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Awesome Thank you.
ill try it with a simple limit2. Didnt know this component existed but it seems to do exactly what i need.

The speed is controlled by the trajectory planner. You can also use the limit3 or simple_tp components.

In your case - for the tool changer - you could use PP mode. Then the speed would be controlled by the drive itself, and you would only need to specify the new position. This mode is not available in the widely used cia402 component, but there have been examples of modifications on the forum, or a simple startup setting via SDO 0x6060=1   + a small amount of HAL logic

Hi everyone,
im currently trying to set up an 18 pocket carousel with a cia402 controlled ethercat stepper motor. 
While I got it working in CSV (velocity mode), CSP so Positioning would be much nicer, faster and more accurate. 

My issue with this however, is that I have no way (or at least none that i know) to regulate the speed when setting the target position over the counts-target pin. Am I missing something or is this just not possible?

How is the typical CIA402 driven drive speed regulated?

When you have come this far with EtherCAT you can just keep on going.
No point in switching to Mesa now. Unless you want a Mesa system of course.

That sounds promising... @andrax
To the folllwing error: fault on my side. The servo was set too soft, and when decelerating there was too much play. Set it a bit harder and now it works. 
Mesa card arrives tomorow. Gonna try my best.

I did a clean install with the 2.9.8 / trixie ISO file, and have the same behavior on a 1980x1080 HDMI monitor, but inconsistantly. Sometimes full screen is correct, and then I get a switch to Gmoccapy not fitting the screen, but I am not yet sure under which conditions that happens.
Scaling 1.1 doesn't help, it just uses 90% of the screen with the gmoccapy still not fitting.
Cheers,
Mark

Try using the sendkeys component linuxcnc.org/docs/html/man/man1/sendkeys.1.html

no problem .. you are welcome, I am proud to cooperate/test this feature for linuxcnc comunity... as you noticed, I am not soo focused in the perfect trajectory but mainly at timing stability... sometimes it's like chasing your own tail

its interesting job and I see many advantages ... I am using TP0 for lathe threading/synchronization of motion for now, but we will wait for new stuff I am looking forward ...

yes I saw but Yang Yang publish new crucking repo few days ago but I have not time to study it ...

Luca which will be the next steps now ?

that dark blue spline at the bottom is the servo-thread.time, in the 100k resolution, which are sharply jumping at start of cloud of points as ... I am not pretty sure how the TP1 works to from the start but other files starting well without that spiking... is it possible to precalculated it or add some waiting to start the motion to smooth the beginning timing? 

How much influence latency of using Mate instead of Xfce gui ?
 

After adding downi915.enable_dc=0 i915.enable_fbc=0 i915.enable_psr=0 to grub, and creating another thread for all non-motion related stuff I got servo-thread time down to ~400000 and tmax 1351609 (did not increase after startup). Not realtime delay errors so far.

Also tried again with [HMOT](CARD0).read-request in the end of servo-thread just for fun. It definitely shortens read.time, servo-thread time drops to around 50000, but something breaks and i get following error spikes in every 75ms (pyvcp refresh rate). I would be interested to know why, any speculations welcome.

But most importantly it seems to be working now. Thanks for help rodw and PCW.

one advantage of using switchable kinematics is that all joints can be homed normally on startup.

I'm currently running 2.9.4. BTW- the error always occurs at line 38, G0 Z0.

ihavenofish wrote:

andrax wrote:

Er, no. It’s not that simple; LinuxCNC isn’t plug-and-play. If you don’t have any prior knowledge, you should put the A6 aside for now and start with simple stepper motors. You’ll first need to learn how the system works and what each component does. With EtherCAT, you’re moving beyond the hobbyist level, and even professionals sometimes find it frustrating.

I only broke 4 mice from throwing them in anger... its fiiiinnnee.

In seriousness though, I find its less about beginner vs expert in CNC stuff, and more about if you are well versed in linux usage. Most of my troubles setting up were because the instructions just assume you know everything about linux already and leave a lot of critical details out. I am working with one of my customers to trying an make a true step by step guide.

If you do know "nothing", step and direction with a mesa card is generally pretty safe cause its mostly done by a wizard. You aren't mucking in the terminal or doing much editing in HAL.

(also important to note ethercat in linuxcnc has some quirks too, its not quite "final" in my opinion)

This sounds familiar to me.
I just ended up tearing the whole setup apart in frustration every time and starting over from scratch.

@Spezidrone, this isn’t meant to be a criticism. But it really is an advantage to build a test system with steppers first. That’s the best way to get to know the system and all its configurations.
Etercat sounds simple. Plug the LAN cable into the servo and it’s plug-and-play. If only it were that easy...
If you really want to go through with this, we’d be happy to help, of course.
Welcome to the world of jitter, EMC, XML errors, Hall errors, jumps, and dmesg error logs.
 

for a simple example of how to use switchable kinematics see:
configs/sim/axis/vismach/millturn

which uses this custom kinematics component:
github.com/LinuxCNC/linuxcnc/blob/master...onents/millturn.comp

for your use case it would look even simpler.

Forward mapping:
and the inverse:
Limit and acc/vel values can be switched as well (this is also shown in the millturn sim)

Axis UI => Machine menu => Show LinuxCNC Status => settings


or from linuxcnc.stat attributes
linuxcnc.org/docs/stable/html/config/pyt...ding_linuxcnc_status

settings
    (returns tuple of floats) - current interpreter settings. settings[0] = sequence number, settings[1] = feed rate, settings[2] = speed, settings[3] = G64 P blend tolerance, settings[4] = G64 Q naive CAM tolerance.

 

lcec.0.n.pos-scale
Set it to how much the encoder increases when moving the axis one mm.
setp lcec.0.2.pos-scale 500
for example, or maybe you have one of those with crazy big numbers. Same anyway.
Read encoder value from lcec.0.2.actual-position (before any scaling)