Overview of UDS OSI model.
UDS is defined by multiple standards which are the main source of information and requirements about this protocol. Full list of standards is included in the table below:
+--------------+-------------+-------------+-------------+-------------+----------------+-------------+ | OSI Layer | Common | CAN | FlexRay | Ethernet | K-Line | LIN | +==============+=============+=============+=============+=============+================+=============+ | Layer 7 | ISO 14229-1 | ISO 14229-3 | ISO 14229-4 | ISO 14229-5 | ISO 14229-6 | ISO 14229-7 | | Application | | | | | | | | | ISO 27145-3 | | | | | | +--------------+-------------+-------------+-------------+-------------+----------------+-------------+ | Layer 6 | ISO 27145-2 | | | | | | | Presentation | | | | | | | +--------------+-------------+-------------+-------------+-------------+----------------+-------------+ | Layer 5 | ISO 14229-2 | | | | | | | Session | | | | | | | +--------------+-------------+-------------+-------------+-------------+----------------+-------------+ | Layer 4 | ISO 27145-4 | ISO 15765-2 | ISO 10681-2 | ISO 13400-2 | Not applicable | ISO 17987-2 | | Transport | | | | | | | +--------------+ | | | | | | | Layer 3 | | | | | | | | Network | | | | | | | +--------------+ +-------------+-------------+-------------+----------------+-------------+ | Layer 2 | | ISO 11898-1 | ISO 17458-2 | ISO 13400-3 | ISO 14230-2 | ISO 17987-3 | | Data | | | | | | | +--------------+ +-------------+-------------+ +----------------+-------------+ | Layer 1 | | ISO 11898-2 | ISO 17458-4 | | ISO 14230-1 | ISO 17987-4 | | Physical | | | | | | | | | | ISO 11898-3 | | | | | +--------------+-------------+-------------+-------------+-------------+----------------+-------------+
- Where:
- OSI Layer - OSI Model Layer for which standards are relevant
- Common - standards mentioned in this column are always relevant for UDS communication regardless of bus used
- CAN - standards which are specific for UDS on CAN implementation
- FlexRay - standards which are specific for UDS on FlexRay implementation
- Ethernet - standards which are specific for UDS on IP implementation
- K-Line - standards which are specific for UDS on K-Line implementation
- LIN - standards which are specific for UDS on LIN implementation
An overview of features that are required to fully implement UDS protocol is presented in the table below:
+--------------+-------------------------------------------+-------------------------------------------------------+ | OSI Layer | Functionalities | Implementation | +==============+===========================================+=======================================================+ | Layer 7 | - diagnostic messages support | - uds.message | | Application | | | +--------------+-------------------------------------------+-------------------------------------------------------+ | Layer 6 | - diagnostic messages data interpretation | To be provided with Database feature. | | Presentation | | | | | - messaging database import from a file | | | | | | | | - messaging database export to a file | | +--------------+-------------------------------------------+-------------------------------------------------------+ | Layer 5 | - Client simulation | To be provided with Client feature. | | Session | | | | | - Server simulation | To be provided with Server feature. | +--------------+-------------------------------------------+-------------------------------------------------------+ | Layer 4 | - UDS packet support | - uds.packet | | Transport | | | | | - bus specific segmentation | - uds.segmentation | | | | | | | - bus specific packets transmission | - uds.transport_interface | | | | | | | | - uds.can | | | | | +--------------+ | To be extended with support for: | | Layer 3 | | | | Network | | - Ethernet | | | | | | | | - LIN | | | | | | | | - K-Line | | | | | | | | - FlexRay | +--------------+-------------------------------------------+-------------------------------------------------------+ | Layer 2 | - frames transmission | External python packages for bus handling: | | Data | | | | | - frames receiving | - CAN: | +--------------+ | | | Layer 1 | | - python-can | | Physical | | | | | | More packages handling other buses to be decided. | +--------------+-------------------------------------------+-------------------------------------------------------+
- Where:
- OSI Layer - considered OSI Model Layer
- Functionalities - functionalities required in the implementation to handle considered UDS OSI layer
- Implementation - UDS package implementation that provides mentioned functionalities
Each layer of OSI Model defines their own Protocol Data Unit (PDU). To make things simpler for the users and our developers, in the implementation we distinguish following PDUs:
- Application Protocol Data Unit (A_PDU) - called diagnostic message or UDS Message in the implementation and documentation. More information about A_PDU can be found in:
knowledge base section - diagnostic message <knowledge-base-diagnostic-message>implementation - diagnostic message <implementation-diagnostic-message>
- Network Protocol Data Unit (N_PDU) - called UDS packet in the implementation and documentation. More information about N_PDU can be found in:
knowledge base section - UDS packet <knowledge-base-uds-packet>- implementation -
uds.packet
- Data Protocol Data Unit (D_PDU) - called frame in the implementation and documentation. We do not have any internal frames documentation. Implementation of frames is usually provided by external packages.
