CAN Write

Write data to the CAN Bus

Since R2023a

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  • CAN Write

Libraries:
STM32 Microcontroller Blockset / STM32F1xx Based Boards
STM32 Microcontroller Blockset / STM32F2xx Based Boards
STM32 Microcontroller Blockset / STM32F3xx Based Boards
STM32 Microcontroller Blockset / STM32F4xx Based Boards
STM32 Microcontroller Blockset / STM32F7xx Based Boards
STM32 Microcontroller Blockset / STM32L4xx Based Boards
STM32 Microcontroller Blockset / (Legacy) STM32 MBED Based Boards / STM32H7

Description

The CAN Write block writes messages to the Controller Area Network (CAN) network connected to the hardware.

The CAN Write block accepts a CAN data that needs to be sent when operation mode is set to Data. The block accepts a 1-D array of type uint8 when data format is set to Raw data.

The block accepts input as Simulink® bus signal when data format is set to CAN Message. To extract data from Simulink bus signal, connect it to CAN pack block.

Note

When the length of data (input array) is different than the length (input scalar), the number of data transmitted over the CAN module is minimum of length of data or input length.

Select the Operation mode and its properties using the block parameters dialog box. Configure the properties of CAN module in the Model Configuration Parameters for STM32 Processor Based Boards.

Examples

Send and Receive CAN or FDCAN Messages on a STM32 processor

Send and Receive CAN or FDCAN Messages on a STM32 processor

Exchange data between STM32 processor based boards using CAN or FDCAN communication.

Ports

Input

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The block accepts messages in Raw data format. To accept the message as a uint8 array, set Data Format to Raw data.

Dependencies

To enable this port, set the Data format to Raw data.

Data Types: uint8

The block accepts messages in CAN Message format.

You can create your messages or you can upload a CAN database file to CAN Pack block.

Dependencies

To enable this port, set the Data format to CAN Message. Also, enable the output type as bus in CAN Pack block

Data Types: CAN Message

The port accepts the length of the CAN data to be transmitted in bytes.

Dependencies

To enable this parameter, set Data format to Raw data and Data length via to Inport.

Data Types: uint8

The port accepts CAN message identifier. The ID can be:

  • 0-2047: for Standard (11-bit identifier)

  • 0-536870911: for Extended (29-bit identifier)

Dependencies

To enable this parameter, set Data format to Raw data and Identifier via to Inport.

Data Types: uint32

The port accepts CAN message identifier type

  • 0 - if its 11-bit standard identifier

  • 1 or any value other than 0 - if its 29-bit standard identifier

Dependencies

To enable this parameter, set Data format to Raw data and Identifier type via to Inport.

Data Types: uint32

Output

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The port outputs message read status.

  • The status is 0, if the block reads new message.

  • The status is 1, if the block reads no new message.

Dependencies

To enable this port, select Output Status parameter.

Data Types: uint8

The port outputs the transmit FIFO fill level.

Dependencies

To enable this parameter, select Output transmit FIFO level parameter.

Parameters

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Module to which the CAN device is connected.

Programmatic Use

Block Parameter: CANModule

Select the CAN read operation mode.

  • Data - Data to write CAN data/message

  • Sleep - Select to set the CAN module in sleep mode. In Sleep operation mode, the block accepts a logical value to put the CAN peripheral in sleep mode.

  • Wakeup - Select to wakeup the CAN module from sleep mode. In Wakeup operation mode, the block accepts a logical value to gets the CAN peripheral in wakeup state.

Programmatic Use

Block Parameter: OperationWriteMode

Select a output type to write message.

  • RAW data – To write message as a N-by-1 uint8 array, select Data format as Raw data.

  • CAN Message – To write message in CAN Message format, select Data format as CAN Message and using CAN pack and ensure to select the output type as bus.

Programmatic Use

Block Parameter: DataFormatWriteMode

Select the Identifier type via Dialog or input port.

  • When you select Identifier Type via inport, the block configures an input port, Id Type.

  • When you select Identifier Type via Dialog, the block accepts CAN identifier type via Dialog.

Dependencies

To enable this parameter, set the Data format as Raw data.

Programmatic Use

Block Parameter: IdentifierTypeVia

Select the message identifier type to be either Standard (11-bit identifier) or Extended (29-bit identifier).

  • 0-2047: for Standard (11-bit identifier)

  • 0-536870911: for Extended (29-bit identifier)

Dependencies

To enable this parameter, set the Data format as Raw data.

Programmatic Use

Block Parameter: IdentifierType

Select the identifier via Dialog or input port.

  • When you select Identifier via inport, the block configures an input port, Id.

  • When you select Identifier via Dialog, the block accepts CAN identifier via Dialog.

Dependencies

To enable this parameter, set the Data format as Raw data.

Programmatic Use

Block Parameter: IdentifierVia

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

Dependencies

To enable this parameter, set the Data Format as Raw data.

Programmatic Use

Block Parameter: Identifier

Select the Data length via Inport or Dialog.

  • When you select Data length via inport, the block configures an input port, Length.

  • When you select Data length via Dialog, the block accepts specified input data size.

Dependencies

To enable this parameter, set the Data format as Raw data.

Programmatic Use

Block Parameter: DataLengthVia

The length of the message, in bytes provided via input.

Dependencies

To enable this parameter, set the Data length via as Dialog.

Programmatic Use

Block Parameter: DataLength

The block sends a remote frame in the CAN message if this parameter is selected. The data at the input port is not sent in the CAN message.

Dependencies

To enable this parameter, set the Data Format as Raw data. For CAN Msg, the Remote Frame is inherited from the request specified in the CAN Pack block.

Programmatic Use

Block Parameter: TransmitRemoteFrame

When you select the Output transmit FIFO fill level parameter, the block configures an output port, FIFO level. The port outputs the transmit FIFO message level.

Programmatic Use

Block Parameter: OutputTxFifoLevel

When you select the Output Status parameter, the block configures an output port, Status. The port outputs the status message.

Programmatic Use

Block Parameter: OutputStatus

Specify how often the block receives message, in seconds. When you specify this parameter as -1, Simulink determines the best sample time for the block based on the block context within the model.

Programmatic Use

Block Parameter: SampleTime

Specify the time in seconds to block the CAN read. For nonblocking, set to 0. You configure Timeout to be the maximum time (in seconds) to wait to complete a read operation.

Programmatic Use

Block Parameter: Timeout

Extended Capabilities

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C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

Version History

Introduced in R2023a

See Also

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