Re: CAN message with DLC > 8 and PIC18

Hi Heinz

I though it may be so, then i should redirect the question to... how to
operate with "multipacket Transport" (J1939/21) because when this Message
is longer I am unnable to read anything.

I will keep researching. Kind regards

Alberto Álvarez

On Wed, Jun 1, 2016 at 11:36 AM, Heinz-Jürgen Oertel <[email protected]>
wrote:

> Am Mittwoch, 1. Juni 2016, 10:59:49 schrieb Alberto Alvarez:
> > Hello list,
> >
> > I am reading that reception buffers in Microchip PIC18 devices have a max
> > length of 8bytes, so I can not receive any message with longer DLC.
> >
> > I am investigating if using a overflow bit I can reach the second part of
> > the longer message but without progress so far.
> > Does anyone have experience with such devices? Do you know if it's even
> > possible?
> >
> >
> > Kind regards
> >
> >
> > Alberto Álvarez
>
>
> According to the classic CAN standard ISO11898 the maximum number of
> payload data bytes a CAN message has is eight. And that's the way all
> available implementations work. They buffer only 8 bytes. You can send a
> message with a DLC=15 but the transceiver only has a transmit buffer of
> eight bytes. And you can receive the DLC 15 but receive only the max number
> of eight bytes.
>
> You can look for newer CAN controllers implementing CAN FD. CAN FD allows
> a payload up to 64 bytes.
>
> Regards
>   Heinz
>