We are sure you mean Scene (instead of "sense"). SCENEs can only be changed by pressing the dedicated front panel Scene buttons (blue) or via MIDI via a System Exclusive message.

Scene is not a standard MIDI function, it is a Yamaha concoction dreamed up for our digital mixing consoles (circa 1987).

Changing sounds can be accomplished, albeit in a different manner, using the FC7 acting as the Super Knob. Examples would be how "CFX + FM EP" changes between acoustic and electric piano, or how "Seattle Sections" changes between ensemble and solo strings,

Each Part can be made to respond uniquely to the movement of the Super Knob, from smooth transitions to absolutely abrupt changes. You can define the Curve Type to a high degree. I'm not sure exactly what your requirements are, but studying the Performances where transitions occur is one way to discover what you are looking for.

Also the XA CONTROL (Expanded Articulation Control) can be used to switch sounds. Typically these are done with the ASSIGN SWITCHES 1/2. These switches can be operated by a Foot Controller and/or Foot Switch by setting the cc number appropriately.

Yes this is what I am looking for:
Changing sounds can be accomplished, albeit in a different manner, using the FC7 acting as the Super Knob. Examples would be how "CFX + FM EP" changes between acoustic and electric piano, or how "Seattle Sections" changes between ensemble and solo strings,
How can I do this ? Please
Thanks
Tho

1) [PERFORMANCE] (HOME)
2) [EDIT] (note this is for global performance edit - do not select a part)
3) Touchscreen (TS): "Control" -> "Control Number"
4) TS: Change "Foot Control 1" or "Foot Control 2" to "Super Knob" by touching the square and turning the DATA DIAL clockwise until "Super Knob" shows, or double-tap and manually enter "96"
5) Be sure FC7 is plugged into appropriate port that matches setting for controlling super knob.

That makes your FC7 spin the superknob.

When you pull up CFX+FM EP (the performance preset) - you can see that the assignable knobs (global) control PART assignable knobs, then those PART assignable knobs, in "turn" change the level of each part (turns one up and the other down). So depending on the superknob position, either one or the other part will be at a higher or lower level - inversely proportional.

You can setup the curve so it's only hard-counterclockwise and hard-clockwise (only one or the other PART is playing). You can even get trickier where the middle position only turns on a 3rd PART. I imagine at some point, it would be difficult to control the foot position to part - but all 8 parts under keyboard control can be selected with a range of the curve. I'd use user curves at the final PART destinations.

Someone else can fill in the blanks or point to previous posts that cover the 1) 2) 3) of setting up the assignable knobs to control PART parameters.

Assuming your parts you are controlling do not start with a volume of 0 (default volume) - then you'll want to use Bipolar curves at the destinations. Basically, a (high) negative value as the output for any input (superknob position) that you want to MUTE the part and "0" as the output for the inputs (superknob positions) that cover the range you want the sound to play at the default level. You can also change to a positive value if you want to increase the volume vs. the default ("boost" the PART volume) or if the level does not match you can use a positive or just slightly negative value to match the volume between all PARTs under control. It would probably be easier to modify the PART default volume so they match and just use a "0" output as "unmuted".

This thread provides more information:

https://yamahasynth.com/forum/simple-program-of-part-volume-on-super-knob#reply-12101