Hi!
I designed such a device and built it into my Kawai K3m and Casio CZ101.
Also the Poly61 and Polysix, Poly800 should be no problem.
Generally spoken each device that works with 3.3V to 5V on the keyboard could be used with the datadial as
I switch analog switches in parallel to the built in buttons. A little microcontroller on the datadial controls the
analog switches according to the encoder movements.
You can find information here:
http://synpro.heimat.eu/datadial.htm Ciao
Peter
http://www.ullrich.at.tt