PX4 CAN Transmit

R2026b

Transmit message to CAN network

Since R2022b

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  • CAN Transmit block

Libraries:
UAV Toolbox Support Package for PX4 Autopilots / PX4 Utility Blocks

Description

Add-On Required: This feature requires the UAV Toolbox Support Package for PX4 Autopilots add-on.

The PX4 CAN Transmit block transmits message to a Controller Area Network (CAN) network by using the PX4 Autopilot CAN port.

Specify the message type and its properties using the block parameters dialog box.

If you simulate a model that contains the PX4 CAN Transmit block without connecting the hardware, the block does nothing. For more information, see Block Produces Zeros or Does Nothing in Simulation (Simulink).

During Connected I/O simulation, this block writes data to the peripherals of the hardware.

Note

To avoid conflict with PX4 UAVCAN, disable UAVCAN before working with PX4 CAN blocks. To disable, set the PX4 parameter, UAVCAN_ENABLE to 0. For more information, see Finding/Updating Parameters.

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. You can create a message or upload a CAN database file. For more information, see Data is input as.

Dependencies

This port appears only when you select the Remote Frame parameter.

Data Types: uint8 | CAN Msg

Output

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Output port to display status of data transmission.

The port outputs one of these values:

  • 0 for a successful CAN transmission.

  • 1 for a failure in opening the CAN.

  • 2 for a failure in setting Baud rate.

  • 3 for a failure in setting CAN Test mode.

  • 4 for a failure in CAN 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 to Raw data.

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

    1. Add a CAN Pack (Vehicle Network Toolbox) block from the Embedded Coder® / 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 an Embedded Coder / Vehicle Network Toolbox license.

The type of message identifier.

Dependencies

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

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 to Raw data. For CAN Msg, Message ID is inherited from the identifier 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 to Raw data. For CAN Msg, Message Length is inherited from the length of the CAN Pack block.

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 that occurred during data transmission. An output of 0 indicates successful transmission.

When you select the 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 to Raw data. For CAN Msg, the Remote Frame is inherited from the request specified in the CAN Pack block.

Programmatic Use: Add Block

To add the block programmatically, use the add_block function with one of these library block paths as the source.

"px4Utilslib/Read Parameter"

Example: add_block("px4Utilslib/Read Parameter","myModel/myBlock",MakeNameUnique="on")

Version History

Introduced in R2022b

See Also