Arbitration Process
 
§  The start of frame bit marks the beginning of the data frame, it consists of a single dominant bit.
 
§  The Arbitration Field consisting of 12 bits: The 11-bit Identifier, which reflects the contents and priority of the message, and the Remote Transmission Request bit. The Remote transmission request bit is used to distinguish a Data Frame (RTR = dominant) from a Remote Frame (RTR = recessive).
 
§  The next field is the Control Field, consisting of 6 bits. The first bit of this field is called the IDE bit (Identifier Extension) and is at dominant state to specify that the frame is a Standard data Frame not an interframe space. The following bit is reserved and defined as a dominant bit. The remaining 4 bits of the Control Field are the Data Length Code (DLC) and specify the number of bytes of data contained in the message (0 - 8 bytes).
 
§  Data field: The data being sent follows in the Data Field which is of the length defined by the DLC above (0, 8, 16, ...., 56 or 64 bits).
 
§  The Cyclic Redundancy Field (CRC field) follows and is used to detect possible transmission errors. The CRC Field consists of a 15 bit CRC sequence, completed by the recessive CRC Delimiter bit.
 
§  The next field is the Acknowledge Field. During the ACK Slot bit the transmitting node sends out a recessive bit. Any node that has received an error free frame acknowledges the correct reception of the frame by sending back a dominant bit (regardless of whether the node is configured to accept that specific message or not).
 
§  Finally, the seven recessive bits that determine the end of frame. [6] [7]
 
B. Local Interconnect Network (LIN): LIN is an asynchronous serial broadcast bus where all messages are initiated by the one single master with at most one slave replying to a given message identifier. The  Local Interconnect Network (LIN) bus was developed to create a standard for low-cost, low-end multiplexed communication in automotive networks. LIN provides cost-efficient communication in applications where the bandwidth and versatility of CAN are not required.
 
 LIN is a single wire communication bus with data rates up to 20 Kbps which is suitable for modules where response time is not a critical issue as mirror controls and window controls. The LIN bus is a polled bus with a single master device and one or more slave devices. The master device contains both a master task and a slave task. Each slave device contains only a slave task.