code: def count_per_m(self):
          
          (self._count_per_m, value) = self.get_cached_attr_int(self._count_per_m, 'count_per_m')
          return value
docs: Returns the number of tacho counts in one meter of travel of the motor. Tacho
          counts are used by the position and speed attributes, so you can use this
          value to convert from distance to tacho counts. (linear motors only)