10
EDID MODES
EDID. What is it, and what is it used for?
Undernormalcircumstances,acomputersourcedevice(digitaloranalog)will
requireinformationaboutaconnecteddevice/displaytoassesswhatresolutions
andfeatures(capabilities)arepossible.Thesourcedevicecanthencaterits
outputtocreateresolutionsand/orfeaturesthatarecompatiblewiththeattached
device/display.ThiscapabilityinformationiscalledEDID(ExtendedDisplay
IdenticationData).AsourcedevicecanonlyacceptandreadoneEDIDdata
structure/recordfromaconnectedsourcedevice/display.Likewise,thesource
devicecanoutputonlyonevideoresolutiontoaconnecteddevice/display.
The importance of EDID with regards to the 8x1 DVI KVM DL Switcher
The8x1DVIKVMDLSwitcherhandlesmultiplesources/inputs.Eachconnected
sourcedevicemustcorrectlyreadoneEDIDdatastructureinordertoaddressits
displaydevicecorrectly.EDIDmanagementiscarefullyhandledbytheSwitcher
toinsurethatEDIDisrecordedandretransmittedtosourcesproperlyatalltimes,
otherwisedisplayofinputsourcesmightnothappencorrectly(oratall).
Managing EDID with the 8x1 DVI KVM DL Switcher
The8x1DVIKVMDLSwitcherhas2modesforroutingEDID:
1. ThedefaultmodeistheLOCALmodewhichwillstoretheEDIDofasource
device(oneforeachinput)intothe8x1DVIKVMDLSwitcher.TheEDID
storedineachLOCALlocationcanbefromalocaldisplaydeviceorfrom
aremotesourceovertheRS-232serialcommunicationsport.The8x1DVI
KVMDLSwitcheralsoincludesabuilt-inEDIDmemorybankwhichcan
storeupto7separateEDIDdatastructureswhichcanthenbeloadedto
eachoftheLOCALEDIDlocations.
2. ThesecondmodeistheDS(DownStream)modewhichfunctionsasa
simpleEDIDpass-through.Inthismode,thedisplaydeviceconnectedtothe
8x1DVIKVMDLSwitcherwillpassitsEDIDdirectlytowhicheverDVIinput
sourceiscurrentlyselected.HDCP is supported in this mode only.
NOTE:The8x1DVIKVMDL/SLSwitcheralsofeaturesanEDIDLockMode,
allowingtheEDIDtobestored.Seethefollowingpagefordetails.
How do I change EDID modes in the 8x1 DVI KVM DL Switcher?
Thereisanbankof4DIPswitcheslocatedonthemaincircuitboardonthe
undersideofthe8x1DVIKVMDLSwitcher.DIPswitch3canbeusedtoset
eithertheDSorLOCALEDIDmodes.Thebankof8DIPswitchesareusedfor
theDL(duallink)onlyfeatureandarediscussedlateronpage12.
TIP: AdvancedEDIDfunctionscanalsobemanagedviatheRS-232serial
communicationsport.Seepage13formoreinformationontheRS-232serial
communicationfeatures.