Sierra Wireless 20070914 TCP an d TCP Pad

Data Communication and Host Modes
Rev 3.0B Feb.08 69
UDP Multicast Mode
UDPMulticastmoderesultsinanydatareceivedfromthehost
serialportbeingsenttoalltheclientsintheaddresslist.The
remoteportnumberistakenfromS53.Toavoidfloodingthe
network,thepacketsaresenttoeachclientwitha20mspause
inbetween.ThereceiptofUDPpacketsworksasinnormal
UDPmode(i.e.boundbythevalueS53and/orAIP).Sinceit
maytakeawhiletotransmitthedatatoallhosts(especiallyif
all20Modbusentriesareusedandnameresolutionsare
required),newdatareceivedfromthehostportisbuffered
untilcurrenttransmissionstoallhosts��arefinished.
EnterthelistoftargetIPsintheaddresslist(ADDRLIST).The
indexnumbersinthelistarenʹtused.Configureforanormal
UDPsession.SettheStartupModeDefaultto83(ATMD83).
ConfiguretheDestinationporttomatchthedeviceportofthe
remotemodems.
TCP an d TCP Pad
WhenthePinPointXisinaTCPsession,allcharacters
receivedontheserialportareassembledintoTCPpacketsand
senttothemodeʹsremoteIPaddress/port,andanypackets
receivedfromtheremoteendoftheTCPconnectionaredisas‐
sembledanddumpedontotheserialline.
ATCPconnectionisestablishedbyoneofthefollowing
methods:
•UsingtheDialTCP(DT)ATcommand.Forexample,
ATDT192.168.3.23/3456.
•TCPautoanswerisenabled(S1),aTCPconnectionrequest
isreceived,andthemodemisnotinadatasession.
•Dataisreceivedontheserialportand
·TheStartupModeDefault(MD)is4(autoTCP)
·TheremoteTCPdestination,asdefinedinS53,success‐
fullyrespondstotheTCPconnectionrequest.
ThevalueofS7(TCPConnectionTime‐out)specifiesthe
numberofsecondstowait,afterinitiatingaTCPconnection
attempt,forasuccessfulconnectiontobeestablished.Ifthe
connectionhasnotbeensuccessfullyestablishedbeforethe
time‐outoccurs,ERROR/BUSYisreturned.
TCPpacketassemblyisaffectedbythevaluesofS50(PAD
ForwardingTime‐out)andS51(PADForwardingCharacter).
Datareceivedintheserialbufferwillbetransmittedwhenthe
idleinter‐charactertime‐outspecifiedinS50(intenthsof
seconds)occursorwhenacharacterisreceivedthatmatches
S51(ifnon‐zero).