Re: stepper encoders

--- In CAD_CAM_EDM_DRO@y..., mmiami johnson <mmiami2002@y...> wrote:

> Has anyone any experience doing this? Is it possible with the demo
> version?
>
> Is it possible in EMC without using a seperate card of some sort?
>
> I have some renco encoders and I would like to use them, yet I

don't

> know a whole lot about using encoders. All I realy know is the pin
> outputs +vcc, gnd , ch a, ch a not, ch b, ch b not, index, index

not.

>
> Could someone explain the basics of hooking up these connections?
>
> Thanks in advance
>
> Troy

Mach1 encoder input is not currently designed to be a "closed loop"
control system. It is there to do some 3D scanning/probing to
digitize 3D objects. Neat but not for basic machine control.
Encoders are typically used in conjunction with servo motors with the
count feedback being used to sense position. Look into the Gecko 320
and 340 motor drives. All you need is a brushed DC servo motor, a
encoder and one of the Gecko's listed above to make one axis of a CNC
machine.

Encoders give phased pulses out. The A channel pulses followed by
the B channel when rotating the shaft. If you reverse the rotation
the phase relationship changes (B proceeds A). Encoders are rated as
either TTL or Differential and by the number of PPR (Pulses per
Revolution) they produce. Usually the part number will often have
the PPR in it. Something like: XXXX-YYY-500-XXX where the 500 would
indicate it was a 500 PPR unit. If you have a scope, you can hook up
the +vcc to +5VDC, the gnd to GND, and put your scope probe on the ch
a pin. (scope gnd to GND). Rotate the shaft and see if you get nice
clean pulses up to 5VDC. The ch a NOT is probably the inverse of ch
a (+5 to gnd pulses). You probably have a TTL dual channel encoder
with Index. The index will give a pulse every so many A B pulses
(perhaps 1 per revolution). The index pulse is not used in the
Gecko's All you need to hook up is +VCC, GND, Ch a, Ch b.

>
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