CAN (Controller Area Network, CANbus) and CANopen®
FAQ (Frequently Asked Questions)

See our main page for a listing of online resources (articles and online training classes) and books.

General

• Q: When and why would I need a higher-layer protocol such as CANopen® instead of plain CAN?
• Q: How does CANopen® compare to DeviceNet?
• Q: Do I need to have my node CANopen® conformance tested?
• Q: Is 127 "really" the maximum number of nodes in a CANopen® network?
• Q: Can the node IDs in a CANopen® network be auto-assigned?
• Q: What is the identifier of a node, message and or variable?

Implementation Issues

• Q: How do I implement CANopen®?
• Q: Which US companies offer CANopen® source code?
• Q: Which US companies offer CANopen® chips or modules for embedded integration?
• Q: What are the memory requirements for a CANopen® communication protocol stack?
• Q: Why do most CANopen® applications use CAN 2.0A (11-bit identifiers) and not CAN 2.0B (29-bit identifiers)?

Physical stuff

• Q: How do I connect a CAN controller to the bus?
• Q: How do I calculate the CAN bit timing of my CAN controller?
• Q: I just implemented my node - and it does not transmit?!
• Q: How can the data bandwidth of a CAN/CANopen® network be increased?

Performance

• Q: How do I calculate worst case message delay times and data bandwidth?
• Q: How fast is a CAN/CANopen® I/O cycle? (read INPUT trasmit via CANopen®, write OUTPUT)

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