Hi @bri4eng ,
Thank you for contacting Digi-Key TechForum! It looks like absolute is the way to go for your application, according to the first paragraph of below post. Non-absolute would only work in an application where it would first follow an initialization or homing process once power is back on, but wouldn’t maintain position without power being present.
Serial Protocol Options for CUI encoders
-Please let us know if you have further questions.