Gefen EXT-DVIKVM-441DL - Manual (Page 13)

10
EDID MODES
What is EDID and what is it used for?
Under normal circumstances, an audio/video source device (digital or analog)
will require information about a connected device/display to assess what
resolutions and features (capabilities) are possible. The source device can then
tailor its output to create resolutions and/or features that are compatible with the
attached device/display. This capability information is called EDID (Extended
Display Identifi cation Data). A source device can only accept and read one
EDID data structure/record from a connected source device/display. Likewise,
the source device can output only one video resolution to a connected device/
display.
The importance of EDID with regards to the 4x1 DVI KVM DL/SL Switcher
The 4x1 DVI KVM DL/SL Switcher handles multiple sources/inputs. Each
connected source device must correctly read one EDID data structure in order
to address its display device correctly. EDID management is carefully handled
by the 4x1 DVI KVM DL/SL Switcher to insure that EDID is recorded and
retransmitted properly, otherwise display of the input sources might not occur
correctly (or at all).
Managing EDID with the 4x1 DVI KVM DL/SL Switcher
The 4x1 DVI KVM DL/SL Switcher uses 2 modes for routing EDID. They are:
1. When the local EDID Mode is ON, (factory default setting) the Switcher
copies the EDID of the connected display to the local memory location as
they are selected. Each device must fully “boot up” before you can select
the next input. The connected device derives EDID information from the
local memory location.
2. When the local EDID Mode is OFF, each time a new source device is
selected, the Switcher connects EDID from the attached display to the
currently selected input source.
Both modes are described in greater detail on the opposite page.
NOTE: The 4x1 DVI KVM DL/SL Switcher also features an EDID Lock
Mode, allowing the EDID to be stored. See the following page for details.
How do I change EDID modes in the 4x1 DVI KVM DL/SL Switcher?
There is a bank of 4 DIP (Dual Inline Package) switches located on the main
circuit board of the Switcher underneath a small piece of silver grey tape on the
underside of the Switcher. When the sticker is removed, there will be two DIP
switch banks visible, one with 4 switches and one with 8 switches. The 8-switch
DIP switch bank is not used here (it is used for the DL (dual link) feature covered
later on page 12.)