Terminology » LIN Bus Frame Analysis & LIN Packet Data Logger Tool

LIN Bus Frame Analysis & LIN Packet Data Logger Tool

automotive lin frame protocol analyzer tool

Introduction : The LIN (Local Interconnect Network) is a low cost, single wire protocol. It is often used for sensor/actuator sub networks in vehicles. It operates as per master-slave architecture where the master initiates a header and the slave responds with data.

LIN Frame Structure

LIN frame is composed of two parts, one used by master called “header” and another used by slave called “response”. Header part generated by master contains Sync Break, Sync Field and PID (Protected Identifier). The response is generated by slave and contains data field and checksum. The same is shown in the following figure.

LIN Frame Structure

Header Fields (LIN Frame Part #1)

Field	Size	Description
Sync Break	At least 13 dominant bits (logic-0) plus 1 bit break delimiter	Signals the start of new frame. The long dominant level lets all slave nodes detect the start, even if their clocks are not aligned.
Sync Field	8 bits of data plus start/stop bit, i.e. 10 bits total	Contains the fixed value 0x55, slaves use this to perform baud rate synchronization by measuring edges.
PID	8 bits (6 bits PID + 2 bits for parity)	Identifies which frame it is (which ID) and provides parity for error checking. The 6-bit ID (0–63) defines the message type, and the 2 parity bits help detect errors in the ID.

Response Fields (LIN Frame Part #2)

Field	Size	Description
Data Field	1 to 8 bytes (8-64 bits of data), on wire it also uses start/stop bits, so there will be 10 bits per byte as per UART LIN bus	Carries the payload / application data
Checksum	1 byte, plus start/stop bits which gives total 10 bits on the wire	Used for error detection; there are two types viz. classic and enhanced based on LIN version. Enhanced checksum used sum of data and PID in its calculation.

LIN Protocol data logger tool

Manufacturers	Product with features
Eletechsup	TTL‑UART to LIN Data Analyzer: Converts TTL-UART signals to LIN bus. Lets you send and monitor LIN frames from a microcontroller / PC. Useful for prototyping LIN master or slave, logging LIN data.
CSS Electronics	Products CANedge2 & CANedge3 : Functions as CAN & LIN Data Logger
TOSUN Technology	TLog1004 - 4 CAN FD + 2 LIN Bus Logger , TLog1002
G.i.N. GmbH	GL4000 Data Logger (with LINprobe)
MACH SYSTEMS s.r.o.	CAN-FD LIN Gateway

Summary: Using a LIN packet data logger tool enables effective capture and decoding of LIN frame traffic. This LIN protocol test and measurement tool offers visibility into header-response cycles, timing behaviour and error detection. It helps in validation and debugging of LIN clusters in automotive systems.