PLC Programming
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CAN Bus

Controller Area Network - robust vehicle bus standard for microcontrollers and devices communication without host computer.

Type: Serial CommunicationSpeed: Up to 1 Mbps (CAN 2.0), 8 Mbps (CAN FD)Released: 1983Organization: ISO (ISO 11898)
8 Mbps (CAN FD)
Bandwidth
110
Max Nodes
40m at 1 Mbps, 1000m at 50 kbps
Max Distance
Yes
Real-Time

Protocol Overview

Controller Area Network - robust vehicle bus standard for microcontrollers and devices communication without host computer.

When to Use CAN Bus

Choose CAN Bus for automotive applications, mobile equipment, harsh environments, or when robust error handling is critical.

Technical Specifications

Physical Layer

  • Physical Layer: ISO 11898-2 (high-speed CAN)
  • Cable Type: Twisted pair
  • Topology: Bus
  • Power Over Cable: No

Data Layer

  • Data Link: Multi-master broadcast
  • Encoding: NRZ
  • Error Detection: CRC-15 (HD=6)
  • Frame Size: 8 bytes (CAN 2.0), 64 bytes (CAN FD)

Performance

  • Scan Time: <10ms typical
  • Deterministic: Yes
  • Real-Time: Yes

Certification

  • Certification Required: No
  • License Cost: Free (ISO standard)
  • Version: CAN FD

Advantages & Disadvantages

Advantages

  • ✓Extremely robust and reliable
  • ✓Excellent error detection (HD=6)
  • ✓Multi-master (no single point of failure)
  • ✓Message priority system
  • ✓Wide industry adoption
  • ✓Real-time capability
  • ✓Low cost
  • ✓Automotive-grade reliability

Disadvantages

  • ✗Limited to 8 bytes (CAN 2.0)
  • ✗Distance/speed tradeoff
  • ✗No built-in security
  • ✗Requires careful bus termination
  • ✗Limited to 110 nodes
  • ✗No standardized higher-layer protocol (use CANopen, DeviceNet, etc.)

Common Use Cases & Applications

Automotive systems
Mobile equipment
Marine applications
Medical devices
Industrial machinery
Building automation

Industry Adoption

Adoption LevelVery High
Market ShareDominant in automotive (>90%)
Geographic PresenceWorldwide
Primary Industries
AutomotiveMobile EquipmentMaritimeMedical DevicesIndustrial

Supported Message Types

Data frame
Remote frame
Error frame
Overload frame

Supported PLC Brands

Bosch
Vector
PEAK
Kvaser
All automotive suppliers

Quick Links

Alternative Protocols

  • LIN
  • FlexRay
  • Automotive Ethernet

Related Standards

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