Local Interconnect Network Overview

Did you know the exact meaning of LIN? I know many of you out there is thinking or searching what is LIN and what is the function of this. LIN is stands for Local Interconnect Network. LIN network is consists have LIN master and LIN slave and one LIN master typically has up to 16 slaves.

Local Interconnect Network group was founded in the late 1990s by the 5 European automakers Volcano Automotive Group and Freescale.  On November of 2002 the first fully version of LIN specification was implemented and published as LIN version 1.3. Version 2.0 of Local Interconnect Network was introduced on September 2003 to expand configuration capabilities and make provisions for significant additional diagnostics features and tool interfaces. For more understanding what is LIN all about check this LIN Video.

Frame Types of LIN:

1. Unconditional Frame. These always carry signals and their identifiers are in the range 0 to 59 (0x00 to 0x3b). All subscribers of the unconditional frame shall receive the frame and make it available to the application (assuming no errors were detected).
2. Event-triggered Frame. The purpose of this is to increase the responsiveness of the LIN cluster without assigning too much of the bus bandwidth to the polling of multiple slave nodes with seldom occurring events. The first data byte of the carried unconditional frame shall be equal to a protected identifier assigned to an event-triggered frame. A slave shall reply with an associated unconditional frame only if its data value has changed. If none of the slave tasks responds to the header the rest of the frame slot is silent and the header is ignored. If more than one slave task responds to the header in the same frame slot a collision will occur, and the master has to resolve the collision by requesting all associated unconditional frames before requesting the event-triggered frame again.
3. Sporadic Frame. This frame is transmitted by the master as required, so a collision cannot occur. The header of a sporadic frame shall only be sent in its associated frame slot when the master task knows that a signal carried in the frame has been updated. The publisher of the sporadic frame shall always provide the response to the header.
4. Diagnostic Frame. These always carry diagnostic or configuration data and they always contain eight data bytes. The identifier is either 60 (0x3C), called master request frame, or 61(0x3D), called slave response frame. Before generating the header of a diagnostic frame, the master task asks its diagnostic module if it shall be sent or if the bus shall be silent. The slave tasks publish and subscribe to the response according to their diagnostic module.
5. User-Defined Frame. These can carry any kind of information. Their identifier is 62 (0x3E). The header of a user-defined frame is always transmitted when a frame slot allocated to the frame is processed
6. Reserved Frame. These shall not be used in a LIN 2.0 cluster. Their identifier is 63 (0x3F).

Source: Wiki