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Hi, I’m working with LinuxCNC and trying to control motion from Python , similar to MDI.

The goal is to stream G-code commands dynamically (generated in Python), but still preserve trajectory planner behavior such as:
* continuous motion
* G64 blending (no full stops between segments)

The problem I see is that standard MDI execution appears to process commands one-by-one, so the planner does not have enough future segments to perform blending. This results in stop-and-go motion.

What I would like to achieve is something like:

* sending multiple G-code commands ahead of time (buffered)
* without waiting for each command to complete
* so the trajectory planner can see upcoming segments

Questions:

1. Is there any supported way to stream G-code from Python into a buffer (not strictly MDI) so that  G64 still work?
2. Does LinuxCNC provide any interface to feed the interpreter continuously (like a queue or pipe) instead of executing discrete MDI commands?
Any pointers or best practices would be greatly appreciated.
Thanks!

To use Ethercat, you need to become a member of The Ethercat Technology Group (ETG). Membership is free. www.ethercat.org/default.htm
But membership is only open to companies or businesses and you need a tax number or equivalent in your country.

Linuxcnc is nothing, just a loose community of users. We don't even have a bank account.

This has been explored by a number of the development team members over the years. Most recently by Steffen Moller who lives in Germany where the ETG and Beckhoff are domiciled. (I may have prodded him in this direction)
I had the opportunity to raise Linuxcnc with Martin Rosten, Chaiman of the ETG when he visited Australia a few years ago. There is no way forward.

But now etherlab have a repository and also host the linuxcnc-ethercat driver and I put that repository into the Linuxcnc installer, there isn't really any need for linuxcnc to get involved. (Except to manage the code base).

I would recommend you and Grandixximo as manufacturers join the ETG.

I have been working on a turn-mill kinematics component. 
 

I am not able to understand how the G43 and G54 and G92 offsets should be accounted for in the kinematics.
I would like to do polar as well as cylindrical interpolation using these kinematics.
Polar interpolation will be turned on by G12.1 and off by G13.1
Cylindrical interpolation will be turned on by G7.1 and off by G7.2
It also uses the adaptive feed to slow down when the radius (Joint 0 position) is very close to 0 i.e., joint 0 is very close to the centerline of rotation.
Any comments on how to account for the offsets or general comments for this component are welcome and appreciated.
-automata

I think is mostly architectural and organizational reasons, not strictly a license conflict. Both LinuxCNC and the IgH EtherCAT Master are **GPLv2**, so there's no real incompatibility there AFAIK. The separation exists because the EtherCAT master is an independent kernel subsystem, linuxcnc-ethercat is essentially a glue layer between two separate projects. Keeping it out-of-tree also lets it move faster without going through LinuxCNC's core review process. There is one additional wrinkle: the "EtherCAT brand and technology" is owned by Beckhoff, which adds an IP layer on top of the open-source licensing.

rodw wrote:

 

Its just a shame the Ethercat license does not allow linuxcnc to manage it.
 

Can you expand on this? People are allowed to develop one and post it, but it cant be "inside" linuxcnc?
 

so on the 225 i still had the io board, so i just used the manuals pinouit on the control. so thats not gonna help.

I have some tc227 data though, ill dig an see if theres anything useful on the encoder - its mostly mechanical drawings.

I was wrong, I've found it, sorry.

It shows a 404 error on Codeberg, and the videos on YouTube won't open at all.

Promise!!! I am hoping that moment is coming soon like any minute I got up to line 197 hal c by commenting out and now I have the stepgen parts. It is amazing that i can have joints 1 and 3 work and o and 2 not work for stepgens. I have checked ini and trivkins and joints all line up correctly shows xyyz and 4 joints but only 2 work with the exact same text in each section???? I will take Rod's suggestions and see if i can get further ahead. One good constilation is I am learning lots all I have to do it put it together before I have a brain anyerism -LOL
Thanks again

thanks Rodw,
I will try that I have been doing similar things in terminal and when get so bogged down I just comment them out and move on and will come back to them later.
I appreciate your help,
Thanks again,George

I think that behaviour was when I had the auto login set up. On power up the computer logged me in without entering user/pw. When it auto logged me out it did come back with a user/pw screen. But I think that timed out and the auto login kicked in.

I am sure, under the configuration changes I made above, that I left the computer logged in with linuxcnc running. When I checked on it later it was running the XFCE desktop but had closed linuxcnc. I'm fairly sure it did a logout/auto login which closed linuxcnc.

I'm also sure running 2.9.8 it logging me out after a set time, between 30-60 minutes. Without auto login it waits with a user/pw screen.

Beyond my comprehension. If you find any insight please let me know. But for now I have 2.9.4 up and running.

Thank you. Hugh

The way to push ahead is to note the error and comment out the line causing it with a #
Then when it opens, open halshow (eg. axis menu: show hal configuration)
Then review the pins. You might just have a minor typo. then edit the commented out line to use the correct pin name

Sorry that did not work for you. Seems odd that settings would force a logout/login. we have not experienced that behaviour 

Please note if you log out, its expected you will have to log in again.

roland100 wrote:

Hello PCW,

I hope to get some help from you again.
I tried to make a custom bit file consisting of these two files 7i96s_2pwmd and 7i96sd_mpgp1. 7i96s2pwmd for pwmgen (Stepgen 4-) and 7i96sd_mpgp1 for mpg on P1.
I used the enfinity software, but it doesn't work because of a version conflict.
Do you know which efinty version works with the 7i96s firmware from the homepage ? Thanks a lot

Did you ever get this working? From the description, this sounds like the firmware I need.  Would you mind posting the bin file?

i just tried to replicate your warning, but i was able t stop and make adjustments and report without running into any of those error pop up. those are actually linuxcnc statement stating that your entered parameters would cause an over travel event, are you certain the parameters you entered would be tool paths within the constrained machine motion envelope?