What do i need exactly for ethercat ? Recommended hardware??

I'm considering going ether at on my next build, is there a ethercat for dummys that would be helpful??

Installing the software is now super simple as the ethercat master and the linuxcnc ethercat driver are available on a repository.
We have included this repo already set up on the 2.9.1 ISO. The 2.9.2/2.9.1a ISO which will be released soon, will improve this a bit. (Mainly removing my repo for the hal driver as it is now hosted by the  ethercat guys.
So basically install 2.9.1, do a sudo apt update and follow the Ethercat Sticky I wrote.

The simplest way would be to use  the fully supported Beckhoff modules and a 24 volt power supply
EK1100 and the clipon modules EL200X inputs, EL101X outputs, EL5151 encoder input

 

There are some Chinese IO board from Rtelligent (has PWM etc) and Deiwu (basic I/O only) which we have configs for in my Github. (should be linked to in the sticky)  github.com/rodw-au/linuxcnc-cia402 . Its been hard to find an alternative to encoder interfaces other than Beckhoff. This one should be OK  www.icpdas.com/en/product/ECAT-2092T and there is one Chiniese I/O board with an encoder input if you are brave.

For drives, it does not matter much but I would strongly suggest  using CIA402 compatible drives that have good documentation available. There is a component by Dominc for these drives.  github.com/dbraun1981/hal-cia402 (which I use)

For an entry level solution you could look at  Rtelligent closed loop steppers ECT60 (Nema 23/24) or ECT86 (Nema 34)  I have both and have used the ECT86 on my mill with a 60v AC toroid.

But for a super clean solution, consider using 220V AC CIA402 servos so you don't need an extra power supply. Rtelligent has some but there are others. User ChapEng has a cheaper one he got moving he will use on a 4th axis so it will just needs mains power and a ethernet cable.

Finally because you understand C, you could look at writing a custom CIA402 homing component that would allow internal homing with prox sensors attached to the drives.  linuxcnc.org/docs/stable/html/man/man9/homecomp.9.html That would be a valuable contribution.
 

I'll check drive specifics, I'm looking at 3.8kw, big machine

For drives: The delta ASDA A2 and A3 series drives come in pretty much any size and can be either made to work using the generic driver or the included driver (for A2, A3 requires a tiny modification to the deviceID). If memory serves right, A3 is cia402 compatible (cant check right now).
Big advantage of the Delta drivers over all the other junk: Proper software, proper documentation, proper ability to tune them.

Edit:
Regarding encoders. Beckhoffs 5101s are stupid expensive. I have now successfully tested using the Delta drives extenc input and accordingly connect my encoders to the respective controller (while still closing the loop within linuxcnc)

Wow, super excellent sticky from Ron, in under an hour installed 2.9.2, wired up Beckhoff EK1100 and a couple EL1018 inputs, typed:

ethercat slaves -v

and presto, lots of valid stuff about the modules. Hooray, no TwinCAT or WIndows needed so far...

My last LinuxCNC install was 2016/2017 with Mesa and that mill is still working 100% perfect, but I've likely forgotten lots about hal and ini and need to learn a LOT more about EtherCAT.

I have a Leadshine CS3E-D1008 closed loop EtherCAT stepper on the way from Damen.cnc, so might luck out and find that Ron's example CIA402 will work if not I think I saw another user have success with D1008 in LinuxCNC.

In the meantime, I dug through /usr/share/examples/sample-configs and haven't seen any EtherCAT references. Maybe the EtherCAT interface code magically creates HAL pins all by itself from the magic XML file? If so that would be great.

So right now I have the Beckhoff "fully supported" modules alive but of course it is in pre-op state as no driver is talking to it.

Is there an example of say a generic Axis hal & ini with a few HAL pins from the Beckhoff input so I could poke in a +24v wire and see a HAL pin change state? In the past once that worked everything just fell into place and it was hal & ini & py gui and off to the races.

But right now I am very very lost with a zillion doc tabs open and no idea how to make the EtherCAT pin appear in Axis...

Anyone know of a trivial hal & ini that just has a few pins to read/write Beckhoff fieldbus pins?

Thanks *very* much.

Well I need to apologize. I did the usual Very Bad Thing which is to keep editing ini and hal until something works. Of course I have pretty much no idea what I am doing, but starting with the Axis simulator, and adding a few loadrt lcec and addf lcec lines and then fixing the assorted errors when starting, after a while it actually started and the green "is it working" light on the Beckhoff EK1100 went from preop blinking to running solid green, and a whole bunch of lovely pins showed up in halshow.

I think it is a real testament to the many developers especially lcec that is actually is possible for an 99.8% ignorant person to get EtherCAT to do anything with no TwinCAT and no Windows.