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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

no retro fits on these i was just saying the memory for program storage is what ever the base model came with at the time. sadly the people i work for don't spend the extra money to upgrade that part of the machine when they buy them.

they guys were old school who have retired or moved on and they hand coded everything in the past so bloated cam programs were never an issue before because of this. the one mori is nothing fancy at all but when i first came out of trade school back in 1991 they had that machine at it's still there so it's 35 years old plus

Yes, the ODrive (Pro) has extensive options for configuration; PID tuning; torque, velocity, position, and trajectory control modes, etc.

Some initial PID tuning was already done, and the intention is to run it in position control mode, driven by step/dir from Mesa + LinuxCNC.

In my original post in this thread, I linked a forum thread in which an ODrive development engineer didn't see an issue connecting an incremental encoder to both ODrive and Mesa + LinuxCNC. In response to concerns about signal levels or ground loops, his response was that "The [ODrive] Pro has common-mode filtered encoder inputs, so it should be able to withstand some AC-mode ground differential. But you can actually make it fully isolated – if you desolder [a couple of components], it’ll isolate the the A/B/Z and Hall encoder inputs". 

So there are a few possible approaches and I'm trying to understand what makes the most sense:

* Encoder feedback to ODrive with LinuxCNC + Mesa in open loop (simplest but accuracy concerns?)
* Encoder feedback directly to both ODrive and LinuxCNC + Mesa (potential signal/ground loop issues, maybe worth a shot anyway)
* Two separate encoders for independent feedback to ODrive and Mesa + LinuxCNC (added cost in funds and space on machine)

 

7i76EU in Portugal
eusurplus.com/index.php?route=product/pr..._62_71&product_id=50
OR
7i96S with 7i84
eusurplus.com/index.php?route=product/pr...t_id=104&search=7i84
eusurplus.com/index.php?route=product/product&product_id=159
Prices are without tax

7i96S in Germany
www.welectron.com/Mesa-Electronics-7i96S...-Ethernet-Controller
Prices are with tax

if all you want is to call a subroutine just drop in a subcall button name it and define the file for it to call and it will. that is the beauty of qtpyvcp is all the hard work is already baked in, just choose your widgets according to your use case.

ok, s im not certain what your implying regarding memory? are you wanting to retrofit the machines?

Note that the 7I76E/7I76ED have been replaced by the 7I76EU

They are also specified here as UINT32. And you say float (Ethercat REAL type).
This doesn't match.
Make the datatype REAL for this variable, read it as a float in the processor and as float-ieee in hal (gous into a float type hal variable)

as you can see, in the twincat ENC1RPM and ENC2RPM is REAL,
I also checked the XML files, they are REAL too,
But output of ethercat xml command, it seems like UINT32, I dont know why,


By the way, I am planning to sell the boards via ebay, and the Turkish local market via n11.com
there is 3. board, it can control 4x RC servo motor, actually it has 4x  isolated PWM output,

Dear All,

For my project I'm looking for a Mesa 7I76E card.
Anyone has such card in perfect working condition for sale?

Thanks in advance,

Frans

I depends on the ODrive performance and tuning, It there a tuning program for the drive?