Multiplexed Networks for Embedded Systems: CAN, LIN, FlexRay, Safe-by-Wire...

7

LIN – Local Interconnect Network

Rome was not built in a day. Neither was the local interconnect network – better known as the LIN bus.

The major developer of the LIN concept was the Motorola company (now Freescale) and the first specification, ‘LIN rev. 0’, appeared in July 1999 (33 pages). A consortium was soon created, in March 2000, including the car manufacturers Audi, BMW, Daimler Chrysler, Volkswagen and Volvo Car Corporation, as well as Motorola Inc. and Volcano Communication Technologies AB. Note that Motorola was in charge of the LIN consortium from 2000 onwards.

After several intermediate versions, particularly LIN 1.2 (November 2000) and LIN 1.3 (December 2002), allowing for various adjustments of the time aspects and electrical signal tolerances of the protocol and software resources, and negotiations with our American colleagues of SAE J2602, the final specification, ‘LIN rev. 2.0’ (125 pages long!), was issued in September 2003. How useful is it to have a stable protocol to enable reliable systems to be developed and perfected!

To make matters clearer for you: ‘LIN 2.0 is a superset of LIN 1.3, and is the version recommended for all new developments’, says the Consortium. So it is goodbye to the many (too many) earlier versions. Note also that this protocol belongs to the LIN Consortium and is not at present standardized by the ISO, and is supplied ‘as is’ (according to the Consortium).

7.1 Introduction

The LIN protocol is mainly intended to support the control ...