Technologies; Basics; Common Problems Related To Edid - Lightware UMX4x4-Pro2 User Manual

4. Technologies

4.1. 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.
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 and the most common extension is 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.

4.1.1. Common problems related to EDID

Problem:
Solution:
Section 4. Technologies
Figure 4-1. EDID communication
„My system consists of the following: a computer, a Lightware UMX4x4-Pro2
matrix, a WUXGA (1920x1200) LCD monitor, and an SXGA (1280x1024)
projector. I would like to see the same image on the monitors and the
projector. What EDID should I chose on the monitor and the projector?"
If you want to see the image on both displays, you need to select the
resolution of the smallest display (in this case SXGA), otherwise the smaller
display may not show the higher resolution image.
UMX4x4-Pro2
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