User's Manual

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GuardianManual001‐5006‐000Rev0 17|Page
2 SYSTEMARCHITECTUREANDNETWORKPLANNING
This section briefly discusses network architecture (including basic network types),
interfacing modems and DTE, data protocols for efficient channel operation, addressing, and
repeaters.
GuardianisdesignedtoreplacewirelinesinSCADA,telemetryandcontrolapplications.TheRS‐232serialport
allowsdirectconnectiontoProgrammableLogicControllers(PLCs)orRemoteTerminalUnits(RTUs).ASCADA
systemisdefinedasoneormorecentralizedcontrolsitesusedtomonitorandcontrol
remotefielddevicesover
wideareas.Forexample,aregionalutilitymaymonitorandcontrolnetworksoveranentiremetropolitanarea.
IndustrysectorswithSCADAsystemsincludeenergyutilities,waterandwastewaterutilities,andenvironmental
groups.
TheGuardianisintendedforuseintheIndustrialMonitoringandSCADAmarket.The
rangeoftheGuardianis
dependentonterrain,RF(radiofrequency)pathobstacles,andantennasystemdesign.Thissectionprovidestips
forselectinganappropriatesite,choosinganantennasystem,andreducingthechanceofharmfulinterference.
2.1 SINGLECOVERAGEAREA
Inanetworktopologywithonlyasinglecoveragearea(allunitscantalktooneanotherdirectly),thereareseveral
commonsystemconfigurations.
Themostcommonisforoneunittobedesignatedasamasterandtherestdesignatedasremotes.Another
systemconfigurationisReport‐by‐Exception.
2.2 NETWORKARCHITECTURE
2.2.1 POINT‐TO‐POINT
Apoint‐to‐pointnetworkisthemostsimpleofallnetworks,andmaybeusedforconnectingapairofPC's,ahost
computerandaterminal,aSCADApollingmasterandoneremote,mobileapplications(likein‐vehicleGPS
receiversandbasestations)orawidevarietyofother
networkingapplications.
Figure2.1–Point‐to ‐PointNetwork
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