Bitrate configuration

These timing and configuration types are shared by automotive.can.bitrate and automotive.sync.can.bitrate.

Reusable bitrate requests and the timing values calculated by Rust.

class automotive.can.bitrate.BitTiming(*, brp: int, tseg1: int, tseg2: int, sjw: int, bitrate: int, sample_point: float)[source]

Resolved timing for one CAN phase.

Variables:

  • brp (int) – Bitrate prescaler.

  • tseg1 (int) – Time segment 1, in time quanta.

  • tseg2 (int) – Time segment 2, in time quanta.

  • sjw (int) – Synchronization jump width, in time quanta.

  • bitrate (int) – Actual calculated bitrate, in bits per second.

  • sample_point (float) – Actual normalized sample point between zero and one.

brp: int
tseg1: int
tseg2: int
sjw: int
bitrate: int
sample_point: float
class automotive.can.bitrate.BitrateConfig(nominal: BitTiming, data: BitTiming | None = None)[source]

Calculated nominal timing and optional CAN-FD data-phase timing.

Obtain this record with BitrateSettings.resolve(backend) or an adapter config’s resolved_bitrate property. It reports Rust’s calculation.

nominal: BitTiming
data: BitTiming | None
class automotive.can.bitrate.BitrateSettings(*, bitrate: int | None = None, sample_point: float | None = None, brp: int | None = None, tseg1: int | None = None, tseg2: int | None = None, sjw: int | None = None, data_bitrate: int | None = None, data_sample_point: float | None = None, data_sjw: int | None = None, max_bitrate_error: int | None = None)[source]

Bitrate-builder inputs, resolved for the selected adapter by Rust.

Parameters:

  • bitrate – Target nominal bitrate in bits per second.

  • sample_point – Normalized nominal sample point; None uses Rust’s bitrate-dependent default.

  • brp – Direct nominal prescaler, used with tseg1 and tseg2.

  • tseg1 – Direct nominal segment 1, in time quanta.

  • tseg2 – Direct nominal segment 2, in time quanta.

  • sjw – Nominal synchronization jump width, in time quanta.

  • data_bitrate – Optional CAN-FD data bitrate in bits per second.

  • data_sample_point – Normalized data-phase sample point.

  • data_sjw – Data-phase synchronization jump width, in time quanta.

  • max_bitrate_error – Maximum bitrate error in hundredths of one percent. None retains Rust’s 50 (0.5%) default.

Supply either a target bitrate or complete direct nominal timing. Explicit settings start without preset timing: setting only bitrate produces Classic CAN. Omitting settings on an adapter retains that adapter’s defaults, including its default FD data bitrate where applicable.

bitrate: int | None
sample_point: float | None
brp: int | None
tseg1: int | None
tseg2: int | None
sjw: int | None
data_bitrate: int | None
data_sample_point: float | None
data_sjw: int | None
max_bitrate_error: int | None
resolve(backend: str) → BitrateConfig[source]

Calculate timing using this backend’s Rust capabilities.

Parameters:

backend – “panda”, “peak”, “vector”, or “j2534”.

Returns:

Calculated nominal timing and optional data timing.

Raises:

  • ValueError – The requested timing cannot be represented.

  • NotSupportedError – This build cannot configure the backend.