
RobustelGoRuggedM1000ProUserGuide
RT_M1000Pro_UG_v01.01 27.12.2011 40/59
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Chapter4. TypicalApplications
4.1 Overview
Cellulardatatransmissionisanincreasinglyattractivemechanism forcommunication withremote,non‐permanent
or mobile devices. Being able to collect and distribute data virtually anywhere without requiring the limitation of
working within specific fixed linenetworks is a powerfulforcefor efficiency and reliability.However, the fact that
cellular datais metered means that the frequency of transmission andamountof data sent in each exchangecan
havesignificantcostandperformanceimpact.
Inordertounderstandthisimpact,letusstartwithafairlytypicalexample,wherethereisadeviceinthefieldand
anapplicationonaserveratacentralsitelocationthatcollectsinformationfromthatdevice.
Ingeneral,thepurposeofcommunicationwiththedevicewillbeforoneoftworeasons:
•Monitoring‐Statusmonitoringdata,suchasthelevelortemperatureofastoragetank,thevelocityandpressure
ofapipeline,theconditionofacontrollerorthestatusofaregister.
•Transactiondata–Discreteeventdata,suchascashorcredittransactions,PBXcallrecordsormission‐criticaland
safetyrelatedalarms.
Status monitoring data is often “polled.” The application sends out periodic queries and gets responses to those
queries.Theapplicationcanusuallyretryifitdoesnotgetananswer,anddeterminethataproblemexistsifitdoes
notgetaresponseafteracertainamountofretries.
Discreteeventdataisusually“unsolicited.” Theapplicationdoesnotexpecttogetinformationonanyregularbasis,
andthereforethefailuretohearfromthedeviceisthenormalcase(thoughsomesortof“alliswell”messagemay
besentatalongerinterval).
Mostapplicationswilllikelyinvolveoneorbothofthesemethods anddataistransmittedinTCPorUDPpackets.
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