The MT has two states: Config and Measurement state. In the Config state, various settings can be read and written and in the Measurement state the MT will output its data messages, which contains data dependent on the current configuration.
There are two different ways to enter the Config state or the Measurement state. At power-up, the MT starts the WakeUp procedure and it will send the WakeUp message. If no action is taken and the OptionFlag is not set to DisableAutoMeasurement, the device enters the Measurement state. If the WakeUpAck message is sent within 500ms after reception of the WakeUp message, the MT enters the Config state.
Prior to entering the Measurement state, the Configuration and eMTS (extended Motion Tracker Settings messages) are sent to the host. The MTi 10-series, MTi 100-series, MTi 600-series, Xsens Avior series and Xsens Sirius series will send these messages by default. For the MTi 1-series, these startup messages can be enabled or disabled using the setOptionFlags command. Configuration data is the configuration that is read from the internal non-volatile memory and will be used in the Measurement State. The data in the Configuration message can always be used to determine the output configuration. The encrypted eMTS data is required to be able to process the data by Xsens software to calculate calibrated inertial data values. Settings in the eMTS data are used to estimate orientation and position.
Another way to enter the Config or Measurement state is to use the GoToConfig or GoToMeasurement messages while the other state is active.
The WakeUp procedure of the MTi
Config state is used to get and/or set various settings of the MT. Most of the settings will change the configuration which defines the device functionality in Measurement state. Settings that change the configuration are, for example, the communication baud rate, sample period, output mode, output settings or synchronization properties.
At power-up, all settings are read from non-volatile memory. All settings are stored in a format developed by Xsens known as the eMTS (extended Motion Tracker Specification), along with other device specific data such as calibration parameters. The format is proprietary, but all settings can be manipulated by using the appropriate Set messages.
Settings changed in Config state are immediately stored in the memory. The memory will retain the latest values even if the device is disconnected from power. Some messages have an additional parameter that requires the user to explicitly specify whether the new values should be stored in non-volatile memory or not. The setting changes are immediate.
NOTE: There are exceptions, such as the baud rate and GNSS receiver settings. The new settings will not be applied immediately; they will be used after the next power-cycle or after a soft-reset.
In the Measurement state, the MT will output its data to the host in a way depending on the configuration settings defined in the Config State. A single message, MTData2, is used for all different data outputs. It is therefore important that the host knows how the device is configured. The current configuration will determine how the message data should be interpreted. A special message, Configuration, contains the information which, with the data received by the host in Measurement state, can be unambiguously interpreted. When logging MTData2 messages it is advisable to include the Configuration message in the data header for future analysis or post-processing.
If the host does not respond to the WakeUp message at power-up (or after issuing a Reset message), the MT will automatically enter the Measurement state. Just before entering the Measurement state, it will send the Configuration message. The configuration settings are all read from the non-volatile memory and are used during operation.
|
Property |
MTi-1/10/100/610/Avior IMU/Sirius IMU |
MTi-2/20/200/620/Avior VRU/Sirius VRU MTi-3/30/300/630(R)/Avior AHRS/Sirius AHRS |
MTi-7/670(G)/G-710 GNSS/INS MTi-8/680(G) RTK GNSS/INS |
|---|---|---|---|
|
Output Configuration |
|
Quaternion: float |
Quaternion: float |
|
Delta_q: float |
|
|
|
|
Delta_v: float |
|
|
|
|
Mag Field: Float |
|
|
|
|
Packet counter |
Packet counter |
Packet counter |
|
|
Sample Time Fine |
Sample Time Fine |
Sample Time Fine |
|
|
Status Word |
Status Word |
Status Word |
|
|
|
|
AltitudeEllipsoid:FP1632 |
|
|
|
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LatLon: FP1632 |
|
|
|
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VelocityXYZ: FP1632 |
|
|
Setting profile |
N/A |
|
General (MTi-7/670(G)/G-710) General_RTK (MTi-8/680(G)) |
|
Output frequency |
100 Hz |
100 Hz |
100 Hz |
|
Baud rate |
115k2 bps |
115k2 bps |
115k2 bps |
|
Output skip factor |
0 |
0 |
0 |
|
SyncIn |
Disabled |
Disabled |
GPS_Clock_Sync |
|
SyncOut |
Disabled |
Disabled |
Disabled |
To change settings, the device must enter the Config state for which the user must first send the GoToConfig message. When there are exceptions, they are mentioned in Messages.