The A-88MKII supports the three pedal functions of a grand piano. By default, the PEDAL jacks on the rear panel are assigned as follows: DAMPER to Hold (CC#64), FC2 to Sostenuto (CC#66), and FC1 to Soft pedal (CC#67).
The RPU-3 piano pedal unit is recommended for this purpose. Connect the R plug to DAMPER, the C plug to FC2, and the L plug to FC1.