Microgate SyncLink GT2 - Differential Input Termination

DifferentialInputTermination
EachportonthecardhasoptionalterminationofRS‐422/485differentialinputs.Whenaresistorpackis
installedinthesocketlabeled‘TERM’,alldifferentialinputsforthatportareterminatedwith120ohms.
Bydefaulttheterminationresistorpackisinstalledforallports.Thepresenceoftheterminationresistor
packdoesnotaffectsingleended(RS‐232/V.28)inputs.
Terminationisusedtoincreasesignalreliabilityathighspeeds(generally1Mbpsormore).Athigh
speeds,receiversateachendofacableshouldbeterminated.Foramulti‐dropsetups(morethan2
devicesonacable),donotterminatereceiversconnectedtothemiddleofthecable.Atslowerspeeds,
theterminationcanusuallyremainwithoutproblem.Removingterminationatslowerspeedsmayallow
theuseoflongercables.
Toremoveaterminationresistorpack,identifythesocketlabeled‘TERM’.Thenremovetheyellow
resistorpackfromtheblacksocketusingaflatheadscrewdriverorequivalenttool.Terminationcanbe
reinstalledbypressingtheresistorpackbackintothesocket.Takecarethatthepinsontheresistorpack
arenotbentandarefirmlyseatedintothesocket.
Figure3 TerminationSockets
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