LIN Frame

A LIN frame is composed of a frame header and a frame response. The frame header is always transmitted by the LIN master, while the frame response is generally sent by a LIN slave (exception: Master Request Frame and Sporadic Frame). Each frame header is made up of three fields: Sync break field, sync field and PID (protected identifier). The sync break field and the sync field serve to produce synchronous timing of all LIN nodes. The PID comprises the identifier (ID) and two parity bits to protect the ID.

The LIN master delegates communication in the LIN cluster by means of the PID. In other words: It defines the sender and receiver(s) of each LIN frame or each frame response. The frame response is comprised of a maximum of eight useful bytes and a checksum. A distinction is made between the "classic" and "enhanced" checksums. The classic checksum only protects the useful data, while the enhanced checksum protects both the useful data and the ID.