Hi Rich,
Like all Tyros and PSR-S/SX models, the Genos is NOT "Half Damper" capable. The FC3A (potentiometer-based) can also be used on the Genos, but it will then work only like a switch-based pedal (e.g. FC4A, FC5).
By the way, Yamaha "momentary switch" pedals such as FC4A or FC5 have a "normally closed" electrical contact (which is opened when the pedal is pressed).
However, pedals with a "normally open" switch can also be used because the polarity of the connected pedals is queried when the keyboard is started. If necessary, the polarity can also be changed manually in the controller display.
Best regards,
Chris