kenmwallace wrote: ↑Fri Jan 20, 2023 1:11 am
The SureServo motors/amps I just bought, advertise an encoder resolution of over 16 million PPR (24 bit), (if I interpreted their specs correctly).
I can't imagine how this is possible. Imagine how small the lines on the encoder disc would have to be. Maybe they use nanometer photo lithography as in making semiconductor chips?
I don't build encoders, but here is my hypothesis. There are a lot less lines than that. The resolution is increased by interpolation or reading between the lines. The output from the disk reader is sine-cosine. This allows a huge number of points to be calculated between each disk mark, based on the resolution of ADCs used to read the SIN/COS analog. The resolution can be absurdly high, which is good for smooth control. The accuracy is not likely to be anywhere near as high as the resolution.
kenmwallace wrote: ↑Fri Jan 20, 2023 1:11 am
As suggested by some other respondents, I do see that the drive offers "electronic gearing" so I can communicate with it at a more manageable pulse rate.
Are encoders that have digital outputs fundamentally different that the good old quadrature encoders?
Thanks in advance.....
High resolution encoders will have a serial protocol that sends the encoder position as a number. The frequency of A/B quadrature protocol gets too high since it can only send 1 count per signal transition.