Absolute vs. incremental encoders

The problem with incremental encoder is that the axes have to be referenced in every new machining session. But the advantage is that it does not need a battery. So, why is incremental encoder not preferred? Referencing would take just one minute.

Looking at cost between the 2 encoder types it also makes more sense to use an incremental encoder.

http://www.clrwtr.com/PDF/Kubler/Kubler-2450-2470-Absolute-Encoders.pdf

http://www.clrwtr.com/PDF/Kubler/Kubler-2430-2440-Encoders.pdf

. But the advantage is that it does not need a battery.

Huh? Why does it need a battery?

Who says it is not preferred?
The absolute is only absolute for one turn anyway. In your very scant information you mention a machining session so that implies it is going through more than one turn.

Hi,
The variety of encoders available now quite incredible and depend on how much you want to pay.

http://pdb2.turck.de/au/DE/products/0000001600038bf50008003a

The data sheet for an encoder I used last year with an arduino controller.
It is absolute, multiturn, it does this by using a 16bit register for single turn angle info and a 7Bit register for turns.

It is contactless and not volatile so it remembers where it stopped on power off.

The only thing is you need a comms system for it rather than the old parallel output.
SSI system on this was easy to use with arduino, this was not a cheap encoder.

Tom... :slight_smile: