def request_data(self):
        """
        request data from the instrument/device
        """
        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
request data from the instrument/device