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Context:
I want to use Linuxcnc for a Ultra-Precision machine.
For that i need Linuxcnc to tell my drives (via Ethercat) the waypoints with high resolution.
I can get 0.5 nanometer resolution out of the Ethercat bus with the 32bit Integer format at the travels that i need. Which is sufficient.

Now as for my question:
From what i gather the path planner and everything works in single-precision floats.
Doing the math on that at 10mm and 500mm positions tells me the resolution between bits of the float number is not enough.
10mm/2^24=0.59nm
500mm/2^24 = 29.80nm

I dont want to waste that much precision in my control for no reason (plus having to convert to the scaled integer value).

Is there a way to change that to double precision floats (64bit) without having to rewrite the whole control?
Also feel free to tell me that my math is wrong^^

Leo
 

when it becomes merged there will be some notes, it will be a pretty big update announcement.

Yes, I think its a good idea and something I have suggested a while ago.
Especially for multi-stage logic, simply connecting pin to pin makes more
sense.

I did indeed modify JOINT_N_SCALE to match the drive configuration and the value in the INI file. and it works fine now. The axis moves exactly with the commanded value. Changing the BASE_PERIOD value to 10000 in the firmware also increases the speed without the joint tracking error occurring.
The only drawback is that if one modifies the STEP_SCALE parameter in the drive, the firmware would necessarily have to be recompiled. That is why it seems like a good idea to remove these parameters from the firmware so that they can be modified at any time.

My first guess is that the sserial channels on the 7I74 are not enabled in the hal file
(with a sserial_port_1=00000000 stanza in the hm2_pci driver loadrt line)

Yes, 7I96/7I96S TB3 pin 12 is the input common.
Isolated inputs accept +-5 to +-36V signals relative to input common.

If you connect +24V to input common, the inputs will be activated
when grounded (connected to the 24V negative output) This
is the normal way to setup the input for NPN sensors
(or switches with a common ground)

Thank you so much for your help, your video helped a lot, I was able to flash on Stlink V2, but how do I install and use pyqcd, I didn't find anything that helped me, I could explain to me, or point someone who has already asked this question to see what He did1

Hello,

I am new to the CNC world, and would like to convert my small-ish lathe to CNC.
I think motors with around 2Nm for Z and around 0.6Nm for X will be sufficient, based on some preliminary measurements. For X I am constrained to Nema 17 size to be able to integrate them well.
For I/O and the spindle encoder, I would like to use a Raspberrry Pi and Beckhoff EtherCAT terminals, which I have already gotten to work (thanks for all the great ressources on here!). I would also like to use EtherCAT-connected drives for the axis (and maybe later the spindle), though I am unsure, which path to take there.

Initially, I was looking at closed-loop stepper drivers such as the Rtelligent ECT60 or the Lichuan CL3-E57H , which close the loop on the driver. But then I also found the Beckhoff stepper terminals  EL7041 and  EL7047 , which would make integration quite elegant as I am already using other Beckhoff terminals. With these however, I am not quite sure if they support closing the loop on the driver. The EL7041 manual mentions some closed-loop control aspects (differing between the standard and the -1000 model), but I don't fully understand what it actually can and can't do. The EL7047 supports closed loop in conjunction with FOC, but it is officially only supported with Beckhoff motors and requires them to be unloaded on startup for referencing. I could not find out if non-FOC closed-loop operation similar to the ECT60 or CL3-E57H is possible as well.
What approach would you recommend here?

In general (e.g. if the Beckhoff drivers can only act as open loop drivers with encoder interfaces), is it advisable close the loop in LinuxCNC when using such an EtherCAT based setup without any FPGA for low level control?

Another option would be AC servo drives (probably the  Lichuan ones due to their comparable cost), at least for the Z axis as I haven't found a Nema 17 sized option that would fit X. These would probably provide better performance, but seem more complex to set up and tune.
What do you think about this alternative?

I am looking forward to your comments, and hope the questions are specific enough. Please let me know if any details are missing.

Best Regards
Daniel

I think I found source of LINUXCNC_CONFIG_PATH:

github.com/LinuxCNC/linuxcnc/blob/ceb434...rc/configure.ac#L702
github.com/LinuxCNC/linuxcnc/blob/ceb434...rc/configure.ac#L724

But I don't know if it will help me in any way.

A friend advised me that it might help if I added the following to pncconf.py:Unfortunately os.environ does not contain 'LINUXCNC_CONFIG_PATH'

  Copy only macros.

Hi, does anyone know how to change the speed sliders so that they stop when released on a touch screen. If I just move a small amount it's fine but if I hold too long they will keep going to the bottom or top of the scale before I can then go back slowly to the speed I want?

It worked with the USER_COMMAND_FILE = filename.py in the last line of the [DISPLAY] section.

I will try what happens if I move it to {RS274NGC]

With the USER_COMMAND_FILE = filename.py at the End of the [DISPLAY] section it works, when I put it in the [RS274NGC] section I cannot see a change.
In my ini file the [RS274NGC] comes after [DISPLAY] (no idea if the position is of relevance)

Greetings Timo