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Yes, the 2 cycle ethercat delay will give a following error of 0.17 mm after 1 ms.
But since you are not using the position feedback inside linuxcnc for more than calculating a following error, it really doesn't matter that the delay is there. A since there is no feedback used by linuxcnc you need to look in the drive for that behavior.

Hey folks. Im working on getting an MPG and other IO going on my ethercat setup, using the 6i25. Ive got the MPG switches selecting axis and x1 x10 x100 correctly. (thanks to this site  wapl.es/cnc/2020/02/23/linuxcnc-jog-wheel-setup.html/  ) and my encoder B phase seems to work according to the hal meter. i cant get any action out of the A. I then switched the settings to use the other DB25 and the same behavior is there. only the B encoder input is doing anything. I ohmed my wiring all the way back to the mesa itself and its good. I can get the B inputs to trigger as expected with a direct jumper between ground and pin 12 of each db25 but even a jumper between ground and pin 11 wont kick A on either DB25. I starting to wonder if theres a mismatch between the pinout and the firmware or something. im using prob_rfx2. Any clues would be great. 

Hi everyone! I’ve recently been working on integrating g-code++ (a lightweight g-code interpreter inspired by the rs274ngc NIST g-code specification) into the LinuxCNC ecosystem. Before I submit a pull request, I’d like to get some community feedback so as to ensure that it fits well and is aligned with the project's direction.

Link to my original repo:  github.com/s-mv/gcode-plus-plus
Link to the LinuxCNC fork:  github.com/s-mv/linuxcnc/tree/s-mv/sterp (s-mv/sterp branch)
Demo video: 

What I’ve Done

• Integrated g-code++ into the LinuxCNC environment.
• Verified it works for 3-axis machines on LinuxCNC.
• Documented the integration process and architecture.
• Set up an ANTLR4-based parser for g-code interpretation.

Key features

• Control flow: Support for

  while

  loops,

  for

  loops,

  if

  statements, imports,

  continue

  , and

  break.

• g-code compatibility: Supports standard G-codes like G0, G1, G2, G3, G20, G21, G54, M3, M4, etc.

Feedback would be greatly appreciated, especially from people who have experience using g-code interpreters with LinuxCNC or have experience maintaining/debugging the project. Eager to make this integration as frictionless as possible so that it meets the needs of the community. Thanks in advance, and I’m looking forward to hearing your thoughts!

Best regards,
s-mv (Shreerang Vaidya)

So, is there a way to get the lowest Z the loaded file will go to?

I don't see anything like that in numbered params. AXIS shows it did a full sim of all the g-code upon loading, but AXIS is not G-code. Could AXIS evaluation be storedand made available to g-code somehow?

Its not easy to add a 3rd MPG to a 7I76E/7I76EU isolated I/O
But it would be easy to add 3 or 4 to the parallel expansion port
of a 7I76E,7I76EU,7I96,7I96S,7I95,7I95T etc as long as the MPG
just has 5V signals

Another easy way to add 4 MPG inputs to almost any card and simplify cabling
is to add a 7I73

 

I have never run this sort of mill- it originally had 3 handwheels, one for each axis, i dont know the resolution of them, but i doubt they were 100ppr, im thinking more like 200-500 to do half thou or 2 tenth motion(assuming 1 rotation was .1"), at least thats what would make sense for me.

i have another question: can a 3rd mpg encoder be added to the firmware of a 7i76e?

Also thanks a lot for the help, and this forum. amazing place!

While your issue appears straightforward, I'm having difficulty grasping the logic control conditions. It would be nice if you hand draw the relevant parts of the system that might put things into prospective. And most importantly list the conditions for disabling the axis.
For example: if ((position < 900) && (position > 1600)) disable the axis (this a fictive example just for illustrations)

www.kollmorgen.com/sites/default/files/p...9032002701_A_5.1.pdf
The Page-86 in above DMC2 drive manual gives general resolver specification recomended by drive

www.wittenstein.de/download/operating-manual-tpm-plus-en.pdf
The Page-36 in this manual has resolver specification used by Wittenstein motor

It uses Tamakawa Brushless resolver
www.tamagawa-seiki.com/products/resolver...martsyn-builtin.html

This does not seem like a delay issue because at 10000 mm/m, a 4.5 mm error
represents about a 27 ms delay (54 servo thread invocations with a 2 KHz servo thread)


It looks like there is some kind of filter between the command and feedback,
it's not just delayed but seems to have bounded acceleration.  This  could
also be because the drive tuning.

It seems like it has poor position loop gain (large static error) but why is it oscillating?
Maybe too much velocity loop gain and not enough position loop gain?
 

I don't have any experience with EtherCAT, but I was just on another forum discussing the Marco Reps config and have the link in the clipboard.
forum.linuxcnc.org/ethercat/56545-step-b...shine-to-pi-5#331624
The "middle" attachment might contain useful tips. (though that is for Leadshine)

If you have plenty of RAM, stuff can "live" in RAM, without HDD latency issues.

HDDs are still good.

"Yes, this is valid, but requires 2 or 4 sticks of RAM, same size, otherwise it defaults back to single channel."

Not exactly, the amount of RAM that is dual-channel for a given pair of DIMMs is twice the capacity of the smallest DIMM.

DIMM = Dual-Inline Memory Module (the gold contacts that connect the RAM to the motherboard are on both sides).

On a parallel port system a 5V relay + a liitle flyback diode should be enough.

1N4148 diodes are cheap and work great to protect the breakout board.

A solenoid is just a coil.

A relay is a coil+switch.

Yes, add your end stops etc to the hal file e.g.:

net X-home remora.input.00 => joint.0.home-sw-in
net Y-home remora.input.01 => joint.1.home-sw-in
net Y-home remora.input.02 => joint.2.home-sw-in

This links the remora input hal pins to other hal pins. It's the basis of any LinuxCNC configuration. You can build quite complex logic by linking hal pins from different components.

Hi...sorry for delay...much distracted here...I am going to follow up on all points..

I have it pretty close now...after I finish a couple things I want to go back and check because it seemed that when I used calibration...changed scale value..then tested by jog and measure...ok..save...then run program...consistently got a substantial difference than the jog test which was at the lame total distance..did same process again without testing by jog and much better..I know sounds voodoish but I will try to replicate later this week..

Thanks so much for your help!!

Rick