Following Error keeps creeping up

hi,
My machine has issue about following error keep rising during Gcode execution. Jogging 3 axis simultaneously at high speed ( 9m/min) for extensive time is ok. Reducing  the speed and accel to 3m/min  and lengthening timing pulse still doesn't fix the issue.
below are my hal and ini

I used the template from PnCconf for 7i96 and modify to fit 7i95
Those number was from that config
My host computer is a Rpi4 so the servo period is higher
The axis are driven by Yaskawa sigma 5 servo motors
What should the P value be for servo system?

Yes, a good default P term for the stepgen  is 1/servo-period
so 1000 for a 1 mS servo period.

The physical meaning of a 1/servo-period P term is that any
measured position deviation is corrected by the next servo period

A P term higher than 1/servo-period will result in correction overshoots

A P term higher than 2/servo-period will result in oscillations.

Having a 0 P term will eventually cause following errors as the stepgen position
drifts due to small differences in the hardware and LinuxCNC clocks.

 

I will change it tmr,
I always thought the drive takes in the step gen and handle the rest. So in case of a open loop system, does P term still need to be 1/servo period?

You can run the stepgen in position mode and not use the PID loop at all,
but its been found that using the PID loop deals better with random latency
spikes.

When using the PID loop, the stepgen is in velocity mode so unless you close the loop
with some P term, the actual stepgen position will drift from the commanded position
due to the small (say 50 PPM) differences in LinuxCNCs clock and the hardware's 
crystal oscillator.

Velocity mode without feedback is a bit like telling someone how to get somewhere
by telling them the speed and direction to go at any given time. Unless the speeds
are perfect you wont end up exactly where you should be.
 

@tommylight
I using pulse train servo system with encoder feedback to 7i95, the question for open loop system is to gain some insight in linuxcnc.
@PCW
Changing P to 500 cause system to oscillate so I adjust it down to 0.1-0.2 still cause an audible hums. Is that a sensible P term? Or should I go lower?