Sontay RF--RXS--B User manual

INNOVATION • QUALITY • COMMITMENT • SUPPORT
... experts in field controls
RF-RXS-B System
USER MANUAL

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Sontay®SonNetRadioSensorSystem
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UserManual
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forthe
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RFRXSBBACnetIPReceiver
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Version1.1
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August2017

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Audience
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Thismanualisintendedforspecifiers,usersandinstallersoftheSontay®SonNetradiosensorsystem.
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Content
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ThismanualprovidesacompletereferencefortheSontay®SonNetradiosensorsystembasedontheRF
RXSBBACnetIPreceiver.
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RelatedDocuments

TheSontay®SonNetradiosensorsystemSiteSurveyKitQuickStartGuide
TheSontay®SonNetradiosensorsystemSiteSurveyKitManual
TheSontay®SonNetradiosensorsystemQuickStartGuide
TheSontay®SonNetradiosensorsystemproductdatasheets
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TableofContents:
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Overview ................................................................................................................. 5
BatteryFittingandReplacement........................................................................................ 5
DisposalofBatteries ..................................................................................................... 5
DevicesTypes ............................................................................................................ 6
BatteryPoweredNodes ...................................................................................... 6
24VPoweredRouters......................................................................................... 8
230VacPoweredRouters................................................................................... 10
TheRFRXSBBACnetIPSystemReceiver .................................................................11
TheRFIOM.................................................................................................. 12
TheRadioNetwork .................................................................................................... 13
NetworkPlanningConsiderations.......................................................................... 14
TheRadioSystem ...................................................................................................... 16
Security................................................................................................................. 16
HowtheSelfHealingTreeNetworkisFormed....................................................................... 16
PropagationOfRadioSignalsinBuildings ............................................................................ 17
ExtensionAerials....................................................................................................... 18
FAQs .................................................................................................................... 19
Configuration&MonitoringSoftware ................................................................................ 20
InstallingCMS ............................................................................................... 21
StartingCMS ................................................................................................ 24
ImportingaSavedLayout .................................................................................. 25
TheCMSDesktopEnvironment ............................................................................ 26
LoggingOnasanAdministrator ............................................................................ 27
ChangingtheAdministratorPassword..................................................................... 27
AutoConfigurationMode .................................................................................. 28
ListingDevices............................................................................................... 29
ChangingDeviceLabels..................................................................................... 30
ViewingDeviceProperties.................................................................................. 31
ChangingDeviceConfigurations ........................................................................... 33
ConfigurableParameters ................................................................................... 33
RFIOMConfiguration ...................................................................................... 35
RFIOMStatusTab .......................................................................................... 35
Changingtheinputconfiguration .......................................................................... 36
Changingtheoutputconfiguration ........................................................................ 37
ManuallyAuthorisingaNewNode......................................................................... 38
RemovingaNodefromtheNetwork ...................................................................... 38
UsingtheGraphicalMapDisplay........................................................................... 39
SettingtheMapDisplayBackgroundImage ............................................................... 39
AddingDevicestotheMapDisplay ........................................................................ 40
IconPlan..................................................................................................... 40
DeviceStatus................................................................................................ 41
LinkStatus................................................................................................... 41
AutoUpdating............................................................................................... 42
RefreshingNodeData ...................................................................................... 42
CommunicationsLog ....................................................................................... 43
ChangingDisplayUnits ..................................................................................... 43
ConfigurationLog ........................................................................................... 44
UsingCMSToDocumentAWirelessNetwork............................................................. 45
SavingandOpeningLayouts ............................................................................... 45
ReceiverPrintPreview...................................................................................... 46
CommissioningMultipleNetworksontheSameSite ................................................................ 47
Precommissioneachnetworkawayfromsite ............................................................ 47
Commissioneachnetworkindividuallyonsite ............................................................ 47
CommissioningaSonNetSystem:AStepByStepGuide ............................................................ 48
BestPractisePoints .................................................................................................... 50
TroubleShooter’sGuide .............................................................................................. 51

