Writing sets the ramp down setpoint. Reading returns the current value. Units
        are in milliseconds and must be positive. When set to a non-zero value, the
        motor speed will decrease from 0 to 100% of `max_speed` over the span of this
        setpoint. The actual ramp time is the ratio of the difference between the
        `speed_sp` and the current `speed` and max_speed multiplied by `ramp_down_sp`.

def ramp_down_sp(self):
        """
        Writing sets the ramp down setpoint. Reading returns the current value. Units
        are in milliseconds and must be positive. When set to a non-zero value, the
        motor speed will decrease from 0 to 100% of `max_speed` over the span of this
        setpoint. The actual ramp time is the ratio of the difference between the
        `speed_sp` and the current `speed` and max_speed multiplied by `ramp_down_sp`.
        """
        self._ramp_down_sp, value = self.get_attr_int(self._ramp_down_sp, 'ramp_down_sp')
        return value