You can download the operation manual for CTR2-Voice here. It will be updated when new versions of the firmware are released.
I’ve also posted a text version of the operation manual at the end of this page. Many blind and sight limited operators prefer a text file over a PDF file when reading with a screen reader.
NOTE: The latest version of Adobe Reader doesn’t know how to deal with the hyperlinks used in the Table of Contents. Open the PDF file in a browser for a better reading experience.