Finding a transmitter's CAN ID

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Finding a transmitter's CAN ID

Rob__V
Hi all,

I am currently working on a project with several embedded platforms connect via CAN:
1 x Linux board connected via SocketCAN
N x embedded boards using the Atmega16M1 (CAN) MCU.

The Linux board is 'treated' as the master and needs to know the CAN ID of each
atmega board that sends it a CAN message. So my question is :

How is the Linux/SocketCAN board able to determine the CAN ID of other networked nodes when they transmit ?

Of course, each CAN node can determine the target ID for each message but
I am not sure if the source ID is known ... outside of arbitration.


Thank you for your time.

All the best,
Rob
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Re: Finding a transmitter's CAN ID

Stefan May
You cannot determine the source of a CAN message as the CAN bus is a
broadcast bus. There is no concept of addressable nodes in CAN.

mfg, Stefan.


On Mo, 2013-08-19 at 07:43 -0700, Rob__V wrote:

> Hi all,
>
> I am currently working on a project with several embedded platforms connect
> via CAN:
> 1 x Linux board connected via SocketCAN
> N x embedded boards using the Atmega16M1 (CAN) MCU.
>
> The Linux board is 'treated' as the master and needs to know the CAN ID of
> each
> atmega board that sends it a CAN message. So my question is :
>
> How is the Linux/SocketCAN board able to determine the CAN ID of other
> networked nodes when they transmit ?
>
> Of course, each CAN node can determine the target ID for each message but
> I am not sure if the source ID is known ... outside of arbitration.
>
>
> Thank you for your time.
>
> All the best,
> Rob
>
>
>
> --
> View this message in context: http://socket-can.996257.n3.nabble.com/Finding-a-transmitter-s-CAN-ID-tp7678.html
> Sent from the Socket-CAN Users mailing list archive at Nabble.com.
> _______________________________________________
> Socketcan-users mailing list
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> https://lists.berlios.de/mailman/listinfo/socketcan-users

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Re: Finding a transmitter's CAN ID

Steffen Rose-2
In reply to this post by Rob__V
Hello,

> How is the Linux/SocketCAN board able to determine the CAN ID of other
> networked nodes when they transmit ?

Within CAN network every CANID should have only one transmitter. It is your
definition to define a rule, which node can send a specific CAN Id.

But in case a node works wrong and send a not allowed CAN Id it is a problem
to determine the transmitter.

--
Mit freundlichen Grüßen / Best regards
Steffen Rose

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