Hello, I would like to ask about the incremental rotary encoder and its connection, specifically the AB phases, thank you very much.
Not so much older style, many still use this method today where machine zero is not known at power up.That pulse was typically used in conjunction with a limit switch in order to start a counter at a specific position on an old style Numerical Control machine moving from a HOME position.
Not necessary if the common 5v RS485 drivers used.Electrically, it looks like two switches.
Connect the common terminal to 0V, and the A and B outputs to v+ through resistors to give logic level outputs.
Generally the term Incremental Encoder refers to the quadrature version, at least as far as the world I operate in.Are we all thinking about the same sort of thing? Rotary encoders can be either devices that measure the rotation of a shaft for motor control, or something that replaces a potentiometer on a panel.
They both work the same way. Just the purpose (and quality of construction) that is different. I was just wondering which the TS was thinking about.Generally the term Incremental Encoder refers to the quadrature version, at least as far as the world I operate in.
The only other that can also use the term, is the same encoder, but the initial detected quad sign waves uses the co-tangent feature to calculate absolute position.
I have fought with those linear encoders and lost more times than not. So we replaced them with commercially made and adjusted ones and avoided wasting hours of fighting with them. The machines using them were built in the UK, by the way.I worked with some of the first incremental optical linear scale encoders where a incandescent lamp was used, rather than LED as came later.
When changing the lamp, the phasing had to be re-done using a double beam 'scope and lissajous figure to set the 90° phasing.
I have cleaned the scales on a few, obtaining cleaning solution and suitable cloth etc from the local Opticians.I have fought with those linear encoders and lost more times than not. So we replaced them with commercially made and adjusted ones and avoided wasting hours of fighting with them. The machines using them were built in the UK, by the way.
by Duane Benson
by Jake Hertz
by Robert Keim
by Aaron Carman