Read Data from BLF Files Using ARXML

This example shows you how to read data from a BLF file using ARXML as the database.

Open the ARXML File

Open the ARXML file DecodingExample.arxml using arxmlDatabase function.

arxmlObj = arxmlDatabase("DecodingExample.arxml")

arxmlObj = 
  Database with properties:

    Name: "DecodingExample.arxml"
    Path: "C:\ExampleManager772791\user.Example_ARXMLCANDecoding\vnt-ex11728030\DecodingExample.arxml"
     CAN: [1×1 shared.vnt.arxml.protocol.CAN]

View Details of the BLF File

Retrieve and view information about the BLF file. The blfinfo function parses general information about the format and contents of the Vector Binary Logging Format (BLF) file and returns the information as a structure.

blfin = blfinfo("BLF_ARXML.blf")

blfin = struct with fields:
                  Name: "BLF_ARXML.blf"
                  Path: "C:\ExampleManager772791\user.Example_ARXMLCANDecoding\vnt-ex11728030\BLF_ARXML.blf"
           Application: "CANoe"
    ApplicationVersion: "18.2.65"
               Objects: 6075
             StartTime: 15-Nov-2024 18:06:16.345
               EndTime: 15-Nov-2024 18:07:17.460
           ChannelList: [2×3 table]

blfin.ChannelList

ans=2×3 table
    ChannelID    Protocol    Objects
    _________    ________    _______

        1         "CAN"       6070  
        2         "CAN"          0  

Read Data from the BLF File

The data of interest was stored in channel 1 of the BLF file. Read the CAN data using the blfread function. You can also provide the ARXML file to the function call to enable message name lookup and signal value decoding.

blfData = blfread("BLF_ARXML.blf", 1, "Database", arxmlObj)

blfData=6070×8 timetable
        Time           ID        Extended       Name                      Data                   Length      Signals       Error    Remote
    ____________    _________    ________    __________    __________________________________    ______    ____________    _____    ______

    0.050294 sec         2048     true       {'Frame2'}    {[            250 0 16 0 4 0 1 0]}      8       {1×1 struct}    false    false 
    0.050526 sec            3     false      {'Frame4'}    {[210 236 104 118 52 187 124 192]}      8       {1×1 struct}    false    false 
    0.050694 sec           16     false      {'Frame5'}    {[                    0 3 89 100]}      4       {1×1 struct}    false    false 
    0.050898 sec         2047     false      {'Frame1'}    {[         226 99 235 64 255 255]}      6       {1×1 struct}    false    false 
    0.051184 sec    536870911     true       {'Frame3'}    {[       0 0 45 10 68 26 184 161]}      8       {1×1 struct}    false    false 
    0.10029 sec          2048     true       {'Frame2'}    {[            237 0 12 0 6 0 0 0]}      8       {1×1 struct}    false    false 
    0.10053 sec             3     false      {'Frame4'}    {[      0 56 252 27 254 13 75 64]}      8       {1×1 struct}    false    false 
    0.10071 sec            16     false      {'Frame5'}    {[                  0 252 200 92]}      4       {1×1 struct}    false    false 
    0.10091 sec          2047     false      {'Frame1'}    {[           68 41 41 64 249 255]}      6       {1×1 struct}    false    false 
    0.1012 sec      536870911     true       {'Frame3'}    {[      0 64 126 0 196 46 248 98]}      8       {1×1 struct}    false    false 
    0.15029 sec          2048     true       {'Frame2'}    {[            118 0 24 0 4 0 0 0]}      8       {1×1 struct}    false    false 
    0.15052 sec             3     false      {'Frame4'}    {[    120 21 188 10 94 69 132 64]}      8       {1×1 struct}    false    false 
    0.15069 sec            16     false      {'Frame5'}    {[                  0 252 161 14]}      4       {1×1 struct}    false    false 
    0.15089 sec          2047     false      {'Frame1'}    {[          41 48 20 192 254 255]}      6       {1×1 struct}    false    false 
    0.15118 sec     536870911     true       {'Frame3'}    {[      0 128 93 2 67 178 109 45]}      8       {1×1 struct}    false    false 
    0.20029 sec          2048     true       {'Frame2'}    {[            152 0 24 0 4 0 1 0]}      8       {1×1 struct}    false    false 
      ⋮

View the signals of interest included in the Frame2 message.

blfData.Signals{1}

ans = struct with fields:
     Signal5: 27
    Signal11: 7

Repackage and Visualize Signal Values of Interest

Use the canSignalTimetable function to repackage signal data from each unique message on the bus into a signal timetable.

signalTimetable = canSignalTimetable(blfData, "Frame2")

signalTimetable=1214×2 timetable
        Time        Signal5    Signal11
    ____________    _______    ________

    0.050294 sec        27         7   
    0.10029 sec       20.5       6.5   
    0.15029 sec         89         8   
    0.20029 sec        -22         8   
    0.25029 sec         68         7   
    0.30029 sec       10.5         7   
    0.35029 sec        -19       7.5   
    0.40029 sec         13         6   
    0.4503 sec        40.5       5.5   
    0.50029 sec       51.5       6.5   
    0.55029 sec         -4       6.5   
    0.60029 sec         -8       6.5   
    0.65029 sec        -14       5.5   
    0.70029 sec        -28       6.5   
    0.75029 sec      -11.5         7   
    0.8003 sec          61         7   
      ⋮

To visualize the signals of interest, columns from the signal timetables can be plotted over time for further analysis. The plot shows the first 5 seconds value for the Signal5.

plot(signalTimetable.Time, signalTimetable.Signal5); 
xlim(seconds([0 5]));