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Monitor CAN Bus with Busmaster

You will need

Physical Connections

Connection diagram

  1. Connect the USB port the Kvaser to your computer.

  2. Connect the D-Sub port of the Kvaser to the CAN port.

    Located on the underside of the dashboard. One port for the VEH CAN bus and one for POWERTRAIN.

    Vehicle CAN ports Vehicle CAN ports

    Only the VEH CAN bus is available.

    Testbench CAN ports

Busmaster Setup

Open Busmaster. Under "Driver Selection" choose "Kvaser CAN."

Busmaster Driver

Under "Channel Configuration," configure a Kvaser channel by selecting it on the left and clicking the >> button. Configure the BaudRate to 500 000 bps.

Busmaster Channel Config

Kvaser channel numbering

The Kvaser has 2 D-Sub connectors to support 2 CAN channels / busses. The cables are labelled Ch.1 and Ch.2, but they appear in Busmaster configuration as Channel 0 and Channel 1, respectively.

Kvaser channel numbering

However, once you start reading CAN messages, they are correctly numbered 1 and 2 again (see next image).

Click "Connect" in the top-left to start viewing CAN messages!

Busmaster connect

The raw binary CAN messages are hard to read. In the next section we will associate a CAN database to allow Busmaster to decode for us.

Interpret CAN Messages

Busmaster only accepts a special .dbf database format. Fortunately, it provides a tool to convert our .dbc files to .dbf.

Under "Tools" select "Format Converter."

Format Converter

Go to "Other Converters" and select "DBC to DBF." Choose a .dbc input file and click "Convert." Note the "Output File" destination.

DBC Convert

Return to the "CAN" tab and click "Database" → "Associate." Choose the .dbf file.

Associate Database

Under "Message Window" enable "Interpret."

Note

"Interpret" is disabled until a database is associated.

Interpret Window

Now look at the Message Window. Each message should have a name (ex. FC_Status) and you can expand the signals by clicking the +.

Interpreted Messages

DBC file corresponding to this screenshot 
BO_ 255 FC_Status: 5 FC
    SG_ GovStatus : 0|8@1+ (1,0) [0|255] "" LVC, PC_SG
    SG_ DiStatus : 8|8@1+ (1,0) [0|255] "" LVC, PC_SG
    SG_ MiStatus : 16|8@1+ (1,0) [0|255] "" LVC, PC_SG
    SG_ BmStatus : 24|8@1+ (1,0) [0|255] "" LVC, PC_SG
    SG_ UserFlag : 32|8@1+ (1,0) [0|255] "" LVC, PC_SG

BO_ 111 LvControllerStatus: 6 LVC
    SG_ LvState : 0|8@1+ (1,0) [0|1] ""  RPI
    SG_ Elapsed : 8|32@1- (1,0) [0|1] ""  RPI
    SG_ Flag : 40|1@1+ (1,0) [0|1] ""  RPI

BO_ 113 SuspensionTravel34: 2 LVC
    SG_ STP3 : 0|8@1+ (1,0) [0|255] "" FC,RPI
    SG_ STP4 : 8|8@1+ (1,0) [0|255] "" FC,RPI

BO_ 257 DashStatus: 1 Dash
    SG_ Status : 0|8@1+ (1,0) [0|255] "" FC

For example:

  • In the DBC, FC_Status has ID 255 which is hex 0x0FF in Busmaster.
  • The Elapsed field is is bits 8-39 of the LvControllerStatus message. The "Data Bytes" are 0x00001F95 which is hex for 8085, matching the interpreted value.

Send CAN Messages

Open the "Transmit Window."

Open Transmit Window

Select "Add Message" and choose a message from the database to send.

Warning

If you are using multiple CAN channels, you must configure the "Channel" column to send the message on the right one.

Edit the "Signal Details" to change the signal values.

Click "Send Message" to send it once, or enable "Repetition" to periodically send the message.

Send Message

Troubleshooting

Can't transmit over Channel 2

There is a bug in the Transmit Window. If you change the transmit Channel to 2, you will lose the message's database information like its name and signals.

You can still send a message over channel 2 but must manually set the bits in the "Data Byte View."

If you only need to transmit over one channel, connect the Ch.1 D-Sub to that bus to avoid this error.

Channel 1: Message has name and signal breakdown

Channel2-Before

Channel 2: Message doesn't have name or signals

Channel2-Before