Controller Area Network (or CAN) is the latest communication system within the automotive world. At its simplest level, it can be thought of as a means of linking all the electronic systems within a vehicle together to allow them to communicate with each other

1. CONTROLLER
AREA NETWORK
FEBIN SHAJI

2. Communication Protocols in
Automotive
CAN (Controller Area Network)
• Developed by: Bosch in the 1980s.
• Purpose: Designed to allow multiple microcontrollers and devices within a vehicle to communicate with each other without needing a host computer.
• Features: It offers robust error handling and detection capabilities, which are essential for ensuring reliability in automotive environments.
• Usage: Widely used in critical vehicle functions such as engine management, braking systems, lighting, air conditioning, and more.
• Data Rate: Up to 1 Mbps.
• Bus Architecture: Differential signaling over a twisted pair cable.
LIN (Local Interconnect Network)
• Developed by: A consortium of automotive manufacturers including Audi, BMW, Daimler, Volvo, and Volkswagen.
• Purpose: A cost-effective, low-speed alternative to CAN for non-safety critical applications.
• Features: It uses a single master with multiple slave architecture, which simplifies the network design and reduces costs.
• Usage: Commonly used for simple control applications like door locks, mirrors, seat adjusters, and other body electronics.
• Data Rate: Up to 20 kbps.
• Bus Architecture: Single wire with a ground.

3. • Developed by: The FlexRay Consortium, a collaborative effort among automakers and suppliers including BMW, Bosch, General
Motors, and others.
• Purpose: To provide a deterministic, fault-tolerant, high-speed bus system necessary for advanced safety and control applications.
• Features: Supports both a star and a bus topology and offers dual-channel setup which can be used for redundancy and increased
bandwidth.
• Usage: Ideal for advanced applications that require precise timing and high data rates, such as x-by-wire systems (steer, brake, shift-
by-wire) and complex driver assistance systems.
• Data Rate: Up to 10 Mbps.
• Bus Architecture: Can use either a single or dual-channel configuration with differential signaling
FlexRay
Ethernet
• Adaptation: Automotive Ethernet adapts the traditional Ethernet technology used in IT for automotive requirements, focusing on low
latency and reduced cabling costs.
• Purpose: To meet the demands of high data rate applications such as advanced infotainment systems, extensive sensor networks for
ADAS, and connectivity with external networks.
• Features: Capable of high-speed data transfer and supporting various data types including video, which is essential for applications like
backup cameras and driver assistance.
• Usage: Increasingly used for diagnostic communication, software updates, and data exchange between ECUs and infotainment modules.
• Data Rate: Ranges from 100 Mbps to 10 Gbps in newer implementations.
• Bus Architecture: Utilizes unshielded twisted pair (UTP), and in some applications, shielded twisted pair (STP) cabling.

5. Introduction to CAN
Controller Area Network (or CAN) is
the latest communication system within
the automotive world. At its simplest
level, it can be thought of as a means of
linking all the electronic systems within
a vehicle together to allow them to
communicate with each other.

6. The CAN bus history

7. CAN (Controller Area Network)
Overview:
Developed by Bosch in the mid-1980s.
Designed to enable microcontrollers and
devices to communicate with each other
without a host computer.
Uses a multi-master, message-oriented
protocol.
Technical Specs:
Data rates up to 1 Mbps.
Message payloads up to 8 bytes.
11-bit (standard) and 29-bit (extended) identifier
fields.
Applications:
Predominantly used in automotive networks for
connecting ECUs (Engine Control Units),
sensors, and actuators.
Overview:
Introduced by Bosch in 2012
Retains the robustness of CAN while increasing
bandwidth and improving data throughput.
Technical Specs:
Data rates up to 8 Mbps
Increased payload size up to 64 bytes.
Maintains the same physical layer and arbitration methods
(using the 11-bit or 29-bit identifier).
Applications:
Suitable for more data-intensive applications within modern
vehicles, such as advanced driver-assistance systems
(ADAS), infotainment, and telematics.
Useful in industries where larger amounts of data need to be
transmitted quickly and reliably.
Overview:
The latest enhancement to the CAN family, introduced
in 2018 to meet future automotive and industrial network
requirements.
Developed by the CAN in Automation (CiA) group as
part of the ongoing evolution of CAN protocols.
Technical Specs:
Data rates up to 10 Mbps,
Increased payload up to 2048 bytes.
Applications:
Applicable in complex industrial control systems where
large data packets are essential, integration with
Internet of Things (IoT) devices, and high-speed
sensors.
CAN FD (Flexible Data-rate) CAN XL (Extra Long)

