Sierra Wireless 20070914 TCP an d TCP Pad

Data Communication and Host Modes
Rev 3.0B Feb.08 58
untilitreceivesanacknowledgementwiththissequence
number.Ifanacknowledgementisnotreceivedwithinthe
time‐outperiod(specifiedinS7),thedatawillberetrans‐
mitted.Thiswillcontinueuntilanacknowledgementis
receivedorthemodemisreset.LikewiseanyUDPpackets
receivedbytheRavenareexpectedtohavethissimpleheader.
TheRavenwillissueanacknowledgementforanyvalid
packetswhicharereceived.
ToconfiguretheRavenforanormalUDPsession,youneedto
settheStartupModeDefaultto73(ATMD73).Ifyouareusing
twomodems,configuretheDestinationIPandPortineachto
pointtoeachother.Serialdatawillthenbesentreliably
betweenthetwo.
Caution: Although it adds reliability, the simple implementation of the
Reliable UDP mode in the does not check for duplicate packets.
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Raven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disassembled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.