different time and therefore spreading out on the screen. Skew becomes
a major problem at high screen resolutions and with long CATx cables. To
correct for skew, the ‘faster’ colors must be delayed to arrive at the same time
as the slowest.