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@rodw
Thanks for the clarification. I think we may be talking about slightly different problem spaces, so I’d like to address your point more directly.

I fully agree that LinuxCNC + HAL + custom C components is extremely powerful, and technically capable of replacing much of what a PLC would do. That is not in dispute.

In our case, however, the decision to use a real PLC is not driven by capability, but by industrial lifecycle and responsibility separation. The PLC is used as a dedicated machine/cell controller that:

• maintains machine state and sequencing independently of the PC
• handles safety interlocks and operator workflow
• is maintainable by technicians familiar with IEC 61131 environments
• remains in a known, deterministic state even if the LinuxCNC PC is rebooted or serviced

While writing HAL components in C is a perfectly valid solution, it assumes long-term availability of developers comfortable with Linux internals, HAL, and custom code. In many industrial environments, that is not a realistic maintenance model.

LinuxCNC remains responsible for what it does best: motion planning, interpolation, and trajectory execution. The PLC acts as the machine controller. This separation is very common in industrial CNC machines and robotic cells.

So the question is not whether LinuxCNC can do everything, but how others have implemented clean responsibility boundaries between a real PLC and LinuxCNC in production machines.

If you’re aware of real-world deployments following this model, those examples would be particularly valuable to the discussion.

I’d like to clarify a few points for readers, as I think some replies are unintentionally mixing different problem domains.

First, regarding PLCs and “ladder-only” assumptions:
Modern industrial PLCs are not limited to ladder logic. Under IEC 61131-3, ladder is only one option. In real industrial machines, Structured Text (ST) is very commonly used for state machines, sequencing, recipe handling, diagnostics, and supervisory motion logic.
In addition, several PLC platforms support compiled C/C++ modules or libraries (for example Beckhoff, B&R, Codesys-based systems, etc.). So PLCs are not inherently low-level or limited to ladder logic.

Second, regarding Beremiz:
Beremiz is an interesting IEC 61131 runtime, but it still runs on the same PC and operating system. In our use case, that does not meet the requirement. One of our core goals is that the machine controller remains independent of the LinuxCNC PC, maintaining machine state and safety even if the PC or LinuxCNC software needs to be restarted or serviced. A soft-PLC running on the same machine does not provide that separation.

Third, regarding remote operation via Wi-Fi or mobile devices:
While this may be acceptable in experimental or supervised environments, it is generally not acceptable in industrial machinery. In an industrial context, machine start/stop authority, mode selection, and operator interaction must be mediated by a certified PLC and physical HMI, with clear local/remote modes, access control, and hardwired safety circuits.
Allowing machines to be started or stopped directly from phones or ad-hoc web interfaces raises significant safety, liability, and maintenance concerns in real production environments.

To clarify our intent: this discussion is not about whether LinuxCNC can do everything. LinuxCNC is excellent at motion planning, interpolation, and trajectory execution, which is exactly why we want it handling motion. The PLC is used as the machine controller, responsible for sequencing, safety, operator workflow, and maintaining a known, safe state independently of the PC.

This is a very common architecture in industrial CNC machines and robotic cells, where a PLC handles cell logic and operator interaction, and a dedicated motion controller executes paths.

We are specifically interested in practical examples of this kind of PLC-driven cell logic combined with LinuxCNC (or otherwise)) as a motion controller, rather than PC-centric or soft-PLC-only architectures.

looks great. I'll have a play.
Does my homecomp you link to work for you without any changes?
github.com/rodw-au/cia402_homecomp
I never had hardware in the end to test it properly.

Hi, I'm very new to CNC, and I have a Maxnc15CL from around the year 2000 and am using a Raspberry Pi 5 to communicate with it using LinuxCNC. The Pi 5 has a parallel port hat from Byte 2 Bot, and I'm able to control the spindle, detect the limit switches, enable the motor encoder feedback loop, and make the motors make noise when I tell the axis to move. I suspect that the motor timing is off, but im not too sure if when I change the values, if it's getting closer or further away from actually moving. If anyone has any ideas on how to make this work, I would greatly appreciate it, and im leaving my hal file and .ini file below. Thank you 

I would like to share my repositories at github, this repository consist of Programs created to automate the creation of EtherCAT configuration files, solutions for all the problems described at this topic as well configs for XYZ, and XYYZ.
topic:
github.com/szolkaa/Automatic-linuxcnc-co...rators-for-ethercat/

Hi all,
I am completely new to this as you can probably tell. I recently bought an old Gerber Dimension 200 for cheap. It’s a beefy chassis that will allow for a great machine by doing some upgrades. I’m doing a complete overhaul of electronics, spindle, steppers, limit switches etc. All of which will be run off a 7i96 board with the SpinX1. I am a bit confused on how to choose a spindle. I’d like it to integrate with the Mesa board well obviously. The wiring just doesn’t make sense to me on what goes where. If anyone has a solid recommendation for a spindle kit or the like please let me know. Will only be doing wood and aluminum, with the occasional steel sheet. Thank you guys for your time and knowledge.

Hallo liebes Forum!

Das ist mein erster Post hier. Bin ganz schön am Anfang meiner LinuxCNC-Reise. Habe zwar schon einige Male an Fräsen gearbeitet, die mit LinuxCNC liefen, aber noch nie ein System selbst aufgesetzt. 

