We set the software limit of PR2 SF as follows.

Drive range of Stepper Motor (upward is minus)
[Before change]
 Current position: -500,000[count](-9.76mm)
 Upper limit, Lower limit: No setting
  Upper and lower limits: No setting Available to drive from 0[count] stack position to -1,750,000[count].

[After change] Set the current position to 0 (add +500,000)
 Current position: 0[count](0mm: reference point)
 Upper limit: 450,000[count](8.78mm)
       (500,000[count](9.76mm):Stacked position)
 Lower limit: -1,200,000[count](-23.43mm) (-1,250,000[count](-24.41mm))