CAN protocol in industrial automation - basics, application and future

What is the CAN protocol?

CAN (Controller Area Network) is an industrial communication protocol developed in the 1980s by Bosch. Initially used in automotive applications, today it is widely used in industrial automation, robotics, transportation and energy systems. CAN enables efficient, fast and secure data exchange between devices without the need for a central controller.

How does the CAN bus work?

The CAN bus operates in a peer-to-peer architecture, where all devices on the network can send and receive messages. Instead of the traditional master-slave model, CAN uses a message prioritization mechanism to effectively manage network traffic without collisions.

• Deterministic transmission - ensures that critical data is transmitted without delay.
• Resistance to interference - the use of NRZ coding and error control ensure transmission stability.
• Efficient bandwidth utilization - each message has an identifier that determines its priority.

Main applications of CAN protocol

The CAN protocol is widely used in various industries:

• Industrial automation - used to control machines and production lines.
• Motorization - manages communication between ECUs in vehicles.
• Railway transportation - enables monitoring and control of on-board systems.
• Medical - used in diagnostic and monitoring devices.
• Smart building systems - integrates lighting, air conditioning and security systems.

Comparison of CAN protocol with other standards

Frequently Asked Questions (FAQ) about CAN protocol

1. What is the difference between CAN and CAN FD?

CAN FD (Flexible Data-Rate) allows the transmission of more data (up to 64 bytes) and operates at a higher transmission speed than standard CAN.

2. Does CAN require a master unit?

No, CAN operates in a peer-to-peer architecture, which means that each device can transmit and receive data independently.

3. How to secure the CAN network against cyber attacks?

CAN has no native encryption mechanisms, so additional solutions such as message filtering, IDS (Intrusion Detection Systems) and encryption at higher layers are used.

4. What are the maximum distances of the CAN bus?

The distance depends on the transmission speed - at 1 Mbps it is up to 40 meters, and at 125 kbps it can reach up to 500 meters.

5. Can CAN work with Ethernet?

Yes, using CAN-Ethernet converters, CAN networks can be integrated with Ethernet systems.

6. What are the limitations of the CAN bus?

The limitations include the length of the wires, the number of nodes and the lack of native encryption mechanisms.

7. What are the main industries using CAN?

CAN is used in industry, automotive, railroad, medical and smart building systems.

8. What companies manufacture CAN-compatible devices?

Bosch, Texas Instruments, NXP, Microchip and Advantech supply circuits and hardware compatible with CAN.

9. What are the alternatives to CAN?

Alternatives include Modbus, Profibus, EtherCAT and Ethernet/IP - the choice depends on application requirements.

10. Is CAN being used in Industry 4.0?

Yes, CAN is integrated into Industry 4.0 solutions, and with CAN FD and integration with IoT, it is gaining new applications.

Summary

CAN is a reliable communication standard widely used in industry and automotive applications. Its deterministic nature and immunity to interference make it remain a key solution for modern control systems. If you are planning to implement a CAN network, check out the available CAN converters and CAN repeaters to optimize your installation.