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Log received CAN messages

  • CAN Log block

Vehicle Network Toolbox / CAN Communication


The CAN Log block logs CAN messages from the CAN network, or messages sent to the block input port, to a .mat file. You can load the saved messages into MATLAB® for further analysis or into another Simulink® model.

Configure your CAN Log block to log from the Simulink input port. For more information, see Log and Replay CAN Messages.

The CAN Log block appends the specified filename with the current date and time, creating unique log files for repeated logging.

If you want to use messages logged using Simulink blocks in the MATLAB Command window, use canMessage to convert messages to the correct format.


You need a license for both Vehicle Network Toolbox™ and Simulink software to use this block.


You cannot have more than one CAN Log block in a model using the same PEAK-System device channel.

Other Supported Features

The CAN Log block supports the use of Simulink accelerator and rapid accelerator modes. Using this feature, you can speed up the execution of Simulink models. For more information on this feature, see Acceleration (Simulink).

The CAN Log block supports the use of code generation along with the packNGo function to group required source code and dependent shared libraries.

Code Generation

Vehicle Network Toolbox Simulink blocks allow you to generate code, enabling models containing these blocks to run in accelerator, rapid accelerator, external, and deployed modes.

Code Generation with Simulink Coder

You can use Vehicle Network Toolbox, Simulink Coder™, and Embedded Coder® software together to generate code on the host end that you can use to implement your model. For more information on code generation, see Generated Code Compilation (Simulink Coder).

Shared Library Dependencies

The block generates code with limited portability. The block uses precompiled shared libraries, such as DLLs, to support I/O for specific types of devices. With this block, you can use the packNGo function supported by Simulink Coder to set up and manage the build information for your models. The packNGo (Simulink Coder) function allows you to package model code and dependent shared libraries into a zip file for deployment. You do not need MATLAB installed on the target system, but the target system needs to be supported by MATLAB.

To set up packNGo:


In this example, gcs is the current model that you want to build. Building the model creates a zip file with the same name as model name. You can move this zip file to another machine and there build the source code in the zip file to create an executable which can run independent of MATLAB and Simulink. The generated code compiles with both C and C++ compilers. For more information, see Code Compilation Customization (Simulink Coder).


On Linux® platforms, you need to add the folder where you unzip the libraries to the environment variable LD_LIBRARY_PATH.



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The CAN Msg input port is available when the Log messages from parameter is set to Input port. Provide an input from another block as a CAN_MESSAGE or a Simulink signal bus of type CAN_MESSAGE_BUS.



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Enter the name and path of the file to log CAN messages to, or click Browse to browse to a file location.

The model appends the log file name with the current date and time in the format YYYY-MMM-DD_hhmmss. Specify a unique name to differentiate between your files for repeated logging.

Specify the name for the variable saved in the MAT-file that holds the CAN message information.

Specify the maximum number of messages this block can log from the selected device or port. The specified value must be a positive integer. The default value is 10000 messages. The log file saves the most recent messages up to the specified maximum number.

Select the source of the messages logged by the block. To log messages from the CAN bus network, select CAN Bus, then specify a Device. To log messages from another block in the model, select Input port, which adds an inport port to the block.

Select the device on the CAN network that you want to log messages from. This field is available only if you select CAN Bus for the Log messages from option.

Specify the sampling time of the block during simulation. This value defines the frequency at which the CAN Log block runs during simulation. If the block is inside a triggered subsystem or to inherit sample time, you can specify –1 as the sample time. You can also specify a MATLAB variable for sample time. The default value is 0.01 simulation seconds. For more information, see Timing in Hardware Interface Models.

Extended Capabilities

Version History

Introduced in R2011b