CAN Transmit

Transmit message to CAN network

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Add-On Required: This feature requires the Simulink Support Package for Raspberry Pi Hardware add-on.

  • CAN Transmit block

Libraries:
Simulink Support Package for Raspberry Pi Hardware / Communication

Description

The CAN Transmit block transmits messages to the CAN network. This block uses SocketCAN which is a device-independent driver for implementing the CAN interface supporting all CAN shields.

The CAN Transmit block supports Raw data and CAN Msg as input types. To use a CANdb (CAN database) file or to specify signals manually, use CAN Msg input type and the CAN Pack block. The CAN Pack block is available from Vehicle Network Toolbox™. For more information on the CAN Pack block, see CAN Pack (Vehicle Network Toolbox).

For more information on how to enable the SPI interface and configure the MCP2515 CAN controller for CAN communication, see Enable and Configure Raspberry Pi for SPI and CAN Communication Using MCP2515 CAN Controller.

You can use CAN Transmit block to interact with a real or virtual CAN interface. To bring up the CAN interface with Raspberry Pi®, refer to the user guide of your CAN shield. For more information on how to set up a virtual CAN interface, see Setup Virtual CAN Interface.

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 to Raw data.

  • CAN Msg — To accept the message in CAN message format, set Data is input as to CAN Msg.

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

To enable this port, select the Output Status parameter.

Parameters

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Enter the name of the real or virtual CAN interface. To find the name of the CAN interface, in the Raspberry Pi terminal, execute the ifconfig command. To configure the CAN interface, see CAN properties.

Data input type used for transmitting messages.

  • 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:

    • Add a CAN Pack (Vehicle Network Toolbox) block to your Simulink® model.

    • Connect the output of the CAN Pack (Vehicle Network Toolbox) block to the input port of the CAN Transmit block.

    • Using the options in the Data is input as list of the CAN Pack (Vehicle Network Toolbox) 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 (Vehicle Network Toolbox) inherits the message properties from the uploaded file.

Note

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

When selected, the block waits for the time specified in the Time out in seconds parameter before transferring data.

  • 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

To enable this parameter, select Wait until data sent.

Select this option to indicate the status of message transfer. Status port outputs 0 for successful transmit and error codes in case of failure. Error codes are listed in this table.

0000ABTFMLOATXERRTXBOTXEPTXWAR
bit7bit6bit5bit4bit3bit2bit1bit0

ABTF: Message Aborted Flag bit

MLOA: Message Lost Arbitration bit

TXERR: Transmission Error Detected bit

TXBO: Bus-Off Error Flag bit

TXEP: Transmit Error-Passive Flag bit

TXWAR: Transmit Error Warning Flag bit

Message identifier type.

Dependencies

To enable this parameter, set Data is input as to Raw data.

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

To enable this parameter, set Data is input as to Raw data. For CAN Msg, the message identifier is inherited from the identifier specified in the CAN Pack (Vehicle Network Toolbox) block.

The length of the message, in bytes.

Dependencies

To enable this parameter, set Data is input as to Raw data. For CAN Msg, the message length is inherited from the length of the CAN Pack (Vehicle Network Toolbox) block.

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

Dependencies

To enable this parameter, set Data is input as to Raw data.

Version History

Introduced in R2019b

See Also

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Topics

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