Ich bin auf der Suche nach Tipps zu folgendem Thema: 
Ich baue gerade eine Mitutoyo QV404 um zur CNC-Portalfräse. 
An der Maschine sind noch die Original Glasmaßstäbe und Lichtschranken (als End- und Referenzschalter) dran: 

So kam die Maschine bei mir an: (Vorbesitzer hat schon angefangen Umbauten vorzunehmen)
 

Beim Auseinendernehmen der Z-Achse, musste ich die Auslese-Einheit der Glasmaßstäbe abnehmen, dabei habe ich ein paar Bilder davon gemacht:
 

 

 

 

Da sieht man an der Seite auch schon gut die Platine mit den Referenz- und Endschranken. 
Das ganze läuft dann hinten an der Maschine auf dieses Board: 

 

 


Denkt ihr, es ist realistisch, diese Teile zu verwenden? 
Ich bin leider im Bereich Elektro/Programmieren nicht so die hellste Leuchte und halte mich dann eher mit ChatGPT über Wasser  , kann mich aber tendenziell ganz gut in neue Felder einarbeiten. 
Falls ja, gibt es vllt gut dokumentierte Beispiele von anderen Forumsmitgliedern, die euch einfallen, wo ich mir ein bisschen was abgucken kann? 
Wie würdet ihr da ran gehen? 

Ich bin eigentlich kurz davor, die Lichtschranken einfach durch induktive Endschalter zu erstetzen und, da die Glasmaßstäbe unverkleidet und somit störanfällig für den Fräsbetrieb sind, auch hier kurz davor diese rauszuwerfen. Aber gleichzeitig auch noch auf der Suche nach guten Gründen sie drin lassen zu können, da Original-Mitutoyo und schön. 

Würde mich über Einschätzungen freuen  
Grüße
David 


 

How is the Schaublin progressing?

Hi all,
I’d like to share a set of programs for automatically generating LinuxCNC configuration files for EtherCAT setups.
Also presentation:
From LinuxCNC 2.9.8 Debian13 Installation via EtherCat Master to the First Motor Movement.

Github repository contains:
1.Linux installation and setup
2. XML generator
3. HAL generator
4. INI generator
5. DOS-style to UNIX line ending converter
6. Example configuration for XYZ
7. Example configuration for XYYZ

github.com/szolkaa/Automatic-linuxcnc-co...rators-for-ethercat/

Hat sich erledigt.
Hatte die Frage auch im Englischen Forum gestellt und letztendlich eine Lösung gefunden.
XHC-WHB04B-06 rotary knob button feed rate not work

Ich bin gerade den Thread nochmal durchgegangen:

Zitat:
Folgendes Problem nervt mich gerade: Ich verfahre per Handrad die X Achse, tw mit vollem G0=7,5m/min, das läuft gut, aber beim Bremsen aus Feeds ab 4m/min kommt fast immer der Fehler motor-0-position error. Auf allen Achsen kommt dieser Fehler.
Ich habe 400W Servos von OMC Stepperonline, die autark ihre Rampen steuern, LCNC bekommt davon nichts mit, die sehen für LCNC ja aus wie Stepper. Keine Glasmaßsstäbe/Encoder zusätzlich.

Ich habe da so einen Verdacht.
Werfe mal Halscope an und beobachte die actual-position, target-position und den Schleppfehler.
Zusatzfrage: Hast du irgendwelche Einstellungen an den Stepperonline vorgenommen? 
 

I have found a solution that works for me.
After wasting a week with Mux trying to build something with 6 input pins + enable, I have now decided on a different approach. Since the rotary control does not have a direct output for the feed, I am tapping the signal from whb.axis.a.jog-scale. Now I just had to convert the value with div2 for jog, feed, and rapid.

Check out Beremiz (beremiz.org).
I equipped it with a HAL interface. Works well with LinuxCNC.
runs under Linux and is open source.

I have upgraded my linuxcnc 2.9.8 on rpi4 bookworm to 2.10pre. After installation estop_latch is not working. It was working as it is on 2.9.8. I can see estop_latch.ok-in = true, estop_latch.reset = true,  estop_latch.fault-in = false etc all good but estop_latch.ok-out never comes true.

My config for estop_latch

    loadrt estop_latch names=estop_latch
    addf estop_latch servo-thread
        
# estop loopback, SPI comms enable and feedback
    net user-enable-out     <= iocontrol.0.user-enable-out        => remora.SPI-enable 
    net remora-status      remora.SPI-status     => estop_latch.ok-in
    net estop-fault_in remora.input.09 => estop_latch.fault-in
    net user-request-enable <= iocontrol.0.user-request-enable    => remora.SPI-reset estop_latch.reset
    net estop-status estop_latch.ok-out => iocontrol.0.emc-enable-in    

But If I dont use estop_latch machine works.

    net user-enable-out     <= iocontrol.0.user-enable-out        => remora.SPI-enable
    net user-request-enable <= iocontrol.0.user-request-enable    => remora.SPI-reset
    net remora-status     <= remora.SPI-status     => iocontrol.0.emc-enable-in

estop_latch was working in 2.9.8 with same config.

setp     wj200-vfd.00.update-hz               0.1

Means you would  get 1 packet every 10 seconds
(so a 2 in 20 seconds)