Fanuc DC servo + 7i77

I have found two articles mentioning the lockings:
1)
LOCKING_INDEXER = 1
in the axis config which would set pins axis.N.unlock & axis.N.is-unlocked, but this prevents coordinated moves, or moving other axes when in unlocked state.
linuxcnc.org/docs/html/config/ini-config.html
Thats not what I want, bacause the machine is capable of simultaneous 5 axis machining by the mechanics, so I just want to lock the table when it is not used. Or If I not using the LOCKING_INDEXER just simpli rely on pins than it will work? I will try it next week.
2)
the other one is the motion.spindle-locked pin, which I think is only for spindles and M19.
linuxcnc.org/docs/html/man/man9/motion.9.html


But these are standard motion components is this what You mentioned or there is a separate hal comp Im not aware of?

I read Your guide, already, but I may need to read it again a few times

Thanks

Yes that is the comp. i never ised it , but maybe it can be modified and recompiled to suit your needs.
As for the tutorial, if you think something is not explained properly, please let me know so i can correct it. As i mentioned there, i am not good at explaining things, that was an exercise for me.

It seems that Im unable to find the correct values for PID. I have managed to get at_pid working, but every time i start it I get different results, and they are sometimes differ with an order of magnitude or two.
Im suspecting that the velocity feedback loop causing my problems, as it is working like a double pid loop (a pid of pid) and interfere with my settings.

Has anyone set up a FANUC DC velocity control unit ever? what would be the correct procedure to set it up?

Thanks

There has been some debate how effective the at_pid component is, or if it even works at all. Personally I've never been able to make it work,

Are your Fanuc drives getting a tack feedback? Most older Fanuc controls/DC amp combos I've worked with have the control generate a tacho signal from the encoder to send to the amp. Without tach feedback I believe you will be running in torque mode, and tuning strategies will be different and probably more difficult.

the drives are receiving a feedback signal based on encoder, these are the relevant settings:
OUTPUT_SCALE = 2857.0
OUTPUT_MIN_LIMIT = -2857.0
OUTPUT_MAX_LIMIT = 2857.0
FEEDBACK_SCALE = 3333.0
FEEDBACK_MIN_LIMIT = -3333.0
FEEDBACK_MAX_LIMIT = 3333.0
net x-output => hm2_5i25.0.7i77.0.1.analogout0
net x-vel-fb <= hm2_5i25.0.encoder.00.velocity => hm2_5i25.0.7i77.0.1.analogout1
velocity control is 6v/1000rpm the feedback should be 7v/1000rpm according to docs.

simple way to generate techo signal
mesa 5i20 + 7i33
setp hm2_5i20.0.pwmgen.04.output-type 1
setp hm2_5i20.0.pwmgen.04.scale 25
setp hm2_5i20.pwmgen.04.enable true
net x-vel-fb => hm2_5i20.0.pwmgen.04.value