Re: CAN Bus over TCP/IP

[Andre Naujoks <nautsch2@gmail.com>]

On 14.06.2014 03:55, John Whitmore wrote:
> Was contemplating something which would allow me to transmit CAN Bus frames
> over TCP/IP. Searching throws up a few papers on the subject but wondered if
> there's an OpenSource implementation already out there or any kind of spec on
> the subject. Thought there might be an RFC on the subject but haven't thrown
> up anything.
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Hi.

Have a look at slcan and the accompanying tools (slcan_attach, ...) from
can-utils in combination with socat or a simple C-implementation that
just forwards data between a pseudo-tty and a socket. I use that setup
to connect multiple virtual machines via CAN for testing purposes.

The final setup would look like this:

candev <-> ptty <-> socat <-> tcp <-> socat <-> ptty <-> candev

I don't know what kind of performance you need, but it should definitely
be worth a look.

For example:
Machine A:
socat -d -d PTY,link=/tmp/slcan,raw TCP-LISTEN:30000 &
slcan_attach /tmp/slcan
ip link set slcan0 up

Machine B:
socat TCP:<machine-A-IP>:30000 PTY,link=/tmp/slcan
slcan_attach /tmp/slcan
ip link set slcan0 up


should connect those two CAN-Busses over TCP.

Regards
  Andre