code: def request_data(self):
          
          output = []
          if not driver_visa_ok:
              logger.info('Request Data Visa Driver Not Ok')
              return output
          
          for item in self.variables.values():
              if not item.visavariable.variable_type == 1:
                  # skip all config values
                  continue
              
              value = self._h.read_data(item)
              
              if value is not None and item.update_value(value, time()):
                  output.append(item.create_recorded_data_element())
  
          return output
docs: request data from the instrument/device