LIN2.0 and LIN2.1

Ronnie,

It depends, LIN 2.0 controllers can work within a LIN 2.1 environment, however, if dynamic configuration is required, this is no longer the case. There are some configuration options in LIN 2.1 that are not available in LIN 2.0 protocol.

Most LIN transceiver datasheets reference LIN 2.1 protocol support, so the customer may just be referencing this with no specific need for the LIN 2.1 protocol itself. Is there any way you can find out what exactly they will be using from LIN 2.1 specifically?

Regards,

Ronnie,

I just wanted to check in again, were you able to get any more information from the customer?

Regards,

LIN 2.1 Spec lists the changes compared with LIN 2.0, as the following description.

If master use LIN 2.1 and slave(TMS320F28035) use LIN 2.1, some  requirements are listed below.

1) Master uses frame with ID 3Ch when make salve sleep mode and when requiring node configuration service to slave. And slave uses frame with ID 3Dh to reply the service which was required to master.

2) LIN frame ID for other control and feedback data  are 0x02h-0x04h

3) LIN communication speed 9600bps or 19200bps

4) For diagnostic, there are 2 types of schedule table, normal schedule table and diagnostic schedule table. If the master receives diagnostic request from slave, it will switch to the diagnostic frame schedule table. After the diagnostic service is finished, the master must switch to the normal schedule table.

5) LIN transceiver follow LIN 2.1 physical layer specification.

6) Slave node will enter sleep mode if LIN bus is inactive in 10 seconds. Slave node in a sleeping LIN cluster may request a wake up by forcing the bus to a dominant state for 2ms. If the master does not issue frame headers with 150ms from the wake up request, a new wake up request should be issued. After 3 attempts to wake up the LIN bus, the node shall wait 2 seconds before next round request, after 3 round request, the node will go to sleep again.

7) Slave node must have baud rate auto-adjustment function.

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If slave uses TMS320F28035, can salve meet above requirements ?

For the changes between LIN 2.0 and LIN 2.1, node capability language specification and configuration language specification are listed, do they have any influence if  slave uses LIN 2.0 ?

In addition, for above requirement No.6, from TMS320F2803x Piccolo Local Interconnect Network (LIN) Module user's guide, we can find the following description,the round request interval time is 1.5s, this time can not be configured.

Ronnie,

For points 1), 2), 3), and 7), the TMS will definitely work, as these are configurations that can be controlled by how the controller software is developed. For point 5), this has to do with the physical transceiver and not the controller, so the TMS has no part in this. It's strange that the TMS device works correctly for the Wakeup Timeouts except for the one timer, I'm not an expert on these processors, so I'm not sure why this timing was chosen.

For point 4), I'm not sure if this is native to the built-in LIN protocol on this processor, but schedule tables regardless of the proceso, are dfined by the LIN cluster designer. So if LIN protocol is supported by this processor, I don't see why these can't be supported by the TMS device as well.

I'm going to pull in an expert for this device to see if they know about the LIN portion of this processor.

Regards,

Ronnie,

As Eric has mentioned, most of the configurations are handled in the controller software, and the F28035 is HW compliant to LIN 2.0. Some research I have done confirms that a LIN2.0 compliant slave can work fine with a LIN2.1 compliant master. There will be a few features that the slave cannot handle, such as dynamic configurations, unless it is handled in the higher-level controller software.

Regarding the 1.5s time-out, that is part of the LIN specification. A slave will go into timeout after 3 unsuccessful attempts to wake up the bus. Additionally, the F28035 LIN slave will enter sleep mode after 4 s of inactivity on the bus. This is the minimum sleep mode specified by the LIN2.1 spec (4s to 10s).

I have a nice LIN Reference poster hanging in my cube that shows comparisons between LIN 1.3, 2.0, and 2.1. you can get this from here: vector.com/vi_infomaterial_orderlist_posters_en.html . Choose the "LIN Poster".

-Mark