G&D DVI-Vision-CAT-AR, Installation And Operating Manual

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Further information
51 · G&D DVI-Vision-CAT
DDC transmission with cache function
The KVM extender supports
Enhanced-DDC
(Enhanced Display Data Channel) to read
out the data from the monitor that is connected to the user module and transmit
them to the computer. This data includes information regarding the preferred reso-
lution and the supported monitor frequencies.
To make sure that the computer connected to the computer module
(
DVI-Vision-CAT-CPU
) can already access the features of the remote monitor during
booting, the KVM extender contains a cache function. Even when the computer
module or the user module are switched off or the devices are not interconnected,
the properties of the most recently connected monitor or a default data block are
provided in the KVM extender.
The monitor’s DDC information is usually transmitted one-to-one to the computer.
Should the KVM extender determine that the display cannot be read without errors
or that the entries are invalid, the information is completed or corrected (if possible).
NOTE: While generating the video signal, some graphics cards differentiate
between digital and analogue output. Such graphics cards generate digitally out-
put image signals with partly non-standardised timings. Such timings do not com-
ply with the monitor’s default to reduce the frequencies of the digital signals.
Usually, this does not affect the
DVI-Vision-CAT system and the digitally connected
displays. Due to the non-standardised timing, analogue monitors might not be
able to display the image size and the image position properly.