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EstimatingNetworkCoverageintheAbsenceofaSiteSurvey...................................................... 56
AttenuationPropertiesofCommonBuildingMaterials................................................... 57
TheInterfacetoBACnetIP ............................................................................................ 58
DefaultIPAddress .......................................................................................... 58
BACnetIPSettings .......................................................................................... 59
ResettingFactoryDefaults ................................................................................. 59
SonNettoBACnetPointsMapping......................................................................... 60
ReceiverMappedPoints.................................................................................... 60
NonCO2EDMappedPoints ................................................................................ 61
CO2EDMappedPoints ..................................................................................... 61
NonCO2RouterMappedPoints ........................................................................... 62
CO2RouterMappedPoints................................................................................. 62
RFIOMMappedPoints..................................................................................... 63
DescriptionofBACnetPointsbyDevice .............................................................................. 64
TheRFRXSBReceiver ...................................................................................... 64
EndDevicewithoutCO2Functionality...................................................................... 64
EndDevicewithCO2Functionality ......................................................................... 64
RouterwithoutCO2Functionality .......................................................................... 64
RouterwithCO2Functionality .............................................................................. 65
RFIOM ...................................................................................................... 65
RFRXSBPICS .......................................................................................................... 66
BACnetRequirements ...................................................................................... 66
BACnetStandardizedDeviceProfile(AnnexL) ............................................................ 66
BACnetInteroperabilityBuildingBlocks(BIBBs)(AnnexK) ............................................... 66
StandardDeviceBindingMethodsSupported............................................................. 67
StandardObjectTypesSupported ......................................................................... 67
AnalogInputObjectType................................................................................... 67
AnalogValueObjectType .................................................................................. 69
BinaryInputObjectType ................................................................................... 76
BinaryValueObjectType................................................................................... 80
MultiStateInputObjectType.............................................................................. 83
MultiStateValueObjectType ............................................................................. 83
OctetStringValueObjectType ............................................................................ 85
DeviceObjectType ......................................................................................... 85
DataLinkLayerOptions .................................................................................... 86
NetworkOptions............................................................................................ 87
SegmentationCapability.................................................................................... 87
DeviceAddressBinding..................................................................................... 87
CharacterSetsSupported .................................................................................. 87
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Overview
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The RFRXSB SonNet Wireless receiver allows quick and seamless integration of SonNet devices into
buildingmanagementsystems.It automaticallymaps data fromSonNet end devices intoBACnetobjects
whicharetransmittedviathevendorindependentBACnetIPcommunicationprotocol,usingasimpleweb
browserinterface.DependingonthelayoutoftheSonNetnetworkitcanconnectupto40nodes.
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The receiver collects data from all other devices on the wireless network, including measurements from
sensors,linkquality,batterylevelsforallbatterypowereddevices,hoursrunforalldevicesandthecurrent
statusofalldevices.
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The wireless devicesare based on directsequence spread spectrumcommunication in the 2.42.5GHz
band,compliantwithIEEE802.15.42006.
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AllnodeshaveauniqueMACaddress,equivalenttoauniqueserialnumber.
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TheRFRXSBhasauniqueEthernetMACaddress.
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Allnodesretaintheirconfigurationpropertiesacrossapowerfailure.
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BatteryFittingandReplacement
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Whenabatteryisinstalled,orwhenitisreplaced,observingthecorrectpolarityisveryimportant.Fitting
thebatteryincorrectlymayresultinpermanentdamagetothedevice.
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Recommendedbatteriesare3.6Vdc2.4AhAAsizeLithiumThionylChloridetypesforspacehousingsensors,
or 3.6Vdc 2.1Ah 2/3 A size LithiumThionyl Chloride types for plant housing sensors, and are not
rechargeable.
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Thistypeofbatteryshouldbestoredinaclean,cool(notexceeding+30°C),dryandventilatedarea.
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DisposalofBatteriesWarning!Fire,ExplosionandBurnHazard
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Do not shortcircuit, crush, disassemble heat above 100°C (212°F), incinerate, or expose the battery
contentstowater.Donotsolderdirectlytothecell.
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NB  All batteries must be disposed of in accordance with EC Directive 2006/66/EC, amended by EU
Directive2008/12/EC.

