Non-linear functions to be used for automatically varying current values of parameters to be set, independently of each other, are prepared in corresponding relation to a plurality of parameter setting operator members, such as faders of a mixer. The scalable encoded bit-stream is formatted to have first and second portions. The traverse cam shaft includes a shaft body, a gear support portion and a gear engaging portion. A local positioning system is arranged to determine a position of the imaging device in the fixed reference frame and generate position data. The sensor may be coupled with a flexible optical wave guide designed to collect and convey the luminescence radiation.