Re: [CAD_CAM_EDM_DRO] Encoder Dithering Specs

Hi Tom

Your question is not clear.(to me). Every state change is acted on. But
here is a relevant discussion;
http://www.cnczone.com/forums/showthread.php?t=10246

Otherwise, the state changes are simply passed directly onto the controlling
software, and error state generated accordingly.
Some interpolating encoders allow you to set a hysteresis, maybe two or
three A/B step changes in either direction before the encoder output
changes.

Regards
Roland


2009/1/14 Tom Hubin <thubin@...>

> Hello,
>
> I am a self-under-employed electrical engineer and was recently involved
> in a discussion about quadrature encoder counting circuit requirements.
> I have no particular equipment in mind. I am just exploring for now.
>
> I have a Sherline CNC mill with stepper motors so this discussion does
> not apply to me yet. But I do expect to graduate to something larger and
> possibly with servos and encoders.
>
> I understand what the counter circuit needs to do in order to count at
> maximum speed in either direction. And I understand what the counter
> circuit needs to do if the encoder dithers as little as one count.
>
> How are the circuits usually specified for dithering less than one
> count. Let's say the encoder A signal is oscillating and the B signal is
> constant.
>
> Pointing me toward typical specs for CNC encoders and controllers should
> be adequate if they address this issue.
>
> Tom Hubin
> thubin@... <thubin%40earthlink.net>
>
>

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