Gefen EXT-DVIKVM-841DL - Manual (Page 14)

10
EDID MODES
EDID. What is it, and what is it used for?
Under normal circumstances, a computer 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 cater its
output to create resolutions and/or features that are compatible with the attached
device/display. This capability information is called EDID (Extended Display
Identification 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 8x1 DVI KVM DL Switcher
The 8x1 DVI KVM DL 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 Switcher
to insure that EDID is recorded and retransmitted to sources properly at all times,
otherwise display of input sources might not happen correctly (or at all).
Managing EDID with the 8x1 DVI KVM DL Switcher
The 8x1 DVI KVM DL Switcher has 2 modes for routing EDID:
1. The default mode is the LOCAL mode which will store the EDID of a source
device (one for each input) into the 8x1 DVI KVM DL Switcher. The EDID
stored in each LOCAL location can be from a local display device or from
a remote source over the RS-232 serial communications port. The 8x1 DVI
KVM DL Switcher also includes a built-in EDID memory bank which can
store up to 7 separate EDID data structures which can then be loaded to
each of the LOCAL EDID locations.
2. The second mode is the DS (Down Stream) mode which functions as a
simple EDID pass-through. In this mode, the display device connected to the
8x1 DVI KVM DL Switcher will pass its EDID directly to whichever DVI input
source is currently selected. HDCP is supported in this mode only.
NOTE: The 8x1 DVIKVM 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 8x1 DVI KVM DL Switcher?
There is an bank of 4 DIP switches located on the main circuit board on the
underside of the 8x1 DVI KVM DL Switcher. DIP switch 3 can be used to set
either the DS or LOCAL EDID modes. The bank of 8 DIP switches are used for
the DL (dual link) only feature and are discussed later on page 12.
TIP: Advanced EDID functions can also be managed via the RS-232 serial
communications port. See page 13 for more information on the RS-232 serial
communication features.