[MaxH]

Hi,
I recently upgraded my Z-Axis with an Animatics Smartmotor SM2320SQ
I still don't know what the best PID tuning would be but it "works" for now.
(Its arround P=700 I=800 D=1200 L=1000) via the Smartmotor Interface.
The only problem I'm currently facing is that the Axis seems to receive too many steps. Its controlled via Step/Dir from the parallel port. The other axes are steppers (Chinese TB controller).

When I move down from Z0 to Z-50 it should theoretically move 40.000 steps (2000 steps encoder) but stops at about 40.100-40.500.
The error balances itself a bit when moving back up but still ends up slightly below the desired position and this error accumulates over time until I end up at/in the machining table.

Its no ratio problem and the SMI shows the right position of the motor (40.167 for example, not the desired 40.000)
It knows where it exactly is.

My problem is now to determine if the servo tuner simply accepts that it wanders down at actualizes its position because it doesn't know that it needs to track the exact position.
OR
That my signaling from the parallel port has problems and some signals come double?
I don't have a digital oscilloscope but on my analog one I see some timming jitter and when spectating slow pulse trails I see some pulses "jumping"
Like having different pauses between pulses.

It's really frustrating, I hope someone might know what to do or owns a Smartmotor and controlls it via step/dir

[mostudio]

hi your encoder is 4000 counts
in your smartmotor software set jour fault max lower to 50 counts and set jour pid loop hard to the point just befour osilate.