StepperOnline A6 Servo

I just got native homing working with an A6 servo the other day.  I have a system with mixed servo drives (two StepperOnline T7 (aka LeadShine EL7) and one StepperOnline A6).  I had to make some custom mods to both the cia402 and custom homecomp components.

Nothing is really documented aside for some sparse comments, so apologies for that.   I can vouch that these modules do work together for homing on an A6 when configured right.  The components are here:

github.com/tangentaudio/linuxcnc-bridgep...tree/main/components

For reference, this homecomp is based originally on the one from marcoreps, not Rod's.

The LinuxCNC config that has the A6 configured on the Z axis is here.  You might want to check out the .ini, .hal and the .xml for hints.

github.com/tangentaudio/linuxcnc-bridgep...eport-ethercat-pyvcp


 

Thanks for sharing your success. I am about to start again for the third time. I keep trying  to add extra stuff in. The first time, my work was obsoleted as the homecomp template was massively changed. Before I started, I did work out that the cia402.comp would never work and at that time changes to homing.c were required.
The homecomp is a very simple but we keep trying to use cia402.comp that as written before custom homing was introduced and was based on drive that homed to index.

I did try building cia402.comp into the homecomp but that was the one that was obsoleted. I don't think it would work because the homing loop sits outside the lcec loop so it will be one step behind.

I think the  best architecture would be to rewrite cia402.comp so it did everything with the drive except homing (inside the lcec loop) and then everything to do with homing was done in the homecomp. 

I think we have all gone off track with how this should work.
Please refer to the template source code
github.com/LinuxCNC/linuxcnc/blob/master...s/homecomp.comp#L257 Note that there is a condition here that decides if this joint should be custom homed or homed normally.
So this pin should be set to 1 if this joint is to be custom homed with setp

But if you look at tangentaudio's code, he (and every body else, me included) uses this pin to trigger homing in cia402 which is wrong!
So we should be creating a new pin start-homing to trigger the cic402.n.home pin.

Can you guys review this and see if you agree?

I did enough work in my new basemod.comp homecomp to prove that this works so I was correct. It makes the barest mods to the homecomp template. Its unfinished but feel free to look at this.
I am half thinking that the homecomp should let cia402 start the homing and then monitor the status word for target reached (bit 4)

github.com/rodw-au/cia402_homecomp

Can you guys review this and see if you agree?

Yes, that is correct. The idea is that we can set the homing type (ie one of the built in procedures or custom procedure) for each joint.

As described in the manpage:
linuxcnc.org/docs/devel/html/man/man9/homecomp.9.html

I'm not surprised I misinterpreted the intent of that pin.  The current state of in-drive homing code and documentation makes it a bit of an "adventure!"