CAN Read

Read message from CAN network

Since R2023a

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  • CAN Read

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 Read block reads messages from a Controller Area Network (CAN) network connected to the hardware.

The CAN Read block outputs a CAN data when operation mode is set to Data. The block outputs values received as [8x1] array of type uint8 when output type is set to Unpacked.

The block outputs Simulink® bus signal when output type is set to Packed. To extract data from Simulink bus signal, connect it to CAN Unpack block. The CAN Unpack block is available from the Vehicle Network Toolbox™.

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

Output

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The block outputs messages in uint8 or CAN Msg format.

The maximum size of the data is [8x1] of uint8 format. The number of bytes defined in the length signifies the valid data of the output.

  • If Output type is set to Unpacked, the received message data is an 8-by-1 array of type uint8.

  • If Output type is set to Packed, the data port is renamed to Msg and the received message data is output as a Simulink bus signal.

This port outputs 0 if the received CAN message is a remote frame.

Data Types: uint8 | CAN Msg

The port outputs message read status.

  • 1 - Unsuccessful.

  • 0 - Successful.

Dependencies

To enable this parameter, select Output Status parameter.

Data Types: uint8

The port outputs the length of the received CAN message in bytes.

Dependencies

To enable this parameter, set Output type to Unpacked.

Data Types: uint8

The port outputs CAN message identifier.

Dependencies

To enable this parameter, set Output type to Unpacked.

Data Types: uint32

The port outputs CAN message identifier type

  • 0 - if its 11-bit standard identifier

  • 1 - if its 29-bit standard identifier

Dependencies

To enable this parameter, set Output type to Unpacked.

Data Types: uint32

Remote message flag. The port outputs 1 if the received CAN message is a remote frame.

Dependencies

To enable this parameter, select Output remote parameter.

The port outputs the received FIFO fill level.

The FIFO level provides the RX FIFO level after reading the message. TX FIFO provides how much of TX FIFO is empty.

Dependencies

To enable this parameter, select Output receive 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 read CAN message

  • Read sleep status - Read the sleep status of CAN module. In Read sleep status operation mode, the block outputs a logical status if the CAN peripheral is in sleep mode.

  • Read last error code - Provides the status set by hardware for last message sent or received on CAN bus.

    The following are the error codes and there respective status.

    • 000 - No Error

    • 001 - Stuff Error

    • 010 - Form Error

    • 011 - Acknowledgment Error

    • 100 - Bit recessive Error

    • 101 - Bit dominant Error

    • 110 - CRC Error

    • 111 - Set by software

Programmatic Use

Block Parameter: OperationReadMode

Select an output type to read message.

  • Unpacked – In Unpacked output type, the block outputs values received as [8x1] array of type uint8. In unpacked type for the CAN Read block, you can enable all the output ports(ID, ID type, Data, Status, Remote, Length, FIFO level).

  • Packed – In Packed output type, the block outputs Simulink bus signal.

Programmatic Use

Block Parameter: OutputTypeReadMode

The CAN Read block outputs a CAN message from read source. You can configure read source filter configuration in the configuration parameters.

Programmatic Use

Block Parameter: ReadSource

When you select the Output Identifier Type parameter, the block configures an output port, Id Type. The port outputs the standard or extended message status.

Dependencies

To enable this parameter, set the Output type as unpacked.

Programmatic Use

Block Parameter: OutputIdType

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

Dependencies

To enable this parameter, set the Output type as unpacked.

Programmatic Use

Block Parameter: OutputRemoteFrame

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

Programmatic Use

Block Parameter: OutputRxFifoLevel

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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