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DevicesTypes
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BatteryPoweredNodes
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BatterypoweredsensornodesareusedinconjunctionwiththeSontay®RFRXSBreceiver,andifrequired
(dependingoninstallationtopography),Sontay®RFRRseries of routers and RFIOMIOmodules. Data is
transmittedback to the receiveratconfigurabletimeintervals,oronaconfigurablechange in measured
value.Eachsensorretainstheseconfigurationsifthebatterybecomesdischargedorrequiresreplacement.
Thesensorsautomaticallyfindthebestpathbacktothereceiver,whichmaybedirectlytothereceiveror
via“parent”routers.
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Topowerabatterypowerednode,jumperJ600mustbefitted.Toswitchoff,removeJ600.
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Batterypowerednodesareavailablein4formats:
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•Space mounting temperature, with setpoint, momentary switch, fan speed, VFC input and CO2
options
oNB  setpoint,momentary switch and fan speed optionsare not availablewiththe CO2
option
•SpacemountingRH&T,withsetpoint,momentaryswitch,fanspeed,VFCinputandCO2options
oNB  setpoint, momentary switch andfan speed options are not availablewiththeCO2
option
•Plantmountingtemperature
•PlantmountingRH&T
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SpaceMountingSpecification:
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RadioOutput:
Frequency2.4GHz
16channels,automaticallyselected,directsequencespreadspectrum
ComplianceIEEE802.15.42006
AerialCharacteristics:
Gain  1.2dBi
VSWR  1.5:1
DataEncryption:  AES128
PowerOutput:  0dBm(1mW@50Ω)
Accuracy:
Temperature±0.3°C
OptionalRH±3%RH
BatteryType:  3.6VAA2.4AhLiSOCl2,nonrechargeable
BatteryLife:  >3years(dependingonconfiguration)
Housing:
Material:  ABS(flameretardant)
Dimensions:  115x85x28mm
Environmental:
Operating: 
Temperature: 10°Cto+50°C
RH:  0to90%,noncondensing
Storage:
Temperature: 10°Cto+80°C
RH:  0to90%,noncondensing
Countryoforigin: UK
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Refertoproductdatasheetsforinstallationinstructions.

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PlantMountingSpecification:
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RadioOutput:
Frequency2.4GHz
16channels,automaticallyselected,directsequencespreadspectrum
ComplianceIEEE802.15.42006
AerialCharacteristics:
Gain  2.0dBi
VSWR  2:1
DataEncryption:  AES128
PowerOutput:  0dBm(1mW@50Ω)
Accuracy:
Temperature±0.3°C
OptionalRH±3%RH
BatteryType:  3.6VAA2.4AhLiSOCl2,nonrechargeable
BatteryLife:  >3years(dependingonconfiguration)
Housing:
Material:  ABS(flameretardanttypeVO)
Dimensions:  115x85x28mm
Mounting:  Holes4mmspaced85mmapart
Protection:  IP65
Environmental:
Operating: 
Temperature: 10°Cto+50°C
RH:  0to90%,noncondensing
Storage:
Temperature: 10°Cto+80°C
RH:  0to90%,noncondensing
Countryoforigin: UK

TemperatureSensorTypes:
Duct
Outsideair
Outsideairwithsolarradiationshield
Immersion
Strapon
Flyinglead

Refertoproductdatasheetsforinstallationinstructions.

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24VPoweredRouters
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24VpoweredroutersareusedinconjunctionwiththeSontay®RFRXSBreceiver,RFIOMIOmodulesand
RFRSseriesofbatterypoweredradiosensors,andareusedtoroutesignalsfrombatterypowerednodes
andotherrouterstothe receiver module, where thesignalstrengthofadirectpath is not sufficient for
reliablecommunications.NBEachroutercansupportamaximumof16“children”,whichcanconsistofa
maximumof8batterypowerednodesand8routers,orupto16routersiftherearenobatterypowered
nodes. Consideration should be given on network planning for redundancy in case of router failure or
damage.

