This sounds like the ethercat driver already does most of what you are
discussing. It would be a good place to start if you planned on building
something.


On Sat, Jan 23, 2021, 2:24 PM John Dammeyer <[email protected]> wrote:

> > From: Nicklas SB Karlsson [mailto:[email protected]]
> >
> > Den 2021-01-23 kl. 01:31, skrev John Dammeyer:
> > >> From: andy pugh [mailto:[email protected]]
> > >> On Fri, 22 Jan 2021 at 23:16, John Dammeyer <[email protected]>
> wrote:
> > >>
> > >>> And I take it from your answer that this sort of driver at this
> point in time does not exist.
> > >> Not as far as I know, but it might be a fairly simple thing to create.
> > >> It need to create HAL pins then gather the data from wherever, and put
> > >> it on the HAL pins.
> > >>
> > >> --
> > > That's probably more of a patchy method.
> > >
> > > CANopen has a number of states and needs some sort of master to
> co-ordinate the state changes.
> > > INIT, PRE-OPERATIONAL and OPERATIONAL are the 3 main ones.  There's
> also an ERROR and STOPPING etc.
> >
> > If I remember correct CANopen devices start in pre-operational mode, a
> > SYNC is usually sent periodically and just because of this.
>
> The start with a RESET status message.  Then PRE-OP.  The SYNC is not
> needed or required.  The transition to OPERATIONAL happens when the NMT
> master decides it's ready for that.
>
> >
> >
> > Once devices are configured data in the PDOs need to be mapped in hal
> > and this require some more driver support.
> >
> >
> > It is probably also useful with SDO communication which is usually used
> > to configure devices. Configuration may equally well may be done by
> > external tool if CiA309-3 gateway is implemented, protocol is text but
> > graphical user interface may communicate using it have, have a simple
> > one currently hardcoded entries.
>
> I disagree.
>
> The full CANopen spec is designed to be infinitely configurable making
> much of it very complicated.  Dynamic configuration of devices on power up,
> although possible isn't required for a fixed hardware product that doesn't
> change.  This adds complexity.
>
> Once I finish my mill cabinet upgrade and a few other projects I do intend
> on getting back to my CANopen Lite project which includes an application
> for working with CANopen messages.
>
> Things were going really well until I ran into the issue that the Lazarus
> sockets library did not support SocketCAN the way that the C and Python
> libraries do.  Which means I have to upgrade sockets.pp first.  And that's
> where I stopped and restarted other unfinished projects.
>
> The attached screen shots show however that it did work with the Lawicel
> CANUSB.  This software is written with the "Write Once" "Compile anywhere"
> model and therefore has been tested and runs on WIN-7, WIN-10, Raspberry
> Pi3B, BeagleBone Black and LinuxCNC.
>
> CANopen Lite is designed to work as a simpler version of CANopen that
> doesn't have all the bells and whistles that a full CANopen implementation
> might.  However it has been tested with COTS CANopen devices like displays,
> battery chargers, and CANopen based servo motors.
>
> In addition to the desktop application there will be a number of different
> CANopen device samples that demonstrate how to create say a display module,
> relay module or I/O module etc.  Maybe even a motor or two.
>
> Mapping HAL PINs into Object Dictionary locations is the easiest way to
> deal LinuxCNC.  A readable configuration file in the same way that the HAL
> file is read on start-up is one way to populate the object dictionary with
> the HAL PINs that someone will want made visible on the CAN bus.  It will
> all depend on how access to the PINs is granted at the core program level.
>
> Anyway, it's a work in progress.  Be a few months before I can get back to
> it and I really want access to Raspberry Pi HAT MCP2515 CAN devices and the
> internal CAN devices in a Beaglebone Black.  And for that, there's some low
> level OS library work required.
>
> John Dammeyer
>
>
>
> _______________________________________________
> Emc-users mailing list
> [email protected]
> https://lists.sourceforge.net/lists/listinfo/emc-users
>

_______________________________________________
Emc-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/emc-users

Reply via email to