In-Vehicle Networking for Heavy Duty Systems Review of CAN / SAE J1939/ ISO 11783

1. In-Vehicle Networking for Heavy Duty SystemsReview of CAN / SAE J1939/ ISO 11783 Network Management ISO 11783 Part 5 J1939-81

2. How do we create new messages? • Is there a block of identifiers/addresses/messages set asidefor experimental use? If so, how do we get information about them? • Use proprietary if you must be compliant • OEM reserved address available • If we make a controller which will remain on the vehicle, how do we get it added to the standard? How long does it take to get something added? • Controller needs a NAME defined, can use self-configuring addressing • Should take ~3 mo to add a new name or message FAQ

3. Tools / Emergencies? FAQ • What kind of diagnostic/programming software tools are available? • http://www.noregon.com/caninterface.html • http://www.vector-cantech.com/ • Is there some kind of provision or protocol for when a controller, etc. can't talk to the micro, etc.? i.e., is there a 911/411 for figuring out what's wrong? • Need a good PC based tool and a test network

4. Network initialization / module naming? • How are ECUs identified? • Are there rules for initialization? • Are there requirements if power supply drops out briefly? FAQ

5. Purpose of Network Management Describes • themanagement of source addressesand the association of those addresses with the actual functional identification of a device • thedetection and reporting of network related errors. • initialisation processes • requirements forreaction to brief power outages • minimum requirements for network connected electronic control units. Provides methods for distributed management of addresses and identity (no master).

6. Network Management Functions • DefinesNAMEs 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 • Definesaddress configuration types • ECU Address configuration • Configurable Address • Service Configurable Address • Command Configurable Address • Self-Configurable Address ECU • (J1939) Arbitrary address capable

7. Network Management Functions • DefinesECU types • Standard • Diagnostic/Development Tool • Network Interconnection • Definesaddress initialisation process • Definesaddresscommanding process • Definespower continuity requirements • ISO and J1939 are different

8. 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)

9. Always sent to Global!

11. 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

12. NAME Structure

13. NAME Hierarchy

14. 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

15. 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

16. State Transitions forself-configuring ECUs

17. State Transitions forNon Self-configuring ECUs

18. 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

19. 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

20. 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.