Data is transmitted back to the receiver at configurable time intervals, or on a configurable change in
measured value. Each sensor retains these configurations if the battery becomes discharged or requires
replacement.Routersautomaticallyfindthebestpathbacktothereceiver,whichmaybedirectlytothe
receiverorviaother“parent”routers.

Topowerarouter,jumperJ500mustbefitted.Toswitchoff,removeJ500.

24Vpowerednodesareavailablein5formats:

•Spacemountingtemperature,withsetpoint,momentaryswitch,fanspeed,VFCinput,PIRandCO2
options
oNB  setpoint,momentary switch and fan speed optionsare not availablewiththe CO2
option
•Space mounting RH&T, with setpoint, momentary switch, fan speed, VFC input, PIR and CO2
options
oNB  setpoint,momentary switch andfan speed options are not availablewith the CO2
option
•Plantmountingwithnosensorfunctions
•Plantmountingtemperature
•PlantmountingRH&T


SpaceMountingSpecification:

RadioOutput:
Frequency2.4GHz
16channels,automaticallyselected
Directsequencespreadspectrum
ComplianceIEEE802.15.42006
AerialCharacteristics:
Gain  1.2dBi
VSWR  1.5:1
DataEncryption:  AES128
PowerOutput:  +10dBm(10mW@50Ω)
Accuracy:
Temperature±0.3°C
OptionalRH±3%RH
PowerSupply:  24Vac/dc
Housing:
Material:  ABS(flameretardant)
Dimensions:  115x85x28mm
Environmental:
Operating: 

Page9of87
Temperature: 10°Cto+50°C
RH:  0to90%,noncondensing
Storage:
Temperature: 10°Cto+80°C
RH:  0to90%,noncondensing
Countryoforigin: UK

Refertoproductdatasheetsforinstallationinstructions.

PlantMountingSpecification:

RadioOutput:
Frequency2.4GHz
16channels,automaticallyselected,directsequencespreadspectrum
ComplianceIEEE802.15.42006
AerialCharacteristics:
Gain  2.0dBi
VSWR  2:1
DataEncryption:  AES128
PowerOutput:  +10dBm(10mW@50Ω)
Accuracy:
Temperature±0.3°C
OptionalRH±3%RH
PowerSupply:  24Vac/dc
Housing:
Material:ABS(flameretardanttypeVO)
Dimensions:115x85x28mm
Mounting:Holes4mmspaced85mmapart
Protection:IP65
Environmental:
Operating: 
Temperature: 10°Cto+50°C
RH:  0to90%,noncondensing
Storage:
Temperature: 10°Cto+80°C
RH:  0to90%,noncondensing
Countryoforigin: UK

TemperatureSensorTypes:
Duct
Outsideair
Outsideairwithsolarradiationshield
Immersion
Strapon
Flyinglead

Refertoproductdatasheetsforinstallationinstructions.



Page10of87

230VacPoweredRouters

The230VacpoweredRFRRMPRrouterscanbeusedinconjunctionwiththeSontay®RFRXSB receiver,
RFIOM IOmodules,24VpoweredRFRR routersandRFRS seriesofbatterypoweredradiosensors,and
areusedtoroutesignalsfrombatterypowerednodesandotherrouterstothereceiver,wherethesignal
strength of a direct path is not sufficient for reliable communications. NB Each router can support a
maximumof16“children”,whichcanconsistofamaximumof8batterypowerednodesand8routers,or
upto16routersiftherearenobatterypowerednodes.Considerationshouldbegivenonnetworkplanning
forredundancyincaseofrouterfailureordamage.

NBtheRFRRMPR230Vachasnosensorcapability.

