Follow

Make a log file compatible with MT Manager

The MTi can process data into orientation on board and data from the MTi, even when it is in binary format is easy to parse into any program. Just follow the message structure in the Low-Level Communication Documentation. However, when data files are needed that need post-processing in MT Manager (e.g. for analysis by Xsens, to process data into various filter profiles or when you find it easier to use MT Manager for exporting data to text), it is required that the file has a correct structure. 

For MT Manager or the API to be able to process files, a header containing the Configuration and the eMTS messages (extended Motion Tracker Specification) must precede the measurement data in the log file.

  • Configuration MID: x0D - FA FF 0D .....
  • eMTS MID: x91 - FA FF 91 ....
  • Measurement data MID: x36 - FA FF 36 ... (repeated until the end of the file)

Retrieving a file that is compatible with MT Manager is possible in several ways:

1. Record a file with MT Manager

This is by far the easiest way. MT Manager will take care of creating a correct mtb file. 

2. Record data via low-level communication

Sometimes, it is not possible to record data via MT Manager, e.g. in drones, embedded applications etc. In that case, there are again several ways to construct a proper file. 

  • Do one of the following:
    1. Start logging and then power on the Motion Tracker. Configuration and eMTS data will be sent by the Motion Tracker on wake-up and will be contained in your log file. To save the file, remove everything before FA FF 0D... and make sure to end with a complete measurement data message, so until the next FA FF 36. Save as .mtb file with a hex editor, e.g. Notepad++ with HexEditor plugin.
    2. Send the reset command to the Motion Tracker and record everything the Motion Tracker transmits afterwards. The first messages from the Motion Tracker will again be the Configuration Data and the eMTS Data. To save the file, remove everything before FA FF 0D... and make sure to end with a complete measurement data message, so until the next FA FF 36. Save as .mtb file with a hex editor, e.g. Notepad++ with HexEditor plugin.
    3. When this is not possible, you need to record just the FA FF 36 (measurement data) messages and paste the configuration and eMTS messages before the first FA FF 36 bytes (where the data starts). You have two options:
      1. When you can connect the MTi to MT Manager, record a file and copy the first part of the mtb file (up to the first data message FA FF 36) in front of the measurement data messages that you recorded with the low-level communication. Make sure to end with a complete measurement data message, so until the next FA FF 36. Please note that the configuration of the Motion Tracker needs to be exactly the same recording the data and the configuration data. This method is not fail-safe, so please use with care! eMTS data is proprietary. Save as .mtb file with a hex editor, e.g. Notepad++ with HexEditor plugin.
      2. When you cannot connect the MTi to MT Manager, you have to request the Configuration and eMTS message from the MTi. The commands for that are "FA FF 0C F5" and the message for requesting the eMTS is "FA FF 90 02 00 FF 70". Both are to be sent in Config Mode. Copy the responses in front of the measurement data messages that you recorded with the low-level communication. Make sure to end with a complete measurement data message, so until the next FA FF 36. Please note that the configuration of the Motion Tracker needs to be exactly the same recording the data and the configuration data. This method is not fail-safe, so please use with care! eMTS data is proprietary. Save as .mtb file with a hex editor, e.g. Notepad++ with HexEditor plugin.

 

Low Level Communication Protocol
For reference about the messages format please see the Low Level Communication Protocol Documentation (LLCP). The LLCP can be found here

The Configuration and eMTS messages are not described in the LLCP in detail because they cannot be set or read by the user. They are meant for XDA only.

Was this article helpful?
0 out of 0 found this helpful
Do you have a question? Please post your question in our Community Forum