User guide

Raven XT
89 20070914
TheRTUconnectstophysicalequipmentsuchasswitches,
pumps,andotherdevicesandmonitorsandcontrolsthese
devices.TheRTUcanbepartofanetworksetupforSuper
‐
visoryControlandDataAcquisition.
Supervisory Control and Data Acquisition (SCADA)
SupervisoryControlandDataAcquisition(SCADA)describes
solutionsacrossalargevarietyofindustriesandisusedin
industrialandengineeringapplicationstomonitorandcontrol
distributedsystemsfromamasterlocation.SCADAencom
‐
passesmultipleRTUs,acentralcontrolroomwithahost
computer(ornetwork),andsomesortofcommunicationinfra
‐
structure.
SCADAallowsfor“supervisory”controlofremotedevicesas
wellasacquiringdatafromtheremotelocations.Program
‐
mableLogicControllersallowforahigherdegreeof
automatedSCADA.
Programmable Logic Controller (PLC)
AProgrammableLogicController(PLC)isasmallindustrial
computerwhichgenerallymonitorsseveralconnectedsensor
inputsandcontrolsattacheddevices(motorstarters,solenoids,
pilotlights/displays,speeddrives,valves,etc.)accordingtoa
user‐createdprogramstoredinitsmemory.Containinginputs
andoutputssimilartoanRTU,PLCsarefrequently
usedfor
typicalrelaycontrol,sophisticatedmotioncontrol,process
control,DistributedControlSystemandcomplexnetworking.
Modbus TCP/IP
ModbusTCP/IPsimplytakestheModbusinstructionsetand
wrapsTCP/IParoundit.SinceTCP/IPisthecommunications
standardfortheInternetandmostnetworkedcomputers,this
providesasimplerinstallation.ModbusTCP/IPusesstandard
Ethernetequipment.
Raven Modbus on UDP
WhenProsoftTechnologyRadioLinxmodemsareusedin
placeofradios,aRavenXTisconnectedtothecentralstation
(host)andaRavenXTisconnectedtoeachremoteunit.When
theRavenXTisconfiguredforModbuswithUDP,theRaven
XTconnectedtothehostcanstorealist
ofIPaddressesor
nameswithmatchingIDs.Whenthehostatthecentralstation
sendsserialdataasapollrequest,theRavenXTatthehost
matchestheRTUIDtoacorrespondingIPofaRavenXTata
remoteunit.AUDPpacketisassembledencapsulating
the
RTUIDandserialdatatransmittedfromthehost.TheUDP
packetisthentransmittedtothespecificRavenXTatthe