Lathe Spindle Encoder: What are the options for EtherCAT?

Hello everyone,
I am looking for available options to read and process a lathe spindle encoder over EtherCAT. For context, the spindle setup consists of an induction motor and a VFD controlled via RS485 or 0-10V.
Here is what I am currently considering:
• Beckhoff encoder modules.
• Mesa cards or other FPGAs. However, I would prefer a pure EtherCAT solution.
• CATIO-A IO board. It is not entirely clear to me whether it can fully support and handle a lathe spindle encoder.
• EtherCAT development boards. Are there any ready-made firmware options available for this specific task?
• Any other options?
I would appreciate any advice, experience, or recommendations you can share!


 

Beckhoff EL5001-0012

Also there is now a  driver for the Beckhoff EL6001/EL6021 serial terminal driver modules to get rid of your PC based serial port connection. This driver publishes a serial tty port to your PC so you can continue to use mb2hal with very little change
ref:  github.com/linuxcnc-ethercat/linuxcnc-ethercat/pull/525

Thanks for the advice.
What are your thoughts on using a LAN9252 + STM32F407 combination for this task?
Specifically, running the open-source SOES (Simple Open EtherCAT Slave)  repository to stream the hardware encoder count over SPI to the LAN9252.
I don't have a tight deadline or an urgent problem to fix; I am mostly interested in learning and getting hands-on experience with the EtherCAT architecture. Is this a viable and stable solution for a lathe spindle encoder under LinuxCNC, or is it not worth the hassle?

 

Hello dberegovoy,

i retrofitted a Maho MH400E and therefore worked with various Beckhoff encoder inputs. Plug and play support is there for pretty much most of their encoder terminals. I tested the EL5021, EL5101, EP5101 and EL5002 terminals. All of them work flawlessly and are available for cheap on ebay, starting at ~50€/piece. If you want to go down the rabbithole of creating yoir own EtherCAT slave, you can certainly do that, but it willl take quite some time and you don't have any support or industrial quality whatsoever.

A list of all supported EtherCAT slaves can be found here:
github.com/linuxcnc-ethercat/linuxcnc-et...mentation/DEVICES.md
Claude also built me drivers for all of my not yet supported terminals:
github.com/PedPEx/linuxcnc-ethercat

Keep us posted with your lathe details

To put it briefly, I was forced to leave my home workshop behind due to the war. But since I love working with machine tools, I later bought myself a couple of used "baby" CNC machines — a Wabeco lathe and a Wabeco mill. I immediately set the stock control systems aside.
The Wabeco lathe has been up and running for over a year now, powered by LinuxCNC + Mesa 7i92 + Chinese 400W servo motors.
As for the Wabeco mill, I’ve rebuilt it, repainted the enclosure, and so on. Right now, I'm very slowly putting it together using the stock stepper motors and a Chinese XC809D controller (which was a gift). To be honest, it hasn't really impressed me so far, so it might just be a temporary solution.
I don’t have an urgent practical need to switch to EtherCAT.
My main driving force is pure curiosity and a desire to figure it out to the point where I can work with it effortlessly. Naturally, the first question that came up was: what is the most elegant way to handle encoders? As a backup plan, I'm considering installing a second network card and running EtherCAT alongside Mesa simultaneously (using Mesa to handle encoders: one for the spindle + manual pulse generators for each axis).
So, here is what has been done so far:
• Installed the IgH EtherCAT Master (EtherLab) + linuxcnc-ethercat + cia402.
• Ordered a Lichuan LC10E servo kit with a 23-bit absolute encoder from AliExpress (currently in transit).
• Bought locally (and quite cheap) an Omron NX-ECC201 coupler (1 pc), ID5342 digital input modules (3 pcs), and OD5121 digital output modules (2 pcs).
The Omron hardware should arrive in a day or two, so I’ll start experimenting with EtherCAT using that, and then the servo kit will arrive. First, I'll take it step by step to learn the ropes, and later I might convert the lathe to EtherCAT. But the ultimate goal here is self-development and the enjoyment of learning something new. The practical benefits are taking a back seat for now, but they might come in handy for future retrofits. Once everything settles down, I really want to bring a small CNC lathe with live tooling over from Europe.

Both machines were put up for sale because the workshop they were in was damaged in a strike. I bought them and I've been slowly rebuilding them since. Here are a few photos from my archive.
As for the specs: Both the lathe and the mill have ballscrews on all axes. The spindles are equipped with monoblock induction motors paired with VFDs (the HS - High Speed version).
On the lathe, I initially wired the spindle via a 0-10V analog signal because I couldn't figure out the RS485 character-based text protocol at the time. However, I finally cracked it this year. Thanks to AI, I managed to write a driver. I used the mill's motor for testing. I’ll be integrating this solution into the lathe a bit later.
So, I’d be glad to hear any advice and look forward to the discussion!
 

Hi everyone, 

I just received my Omron NX-ECC201 today. The first thing I did was verify that it works, and I couldn't resist playing around with it a bit—I successfully toggled the LEDs on the output module directly from a Linux terminal via EtherCAT. 

Now I am planning the next steps for my machine setup. I need to process an encoder signal, and after doing some research, it seems that the NX-EC0222 or NX-EC0122 modules would be the best fit since they support differential signals. 

However, my current machine encoder operates on a 5V TTL signal. This leaves me with two main options: 

1. Convert the 5V TTL signal up to 24V single-ended.
2. Convert the 5V TTL signal into a differential signal to feed it directly into the NX-EC0222.

I am leaning towards the second option (differential) because I feel it is much more noise-immune and future-proof for upcoming retrofit projects. 

I would really appreciate your advice on choosing the best Omron module for this setup to help me narrow down my search. 

Thanks in advance!
 

Quick update: I made a mistake with the part numbers in my previous post. 

The NX-EC0222 and NX-EC0122 modules do not support differential signals. The correct Omron modules for a differential line driver setup are actually the NX-EC0132 or NX-EC0142. 

Also, I'm interested in pairing one of these encoder modules with an NX-DA3605 analog output module to control a heavy-duty CNC lathe spindle via ±10V (both for speed and C-axis positioning), as I have an eye on one such analog module. Has anyone here tried this specific combination? Any success or failure stories with this setup?