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Log and Replay CAN FD Messages

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This example shows you how to log and replay CAN FD messages using MathWorks Virtual CAN FD channels in Simulink®. You can update this model to connect to supported hardware on your system.

Load the saved CAN FD message from sourceFDMsgs.mat file from the examples folder. The file contains CAN FD messages representing a 90 second drive cycle around a test track.

Convert these messages to a format compatible with the CAN FD Replay block and save it to a separate file.

  Name                        Size               Bytes  Class        Attributes

  canFDMsgTimetable      100000x12            45411726  timetable              
  canFDMsgs                   1x1              8401848  struct

CAN FD Replay Model

This model contains:

  • A CAN FD Replay block that transmits to MathWorks Virtual Channel 1.

  • A CAN FD Receive block that receives the messages on a CAN FD network, through MathWorks Virtual Channel 2.

The CAN FD Receive block is configured to block all extended IDs and allow only the WheelSpeed message with the standard ID 1200 to pass.

The Wheel Speeds subsystem unpacks the wheel speed information from the received CAN FD messages and plots them to a scope. The subsystem also logs the messages to a file.

Visualize Wheel Speed Information

The plot shows the wheel speed for all wheels for the duration of the test drive.

Load the Logged Message File

The CAN FD Log block creates a unique file each time you run the model. Use dir in the MATLAB Command Window to find the latest log file.

WheelSpeeds_2018-Apr-30_132033.mat  

  Name                        Size               Bytes  Class        Attributes

  canFDMsgTimetable      100000x12            45411726  timetable              
  canFDMsgs                   1x1              8401848  struct                 
  outFDMsgs                   1x1               841848  struct

Convert Logged Messages

Use canFDMessageTimetable to convert messages logged during the simulation to a timetable that you can use in the command window.

To access message signals directly, use the appropriate database file in the conversion along with canSignalTimetable.

ans =

  15x12 timetable

       Time        ID     Extended         Name          ProtocolMode       Data        Length    DLC      Signals       Error    Remote     BRS      ESI 
    __________    ____    ________    _______________    ____________    ___________    ______    ___    ____________    _____    ______    _____    _____

    75.393 sec     576     false      {0x0 char     }     {'CAN FD'}     {1x4 uint8}      4        4     {0x0 struct}    false    false     true     false
    75.397 sec    1200     false      {'WheelSpeeds'}     {'CAN FD'}     {1x8 uint8}      8        8     {1x1 struct}    false    false     true     false
    75.398 sec     128     false      {0x0 char     }     {'CAN FD'}     {1x7 uint8}      7        7     {0x0 struct}    false    false     true     false
    75.398 sec     133     false      {0x0 char     }     {'CAN FD'}     {1x8 uint8}      8        8     {0x0 struct}    false    false     true     false
    75.398 sec     144     false      {0x0 char     }     {'CAN FD'}     {1x8 uint8}      8        8     {0x0 struct}    false    false     true     false
    75.398 sec     528     false      {0x0 char     }     {'CAN FD'}     {1x7 uint8}      7        7     {0x0 struct}    false    false     true     false
    75.399 sec     529     false      {0x0 char     }     {'CAN FD'}     {1x8 uint8}      8        8     {0x0 struct}    false    false     true     false
    75.399 sec    1201     false      {0x0 char     }     {'CAN FD'}     {1x8 uint8}      8        8     {0x0 struct}    false    false     true     false
    75.399 sec     512     false      {0x0 char     }     {'CAN FD'}     {1x8 uint8}      8        8     {0x0 struct}    false    false     true     false
    75.399 sec     513     false      {0x0 char     }     {'CAN FD'}     {1x8 uint8}      8        8     {0x0 struct}    false    false     true     false
    75.399 sec     533     false      {0x0 char     }     {'CAN FD'}     {1x8 uint8}      8        8     {0x0 struct}    false    false     true     false
    75.4 sec      1312     false      {0x0 char     }     {'CAN FD'}     {1x5 uint8}      5        5     {0x0 struct}    false    false     true     false
    75.405 sec    1200     false      {'WheelSpeeds'}     {'CAN FD'}     {1x8 uint8}      8        8     {1x1 struct}    false    false     true     false
    75.406 sec    1201     false      {0x0 char     }     {'CAN FD'}     {1x8 uint8}      8        8     {0x0 struct}    false    false     true     false
    75.408 sec    1296     false      {0x0 char     }     {'CAN FD'}     {1x3 uint8}      3        3     {0x0 struct}    false    false     true     false


ans =

  15x4 timetable

       Time       RR_WSpeed    RF_WSpeed    LR_WSpeed    LF_WSpeed
    __________    _________    _________    _________    _________

    75.397 sec      41.19        40.04        41.19        39.95  
    75.405 sec       41.2        40.04        41.21        39.97  
    75.414 sec      41.22        40.05        41.26        40.03  
    75.424 sec      41.25        40.13         41.3        40.05  
    75.433 sec      41.19        40.14        41.28        40.08  
    75.441 sec      41.17        40.18        41.31        40.14  
    75.45 sec       41.31        40.27        41.31        40.17  
    75.458 sec      41.37        40.25        41.31        40.19  
    75.466 sec      41.39        40.22         41.3        40.19  
    75.475 sec      41.39        40.25         41.3         40.2  
    75.483 sec      41.37        40.26        41.33        40.21  
    75.492 sec      41.44        40.35        41.33        40.19  
    75.501 sec      41.51        40.44        41.36        40.22  
    75.509 sec      41.58        40.47        41.44        40.29  
    75.517 sec      41.63        40.45        41.44        40.31

MathWorks CAN FD Virtual channels were used for this example. You can however connect your models to other supported hardware.

Vehicle Network Toolbox Documentation

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