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I'm intended to design a CAN system for a automotive scan tool. So, I need to comprise the main CAN standars used nowadays. Searching on the web I found the following options:

  • ISO 11519-2:1994 – Low-speed CAN transceiver
  • SAE J2411:2000 – Single-wire CAN transceiver
  • ISO 11898-2:2003 – High-speed CAN transceiver
  • ISO 11898-1:2015 - CAN FD transceiver

I know that CAN FD is backward compatible with CAN 2.0, but the phisycal layer of CAN Low-Speed is not, so I need a separeted transceiver to it. My doubt is about Single Wire CAN(SW CAN), Can I use one of the lines of standard ISO 11898-2 (CANH for example) to communicate on a Single Wire CAN bus ?

In the following figure I summarized the idea and the doubt.

CAN illustration

So, I would like to know, can I use a regular transceiver (Differential CAN lines), but using just one line, to communicate in a Single Wire bus or is mandatory to have a Single Wire CAN transceiver ?

There is similar question, without answer, that were made in the following post:

Interoperability between regular and single-wire CAN bus

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    \$\begingroup\$ Do you actually know that you need to support low-speed and single-wire though, or is that just speculation? They are pretty exotic and not commonly used. \$\endgroup\$
    – Lundin
    Commented Jun 9, 2020 at 8:22
  • \$\begingroup\$ @Lundin I'm not sure how often it can be useful. But, we have reports of cars that use it. So, I decided to maintain it. \$\endgroup\$
    – Daniel
    Commented Jun 9, 2020 at 12:52
  • \$\begingroup\$ If you want to support weird old stuff, I would guess that something like J1850 is far more common than low-speed or single-wire, at least for OBD. Haven't used it myself, so I don't know much about it. \$\endgroup\$
    – Lundin
    Commented Jun 9, 2020 at 13:12
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    \$\begingroup\$ Maybe it would be OK to poke the car mechanics site about which buses that are commonly used on the market (check at their meta if such questions are on-topic). At any rate you'll probably have to decide a year from which you will start to support existing buses. Supporting everything from 1990 and beyond will be a huge task. \$\endgroup\$
    – Lundin
    Commented Jun 9, 2020 at 13:26
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    \$\begingroup\$ mechanics.stackexchange.com but I don't know what's on-topic there. Just like any SE site, I don't imagine that they like too broad questions. \$\endgroup\$
    – Lundin
    Commented Jun 9, 2020 at 14:11

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