Re: Re: Two Q's: Servo Hum and FreqMod issues

Oops. Input and output scale are the number of pulses per unit distance.
They are not a measure of the gain of the axis. Axis gain (P) is
disabled with steppermod so that will not help you a bit.

With your slow pc steppermod is the one to use. If you set the number of
pulses per unit and max velocity to high, steppermod will cause your pc
to crash or be really erratic. Short of that you should be okay.

If these motors are sitting loose on the bench you may just be hearing
some standing wave sort of rattle. This can happen with loose motors
that have very low inertial loads.

HTH

Ray

BTW -- Freqmod does not use external feedback but it does use the tuning
parameters P -> FF2. Smdromod does use encoder feedback from the
Kulaga/Mauch ISA board.

On Friday 09 August 2002 10:00 am, you wrote:
> Message: 9
>    Date: Fri, 09 Aug 2002 10:31:59 -0000
>    From: "jbordens" <jake@...>
> Subject: Re: Two Q's: Servo Hum and FreqMod issues
>
> Norm,
>
> Hmm, my output/input scale is already pretty high (20000).
> StepperMod is working well for me, so I can stick to it. ;)
> I just thought that FreqMod's behavor was a bit odd.  I suspect its
> looking for a closed loop which just isn't there, but as far as I
> can tell, my settings are right.
>
> Mariss,
>
> I'll play with my gain a bit.  I guess when I tuned them my pulse
> generator wasn't putting out enough pulses to really get the motor
> spinning fast enough to hum/rumble.  Now that I'm hooked to real
> software, I get the hum.