Specification:
RadioOutput:
Frequency2.4GHz
16channels,automaticallyselected
Directsequencespreadspectrum
ComplianceIEEE802.15.42006
AerialCharacteristics:
Gain  2.0dBi
VSWR  <2:1
DataEncryption:  AES128
PowerOutput:  +10dBm(10mW@50Ω)
PowerSupply:  85–240Vac@50/60Hz
Housing:
Material:ABS(flameretardant)
Dimensions:116x106x52mm
Environmental:
Ambient: 
Temperature: 30°Cto+70°C
RH:  0to90%,noncondensing
Protection:  IP30

Page11of87
TheRFRXSBBACnetIPSystemReceiver

The SonNet®RFRXSB receiver collects data from all other devices on the radio network, including
measurementsfromsensors,linkqualityforalllinksformedinthenetwork,batterylevelsforallbattery
powered devices, hours run for all devices and the current status of all devices.NB Each receiver can
supportamaximumof16“children”,whichcanconsistofamaximumof12batterypowerednodesand4
routers,orupto16routersiftherearenobatterypowerednodes.

•AnRJ45EthernetsocketisprovidedforconnectiontoBACnetIPsystems.
•A USB socket is provided for connection to a PC or laptop running the Sontay SonNet CMS
software.

NBIftheUSBportofanRFRXSBreceiverisconnected,theEthernetportistemporarilydisableduntilthe
USBportisdisconnectedagain.

ReceiverSpecification:

RadioOutput  2.4GHz,16channelsautomaticallyselected
Directsequencespreadspectrum
Compliance  IEEE802.15.42006
AerialCharacteristicsGain3.0dBi
VSWR<2:1
Dataencryption  AES128
Powersupply  24Vdc±15%
24Vac±15%,50/60Hz
Communication:
USB2.0
RJ45Ethernet(forBACnetIPprotocol)
BIBBssupported
DSRPB
DSWPB
DMDDBB
DMDOBB
DMDCCB
DSRPMB
DMRDB
Environmental:  
OperatingTemp.10˚Cto+50˚C
OperatingRH 090%,noncondensing
StorageTemp 10to+80˚C
StorageRH 090%,noncondensing
Dimensions  100x95x65mm
Weight150g
Countryoforigin UK

Refertoproductdatasheetsforinstallationinstructions.



Page12of87

TheRFIOM

TheRFIOMactsaslocalI/OwithconnectivitytotypicalHVACequipmentsuchasfancoilunits(FCUs)and
variableairvolume(VAV)boxes.TheRFIOMreadsitsdigitalandanalogueinputsandtransmitsthevalues
wirelesslytoaBMScontrollerviatheRFRXSBreceiver.TheRFIOMreceivesitsoutputvalueswirelessly
fromaBMScontrollerviatheRFRXSBreceiver.TheRFIOMhasfullrouterfunctionality.

Typically,asimplesystemwillconsistof;

•BatterypoweredEDs
•Poweredrouters(ifrequired)
•RFRXSBreceiver
•RFIOMs

The EDs (and routers, where applicable) operate in the normal way. Data from the receiver is made
availabletothecontrollerviaBACnetIP.TheSonNetdatapointsarethenusedbythecontrolleraspartofa
controlstrategy,whichwill typicallycalculateheatingandcoolingdemands,damperpositionsetc.These
calculated control values will then be passed back to the receiver via BACnet IP and passed from the
receiveroverthewirelessnetworktotheRFIOM.
TheRFIOMoutputsaredefinedasBACnetobjectssothattheirvaluescanbesetbythecontrolstrategyvia
thereceiver.

RFIOMSpecification:

RadioOutput:
Frequency2.4GHz,16channels,automaticallyselected,Directsequencespreadspectrum
Compliance  IEEE802.15.42006
AerialCharacteristics:
Gain  2.0dBi
VSWR  2:1
DataEncryption: AES128
PowerOutput:  +10dBm(10mW@50Ω)
PowerSupply:  24Vac/dc
Inputs:
4xuniversalinputs;
  420mA(looporexternallypowered),into750Ωmaximumimpedance
  010Vdc,into4k7Ωminimumimpedance
  Resistive,1.5kΩminto60kΩmax
  Digital,VFC
Outputs:4x010Vdclinear,@20mAperoutput
LEDIndication:
Network
Data
Digitalinput 
Housing:  DINRailH86mmxW58mmxL104mm(excludingaerial)
Environmental:
Operating:
Temperature:10°Cto+50°C
RH:  0to90%,noncondensing
Storage:
Temperature:10°Cto+80°C
RH:  0to90%,noncondensing
Countryoforigin:UK

Page13of87

TheRadioNetwork

A Sontay® SonNet radio system is comprised of a receiver, battery powered sensors, RFIOMs and
permanentlypoweredrouters.

