Appendix H - EDID Programming
119
Hardware Reference Manual – DXLink™ Twisted Pair Transmitters/Receiver
EDID Programmer View
From the EDID Programmer view, EDID EEPROM chips for the HD-15 (VGA) connector on the Transmitter can be re-programmed if
necessary.
NOTE:
The EDID Programmer will not work in conjunction with the HDMI connector on the TX.
EDID Overview
EDID (Extended Display Identification Data) is a data structure established by the Video Electronics Standards Association (VESA)
to enable plug-and-play support by enabling easy configuration of a computer’s graphics subsystem based on the capabilities of
the attached display device.
EDID information includes items such as the following:
Manufacturer’s name
Product type
Supported video resolutions and refresh rates
Color space and filter chromaticity
Detailed timings
When a computer is directly connected to a display device, it can use the display device’s EDID information to determine an initial
compatible video signal to send. With the computer’s display controls, the user can modify this selection to another compatible
signal based on the provided EDID information.
DXLink Equipment and EDID
In cases where the HD-15 (VGA) input on a DXLink Transmitter are used and a resolution incompatibility exists (or if the source
device needs a specific resolution or a limited set of resolutions), the DXLink Transmitters have the ability to update the VGA EDID
emulation file (by updating the EEPROM chip) which comes preloaded with an AMX VGA EDID set.
The AMX VGA EDID set consists of a number of common EDID settings (for VGA timing details, see page 107). In most cases, the
DXLink Transmitter can be used as is from the factory with no adjustments.
The DGX Configuration Software with EDID programming functionality has been provided for cases where a user defined VGA EDID
set is desired (this must be a subset of the supported input resolutions shown in Appendix E; see page 107).
The EDID Programmer view can be used for writing user defined VGA EDID data to the DXLink Transmitter’s HD-15 input.
Reading and Saving EDID Data from a DXLink TX’s HD-15 (VGA) Input Connector
The DGX Configuration Software reads the EDID data from the USER EDID 1 EEPROM location, regardless of the VIDIN_EDID
setting.
IMPORTANT:
Unless a custom EDID has been previously written to the input, attempting to read the EDID will result in a Read Error
message.
The EDID data can be read to confirm the correct EDID has been programmed.
To read and save EDID data from a DXLink Transmitter:
1.
On the PC, open the DGX Configuration Software and select the EDID Programmer tab.
2.
Under Inputs/Outputs on the left, expand the device tree, and select the HD-15 input.
3.
Click Read to read the VGA EDID information currently on the HD-15 input.
4.
The EDID data appears in the EDID read-only field on the right.
TIP:
In the EDID Programmer view, the Save to File option under the File menu can be used to save the EDID information as an .edid
file. The saved file can be opened as a text file (from the File menu, select Open File) and edited or opened and written to an input
(click the Write button).
Read Error Message
A Read Error message will appear if the Transmitter has never been programmed with a valid/custom EDID or if the unit has been
programmed with a corrupted EDID. A Read Error message will also appear when attempting to read the EDID after sending a
FACTORYAV SEND_COMMAND, which re-initializes the VGA USER EDID 1 EEPROM and resets the VIDIN_EDID setting to ALL
RESOLUTIONS (which is AMX_0500_003).
