Lightware HDMI-3D-OPT-TX210A, Руководство пользователя, Страница: 17 / 106

3. Technologies
3.1. Basics
EDID stands for Extended Display Identification Data. Simply put, EDID is the passport of
display devices (monitors, TV sets, projectors). It contains information about the display’s
capabilities, such as supported resolutions, refresh rates (these are called Detailed
Timings), the type and manufacturer of the display device, etc.
After connecting a DVI source to a DVI display, the source reads out the EDID to determine
the resolution and refresh rate of the image to be transmitted.
EDID communication
Most DVI computer displays have 128-byte long EDID structure. However, Digital Televisions
and HDMI capable displays may have another 128 bytes, which is called E-EDID (Extended
EDID) and defined by CEA (Consumer Electronics Association). This extension contains
information about additional Detailed Timings, audio capabilities, speaker allocation and
HDMI capabilities. It is important to know, that all HDMI capable devices must have CEA
extension, but not all devices are HDMI capable which have the extension.
3.2. Common problems related to EDID
Problem: „I have changed to a different EDID on HDMI-3D-OPT-TX210RAK to
have a different resolution but nothing happens.”.
Solution: Some graphics cards and video sources read out the EDID only after
power-up and later they don’t sense that EDID has been changed.
You need to restart your source to make it read out the EDID again.
Problem: „I have a HDMI-3D-OPT-TX210RAK and I’m using a Lightware
factory preset EDID. I would like to be able to choose from different
resolutions, but my source allows only one resolution.”
Solution: Most Lightware factory preset EDIDs allow only one resolution, forcing
the sources to output only that particular signal. You need to select
the Universal EDID that supports all common VESA resolutions, see
the factory EDID list.
3.3. Advanced EDID Management
Each DVI sink (e.g. monitors, projectors, plasma displays, and switcher inputs) must
support the EDID data structure. Source BIOS and operating systems are likely to query
the sink using DDC2B protocol to determine what pixel formats and interface are supported.
DVI standard makes use of EDID data structure for the identification of the monitor type
and capabilities. Most DVI sources (VGA cards, set-top boxes, etc.) will output DVI signal
after accepting the connected sink’s EDID information. In case of EDID readout failure or
missing EDID, the source will not output DVI video signal.
The transmitters provide Lightware’s Advanced EDID Management function that helps
Who are
you?
I am a monitor.
Here is my EDID.
Now I know what
I can send.
HDMI-3D-OPT-TX200 series
User’s manual
Technologies Page 17 / 106