Yamaha YK-X Series User Manual page 86

CHAPTER 4 Adjustment
8) After the absolute reset is completed, check that the machine reference value
displayed on the MPB is between 40 and 60 (recommended range). If the
machine reference value is outside the recommended range, then the next
absolute reset may not be properly performed. In this case, refer to "3-4 Chang-
ing the origin position and adjusting the machine reference", and make the
necessary adjustments.
Plus side
Return-to-origin direction
Origin position at shipment
Fig. 4-2
4-6
Return-to-origin is
impossible from this area.
Minus side