Routers, though permanently powered, can also have sensing elements, accomplishing both router and
sensorsfunctions.Routers,RFIOMsandsensorscaneithercommunicatedirectlywiththereceiverorvia
otherroutersandRFIOMs.RFIOMsandroutersarerequiredtobepermanentlypoweredastheyneedto
stay “awake” at all times to allow signals from “child” nodes to be forwarded to their “parent” nodes.
Batterypoweredsensorsonly“wake”forveryshortperiodstosenddata.

Thereceivercansupportamaximumof16directlyconnected“child”devices,ofwhichamaximumof12
can be battery powered EDs (End Devices), plus up to 4 routersor RFIOMs. If no EDs are directly
connected,thereceivercanacceptupto16directlyconnectedroutersorRFIOMs.

RFIOMsandrouterscansupportamaximumof16directlyconnected“child”devices,ofwhichamaximum
of8canbeEDs,plusupto8routers.IfnoEDsaredirectlyconnected,therouterorRFIOMcanacceptup
to16directlyconnectedroutersorRFIOMs.




There can be a maximum
depthof8layersofrouters
in a network and a
maximum of 40 nodes per
network with the RFRXSB
receivers.

Page14of87
NotethatEDscanonlyroutetheirsignalstothereceiverdirectlyorthroughRFIOMsandrouters,andnot
throughotherbatterypowereddevices.

WhenplanningaSonNetradionetwork,itisstronglyrecommendedthattheSontay®SonNetSiteSurveyKit
beused.Thiseasytousepackageallowsinstallerstotestsignalstrengthsbetweenlocationsrequiredfor
EDsandthereceiverpriortoinstallingthefullsystem.Itcanalsoidentifywhetherroutersareneededto
ensurereliablecommunicationsbetweenalldevicesonthenetworkbacktothereceiver.Thisremovesany
guessworkfromplanningasystemandallowstheinstallertoorderexactlyandonlythedevicesrequired.

SeetheSontay®SonNetradiosensorsystemSiteSurveyKitQuickStartGuideandTheSontay®SonNetradio
sensorsystemSiteSurveyKitManualforfulldetails.

NetworkPlanningConsiderations

WhenplanningaSonNetradiosystem,itisalwaysworthconsideringtheplacementofrouters,andshould
becapableofhandlingtheconsequencesofarouterfailingorbeingdamaged.

Example:

Consideranetworkwitharequirementfor16EDs:






1. At least one router is required, as
16 directly connected EDs will
exceed the maximum limit of 12
(see page 13). Four EDs will be
orphaned.












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

2. A single router (R1) will work,
butgivesnoredundancyifthe
routershouldfail.






Page15of87
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
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
3. Optimal network uses
2routers,R1andR2.








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



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




4. If either of the
routersfails, the
network can still be
maintained, as the 2
orphanedEDscanre
route via the other
router.


Page16of87

TheRadioSystem

TheradiosystemusedbytheSontaySonNetdevicesisdividedinto3sectionsor‘layers’.

1. Theradiolayeriswherephysicalcontroloftheradiosignalisdone.Thisconformstointernational
standard 802.15.4, and determines the frequency of the radio signals, the number of ‘channels’
availableforuse,thebandwidthandpowerlevelofthesignaletc.Thereare16channelsavailable,and
thebestoneisautomaticallyselectedbythereceiver.ThefrequenciesusedareintheISM(Industrial,
ScientificandMedical)2.4GHzband,withamaximumdatarateof250kb/s.
2. Thenetworkmanagementlayeriswheretheselfhealingtreefunctionalityisrun,whichcontrols
networktopology.
3. The application layer determines what the device does –i.e.makesitatemperaturesensing
device, a router or a receiver. SonNet devices use specific applications, and include features such as
configurationproperties.

