code: def speed_sp(self):
          
          self._speed_sp, value = self.get_attr_int(self._speed_sp, 'speed_sp')
          return value
docs: Writing sets the target speed in tacho counts per second used for all `run-*`
          commands except `run-direct`. Reading returns the current value. A negative
          value causes the motor to rotate in reverse with the exception of `run-to-*-pos`
          commands where the sign is ignored. Use the `count_per_rot` attribute to convert
          RPM or deg/sec to tacho counts per second. Use the `count_per_m` attribute to
          convert m/s to tacho counts per second.