Change Stepgen Control Type Online [SOLVED]

Hi, in our experimentation we need to switch from a "velocity" control to a "position" control and viceversa, online.
Our setup consist in a 6i25+7i76 mesa card, so we can see both control type after the loading of the hostmot driver.

All seems to work, exept the displayed coordinates in the Display section. Probably we miss to net something.
Downside I attached the M code that we wrote to do the switch.
Someone know this issue?
Are the coordinates displayed the stepgen-position-feedback or stepgen-velocity feedback?

Thank you in advance

M110
M111

alessandro torre wrote: Are the coordinates displayed the stepgen-position-feedback or stepgen-velocity feedback?
exit 0[/code]

They are supposed to be position feedback, but the number is going to be what ever you have connected to "emcmot.03.pos-fb", and it appears that you are switching it between the velocity and position feedbacks of the step gen.

What are you trying to accomplish? Perhaps we could suggest a better option, if we knew more.

Sorry, I solved. I wronged the signal. The right one is:

halcmd net motor.03.pos-fb hm2_5i25.0.stepgen.03.position-fb
instead of:
halcmd net emcmot.03.pos-fb hm2_5i25.0.stepgen.03.position-fb

Now it works!
We are trying to generate the 4th coordinates by a component that reads the velocity of X and Y.
In this way the trajectory planner, seems to work properly and we have a better extrusion in the corner.

The problem was that when the machine did rapid movements, or movements without extrusion we needed to disconnect the 4th axis from the X and Y. If there was a retraction in the gcode, the machine can follow that retraction, without conversions or post processing.
In the picture attached, you can see the difference in the corners. On the left with normally sliced gcode, on the right with the nozzle linked to the X and Y velocity.

Thank you

I think that re-wiring HAL like this feels somehow wrong. It's like re-wiring a circuit rather than operating a switch.
As it is all software there is probably no practical reason to not do it your way, but you could probably do things with a few HAL "mux" component to switch between the control modes on the basis of motion mode. (motion.motion-type : linuxcnc.org/docs/2.7/html/man/man9/motion.9.html )

The Mesa stepgen control-type pin is a HAL pin, so can be switched by HAL logic, but it might be better to leave it in velocity mode and switch between different PID controllers depending on operating mode.