BS ISO 15765-1 pdf download

BS ISO 15765-1 pdf download Road vehicles — Diagnostic communication over Controller Area Network (DoCAN) Part 1: General information and use case definition
4 Conventions
ISO 15765 is based on the conventions discussed in the Osl Service Conventions (ISO/IEC 10731) as theyapply for diagnostic services.
5 Overview of lSO 15765
5.1General
ISO 15765 is applicable to vehicle diagnostic systems implemented on a CAN communication network asspecified in lsO 11898.
ISO 15765 has been established in order to define common requirements for vehicle diagnostic systemsimplemented on a CAN communication link as specified in lSO 11898.
Although primarily intended for diagnostic systems, IS0 15765 has been developed to also meet requirementsfrom other CAN-based systems needing a network layer protocol.
5.2Open Systems Interconnection (Osl) model
ISO 15765 is based on the Open Systems Interconnection (OSI)Basic Reference Model as specified inISO/IEC 7498-1 which structures communication systems into seven layers.
All parts of lS0 15765 are guided by the OSl service conventions as specified in ISO/IEC 10731 to the extentthat they are applicable to diagnostic services. These conventions define the interaction between the serviceuser and the service provider through service primitives.
The aim of this subclause is to give an overview of the OSl model and show howit has been used as a guidelinefor this part of ISO 15765.It also shows how the OSl service conventions have been applied to SO 15765.The OSl model structures data communication into seven layers called, from top down，application layer(layer 7), presentation layer (layer 6), session layer (layer 5), transport protocol layer (layer 4), network layer(layer 3), data link layer (layer 2) and physical layer (layer 1).
A subset of these layers is used in ISO 15765,which specifies the application,session, transport protoco.network, data link and physical layers for DoCAN.
The purpose of each layer is to provide services to the layer above.The application layer provides services to thediagnostic application. The active parts of each layer, implemented in software, hardware or any combinationof software and hardware, are called entities. In the OSl model, communication takes place between entitiesof the same layer in different nodes. Such communicating entities of the same layer are called peer entities.The services provided by one layer are available at the Service Access Point (SAP) of that layer. The layerabove can use them by exchanging data parameters.
IS015765 distinguishes between the services provided by a layer to the layer above it and the protocol usedby the layer to send a message between the peer entities of that layer. The reason for this distinction is to makethe services,especially the application layer services and the transport layer services, reusable for CAN andfor other network types. In this way, the protocol is hidden from the service user and it is possible to changethe protocol if special system requirements demand it.