Advanced Search

Follow the last line here github.com/linuxcnc-ethercat/linuxcnc-et...uration-reference.md
Example of sdoconfig

What's tricky is the byte order of the data. LSB first, so "1" becomes "01 00" and so on.

Does anyone have examples of initCmds or sdoconfig? i want to try sending my drives SDOs to set some parameters but am struggling to figure out how exactly to create a proper XML to call using initCmds, or alternatively how to format/add some lines with sdoConfig in my main XML. the whole index/ sub index thing also confuses me (like how does one know what syncmanager idx it should be Ect...) . If anyone has a dummys guide to how all the ethercat address stuff works LMK. It seems linuxcnc uses its own special formatting compared to "normal" ethercat XML? anyway, I want to try setting my servos to absolute mode (i have batteries on the encoders) through the SDO. 

I would look at the datatypes in the MCU and make sure they are right there.
Linuxcnc reads out this info from the board/mcu.
Can't see from the video but looks like LAN9252 plus mcu.
Then this info comes from the mcu, not the eeprom or esi file.

 

> Just wondering if the existing tang primer 20K plugin will work for the tang primer 20k Lite board?

works !

Thanks! I really appreciate all the advice. Will give it a try tomorrow and report back.

Start with generic values, should be 5000/5000, direction is not important so leave it at 20000.
You can safely try Gecko settings, mark the motor pulley/shaft with a marker and set it to go back and forth several turns and several times, see if it returns exactly where you marked it, if it misses even by a very small bit, do not use those settings on a production machine.

Just wondering if the existing tang primer 20K plugin will work for the tang primer 20k Lite board? It is a simpler board than the dev board and has 117 available IO. It's not a great deal more expensive than the nano9k.

I have minimal documentation on the AXYZ stepper drives (AXI 2200 microstepper). I have a wiring diagram and some calibration data for the machine size, steps/mm, velocity and acceleration. However, I don’t have specs on the drive step timing (ie step time, step space, dir hold, dir setup) in nanoseconds.  

Is it safe to just try a few of the pre-configured Geko drives and see what happens? Overall, how big of
an issue is this and what are my options to figure it out?

 

 

Yes, G1 moves are controlled by the feed rate but G0 moves are at full machine speed
Also multi-axis G1 are coordinated but G0 moves are not.


You  could use some logic (say not + or components) or the lut5 component
in conjunction with your external spindle-at-speed signal to force  spindle-at-speed
true either when the spindle is on and the external spindle-at-speed is true or
the spindle is off.

A lut5 example might look like this:

setp lut5.0.function 0x0d
net spindle-on lut5.0.in-0
net ext_spindle-at-speed lut5.0.in-1
net spindle-at-speed lut5.0.out

A lut5 function value of 0x0d means it's output will be true either when in-0
(spindle-on) is false or if both in-0 (spindle-on) is true and in-1 (ext-spindle-at-speed)
are true.


man lut5

 

If I understand what I've just read correctly, G0 moves are full speed, whereas G1 are controlled?

This would explain why the tool change/probing code I used as the basis for mine uses G1 calls.

However if it is only the first feed move after the spindle start that matters then I may be able to work around it by making the first move a rapid one?

I'll have a look at whether there's a way to have a "true" value when it is stopped anyway.

thanks for the quick response.   NO i have been looking a bit for latency improvment,  but i did not get anywhere,   I am trying to get a actual AC servo to practice  with, and i am still looking at breakout boards,    AND wondering if it will just be easier to go with Mesa boards???

   i hate to say it but i am going to have to start from scratch with your suggestions,    But i am trying to search them now.   

Thanks 

The latency will limit your maximum speed but not interfere with basic LinuxCNC operation.

Have you gone through the various latency improvement options:

Disable all speed switching/turbo modes in the BIOS

Disable any power management in the BIOS (C states > C1 etc)

Disable hyperthreading

Set isocpus-L in kernel command line (with grub)
(where L is the last processor so 3 for example with a 4 core machine)
 

Good afternoon.    Well after a few mis-starts,   I am pretty sure I have a good Linuxcnc 2.9.4 install with Debian 12,; on a old Lenovo Thinkcenter  with a core3 processor, and a single onboard parallel port and a 1Tb Solid state HD      I have run a latency test, and the results are not super great, and quite a bit worse today than yesterday.  (yesterday the servo thread was  69200, and the base thread was 32900).   Here is a photo from today; after i opened up some calculators and the video player with no video to play..    Is this going to be a non starter because of the latency?    This computer was a freebee,    i was going to try a old windows XP machine, and i found out last night that would not work regardless,   So this is what i have for now.    If this is going to be a non starter for latency  i would like to know sooner than later  I am just barely capable of basic Linux navigation with a bit of help from google.    I had older Linux version 3 years back that seemed a bit different, I am trying to learn the newer version.       I am not sure i am even testing correctly.   I am have the LinuxCnc on a boot thumbdrive.    and once the computer is booted,  i am starting the Latency test from the Applications menu topmost left screen.    Then the CNC tab, and then Latency test.    As far as i can tell this HAS NOT started the actual LinuxCnc program which i thought was the correct way to go?     If i just run the latency test and do not exercise the machine i get  servo at 9139, and Base thread at 19360     The computer as i said is a freebee.   My IT friend gave it too me and we changed the OS to Linux,   and we then got the LinuxCNC image burned to the thumb drive.          I am not savy enough to know ,   But If we just wiped out the old OS which i think we did,   can or is there still some junk maybe running or causing problems from the old windows OS  or the hard drive,   that can mess with the latency????     When I open LinuxCnc it opens to the configuration selector  ( good?),   But i don't think i am ready for anything else at this time;?   If the Latency can be solved,  then I believe i still need to pick a parallel port breakout board  Correct?     For the breakout board i have been looking at the c10G and C11G break out boards,    I am hoping for a bit of help picking the break out boardI have a few different applications in mind for LinuxCnc, but the first application will be a  3 Axis Lagun mill that used to have a Crusader M control.   the machine went under salt water up to the quill,   the  ball screws seem ok , and the head and quill still work,   but the old Crusader M control and the old DC servos are toast,        I wouild like to put new AC servos back on the mill,  and i have been leaning toward the ClearPath  servo with amp combo, and i wanted to keep to the parallel port for now.    So is the latency going to be a problem?   can it be fixed?   Should i just find another computer?thanks 

That must be related to the source of your spindle-at-speed signal.

Maybe its always false at a zero speed, which will cause issues with
LinuxCNC if you try doing a cutting move (G1 etc) with the spindle off.

Do you need to do cutting moves with  the spindle off?

If so:

If you have a spindle encoder, you can generate a spindle-at-speed signal
by comparing the commanded spindle speed with the actual (from encoder)
spindle speed with the "near" hal component.

If you do not have a spindle encoder you could add some logic to force
spindle-at-speed true when the spindle is off (M5)

Hmmm, second time I'm writing this as the last one seemed to vanish. So sorry if it winds up as a double post

Running whilst monitoring spindle-at-speed
It starts off false
M3 S10000, stays false until reachin the correct speed, then goes true
M5 turns false, and stays false even when the spindle has wound down

It don't know if this is correct, or if M5 is conceptually setting a speed of zero, and therefore spindle-at-speed should be true when the spindle stops