uds.segmentation.can_segmenter

Segmentation specific for CAN bus.

Module Contents

Classes

CanSegmenter

Segmenter class that provides utilities for segmentation and desegmentation on CAN bus.
class uds.segmentation.can_segmenter.CanSegmenter(*, addressing_format, physical_ai=None, functional_ai=None, dlc=CanDlcHandler.MIN_BASE_UDS_DLC, use_data_optimization=False, filler_byte=DEFAULT_FILLER_BYTE)[source]

Bases: uds.segmentation.abstract_segmenter.AbstractSegmenter

Inheritance diagram of uds.segmentation.can_segmenter.CanSegmenter

Segmenter class that provides utilities for segmentation and desegmentation on CAN bus.

Configure CAN Segmenter.

Parameters

  • addressing_format (uds.can.CanAddressingFormatAlias) – CAN Addressing format used.

  • physical_ai (Optional[AIArgsAlias]) – CAN Addressing Information parameters to use for physically addressed communication. Leave None if the segmenter will not be used for segmenting physically addressed messages.

  • functional_ai (Optional[AIArgsAlias]) – CAN Addressing Information parameters to use for functionally addressed communication. Leave None if the segmenter will not be used for segmenting functionally addressed messages.

  • dlc (int) – Base CAN DLC value to use for CAN Packets.

  • use_data_optimization (bool) – Information whether to use CAN Frame Data Optimization during segmentation.

  • filler_byte (uds.utilities.RawByte) – Filler byte value to use for CAN Frame Data Padding during segmentation.

property supported_packet_classes(self)

Classes that define packet objects supported by this segmenter.

Return type

Tuple[Type[uds.packet.PacketAlias], Ellipsis]

property addressing_format(self)

CAN Addressing format used.

Return type

uds.can.CanAddressingFormatAlias

property physical_ai(self)

CAN Addressing Information parameters used for physically addressed communication.

None if physically addressed communication parameters are not configured.

Return type

Optional[AIParamsAlias]

property functional_ai(self)

CAN Addressing Information parameters used for functionally addressed communication.

None if functionally addressed communication parameters are not configured.

Return type

AIParamsAlias

property dlc(self)

Value of base CAN DLC to use for CAN Packets.

Note

All output CAN Packets (created by segmentation()) will have this DLC value set unless CAN Frame Data Optimization is used.

Return type

int

property use_data_optimization(self)

Information whether to use CAN Frame Data Optimization for CAN Packet created during segmentation.

Return type

bool

property filler_byte(self)

Filler byte value to use for CAN Frame Data Padding during segmentation.

Return type

uds.utilities.RawByte

desegmentation(self, packets)[source]

Perform desegmentation of CAN packets.

Parameters

packets (uds.packet.PacketsSequence) – CAN packets to desegment into UDS message.

Raises

  • SegmentationError – Provided packets are not a complete packets sequence that form a diagnostic message.

  • NotImplementedError – There is missing implementation for the provided CAN Packets. Please create an issue in our Issues Tracking System with detailed description if you face this error.

Returns

A diagnostic message that is an outcome of CAN packets desegmentation.

Return type

Union[uds.message.UdsMessage, uds.message.UdsMessageRecord]

segmentation(self, message)[source]

Perform segmentation of a diagnostic message.

Parameters

message (uds.message.UdsMessage) – UDS message to divide into UDS packets.

Raises

  • TypeError – Provided value is not instance of UdsMessage class.

  • AmbiguityError – Segmentation cannot be completed because CAN Segmenter is not properly configured.

  • NotImplementedError –

    There is missing implementation for the Addressing Type used by provided message. Please create an issue in our Issues Tracking System with detailed description if you face this error.

Returns

CAN packets that are an outcome of UDS message segmentation.

Return type

uds.packet.PacketsDefinitionTuple

is_complete_packets_sequence(self, packets)[source]

Check whether provided packets are full sequence of packets that form exactly one diagnostic message.

Parameters

packets (uds.packet.PacketsSequence) – Packets sequence to check.

Raises

  • ValueError – Provided value is not CAN packets sequence.

  • NotImplementedError –

    There is missing implementation for the provided initial packet type. Please create an issue in our Issues Tracking System with detailed description if you face this error.

Returns

True if the packets form exactly one diagnostic message. False if there are missing, additional or inconsistent (e.g. two packets that initiate a message) packets.

Return type

bool

__physical_segmentation(self, message)

Segment physically addressed diagnostic message.

Parameters

message (uds.message.UdsMessage) – UDS message to divide into UDS packets.

Raises

SegmentationError – Provided diagnostic message cannot be segmented.

Returns

CAN packets that are an outcome of UDS message segmentation.

Return type

uds.packet.PacketsDefinitionTuple

__functional_segmentation(self, message)

Segment functionally addressed diagnostic message.

Parameters

message (uds.message.UdsMessage) – UDS message to divide into UDS packets.

Raises

SegmentationError – Provided diagnostic message cannot be segmented.

Returns

CAN packets that are an outcome of UDS message segmentation.

Return type

uds.packet.PacketsDefinitionTuple