Re: re:tach's

Ballendo,

That was really cool! I moved all my stuff to the "circuits" folder.
Didn't know you could do that.

The synthesized (or multiplied) are exactly related to the input
pulse train; they have to be because they are phase-locked. If your
step pulse freq. is say 2,174.3 Hz, then the output will be 21,743
Hz. If you send 54,309 pulses, then there will be exactly 543,090
output pulses.

The PLL lock range is +/- 8 cycles. In some ways it works like the
servodrive except there is a voltage controlled oscillator where the
motor would be.

The input STEP pulses go to a 4-bit "up" counter. The VCO is divided
by 10 and goes to a 4-bit "down" counter. The outputs of the counters
go to a 4-bit adder, whose sum goes to a non-linear D to A converter.
The D to A output goes to a PID filter and then on to the VCO input.

Sudden changes in the input step rate "accelerates" or "decelerates"
the VCO output frequency. The number of pulses generated (when
divided by 10), are servoed to exactly match the number of step
pulses received at any given moment.

Mariss
Geckodrive Inc.

--- In CAD_CAM_EDM_DRO@egroups.com, ballendo@y... wrote:
> Mariss,
>
> Thank you for the response. Are you able to move your previously
> posted files around?
>
> Re: G210 and G340:
> So, the synthetic pulses are not necessarily directly related to
the
> rate of the input pulse train? At all speeds or just at low speeds?
>
> I guess this makes sense, since you are not trying to increase
> resolution, simply allow "high-count machine requirements" to be
met
> by "lo-count capable controllers" (software or otherwise).
>
> And, at low speeds the stepper motor is best able to deal with
> a "rough"(read variable rate) input pulse stream.
> The servo just queues 'em up anyway in the "target" register. Did
> this with a DanCAM "servo" many years ago...
>
> Or have I completely missed the boat?
>
> Ballendo