8. MULTI-MASTER
COMMUNICATION:
CAN ALLOWS MULTIPLE
MICROCONTROLLERS TO
COMMUNICATE WITH EACH
OTHER WITHOUT NEEDING A
MASTER CONTROLLER. EACH
NODE (OR DEVICE) ON THE
NETWORK CAN SEND OR
RECEIVE MESSAGES.
MESSAGE PRIORITY:
EACH MESSAGE ON A CAN
NETWORK HAS A PRIORITY,
DETERMINED BY THE
IDENTIFIER OF THE
MESSAGE. LOWER
IDENTIFIER VALUES HAVE
HIGHER PRIORITY. THIS
ENSURES THAT CRITICAL
MESSAGES FOR VEHICLE
SAFETY AND OPERATION
GET TRANSMITTED FASTER.
ERROR HANDLING:
CAN HAS SOPHISTICATED
ERROR DETECTION AND
CORRECTION CAPABILITIES. IT
USES MECHANISMS LIKE
CHECKSUMS, FRAME CHECKS,
AND ACKNOWLEDGMENT
CHECKS TO ENSURE DATA
INTEGRITY AND RELIABLE
COMMUNICATION.
FLEXIBILITY AND SCALABILITY:
THE PROTOCOL IS FLEXIBLE AND
SCALABLE, ALLOWING FOR THE
ADDITION OR REMOVAL OF
NODES WITHOUT MAJOR
CHANGES TO THE NETWORK.
NODES CAN BE ADDED TO THE
CAN NETWORK AS NEEDED, WITH
EACH NODE CAPABLE OF
SENDING AND RECEIVING
MESSAGES INDEPENDENTLY OF
THE OTHERS.
ROBUSTNESS:
CAN NETWORKS ARE
DESIGNED TO OPERATE
RELIABLY IN THE HARSH
ENVIRONMENTS OF
AUTOMOTIVE
APPLICATIONS, WHERE
THEY MAY BE
SUBJECTED TO HIGH
LEVELS OF ELECTRICAL
NOISE AND
INTERFERENCE.
Key Features/Advantages of CAN:

9. How CAN Works:
Data Transmission: Nodes on a
CAN network communicate
through frames. A typical CAN
frame includes fields such as Start
of Frame, Arbitration Field
(includes the message ID), Control
Field, Data Field, CRC Field, ACK
Field, and End of Frame.
Arbitration: If two nodes transmit
at the same time, the node with
the higher priority (lower
identifier value) automatically gets
the right to use the bus. This is
handled without any loss of data
through a process called
arbitration.
Bus Levels: CAN uses two bus
levels, CAN High and CAN Low.
The difference in voltage between
these two levels determines
whether there's a dominant
(logical 0) or recessive (logical 1)
bit being transmitted. This
differential setup helps make CAN
resistant to electrical interference.

10. CAN frame

11. SOF: Start of Frame bit. It marks start of message. It is used to synchronize nodes on the CAN bus.
ID: The ID is the frame identifier - It is 11 bit (binary) in size. It establishes priority of message. Lower the value, higher is the
priority.
RTR: It stands for Remote Transmission Request bit. This field is dominant when node requires information from another remote
node. All the nodes receive request, and all the nodes receive reply. Specific node processes the request based on identifier and
transmits the reply.
Control: The Control contains the Identifier Extension Bit (IDE) which is a 'dominant 0' for 11-bit. It also contains the 4-bit Data
Length Code (DLC) that specifies the length of the data bytes to be transmitted (0 to 8 bytes)
Data: Carries the data being transmitted. Its length is indicated by the DLC and can be up to 8 bytes in classical CAN. In CAN FD,
this can be up to 64 bytes.
CRC: it stands for Cyclic Redundancy Check. A 15-bit field plus a delimiter bit used for error detection. It helps ensure the integrity
of the transmitted data.
ACK: The ACK slot indicates if the node has acknowledged and received the data correctly.
EOF: The EOF marks the end of the CAN frame.

12. CAN Network Architecture
Rt: Proper termination of the CAN network with resistors
at each end of the main bus is crucial. This helps to
reduce reflections and maintain signal integrity
across the network.

13. CAN High (CAN_H) & CAN Low (CAN_L)
CAN High (CAN_H): This wire carries the CAN high signal.
When transmitting a dominant bit, CAN High is at a higher voltage relative to
CAN Low. Typically, CAN High might be around 3.5 volts.
CAN Low (CAN_L): This wire carries the CAN low signal. That carries a
voltage around 1.5 volts.
Cabling: Typically, twisted pair wiring is used for CAN High and CAN Low to
further enhance noise rejection. Twisting the wires together at regular
intervals helps ensure that any interference affects both wires equally,
cancelling out the noise
Benefit:
Reliable Communication: Ensures reliable data transmission even in environments
with high electromagnetic interference, such as near motors, high currents, and other
electronic components common in vehicles and industrial equipment.

14. CANoe
CANoe is a comprehensive software tool developed by
Vector Informatik for development, testing, and analysis
of entire ECU networks and individual ECUs.
Usage:
• Developing and testing software for automotive ECUs.
• Setting up and monitoring vehicle network systems.
• Ensuring compliance with network communication protocols and standards.
• Simulating and testing network traffic under various conditions.
Simulation: CANoe can simulate ECUs and entire networks, enabling developers to test and validate
network communication and behavior long before the actual hardware is available.
Testing: It offers extensive testing capabilities, including automated testing and test reporting.
This is crucial for validating complex interaction patterns between different vehicle ECUs.
Analysis: The tool provides powerful analysis capabilities, which are vital for diagnosing and
troubleshooting communication issues in the network.
Visualization: CANoe includes capabilities to visualize network traffic, signal plotting, and logging,
which are essential for real-time and post-process analysis.

15. Applications of CAN
2.Industrial Automation
• Control Systems
• Robotics
• Sensor Networks
3.Marine Applications
• Navigation Systems
• Engine Controls
4.Medical Equipment
• Patient Monitoring Systems
• Surgical Instruments
• Diagnostic Devices
5.Building Automation
• HVAC Systems
• Access Control Systems
• Elevator Controls
Automotive Industry
Engine Management Systems: Temperature sensors, pressure sensors, and fuel injectors.
Dashboard Instruments: Speedometer, tachometer, and fuel gauge
Safety Systems: Airbags, anti-lock braking systems (ABS), and electronic stability control.
Comfort and Convenience Features: Electric power steering
Advanced Driver Assistance Systems (ADAS) : Adaptive cruise control, lane keeping assistance,
and collision detection.

16. Thank You