What Is CAN Bus?

Controller Area Network (CAN) is a robust serial bus protocol developed by Bosch for automotive applications, now ubiquitous in industrial and energy systems. It uses a differential two-wire physical layer (CAN_H, CAN_L) with 120-ohm termination at each end. CAN 2.0 supports up to 1 Mbps, while CAN FD reaches up to 8 Mbps with 64-byte payloads. The protocol’s non-destructive arbitration ensures higher-priority frames always win without data corruption.

Key Takeaways

• Real-world engineering considerations from 10+ years of STM32 development
• Practical tradeoffs between performance, cost, and time-to-market
• Direct experience across industrial, energy, and IoT deployments

Frequently Asked Questions

CAN 2.0 vs CAN FD?

CAN FD increases payload from 8 to 64 bytes and allows dynamic bit-rate switching up to 8 Mbps. CAN FD controllers interoperate with classical CAN nodes on the same bus via arbitration.

How many nodes per bus?

Standard CAN supports up to 110 nodes per segment. Practically, 30-40 nodes before bus loading and signal integrity become concerns. Use repeaters or bridges for larger networks.

Designing a CAN bus network for your next project? Get in touch with our engineering team for a free consultation.

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