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@Tommy: What do you mean with "China is running a misinformation campaign?", do you refer to some spam we see occasionally here?

@mars: Does, "I also understand that the Mesa card is solid but the price is less than desirable.", mean you wish it was more expensive so that more people would become motivated to follow up with other options?

You might want to try 's_orient.comp', this modified version of 'orient.comp' provides an input that is to be connected to your encoder-index signal and will look for the index before orienting the spindle.
forum.linuxcnc.org/media/kunena/attachme...ient_2025-03-18.comp

- download the file and rename to 's_orient.comp'

- to install you need the 'halcompile' tool (you might need to install the 'linuxcnc-dev' package if your are on a package installation of linuxcnc)

- $ halcompile --install {your-path-to-the-file-here}/s_orient.comp
(you will need to use 'sudo' to execute this command on a package installation)
The output should look something like this:
- in your hal file change 'loadrt orient {...}' to 'loadrt s_orient {...}' and connect your encoder index signal to the orient component (you might have to modify your pin names to 's_orient')

Do i understand that with mode 0 offset is 1, with mode 1 offset is -1, with mode 2 offset is 0 ? because during tests i seemed to find these shifts.

That man page info appears to be left over from the original code. This particular logic was then modified some time later without updating the man page info:

github.com/LinuxCNC/linuxcnc/commit/b2cd...919af6524f3b82e3eb33

 
linuxcnc.org/docs/devel/html/en/gcode/m-code.html#mcode:m19

I don't think that is correct.  'M19' does NOT seem to set 'spindle.n.index-enable'.
Testesd on real hardware using current master version :

 


 

hi

i made a vismach model... i update it to the home position i want.. its 1:1 after homing th real arm.

 

i dont know if it helps but if i home in this position. x0y0z0a0.5b0c0 in Identity/Joint Mode

 

and in the world mode

 

but if i jog in world mode  x + - i see the real failure on the vismach model..

 

same in Y

 

i dont know if this explain some wrong dh parameters?! but in some positions the A axis.. joint 4 on the arm starts flipping

thanks

Man page Description :
The spindle is assumed to have stopped in an arbitrary position. The spindle encoder position is linked to the position pin. The current value of the position pin is sampled on a positive edge on the enable pin, and command is computed and set as follows: floor(number of full spindle revolutions in the position sampled on positive edge) plus angle/360 (the fractional revolution) +1/-1/0 depending on mode.

Do i understand that with mode 0 offset is 1, with mode 1 offset is -1, with mode 2 offset is 0 ? because during tests i seemed to find these shifts.

I think this shows the basics of the summed PIDs.
 

'orient.N.poserr' must be smaller than 'orient.N.tolerance' for 'orient.N.is-oriented' to go true ('orient.N.tolerance' = 0.5 by default)

Have a look at the man page:
www.linuxcnc.org/docs/html/man/man9/orient.9.html

Thank you guys for your replays.

To  cmorley
I am using LinuxCNC 2.9.10
 

I've not used M19 but it looks like the orient component does not use index at all.
 
Though M19 does use index:

"Spindle orientation requires a quadrature encoder with an index to sense the spindle shaft position and direction of rotation."

So I would expect spindle.0.index-enable to be set true at some point.

i do the g00 x0y0z0 a0b0c0.. but correct would be without a0?

Not sure what you mean here. The point is to get all joints moved to their zero position in joint mode (ie 'trivkins') to be able to check if the home pose is correct.
Note that from this pose (the flange pointing straight down) you won't be able to switch directly to world mode (ie 'genserkins') because it is a singularity. See next comment.

homeing : i need on joint 4 or 5 ( joints here not linuxcnc.. i men robot) a 1deg. offset..if i dont have it.. kinematic errors came after homing... like in the example.. but with the puma560 genser simulator.. i can rebuild the existing failures....

You can set a 'HOME' value in your ini file so the joint is moved out of the singular pose before the mode is switched to world.
linuxcnc.org/docs/html/config/ini-homing.html#_home

I would have thought that with "Raspberry PI with GPIO" you would have already had your cheap low-cost HW assisted engine.  If you must use a PC and don't want to find one with a parallel port, low-end Mesa cards are my suggestion (like the 7i92TH or 7i96S).  I think with Remora you'd "get what you paid for" and eventually a low-end Mesa card would be a better bargain, and much more turn-key and supported.
 

Thanks for your response. I realize that an old PC with parallel port works. Counting on an old PC going forward is not something that appeals to me. I also understand that the Mesa card is solid but the price is less than desirable. Noting that I am not an expert, it seems that the Remora with RP2040 over ethernet should be up to the job and be far cheaper than the Mesa cards. Unfortunately,, I don't have the skills to write the SW so the question remains: Is/or will be Remora with RP2040 ready for prime time? Note: currently I have the Raspberry Pi 5 running Linuxcnc using its GPIO port (buffered with some simple buffer HW but not aux processor) and it will probably meet my needs. That said, a solution based on a cheap aux processor would be a big benefit.

ok the first pose is what i wish... arm is on the right side from the " tower" this means there is a -Y correct.

i played a little bit arround...

what i found: some failures are "softlimit positiv reached 500" i open the min max limits to 750 - 750... still for play more arround. after this message i get position error... but ich can manual jog in jooint mode many more deg. and all speeds are slow!

you wrote :

Lets verify your home pose:

1. Home the arm
2. Activate 'Identity' mode
3. Remove all offsets (MDI: g10 l2 p0 x0 y0 z0 a0 b0 c0)
4. Move all joints except joint_4 to zero (MDI: g0 x0 y0 z0 a0 b0 c0)
5. Take a screenshot of the axis gui window
6. Take a picture from the side (ie the Y direction) of your robot
7. Post the two images


i do the g00 x0y0z0 a0b0c0.. but correct would be without a0?

i have really issues with the right hand rule and rotate and flip the coordinatesystem.. i must build something with toothpicks and a cheese cube.. ...


homeing : i need on joint 4 or 5 ( joints here not linuxcnc.. i men robot) a 1deg. offset..if i dont have it.. kinematic errors came after homing... like in the example.. but with the puma560 genser simulator.. i can rebuild the existing failures....


if i throw in the ini the line in:
RS274NGC_STARTUP_CODE = G21 G10L2P0 x19.2 y5.5 z9.4 a90 b0 c90 (debug, ini: startup offsets1 set)

this line is from the gesner kins puma 560 example
it works better on my real puma

Mars wrote:

* Not old PC desk top based or some kind of windows parallel I/O
 

This is puzzling, so no, just do not mix anything LinuxCNC related with windows, nor parallel port, china is running a misinformation campaign so do not fall for it, parallel port works perfectly fine with Linux.
LinuxCNC on old PC with parallel port works absolutely perfectly even on big industrial machines, despite what you hear/read on the net, and do not base your opinion about stuff from windows users using mach3 as that is inherently not a reliable combination.
Since you want something reliable with no tinkering, get pc and a Mesa card, nothing ever beats it in ease of setup and use, and reliability, and even on price.