Controller Area Network (CAN)

1
Controller Area Network (CAN)

• ??????? ?????
• ???

2
??

• CAN ??
• ?????
• ????
• ?????

3
CAN ??

• ??BOSCH???1983?????,1986???SAE????,1993???ISO
  11898????
• ????????
• ????
• ?????????
• ????????????????
• ??????,?????1 Mbps
• ??????,??????????

4
CAN ????
http//www.ti.com/
5
?????
6
ISO/OSI Reference Model
http//www.ti.com/
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ISO 11898 Standards

• Part 1 Data link layer and physical signaling,
  2003
• Part 2 High-speed medium access unit, 2003
• Part 3 Low-speed, fault-tolerant,
  medium-dependent interface, 2006
• Part 4 Time-triggered communication, 2004
• Part 5 High-speed medium access unit with
  low-power mode, 2007

8
SAE J1939 set of profiles

• J1939/11 Physical layer (250 kbit/s, twisted
  shielded pair)
• J1939/13 Off-board diagnostic connector
• J1939/15 Reduced physical layer (250 kbit/s,
  unshielded twisted pair)
• J1939/21 Data link layer
• J1939/31 Network layer
• J1939/71 Vehicle application layer
• J1939/73 Application layer diagnostics
• J1939/74 (Draft) Application - Configurable
  messaging
• J1939/75 Application layer - Generator sets and
  industrial
• J1939/81 Network management

9
ISO Standards (application layer)

• 11783-113/Isobus Tractors and machinery for
  agriculture and forestry -- Serial control and
  communications data network (20012009,?????)
• 11992-14 Road vehicles -- Interchange of
  digital information on electrical connections
  between towing and towed vehicles
  (20032008,?????)
• 17356-16 Road vehicles -- Open interface for
  embedded automotive applications (20052006)

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Application layers

• CANopen (http//www.can-cia.de/,CiA DS-301)
• CANaerospace (http//www.canaerospace.net/,??)
• ISObus/ISO 11783 (http//www.isobus.net/,???)
• DeviceNet (http//www.odva.org/)
• NMEA 2000 (http//www.nmea.org/,????)
• MilCAN (http//www.milcan.org/,????)
• SafetyBUS p (http//www.safetybus.de/,?????)
• CAN Kingdom (http//www.kvaser.se/)

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???????

• ??????????
• Electronic Control Unit (ECU)
• ??ABS?????????? ...
• ???????????????????? ...
• ??????????????? ...
• ????
• CONSULT
• OBD II (On Board Diagnostic II)
• CAN bus

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CAN bus ???

• ?????????????
• ????????????????
• ??????????
• ????????????
• ???????????????
• ?????????????
• ??????????????
• ...

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????????

• 1 ????
• 2 MK60E??????
• ???????
• 10 ????
• ???????
• 8 ????????
• 11 ???????
• 12 ?????
• 13 ?????
• 14 ???????
• 3 ??????????
• 4 Gateway data transmitter
• 5 ???????
• LIN (Local Interconnect Network)
• 6 ??????
• 7 ??????
• 9 ??????

http//www.aa1car.com/library/can_systems.htm
14
?????????
http//www.infineon.com/
15
???????
http//www.nmea.org/
16
CAN ?????????
17
??????
18
????
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CAN ????

• Transfer rate 1 Mbps max.
• Max. message length 8 bytes
• Carrier Sense Multiple Access/Bitwise Arbitration
  (CSMA/BA)
• Fault tolerance 15 bits CRC ACK
• Media twisted pair

20
Frame ??
21
Non-Destructive Bitwise Arbitration
Stock Flight Systems
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Data rate vs. bus length
?? Baud rate
1 Mbit/s 40 m
500 kbit/s 100 m
250 kbit/s 200 m
125 kbit/s 500 m
50 kbit/s 1 km
10 kbit/s 6 km
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Error detection and error confinement

• Frame level
• Cyclic Redundancy Checks (CRC)
• Frame check
• ACK error check
• Bit level
• Bit monitor
• Bit stuffing

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CAN-H ?? GND ??
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CAN-L ?? GND ??
26
?????
27
????
PCMCIA CAN interface
Encoder
Inclinometer (???)
???????????
???????
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Silicon Labs C8051F5xx
US99
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Infineon

• XC800 family (High performance 8bit 8051)
• C166/XC166/XE166/XC2000 family (16 bit)
• TriCore family (32 bit)

Starter kit XC888, EUR149 CPU clock 24 MHz 32
Kbyte Flash 1.75 Kbyte RAM USB, JTAG, CAN, LIN
Starter kit TC1767, EUR600 CPU clock 133 MHz 2
MByte program flash 92 Kbyte on-chip SRAM USB,
JTAG, CAN, FlexRay
Starter kit C167CS, EUR199 CPU clock 25 MHz 256
Kbyte Flash 6411 Kbyte RAM RS-232, CAN
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Atmel AVR-based Microcontroller

• AT90CAN32/64/128
• ATmega32/64M1, ATmega32/64C1

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Freescale

• 8-bit
• HC08
• 16-bit
• S12/S12X
• 68HC12
• 68HC16
• 56800 Digital Signal Controller
• 32-bit
• 68K/ColdFire
• ARM-based
• Power

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Microchip

• MCP2502x/5x
• MCP2510/15/51

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????
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Reference

• http//www.can-cia.de/
• http//www.mjschofield.com/
• http//www.aa1car.com/library/can_systems.htm
• http//www.aa1car.com/library/us796obd.htm
  (Understanding Onboard Diagnostics OBDII Past,
  Present Future)

35
LIN (Local Interconnect Network)

• Single master, up to 16 slaves (i.e. no bus
  arbitration).
• Single wire communications up to 19,2 kbit/s _at_ 40
  meter bus length.
• Guaranteed latency times.
• Variable length of data frame (2, 4 and 8 byte).
• Configuration flexibility.
• Multi-cast reception with time synchronization,
  without crystals or ceramic resonators.
• Data checksum and error detection.
• Detection of defect nodes.
• Low cost silicon implementation based on standard
  UART/SCI hardware.
• Enabler for hierarchical networks.
• Operating Voltage of 12 V.

36
FlexRay

• synchronization
• Synchronous and asynchronous data transmission
  (scalable).
• Support of a fault tolerant synchronized global
  time base.
• Scalable electric/electronic architectures to
  support different platforms.
• Single Channel gross data rate of 10 Mbit/sec
• protocol
• Deterministic data transmission, guaranteed
  message latency and message jitter.
• Support of redundant transmission channels.
• Fault tolerant and time triggered services
  implemented in hardware.
• Arbitration free transmission.
• flexible configuration - physical layer
• Support for bus and star topologies.
• Fast error detection and signaling.
• Support of wake-up/sleep functionality via bus.