The pins already exist:

joint.N.vel-cmd - velocity command per joint
joint.N.acc-cmd - acceleration command per joint
joint.N.jerk-cmd - jerk command (useful for S-curve)

These are updated every servo cycle after cubic interpolation, so they represent instantaneous commanded values suitable for feedforward.
For your cia402 component rewrite:

0x60B1 (velocity feedforward) can use joint.N.vel-cmd directly
0x60B2 (torque feedforward) needs joint.N.acc-cmd × inertia, you can do this with a mult2 in HAL or inside your component

No TP changes needed. Just wire the existing pins to your component and map them to the PDOs.

At the moment only joint 0-1-2 jerk-cmd is calculated proper I think, later on we will do all.

Thank you very much for the explanation and for providing the complete 7I76 firmware image.
That clarifies the architecture and recovery path perfectly.

I will try external programming on my side based on this.
If I run into anything unclear, I may follow up.

Thanks again for your help.

Hello,I work for a company that provides on-site and in-factory service and maintenance for heavy-duty industrial and construction machinery.We are currently developing a large custom machine for laser cleaning and automated painting of heavy equipment and structures. The system will use LinuxCNC as the motion controller, but the machine will be operated by multiple technicians who do not have a G-code programming background.For this reason, we are evaluating the use of a PLC + LinuxCNC architecture, where:

• LinuxCNC handles motion control
• A PLC and HMI handle operator interface, recipes, and simple machine operation (start/stop, part selection, dimensions, safety, etc.)

I would like to hear from others who are using LinuxCNC in an industrial environment with PLC + HMI, especially for machines operated by non-CNC specialists.In particular, I am interested in:

• How you split responsibilities between PLC and LinuxCNC
• How you manage recipes and part parameters
• How you design a simple HMI for operators
• Any recommended PLC platforms or architectures that integrate well with LinuxCNC

Any real-world examples or lessons learned would be greatly appreciated.Thank you.

Another error I found is in the io_decoder-keymap.cfg file. In the example, there are comments with #, and when LCN is run, errors appear. I deleted all the extra lines and only left the lines that assign keys to the inputs.

Well 41.8 degrees C here a couple of days ago. A far cry from the -20 degrees C we experienced in Canada at the end of December!

Boy that was easy. I guess I never tried this before without homing every axis.  Thank you!

Hello I have been trying to get theses stepper drives configured along with a beckhoff EK1100 and have had no luck at all. I have followed the Ethercat step by step instructions and seem to have hit a wall. Any help would be appreciated. Attached is my pdos and ethercat slaves

 

 

grandixximo wrote:

The CiA 402 standard provides feedforward objects exactly for this: 0x60B1 (velocity offset) and 0x60B2 (torque offset). The master can send position plus velocity feedforward so the drive can anticipate acceleration. This is the standard's solution, it just needs to be mapped in lcec.
Also, good drives interpolate internally. The servo loop runs faster than the bus cycle (Maxon runs 0.4ms internal vs 1ms bus). The drive doesn't jump between positions, it interpolates. That's what 0x60C2 configures.
 

Can we explore this on another topic when I get to it? I wanted to rewrite dominic's cia402 component to make it easier to maintain and properly deal with homing so it comes into line with the custom homing that wasn't around when it was written. So it would be perfect for inclusion. Could the new TP have output pins that could be taken as input to calculate these?   Or how would we do it? Any conversion/massaging would be done in the revised component.

COFHAL wrote:

Thanks, I had an error in the rules file, that's why that error appeared.

Thanks COFHAL! You're right, I found the typo in the README and demo files. I missed a curly bracket in the part of the udev rule.I've just pushed the fix to the repository. This is exactly why community feedback is so important! Now everything should set up correctly with a simple copy-paste.

Could you post your CoreDC.hal file? I am trying to setup a gantry router with steppersonline ethercat drives. and have hit a wall with this setup

Dear tommylight, well, I didn't try that until now. I will have that in mind if I get back to my machine at better temperatures. Actually, I have something around 8°C thats not very comfortable for sitting and fiddeling in my garage.
I will come back asap.

Moin Andrax, die Idee ist super. Tatsächlich habe ich beim Servo den zugehörigen Bremswiderstand aber immer angeschlossen gehabt.
Dagegen spricht, dass ich die gleichen Abweichungen beim Tausch auf einen 3,5 Nm CL Stepper auch hatte.
Momentan hab ich noch Winterpause, meine Garage mit der Fräse ist nur 8° kalt, das ist zu ungemütlich um da große Diagnostik zu machen.

Was ich schon vorbereitet habe ist der (vorübergehende) Wechsel von LCNC zu einer Estlcam Controller Karte, bei der man nichts verfusen kann an Motoreinstellungen. ICh will wissen, ob ich weiter an der MEchanik suchen muss oder in der Konfig von LCNC. Aber auch dafür brauche ich etwas mehr Temperatur im Raum. Danke für Deinen Input,ich melde mich wieder!

Hi Andrax, that's a great idea. Actually, I always had the corresponding braking resistor connected to the servo.
The downside is that I had the same deviations when switching to a 3.5 Nm CL stepper.
I'm currently on winter break, and my garage with the milling machine is only 8°C, which is too uncomfortable to do any major diagnostics.

What I have already prepared is the (temporary) switch from LCNC to an Estlcam controller card, where you can't mess up the motor settings. I want to know whether I need to continue looking at the mechanics or at the LCNC configuration. But for that, I also need a slightly warmer room temperature. Thanks for your input, I'll be in touch!