Using MESA 7i77 for servo drive tuning, +/-10V oscillator 0.5Hz

Hello all,

I am currently redoing the electrics for a milling machine, which uses Contraves NC400 drives and contraves servo motors.
They are controlled by analog +/-10V and the drive uses a tacho as feedback. In addition there are Haidenhain ROD 420 incremental rotary encoders installed.

Before beginning to tune the closed loop with linuxcnc and the encoders, I want to tune the drives first.
Acc. to the manual, a symmetrical rectangular wave with amplitudes between 1V and 10V and frequency of ~0.5Hz is required for this.
With this, a measurement via oscilloscope of the motor response is possible and then tuning via some potentiometers on the drive.

Now of course I could buy a signal generator, but as the 7i77 is there I thought I could use it and halcmd and a small script instead.
Do you think this is possible?

Regards,
Daniel

Yes that should not be hard to do. There is actually a pretty good example in the Linuxcnc documentation of using the Siggen hal component to generate different wave forms (one of which is a square wave) in the tutorial for HalScope.
linuxcnc.org/docs/html/hal/tutorial.html#_halscope

Follow the tutorial for setting up the Siggen and HalScope, then also connect Siggen output to the analog pin for the 7i77. If you have the encoder feedbacks working, you can also monitor what the motor's reactions are to the Siggen signal.

Thank you for the hint, it was very easy to setup and worked perfectly.

Should make the same setting on my NC400.
Have a working config how do I get around emergency stops etc.
Do you have linuxcnc (AXIS) running at the same time?
Feel free to explain more and share config if possible?

Unlink the pins you need to connect to siggen, connect them and then it worked for me - but it's already quite some time ago...