Get Started with CAN Communication in MATLAB

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This example shows you how to use CAN channels to transmit and receive CAN messages. It uses MathWorks virtual CAN channels connected in a loopback configuration.

Create a Receiving Channel

Create a CAN channel usingcanChannelto receive messages by specifying the vendor name, device name, and device channel index.

rxCh = canChannel("MathWorks","Virtual 1", 2);

Inspect the Channel

Use thegetcommand to obtain more detailed information on all channel properties and their current values.

get(rxCh)

ArbitrationBusSpeed: [] DataBusSpeed:[]接收rorCount: 0 TransmitErrorCount: 0 InitializationAccess: 1 InitialTimestamp: [0x0 datetime] SilentMode: 0 TransceiverState: 'N/A' BusSpeed: 500000 NumOfSamples: [] SJW: [] TSEG1: [] TSEG2: [] BusStatus: 'N/A' TransceiverName: 'N/A' Database: [] MessageReceivedFcn: [] MessageReceivedFcnCount: 1 UserData: [] FilterHistory: 'Standard ID Filter: Allow All | Extended ID Filter: Allow All' MessagesReceived: 0 MessagesTransmitted: 0 Running: 0 Device: 'Virtual 1' DeviceChannelIndex: 2 DeviceSerialNumber: 0 DeviceVendor: 'MathWorks' ProtocolMode: 'CAN' MessagesAvailable: 0

Start the Channel

Use thestartcommand to set the channel online.

start(rxCh);

Transmit Messages

The example functiongenerateMsgscreates CAN messages usingcanMessageand transmits them usingtransmitat various periodic rates. It generates traffic on the CAN bus for demonstration purposes.

typegenerateMsgs

function generateMsgs() % generateMsgs Creates and transmits CAN messages for demo purposes. % % generateMsgs periodically transmits multiple CAN messages at various % periodic rates with changing message data. % % Copyright 2008-2016 The MathWorks, Inc. % Create the messages to send using the canMessage function. The % identifier, an indication of standard or extended type, and the data % length is given for each message. msgTx100 = canMessage(100, false, 0); msgTx200 = canMessage(200, false, 2); msgTx400 = canMessage(400, false, 4); msgTx600 = canMessage(600, false, 6); msgTx800 = canMessage(800, false, 8); % Create a CAN channel on which to transmit. txCh = canChannel('MathWorks', 'Virtual 1', 1); % Register each message on the channel at a specified periodic rate. transmitPeriodic(txCh, msgTx100, 'On', 0.500); transmitPeriodic(txCh, msgTx200, 'On', 0.250); transmitPeriodic(txCh, msgTx400, 'On', 0.125); transmitPeriodic(txCh, msgTx600, 'On', 0.050); transmitPeriodic(txCh, msgTx800, 'On', 0.025); % Start the CAN channel. start(txCh); % Run for several seconds incrementing the message data regularly. for ii = 1:50 % Increment the message data bytes. msgTx200.Data = msgTx200.Data + 1; msgTx400.Data = msgTx400.Data + 1; msgTx600.Data = msgTx600.Data + 1; msgTx800.Data = msgTx800.Data + 1; % Wait for a time period. pause(0.100); end % Stop the CAN channel. stop(txCh); end

Run thegenerateMsgsfunction to transmit messages for the example.

generateMsgs();

Receive Messages

OncegenerateMsgscompletes, receive all available messages from the channel using thereceivefunction.

rxMsg = receive(rxCh, Inf,"OutputFormat","timetable");

Useheadto extract the first few rows of received messages for preview.

head(rxMsg)

ans=8×8 timetableTime ID Extended Name Data Length Signals Error Remote ___________ ___ ________ __________ ___________________ ______ ____________ _____ ______ 0.11087 sec 100 false {0x0 char} {1x0 uint8 } 0 {0x0 struct} false false 0.11088 sec 200 false {0x0 char} {[ 0 0]} 2 {0x0 struct} false false 0.11089 sec 400 false {0x0 char} {[ 0 0 0 0]} 4 {0x0 struct} false false 0.11089 sec 600 false {0x0 char} {[ 0 0 0 0 0 0]} 6 {0x0 struct} false false 0.11089 sec 800 false {0x0 char} {[0 0 0 0 0 0 0 0]} 8 {0x0 struct} false false 0.13588 sec 800 false {0x0 char} {[1 1 1 1 1 1 1 1]} 8 {0x0 struct} false false 0.16088 sec 600 false {0x0 char} {[ 1 1 1 1 1 1]} 6 {0x0 struct} false false 0.16088 sec 800 false {0x0 char} {[1 1 1 1 1 1 1 1]} 8 {0x0 struct} false false

Stop the Channel

Use thestopcommand to set the channel offline.

stop(rxCh);

分析接收到的消息

MATLAB provides a powerful environment for performing analysis on CAN messages. Theplotcommand can create a scatter plot with message timestamps and identifiers to provide an overview of when certain messages occurred on the network.

plot(rxMsg.Time, rxMsg.ID,"x") ylim([0 2047]) xlabel("Timestamp") ylabel("CAN Identifier")

Figure contains an axes object. The axes object contains an object of type line.