code: def read_data(self, device_property):
          
          if self.inst is None:
              logger.error("Visa-MDO3014-read data-Self.inst : None")
              return None
          if device_property == 'present_value':
              return self.parse_value(self.inst.query(':READ?'))
          else:
              value = self.inst.query(device_property)
              logger.info("Visa-MDO3014-read data-property : %s - value : %s" %(device_property, value))
              return self.parse_value(value)
          return None
docs: read values from the device