Two protocols and one electrical interface
CAN and LIN define message exchange; RS-485 specifies electrical signalling, not a message protocol.
CAN bus
Robust differential communication with priority-based arbitration and broadcast frames.
02 / SCHEDULEDLIN bus
A low-cost, single-wire network built around scheduled messages and simple nodes.
03 / PHYSICAL LAYERRS-485
Differential, multipoint electrical signalling used by several higher-level protocols.
How the technologies differ
| Characteristic | CAN (high-speed) | LIN | RS-485 |
|---|---|---|---|
| What it specifies | CAN data link; high-speed CAN also has a defined physical layer | Communication protocol and single-wire physical layer | Balanced electrical interface; no frame or addressing rules |
| Typical use | Embedded and vehicle networks | Low-cost automotive subsystems | Industrial multipoint serial links |
| Typical wiring | CAN_H / CAN_L pair | One signal conductor with a ground reference | Differential pair, often 2-wire half-duplex |
| Who controls access? | Priority-based arbitration | Commander-controlled schedule | Defined by the protocol above RS-485 |
| Termination | Normally 120 Ω at each end of a high-speed segment | Pull-up/bias arrangement; not CAN-style termination | Match cable impedance at line ends where needed |
The RS-485 column describes an electrical interface, not a peer protocol to CAN or LIN. Actual wiring and signal limits depend on the equipment and transceivers.
Start with the fundamentals
Most intermittent communication faults involve a small set of causes: incorrect topology, missing termination, damaged cable, shielding/grounding issues, mismatched configuration or a failing node.
Open the troubleshooting guideConfirm protocol, physical layer and baud rate.
Check topology, polarity and termination.
Compare device diagnostics with bus measurements.
Standards and organizations
Use these sources for current specifications and implementation guidance: