ASD-A2 EtherCAT on LinuxCNC

Hello.
So I'm back.
It lasted without a mistake for a few weeks. I managed to record the behavior on video.
Here is the video
1.red - joint.0.f-error ("X" axis)
2.blue - joint.1.f-error ("Y" axis)
3.green - joint.2.f-error ("Y" axis)
4.purple - joint.3.f-error ("Z" axis)
5.orange - lcec.0.pll-out
6.green - lcec.0.pll-err (it is marked on the video - therefore it is white)

Sometimes he doesn't do it all week.
Sometimes he does it twice a day.
Sometimes he does it all day.
Sometimes it stops making mistakes on its own.
Sometimes I have to restart Linuxcnc to stop making mistakes.

Does anyone know where the problem might be?

Thank you very much Jirka

Hi jirkam
Can you attach your final configuration files like XML, INI, HAL,... ?

Hi
I found out that if I turn on the drivers first and only the PC after about 10 seconds, then it doesn't make the error.
Thank you.
Jirka

Hello Jirka,

i have noticed an "~big" error in your hal file.

you adding lcec.real-all and write-all at the beginning of the hal file.

caused that liunxcnc builds its execution order of task functions in the order they are placed in the hal file, your servo-thread calls ec-read and then immediatly writes out lcec-write. So nothing is done with the Data in the meantime. Lcec.write-all uses "old"data from the last cycle . Which causes timing issues and leads to an bad servo tuning.

the right order would be:

addf lcec.read-all (gets data from hardware)
addf motion, value-converts, pids, classicladder etc.. (works with the data)

last addf lcec.write-all (send new data to hardware).


In your case lcec.write-all is called in front of motion and pids. So it sends "old" data from the last cylce to the drives without the new calculations. You got an 1
cycle offset between input and output data.

(you can search for "execution order" in the forum, i have descripted this in detail somewhere)

Hello "db1981"
Thank you very much for the tip.

When I write it like this:

so will it be ok?

Will the servos behave completely differently, or will the behavior change slightly?

Thank you very much.
Jirkam

that is the correct order.

you are not using pids in linuxcnc. So the behavior will change slightly.