canMessage

Build CAN message based on user-specified structure

Syntax

message = canMessage(id,extended,datalength)

message = canMessage(id,extended,datalength,ProtocolMode="CAN FD")

message = canMessage(candb,messagename)

Description

message = canMessage(id,extended,datalength) creates a CAN message object from the raw message information.

message = canMessage(id,extended,datalength,ProtocolMode="CAN FD") creates a CAN FD message. The default ProtocolMode is standard "CAN".

message = canMessage(candb,messagename) creates a message using the message definition in the specified database. Because ProtocolMode is defined in the message database, you cannot specify it as an argument to canMessage when using a database.

Examples

Create a CAN Message

Create a CAN message with an extended ID format.

message1 = canMessage(2500,true,4)

message1 = 

  Message with properties:

   Message Identification
    ProtocolMode: 'CAN'
              ID: 2500
        Extended: 1
            Name: ''

   Data Details
       Timestamp: 0
            Data: [0 0 0 0]
         Signals: []
          Length: 4

   Protocol Flags
           Error: 0
          Remote: 0

   Other Information
        Database: []
        UserData: []

Create a CAN FD Message

Create a CAN FD message with a standard ID format.

message2 = canMessage(1000,false,64,ProtocolMode="CAN FD")

message2 = 

  Message with properties:

   Message Identification
    ProtocolMode: 'CAN FD'
              ID: 1000
        Extended: 0
            Name: ''

   Data Details
       Timestamp: 0
            Data: [1×64 uint8]
         Signals: []
          Length: 64
             DLC: 15

   Protocol Flags
             BRS: 0
             ESI: 0
           Error: 0

   Other Information
        Database: []
        UserData: []

Create a Message with Database Definitions

Create a message using the definitions of a CAN database.

candb = canDatabase("C:\myVNTData\VehicleInfo.dbc")
message3 = canMessage(candb,"WheelSpeeds")

message3 = 

  Message with properties:

   Message Identification
    ProtocolMode: 'CAN'
              ID: 1200
        Extended: 0
            Name: 'WheelSpeeds'

   Data Details
       Timestamp: 0
            Data: [0 0 0 0 0 0 0 0]
         Signals: [1×1 struct]
          Length: 8

   Protocol Flags
           Error: 0
          Remote: 0

   Other Information
        Database: [1×1 can.Database]
        UserData: []

Input Arguments

id — ID of message

numeric value

ID of the message, specified as a numeric value. If this ID used an extended format, set the extended argument true.

Example: 2500

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64

extended — Extended message ID format

true | false

Extended message ID format, specified as true or false. The logical value true specifies that the message ID is in 29-bit extended format, false specifies 11-bit standard format.

Example: true

Data Types: logical

datalength — Length of message data

integer value 0 to 64

The length of the message data in bytes, specified as an integer. Supported values depend on the protocol mode:

• For ProtocolMode="CAN" (default) — datalength must be an integer value of 0 to 8.

• For ProtocolMode="CAN FD" — datalength must be an integer value of 0 to 8, 12, 16, 20, 24, 32, 48, or 64.

Example: 8

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64

candb — CAN database

CAN database object

CAN database, specified as a database object. The database contains the message definition.

Example: candb = canDatabase("CANdb.dbc")

messagename — Name of message

char vector | string

The name of the message definition in the database, specified as a character vector or string.

Example: "VehicleDataMulti"

Data Types: char | string

Output Arguments

message — CAN message

CAN message object

CAN message, returned as a CAN message object, with can.Message Properties.

Version History

Introduced in R2009a