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CAN Transmit

Transmit message to CAN network

  • Library:
  • Simulink Support Package for Arduino Hardware / Common

Description

The CAN Transmit block transmits message to a Controller Area Network (CAN) network by using the CAN shield. The CAN shield is connected to the Serial Peripheral Interface (SPI) pins on the hardware.

Click View pin map to open the Arduino Pin Mapping table .

To know how to assign pins for the block, see Arduino Pin Mapping for Timer Independent Blocks.

Specify the message type and its properties using the block parameters dialog box. Specify the CAN properties of the model in the Configuration Parameters dialog box.

This block supports only MCP2515-based CAN shields.

If you simulate a model that contains the CAN Transmit block without connecting the hardware, the block does nothing. For more information, see Block Produces Zeros or Does Nothing in Simulation.

Ports

Input

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The block accepts messages in Raw data and CAN Msg formats.

  • Raw data – To accept the message as a uint8 vector array, set Data is input as as Raw data.

  • CAN Msg – To accept the message in CAN message format, set Data is input as as CAN Msg. You can create your messages or you can upload a CAN database file. For more information, see Data is input as.

Data Types: uint8 | CAN Msg

Output

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Output port to display status of data transmission. For more information, see Output Status.

Dependencies

This port appears only when you select the Output Status parameter.

Parameters

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Select the type of the message at the input port.

  • Raw data – To accept the message as a uint8 vector array, set Data is input as as Raw data.

  • CAN Msg – To accept the message in CAN message format, set Data is input as as CAN Msg and then perform these steps:

    1. Add a CAN Pack (Vehicle Network Toolbox) block from the Vehicle Network Toolbox™to your model.

    2. Connect the output of CAN Pack block to the input port of the CAN Transmit block.

    3. Using the options in the Data is input as list of the CAN Pack block, specify if you want to create your messages or you want to upload a CAN database file. If you choose to upload a CAN database file, the CAN Pack inherits the message properties from the uploaded file.

    Note

    To use CAN Pack block, you must have a Vehicle Network Toolbox license.

When you select the Output Status parameter, the block configures an output port. The port outputs the status of the data transmission as a uint8 integer. Each bit in the integer corresponds to the type of error occurred during data transmission. An output of 0 indicates successful transmission.

  • on — When you select this parameter, the block operates in the Blocking mode. If the message received in the previous time step is sent, the block accepts message from the input port. If the send operation is in progress, the block waits for the time specified in the Time out in seconds parameter, and then it accepts message from the input port.

    A task overrun occurs if the target hardware is still waiting for the requested message to be sent when the next send operation is scheduled to begin. To fix overruns:

    • Increase the sample time of input message.

    • Reduce the length of message at the input port.

  • off — When you clear this parameter, the block operates in the Non-blocking mode. If the transmission of the message received in the previous time step is still in progress, the message at the input port at the given time step is dropped.

Specify the wait time for sending the message. After the specified time, the block times out.

Dependencies

This parameter appears only when you select the Wait until data sent parameter.

Message identifier, which is 11 bits long for the standard frame or 29 bits long for the extended frame, specified in decimal, binary, or hex. For binary and hex formats, use bin2dec(' ') and hex2dec(' '), respectively, to convert the entry. The message identifier is coded into a message that is sent to the CAN bus.

Dependencies

This parameter appears only when you select Data is input as as Raw data. For CAN Msg, Message ID is inherited from the identifier specified in the CAN Pack block.

The type of message identifier.

Dependencies

This parameter appears only when you select Data is input as as Raw data. For CAN Msg, Identifier Type is inherited from the type specified in the CAN Pack block.

The length of the message, in bytes.

Dependencies

This parameter appears only when you select Data is input as as Raw data. For CAN Msg, Message Length is inherited from the length of the CAN Pack block.

When you select the Request Remote Frame parameter, the remote frame of the message is set to 1 indicating that the block is requesting the transmission of a specific identifier.

Dependencies

This parameter appears only when you select Data is input as as Raw data. For CAN Msg, the Request Remote Frame is inherited from the request specified in the CAN Pack block.