Edid Management; Understanding The Edid; Advanced Edid Management - Lightware HDMI-TPS-TX210 User Manual

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10.Technologies
10.1. EDID Management
10.1.1. Understanding the EDID
The Extended Display Identification Data (EDID) is the passport of display devices (monitors, TV sets,
projectors). It contains information about the capabilities of the display, such as supported resolutions,
refreshrates(thesearecalledDetailedTimings),thetypeandmanufacturerofthedisplaydevice,etc.
After connecting a source to a display (DVI, HDMI, DP), the source reads out the EDID to determine the
resolutionandrefreshrateoftheimagetobetransmitted.
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 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 with CEA extension are HDMI capable.
Common Problems Related to EDID
Problem: "Mysystemconsistsofthefollowing:acomputer,aLightwaredevice,aWUXGA(1920x1200)
LCDmonitor,andanSXGA(1280x1024)projector.Iwouldliketoseethesameimageonthe
monitorandtheprojector.WhatEDIDshouldIchooseontheLightwaredevice?"
Solution: Ifyouwanttoseetheimageonbothdisplays,youneedtoselecttheresolutionofthesmaller
display(inthiscaseSXGA),otherwisethesmallerdisplaymaynotshowthehigherresolution
image.
Problem: "IhavechangedtoadifferentEDIDonaninputportoftheLightwaredevicetohaveadifferent
resolutionbutnothinghappens."
Solution: SomegraphicscardsandvideosourcesreadouttheEDIDonlyafterpower-upandlatertheydo
notsensethatEDIDhasbeenchanged.Youneedtorestartyoursourcetomakeitreadoutthe
EDIDagain.
EDID Communication
Appliedfirmwarepackage:v1.2.0 | LDCsoftware:v2.2.0
HDMI-TPS-TX200series–User'sManual
10.1.2. Advanced EDID Management
Each DVI sink (e.g. monitors, projectors, plasma displays, etc...) must support the EDID data structure.
SourceBIOSandoperatingsystemsarelikelytoquerythesinkusingDDC2Bprotocoltodeterminewhat
pixelformatsandinterfacearesupported.DVIstandardusesEDIDdatastructuretoidentifythemonitortype
andcapabilities.MostDVIsources(VGAcards,settopboxes,etc.)willoutputDVIsignalafteracceptingthe
connectedsink'sEDIDinformation.InthecaseofEDIDreadoutfailureormissingEDID,thesourcewillnot
outputDVIvideosignal.
Lightware devices provide the Advanced EDID Management function that helps system integration. The
built-inEDIDRoutercanstoreandemulatefactorypre-programmed-andUserprogrammableEDIDs.The
EDIDoftheattachedmonitorsorprojectorsforeachoutputarestoredinanon-volatilememory.Thisway
theEDIDofamonitorisavailablewhenthemonitorisunpluggedorswitchedoff.
AnyEDIDcanbeemulatedonanyinput.AnemulatedEDIDcanbecopiedfromtheEDIDrouter'smemory
(staticEDIDemulation),orfromthelastattachedmonitor'smemory(dynamicEDIDemulation).Forexample,
theLightwaredevicecanbesetuptoemulateasinkdevice,whichisconnectedtooneoftheoutputs.In
thiscase,theEDIDautomaticallychanges,ifthemonitorisreplacedwithanotherdisplaydevice(aslongas
it has a valid EDID).
EDIDisindependentlyprogrammableforallinputswithoutaffectingeachother.Allinputshavetheirown
EDID circuit.

INFO: The user is not required to disconnect the video cable to change an EDID as opposed to other
manufacturer'sproducts.EDIDcanbechangedevenifasourceisconnectedtotheinputandpowered
ON.

INFO: WhenEDIDhasbeenchanged,theroutertogglestheHOTPLUGsignalfor2seconds.Somesources
donotsensethissignal.Insuchcases,thesourcedevicemustberestartedorpoweredOFFandONagain
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