LIN – Local Interconnect Network

The Local Interconnect Network (LIN) bus system was developed by the LIN consor­tium until 2010. It comprises the physical layer, the bus protocol, the inter­face to the app­li­cation and a uni­form format for describing an entire LIN. The achieved status 2.2A of the speci­fi­cation was transferred to ISO and published as ISO standard 17987-1, Road vehicles – Local interconnect network (LIN) – Part 1–8.

The serial communication system is very cost effective to connect sensors and actu­ators in vehicle networks as sub­system to existing bus systems. LIN is mainly used where the bandwidth of CAN is not needed. Classical applications are the networking of doors or seats within the vehicle.

Function

A LIN consists of a master and one or more slaves. The number of slaves is normally limited to 16. A master is typically a micro­controller that connects the local inter­connect network to the CAN fiel­dbus as a bridge. The master determines the chrono­logical order of all messages on the LIN. To do this, it sends the message start via the so-called header. This contains an iden­ti­fier that addresses a row in the con­fi­guration table.

The table defines which subscriber should send the data part of the message of up to eight bytes in size. It also describes what the data is and which subscriber should read the message. Each slave must save the part of the table that is relevant for him. A dy­namic change of the con­fi­gu­ration during operation (plug and play) is not intended. Design tools for the con­fi­guration table ensure that no col­lis­ions occur during operation.