===== CAN Bus Wiring Guide =====

Proper CAN wiring is essential for stable communication between the BMS and connected devices like CMUs, inverters, chargers, etc.

{{:canbus.jpg?nolink&500|CAN Bus Diagram}}

==== Basic Wiring Rules ====

  * CAN uses **two lines**: ''HIGH''  (CAN-H) and ''LOW''  (CAN-L)
  * All devices are connected in **parallel**  along one continuous **bus line**
  * No star topology or long branches – only short drop lines (max. **500 mm**) to each device

==== Termination Resistors ====

  * A **120 Ω resistor**  must be placed at **each end**  of the bus
  * The BMS and last CMU typically provide termination if configured correctly
  * Only **two resistors total**  on the bus – no more, no less

''⚠️ Missing or incorrect termination leads to unstable or no communication''

==== Example Devices on the Bus ====

  * **BMS:**  Master device
  * **CMUs:**  Cell Management Units – multiple allowed
  * **Other extensions:**  e.g. displays, current sensors, inverter Each device has a **CAN HIGH / CAN LOW**  pair that must be connected to the main line.
''🛠️ Make sure the **CAN baud rate and ID settings**  match across all devices on the bus \\ Check under **Connections → CAN Bus**  for configuration options''