Re: Encoder line count.....

--- In CAD_CAM_EDM_DRO@y..., "doug98105" <dougrasmussen@c...> wrote:

> Group,
>
> Are encoder line counts usually expressed in an abreviated form?

For

> instance, I have an encoder with a line count of 2048 (a power of

two

> thingie). Would this be referred to as a 2000 line encoder for

ease

> of description.
>
> Likewise when you say 1000 line encoder is that really one with

1024

> lines? Or does a 1000 line unit have exactly 1000 lines?
>

In the encoders I have seen when they say 1000 lines they mean 1000
lines. That will give exactly 1000 pulses per revolution. Since
encoders are based on a photo device sensing a physical line passing
the sensor(s) the count is the count...period. Don't forget that
most rotary encoders have a two phase output that is 90 deg out of
phase so you really get 1000 pulse per channel. External electronics
are then used to sense which direction the shaft is turning and to
turn the output into X4 (4000 pulses). USDigital (www.usdigital.com)
has both low cost encoders and the chips to do the quadrature
encoding. In the end you have to be able to determine how many
pulses are equal to one inch of axis travel and let the controller
software deal with the scaling.