User manual

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 DocumentMT0100P.N
©XsensTechnologiesB.V. MTiandMTxUserManualandTechnicalDocumentation
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5 Basiccommunication
5.1 Introduction
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Thissection describes thebasicsof how to communicatewiththeMTi / MTxdirectlyon low‐levelusingRS‐
232/422/485 serial communication with orwithout the use of an Xsens USB‐serialconverter.Foradetailed
andcompletelistofallmessagespleaserefertotheMTLow‐levelCommunicationDocumentation.
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NOTE:YoucanskipthischapterifyouplantoonlyinterfacewiththedeviceusingXsens’GUIsoftwareorSDK
API.
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Thecommunicationprotocol,whichismessagebased,enablestheusertochangetheconfigurationoftheMTi
orMTx and toretrievethe datafromthedevice. The communicationprotocolused  for theMTi and MTx is
compliant to the MotionTracker communication protocol
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. The configuration is fully user‐settable, e.g. 
samplefrequency,in‐ &outputsynchronization,baudrateand data output modes, can all bechangedto fit
yourrequirements.
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All configuration changes must be made while the device is in the so‐called Config State. In this state the
device accepts messages that set the output mode or changes to other settings. Whenever the preferred
configurationiscompletedtheusercansetthedevicetoMeasurementState.Inthisstatethedeviceoutputs
databasedthecurrentconfigurationsettings.
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5.2 States
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TheMTi/MTxhastwostates,i.e.ConfigState and MeasurementState.IntheConfigStatevarioussettings
can be read and written. In the Measurement State the device will output its data message whichcontains
datadependentonthecurrentconfiguration.
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There are two different ways to enter the Config State or the Measurement State. At power‐up the device
startstheWakeUpprocedure,ifnoactionistaken itwillthenenterMeasurementStatebydefault,usingits
lateststoredconfiguration.
PriortoenteringtheMeasurementState,theConfigurationmessageisalwayssenttothehost
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.Thisis
the configuration that is read from the internal non‐volatile memory and will be used in the Measurement

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 The MotionTracker‐host protocol is a fully documented standard message based protocol developed by
Xsenstailormadefortheneedsofinertialsensors.
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 If the device is set to RAW OutputMode the device will send additional encrypted data to the host after
sendingtheConfigurationmessage.Theencrypteddataprimarilycontainsthecalibrationvaluesofthe
Measurement
WakeUp
procedure
WakeUpAck
received by device
No WakeUpAck
received by device
GotoMeasurement
GotoConfig
Config