In-Vehicle Networking Lecture 3 ISO 11783 Part 3 / J1939-21 Data Link Layer BAE 5030 - 363 Spring 2009 Instructor: Marvin Stone Biosystems and Agricultural Engineering Oklahoma State University January 9, 2009 BAE 5030-363

ISO 11783/J1939 communications system ISO 7498 – Open Systems Interconnection (OSI) January 9, 2009 BAE 5030-363

J1939 Document numbering January 9, 2009 BAE 5030-363

ISO 11783 Document Status (9-10-2007) January 9, 2009 BAE 5030-363

Document Status (out of date!) For numbering only January 9, 2009 BAE 5030-363

January 9, 2009 BAE 5030-363

January 9, 2009 BAE 5030-363

ISO 11783 Data Link Layer - General Based on CAN 2.0b 29 bit identifiers Defines the identifier meaning Physical Addressing ( 256 addresses) Independent priority field Data content identifier independent of sender Two message structures Type 1 - Destination Specific - both source and destination Type 2 - Extended - Only source address Defines requests and acknowledgement Defines proprietary message structure Includes a Transport Protocol with two modes Managed Connection BAM January 9, 2009 BAE 5030-363

Two identifier types (PDUs) Message Capabilities Two identifier types (PDUs) ECU to ECU ECU to All TYPE PDU 1 P P P R G Parameter Group Destination Addr Source Address Parameter Group PDU 2 P P P R G -- PDU Format -- Group Extension - Source Address Priority First 8 Bits Reserved Between 240 and Page Bit 255 January 9, 2009 BAE 5030-363

8670 Parameter Groups can be defined 480 PDU1, 8190 PDU2 Identifier Structure PDU2 Priority PDU1 8670 Parameter Groups can be defined 480 PDU1, 8190 PDU2 January 9, 2009 BAE 5030-363

PGN - Parameter Group Number January 9, 2009 BAE 5030-363

Message Capabilities Global January 9, 2009 BAE 5030-363

Message Capabilities One to One PDU1 January 9, 2009 BAE 5030-363 SOURCE DESTINATION -- Parameter Group -- Source Address Destination Addr. P January 9, 2009 BAE 5030-363

Message Capabilities Not in 11783 January 9, 2009 BAE 5030-363

Message Capabilities January 9, 2009 BAE 5030-363

Reply’s to Requests January 9, 2009 BAE 5030-363

Message Capabilities January 9, 2009 BAE 5030-363

January 9, 2009 BAE 5030-363

Message Capabilities January 9, 2009 BAE 5030-363

Message Capabilities 200 ms between data packets! January 9, 2009 BAE 5030-363

Design Recommendations REQUEST SCHEDULING The scheduling of a request should be canceled if information requested is received prior to request being sent. Parameter Groups should not be requested if they are recommended to be broadcast. January 9, 2009 BAE 5030-363

Design Recommendations DEVICE RESPONSE TIME AND TIME-OUT DEFAULTS All devices, when required to provide a response, must do so within 0.20 s. All devices expecting a response must wait at least 1.25 s before giving up or retrying. January 9, 2009 BAE 5030-363

Design Recommendations REQUIRED RESPONSES A response is required for a global request from all devices that have the requested PG, even the requester. Acknowledgments are not allowed for global requests. There is no restriction on minimum response time! January 9, 2009 BAE 5030-363

Design Recommendations CTS NUMBER OF PACKET RECOMMENDATION During normal vehicle operation it is recommended that the maximum number of packets that can be sent per CTS be set to 16. January 9, 2009 BAE 5030-363