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Ca npp t

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overview and working of CAN protocol .
application of CAN protocol.
CAN protocol fault confinement
what can is?
why we need CAN protocol?
how CAN protocol works

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Ca npp t

  1. 1. SIDDAGANGA INSTITUTE OF TECHNOLOGY “CAN (Controller Area Network ) Protocol” Technical seminar on Darshan K S 1SI12EC129 VII sem, EC ‘A’ Guided by Dr. R.KUMARASWAMY Professor & Head, Dept. of E&C 6/10/2015 CAN (Controller Area Network) Protocol 1
  2. 2. Outline 1. What/Why CAN ? 2. CAN bus introduction 3. Overview of CAN 4. CAN Application / Bus level 5. Message Frames 6. Error Handling / Fault confinement 7. Bit Stuffing 8. References 6/10/2015 CAN (Controller Area Network) Protocol 2
  3. 3. Why CAN ? 6/10/2015 CAN (Controller Area Network) Protocol 3 • Wiring-reduction, Cost reduction with CAN. Figure 1 Figure 2
  4. 4. What CAN ? 6/10/2015 CAN (Controller Area Network) Protocol 4 • CAN is a multi-master serial bus that allows an efficient transmission of data between different nodes. With its flexibility and robustness against electrical interferences
  5. 5. CAN Node Consists of … 6/10/2015 CAN (Controller Area Network) Protocol 5 • Host Processor • CAN Controller • CAN Transceiver
  6. 6. CAN bus introduction • Controller Area Network (CAN) • Originally developed by Robert Bosch for automobile in- vehicle network • CAN bus provides communication between controllers, sensors, and actuators. • Very reliable and robust well proven technology 6/10/2015 CAN (Controller Area Network) Protocol 6
  7. 7. Overview of CAN • Multi drop, multi-Master Bus Access • Message Broadcasting • Message Priority (No Node IDs) • Limited Data Length (0…8 bytes) • 1 Mbit/sec Data Rate • Excellent Error Detection & Fault Confinement 6/10/2015 CAN (Controller Area Network) Protocol 7
  8. 8. CAN Application • Automotive • Military vehicles • Industrial machinery • Medical systems • Agricultural machinery • Marine control and navigation • Elevator control systems 6/10/2015 CAN (Controller Area Network) Protocol 8
  9. 9. Bus Level 6/10/2015 CAN (Controller Area Network) Protocol 9 0 - Dominant bit 1 - Recessive bit
  10. 10. Bus Level 6/10/2015 CAN (Controller Area Network) Protocol 10
  11. 11. Message Frame Format • There are two types of CAN implementations depending on the size of the identifier field 1. Standard CAN Frame format :(11 bit wide identifier field) 6/10/2015 CAN (Controller Area Network) Protocol 11
  12. 12. Message Frame Format 2. Extended CAN Frame format : (29-bit wide identifier field) 6/10/2015 CAN (Controller Area Network) Protocol 12 CAN Base frame format with the addition of : • Substitute remote request (SRR) • Identifier extension (IDE) • r1 – reserve bit
  13. 13. Bus Arbitration Principle 6/10/2015 CAN (Controller Area Network) Protocol 13 • Bit wise arbitration across the Arbitration Field • Dominant Bus Level = 0, Recessive Bus Level = 1
  14. 14. Message Frames 6/10/2015 CAN (Controller Area Network) Protocol 14 • Data Frame – Broadcasts a message to the CAN bus • Remote Frame – Requests transmission of message • Error Frame – Signals error condition • Overload Frame – Special Error Frame
  15. 15. Error Detection Method The CAN protocol implements following type of errors detection • Bit Error : The sending node monitors the bus to ensure that the data transmitted is same as the data received. • Stuff Error : If a 6th successive bit (either 0’s or 1’s ) is detected, the stuff error is reported. • CRC Error : Comparison of received CRC sequence and calculated CRC. Provides detection of local receiver errors. • Form Error : A form error is detected when a fixed form bit (constant bit ) is different than what is expected. • Acknowledgement Error : An ack. Error is detected whenever sender does not monitor a dominant bit in the ACK slot. ACK confirms only the successful transmission. 6/10/2015 CAN (Controller Area Network) Protocol 15
  16. 16. Fault Confinement • CAN Node Error States 6/10/2015 CAN (Controller Area Network) Protocol 16
  17. 17. Maximum Bus Length 6/10/2015 CAN (Controller Area Network) Protocol 17 • Bus Length is limited due to Bit Monitoring (Signal Propagation Time)
  18. 18. Conclusion • Controller Area Networks applications are emerging and gaining high ground in many applications from automobile industry to automation and factory industries. • CAN is ideally suited in applications requiring a large number of short messages with high reliability in rugged operating environments • it is especially well suited when data is needed by more than one location and system-wide data consistency is mandatory. 6/10/2015 CAN (Controller Area Network) Protocol 18
  19. 19. References [1] Othman, H.F.; Aji, Y.R.; Fakhreddin, F.T.; Al-Ali, A.R. Controller Area Networks: Evolution and Applications, 2nd Information and Communication Technologies, 2006,vol. 2, pp. 3088 - 3093. [2] Robert Bosch GmbH, “CAN Specification”, Version 2.0, 1991. [3] Pazul, K. Controller Area Network (CAN) Basics, Microchip Technology Inc, 1999. [4] Steve Corrigan, Introduction to the Controller Area Network (CAN), Texas Instrument, Application Report, 2008. [5] Controller Area Network (CAN), LAN in vehicle communications protocol, SAE JI583 Mar90, SEA Information Report, pg, 20, 226-248 6/10/2015 CAN (Controller Area Network) Protocol 19
  20. 20. THANK YOU 6/10/2015 CAN (Controller Area Network) Protocol 20

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