Re: [CAD_CAM_EDM_DRO] Re: Encoder Indexer Option

braidmeister wrote:

>So what id the difference between a differential encoder and the one
>that I spec'd out? How does that relate to quaruture?
>
>-Brady
>

There is no difference in operation, only in how each quadrature channel
(and index, if you have it) is transmitted back to the controller.

Both types of encoders have power and ground connected. In a
"single-ended" system, all of the signals share the ground pin as the
minus side of the signal (remember that you always measure a voltage
between two points). In a differential encoder, each signal has two
wires, and they swap polarity when the signal changes from high to low
or low to high (ie, a high means that the A signal is at 5V, and the
notA signal is at ground, a low means that the A signal is at ground,
and the notA is at +5V).

It is a more noise-immune transmission method, because you always expect
a voltage difference on the signal pair - having both signals at ground
potential isn't a valid state. It gives an added measure of security
for some systems, because you know that if any encoder pair is ever at
the same voltage level, there is a problem with the encoder or the
wiring. Althouh the Rutexes do take differential signals in, I don't
think they detect failures this way.

- Steve