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tuxcnc wrote:

.... or it is called at the wrong moment (LinuxCNC starts and maybe something jams, but only then and only once).

Usually the call to OpenGL subsystem used by Gremlin will do this, more often with NVIDIA graphic cards and some integrated Intel ones.
Despite bumping into this occasionally, i could never invest more time in finding the exact issue is/was.
Gremlin is the tool path preview used on some LinuxCNC GUI's

Once again.
Many times I had the problem with the "Unexpected realtime delay on task" message, which meant nothing and only annoyed the user because neither latency-test nor latency-plot showed anything wrong.
This has nothing to do with compiling LinuxCNC yourself, except that compiling it yourself allows you to disable this message.
As for the message itself, I suspect that either the procedure displaying it is bad, or it is called at the wrong moment (LinuxCNC starts and maybe something jams, but only then and only once).

Like pic attached..

Thank you, guys, for your help! I appreciate that. 

I tried Rod's advice and got an xml part with the needed registers. This seems like a bit of progress. I took the needed parts from the auto-config.xml file and copied them to my own ethercat-conf.xml (slave ID 3). However, I tried adapting my hal file for the A axis (for which the driver is for) similar to the servo drives I already integrated, but was not able to get any reaction of the stepper motor that was connected on the stepper driver. It's a closed loop motor, but to exclude possible errors, I switched the driver to open loop mode for now. I tried reading some registers back with the ethercat read_register command and the values seem to be valid so far. The driver is in OP mode. But I assume, I've done something wrong in my hal file. If I try to move the A axis, the motor doesn't turn in any way. After some (theoretical) distance after pressing the A+/A- button in LinuxCNC, I get a joint following error. I'm not sure, if the PC really is talking to the stepper driver. If I try to move the axis, I would assume the target position register is updated somehow. But if I read the register value using the ethercat read_register command, I always get the same number.
Could you please do me a favor and have a look at my files I attached? Is there a possibility to guess the problem? I'm quite confident, that I may get everything I need for my machine to work. The A axis is the only missing piece. I don't want to integrate another controller like the PoKeys57CNC I have laying around. Ethercat is a really nice solution.
Thank you very much.

Christian

rodw wrote:

The biggest issue is not using the dkms drivers with realtek NIC's. Try to always use Intel NIC's.

Those will cause the "error finishing read", not latency error, so for now do not bother with it, see here:
forum.linuxcnc.org/38-general-linuxcnc-q...ead-and-irq-affinity

Its nothing to do with building LinuxCNC. As time goes on, the hardware manufactuters add more power saving features which induce latency so it takes more work to get it under control. Trixie is no worse than Bookworm. The biggest issue is not using the dkms drivers with realtek NIC's. Try to always use Intel NIC's. I've covered this and other steps in a few videos over the last 12 months or so on my YouTube channel.

See www.linuxcnc.org/2026/08/25/LinuxCNC-Meetup-in-Stuttgart/

I assume you have installed the RT kernel...
As for the error message that appears immediately after starting LinuxCNC, I have been blocking it for a long time (I always compile LinuxCNC myself).
I suspect that the cause of this error is the procedure for checking it.
I reported it once, but no one was interested.
Anyway, the message was almost always displayed, but latency-test or latency-plot didn't show anything alarming...

Hi
After many happy years on Bookworm LinuxCNC I have upgraded to Trixie. I ended up installing Debian OS and then installing LCNC ( I could not get the download from LCNC website to work).  Anyway, I have the machine running again, but as soon as I start the program, I get the dreaded latency error message.  I have turned off everything that is not needed in the bios, but still get the message. I understand there are ways to manipulate how the cores work in the computer.  Can someone point me to some step-by-step instructions?
Thanks

 

The CATIO-A Ethercat I/O module is a well priced I/O module available on AliExpress. A config and documents for it is on the forum elsewhere. One of the interesting features is that it includes MODBUS RTU built in so you can use it to control your spindle. I am using it with a EV210 VFD that came with a single phase 2.2 kW spindle. Its a bit tricky though because:

1. The serial port is slow by its very nature. The servo-thread so the lcec.write-all command tends to flood the serial port causing overruns.
2. The fastest I could reliably communicate to my cheap Chinese EV210 is 38400 baud
3. The SDO's are kind of read only so once you write to them, you can't write to them again without power cycling.