Security

AllSonNetsystemdeviceshavethesame,uniquenetworkidentifier.OnlydeviceswiththecorrectIDwillbe
allowedtojointhenetwork.TheIDusedbysystemdevicesisdifferentfromtheIDusedforsitesurveykit
(SSK) devices. Hence, SSK devices cannot join a system network and vice versa. When a SonNet system
networkhasbeenformed,itcanbe‘locked’topreventanyunauthoriseddevicesjoining,eveniftheyare
SonNetdevices.CMScanbeusedtosubsequentlyauthoriseextraSonNetsystemdevicesifrequired.

AlldatatransmittedbySonNetdevicesisencryptedusingAES128.

HowtheWirelessNetworkisFormed

Thenetworkisformedbasedon3rules,andinaspecificorderofpriority.

1. Howmany‘hops’adeviceisawayfromthereceiver.

Ifadevicecancommunicatedirectlywiththereceiver,itwill,evenifthelinkqualityispoorerthanifit
wentthrougha router orRFIOM. Ifadevicehasa choiceofmorethanonerouterorRFIOM,itwill
choosetherouterorRFIOMclosesttothereceiver(theleast number ofhopsaway),evenif the link
qualityispoor.

2. Thenumberof‘child’devicesarouterorRFIOMalreadyhas.

ARFIOMorroutercanhaveamaximumof16‘children’.IfadevicehasachoiceofmorethanoneRF
IOMor router of the same ‘hop’ level, it will choose the router or RFIOM with the least number of
children,evenifthelinkqualityispoor.

3. SignalStrength(linkquality).

Finally,ifadevicehasachoiceofmorethanoneRFIOMorrouterofthesametierlevelandthesame
numberofchildren,itwillchoosetherouterorRFIOMwiththebestlinkquality.

If,foranyreason,adevice(ED,RFIOMorrouter),losesitspreferredpathbacktothereceiver,itwill
automatically search for an alternative – still obeying the 3 rules above in sequence. If, despite
employingDirectSequenceSpreadSpectrum(DSSS)techniques,interferenceonthecurrentlyoccupied
channel prevents communications, the receiver will automatically look for another channel which is
clear.Allotherdevices,havinglosttheirlinkstothereceiver,willthenalsoautomaticallyscanthe16
channelsuntiltheyfindthereceiveragain,andthenetworkwillreformwithoutuserintervention.

Page17of87

PropagationofRadioSignalsinBuildings

Thepropagationofmicrowaveradiosignalsinabuildingcanbeaffectedinseveralways:

Attenuation



Radiosignalstrengthisattenuatedwhenitpassesthroughair.Signalsare
attenuated much more when passing through other media, such as
materialstypicallyusedin construction, such as brick,stone, wood and
especiallysteel.




Reflection



Dependingonthe building,radio signals can take manypaths from the
transmittertothereceiver,ratherthanjustonesinglepath.

‘Multipath’ signals can have the effect of cancelling each other out,
reducingoverallreceivedsignalstrength.




Scattering




Scatteringtheradiosignalcanalsoreduceitssignalstrength.





Receiver
Transmitter

Page18of87
ExtensionAerials

WhenusingtheRFAERIALPM2or RFAERIALPM5extensionaerials,itisimportanttoobservesomebasic
rulesforsitingandmounting.

1. Alwaysensurethereisamuchclearspacearoundtheaerialaspossible.
2. Generallyspeaking,wherepossiblemounttheaerialashighaspossibleonthesamefloorasthe
routersandEDs
3. Don’tmountbetweenmetalsurfaces(forexamplesteelIbeams)inceilingspaces
4. Whereverpossible,mounttheaerialonametalgroundplane(suchasthetopofametalpanel)
5. ThecoaxialcableusedfortheRFAERIALPM2or RFAERIALPM5extensionaerialsissemirigid
andshouldnotbebentattoosharpanangleortootightaradius.Itisrecommendedthatthe
minimumbendingradiusis5cms
6. Alwaysmounttheaerialvertically.Thisproducestheoptimumradiationpatternandsignal
strength
7. Extensionaerialscanbeusedwithreceivers,routersandRFIOMmodules.
8. Aerialextensionsshouldnotexceed5mtopreventexcessivelossofsignal.