SAE J1939 / ISO 11783 Network Management Lecture 5 Network Management ISO 11783 Part 5, J1939-81 BAE 5030 - 353 Spring 2009 Instructor: Marvin Stone Biosystems and Agricultural Engineering Oklahoma State University Feb 9, 2009 BAE 5030-353

Purpose of Network Management Describes the management of source addresses and the association of those addresses with the actual functional identification of a device the detection and reporting of network related errors. initialization processes requirements for reaction to brief power outages minimum requirements for network connected electronic control units. Provides methods for distributed management of addresses and identity (no master). Feb 9, 2009 BAE 5030-353

Network Management Functions Defines NAMEs for ECUs Provides hierarchical naming structure Three Hierarchical Levels Device Class -> function-> ECU Provides instance count for each level Provides identification of manufacturer of ECU Provides type IDs for Class and Function Defines address configuration types ECU Address configuration Configurable Address Service Configurable Address Command Configurable Address Self-Configurable Address ECU (J1939) Arbitrary address capable Feb 9, 2009 BAE 5030-353

Network Management Functions Defines ECU types Standard Diagnostic/Development Tool Network Interconnection Defines address initialization process Defines address commanding process Defines power continuity requirements ISO and J1939 are different Feb 9, 2009 BAE 5030-353

Messages defined for Network Management Request for Address Claim Normal Request Message of the Address Claim PGN Address Claim Commanded Address Cannot Claim Address Claim of the Null Address (254) Feb 9, 2009 BAE 5030-353

Messages for address management Always sent to Global! Feb 9, 2009 BAE 5030-353

Feb 9, 2009 BAE 5030-353

NAMEing - ECU Identity within the network ECUs have a NAME and address (numeric ID) Address Provides unique identity within a session Included in every message to provide message uniqueness NAME Provides high probability of a unique identifier within a connected system Provides some functional identification of ECUs Used to arbitrate in the case of an address selection conflict Feb 9, 2009 BAE 5030-353

NAME Structure Feb 9, 2009 BAE 5030-353

NAME Hierarchy Feb 9, 2009 BAE 5030-353

Second ECU of a Rate Control unit on third Planter NAME Example Second ECU of a Rate Control unit on third Planter Self-Configuring - True = 1 Industry Group - Agriculture and Forestry = 2 Device Class - Planter/Seeders = 4 Device Class Instance - Third Planter = 2 Function - Rate Control (undefined) = 255 Function Instance - First undefined = 0 ECU Instance - Second ECU = 1 Feb 9, 2009 BAE 5030-353

Initialization Process Given in the text of the document Following figures Provides distributed methods for ECUs to secure the use of an address Provides processes for both self and non-self configuring ECUs Feb 9, 2009 BAE 5030-353

State Transitions for self-configuring ECUs Feb 9, 2009 BAE 5030-353

State Transitions for Non-Self-configuring ECUs Feb 9, 2009 BAE 5030-353

NAME-Address Table Maintenance Addresses of ECUs may change May occur on initialization (initial address conflict) New ECUs are added since last power-up Could occur during operation New ECUs are powered during operation Self-Configuring ECUs lose conflicts with non-Self-Configuring ECUs Self-Configuring bit in NAME gives non-self-configuring ECUs priority Change of Addresses of ECUs rare ECUs retain successfully claimed address for next power-up Changes occur on re-configuration Feb 9, 2009 BAE 5030-353

NAME-Address Table Maintenance Must maintain current “NAME to Address” relationship For ECUs to which destination specific messages are sent Commands, Requests May need current “NAME to Address” relationship For ECUs that are Listened to If the information is sender dependent Procedure Listen to address claims Update table for those of interest Maintain across power disruptions Feb 9, 2009 BAE 5030-353

Reaction to Power Supply Voltage Disturbances and Interruptions < 10 ms, interruptions spaced by at least 100 ms: NO Loss of normal network communications nor loss of in-process messages. NO Processor reset. NO Loss of data in volatile memory, including network configuration information and/or messages in progress over the network. > 1s Power is not restored within 1 second then the ECU must reset and complete a Power On Self Test (POST). Between 10ms and 1s Internal requirements determine if a reset is required. Feb 9, 2009 BAE 5030-353