Re: [Emc-users] CANopen over Ethernet CiA 309 --> Ethercat seems to work

[Nicklas K. <nic...@gm...>]

> But if 99% of the devices out there are physical CAN bus based and there is
> already a CANopen driver for Linux,  is the interface to CANopen transparent
> for both systems?

CiA309 should be transparent for both systems but are probably of less use for an ordinary CAN bus but to access the hardware bus some extra hardware is required.

It seems I got SDO communication up and running via Ethercat according to CiA 309 but I have not yet tested write access only read.

> What I mean, and I may not be clear on this, is if the LinuxCNC has the
> capability of being a CANopen Master then how do you see your code handling
> both bus architectures?   Or should it?

It is an Ethercat master but messages sent follow CANopen.

> ...
> From the G-Code (M07) perspective the Pump On results in the periodic PDO
> 0x287 to have Bit 3 in Byte 1 set.   An M09 would turn off both mist and
> flood so Bits 2 and 3 would be cleared.  The PDO message could be periodic
> or periodic and on change of state for faster response.

Periodic I consider good in a real system and it also have the advantage broken cable could be handled.

> So I guess I'm asking how does an M07 become either (or both) an Ethercat
> CANopen  message and/or a physical CAN bus CANopen message?

In the Ethercat master I added hal pins, some are bits connected to a bit in sent messages. This configuration should ideally be possible to do in configuration file and templates for standard communication profiles would certainly be useful if available.

I found the simple_test program in soem lack a gnu GPL copyright notice and are waiting for confirmation E-mail from github before I could upload.


Regards Nicklas Karlsson