def to_json(self):
        """
        :return: str
        """
        json_dict = self.to_json_basic()
        json_dict['pulses'] = self.pulses
        json_dict['counter'] = self.counter
        json_dict['kwh'] = self.kwh
        json_dict['delay'] = self.delay
        json_dict['watt'] = self.watt
        json_dict['channel'] = self.channel
        return json.dumps(json_dict)