1. In-Vehicle Networking
Lecture 3 ISO Part 3 / J Data Link Layer
BAE
Spring 2009
Instructor: Marvin Stone
Biosystems and Agricultural Engineering
Oklahoma State University
January 9, 2009
BAE

2. ISO 11783/J1939 communications system
ISO 7498 – Open Systems Interconnection (OSI)
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3. J1939 Document numbering
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4. ISO 11783 Document Status (9-10-2007)
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5. Document Status (out of date!)
For numbering only
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6. January 9, 2009
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7. January 9, 2009
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8. 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
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BAE

9. 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
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BAE

10. 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
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11. PGN - Parameter Group Number
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12. Message Capabilities
Global
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13. Message Capabilities One to One PDU1 January 9, 2009 BAE 5030-363
SOURCE
DESTINATION
-- Parameter Group --
Source Address
Destination Addr. P
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14. Message Capabilities
Not in 11783
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15. Message Capabilities
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16. Reply’s to Requests
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17. Message Capabilities
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18. January 9, 2009
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19. Message Capabilities
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20. Message Capabilities 200 ms between data packets! January 9, 2009
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21. 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.
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22. 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

23. 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

24. 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
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