To deal with the SDO issue and the resulting flood of errors if done in the xml file, I decided to set them in a separate bash script that only needs running once per power cycle before you run LinuxCNC. This could be improved.

I've had a couple of goes at cracking this over the last 12 months or so and I finally got it working today!
A complete working config is attached. The HAL stuff is actually very similar to using the  Mb2Hal driver. Some hal features may be specific to my VFD as I found it that the scaling of the feedback changed once it reached 100 Hz. The other difference  is that Mb2Hal has some float pins but here I needed to convert some values to and from floats and unsigned integers to get a properly scaled Spindle at speed.

People worry about using modbus to control their spindle because its not real time. Well that does not matter because if you look at the LinuxCNC architecture, spindle control is not real time anyway.

What about rigid tapping they say? Well it also does not matter either because LinuxCNC synchronises Z axis motion with the spindle motion so the Z follows the lead from the Spindle!

There is also a lot of feedback data provided by modbus on speeds, torque current and the like which help you gain better control of your machining and it does not consume any pins. (A fully configured 0-10 volt spindle consumes 4 pins, forward relay, reverse relay, PWM pin for 0-10 volt control and a spindle at speed signal back from the VFD if its correctly configured. So all f those pins can be released if using modbus control.

Finally, Modbus gives you much greater immunity to electrical noise due to twisted pair and error checking in the protocol. Not only that, the speed is much more accurate and it will respond to torque spikes.

 

I believe there is a 5 axis configuration...

There are several.
So what exactly do you mean by 'xyzab'? That can mean a few different kinematics.

For posterity's sake, I ended up buying an SI-5 isolator board for my KBIC-240ds. I bought two PWM-to-analog converters, and both featured no optical isolation between all grounds. If you want true isolation (which you need for the KBIC-240ds), it seems that you need to buy this separate component or some sort of dedicated device that gives you galvanic isolation. My spindle seems to be working quite well currently.

Hi,

I have a 5 axis homemade machine xyzab...I get gcode from CNCToolkit in Gmax....works pretty well other than tool offset...My linuxcnc is set up in Trivkins...My questions..  I believe there is a 5 axis configuration...

Is it very involved to switch?

Can tool diameter offsets be used?

Would it be better to try and modify CNCToolkit post to use tool offset? 

I am going off a surface...x y offsets I can draw...the biggest issue is allowing for tool diameter in adjusting z axis for b movents.

Thanks for any help!!

Rick

 

Ok, that icon means 'no layout' - makes sense for an indeterminate user layout.

But, sadly, no longer suspicious

Back to stumped.

Had another go at it after updating again.  Here's what I've found:

• qrc file issues are gone.  No error message that the qrc can't be found - that's a win.
• Created six hal LEDs - 3 in main window user tab, 3 in sidebar user tab
  • All six LED hal pins are present in halshow - still good
  • main window user tab LEDs are displayed
  • sidebar user tab does not display LEDs or anything else (Qlabels)

Poking around in the editor, it looks like the sidebar user tab selector button is linked to "page 3" of the stack widget, which should correspond with the 4th page (page-0 being 1st).

When selected, the user sidebar tab is empty, so I think that confirms the right stack page is being selected, but the user ui file isn't being loaded.

No error messages in terminal during startup, and I didn't change any file names or paths from the templates.

The only thing suspicious I can see is what looks like an 'inactive' icon next to the sb_page_4 object in the object window.  Or I'm misinterpreting the icon - not sure.