kepware mqtt 整理

### Kepware MQTT Integration Configuration and Best Practices

#### Overview of KEPServerEX with MQTT
KEPServerEX integrates seamlessly with the MQTT protocol through its IoT Gateway plugin, enabling efficient data exchange between industrial devices and cloud platforms or other systems. The core component facilitating this interaction is the MQTT Agent within the IoT Gateway plug-in[^1]. This setup allows for both publishing device data to an MQTT broker as well as subscribing to topics from which it can receive commands or updates.

#### Setting Up MQTT Client/IoT MQTT Plugin in KEPServerEX
To configure KEPServerEX's MQTT capabilities fully:

- **Install IoT Gateway Plug-In**: Ensure that the IoT Gateway plug-in has been installed on top of KEPServerEX.

- **Configure Channels & Devices**: Set up channels corresponding to different communication protocols used by connected hardware such as PLCs. Within these channels, define specific devices whose tags will be published via MQTT.

- **Create a New Device Under IOT Protocol**: Choose "MQTT Client" when adding new devices under the IOT protocol section. Here one specifies details like server address (Broker), port number, client ID among others required for establishing connections[^2].

- **Define Tags Mapping Rules**: Establish rules mapping local tag names inside KEPServerEX into topic paths understood by external applications consuming messages over MQTT networks.

# Example Python code snippet showing how you might set properties programmatically using kepconfig library
import kepconfig

mqtt_client_properties = {
    'common.ALLTYPES_NAME': 'My_MQTT_Client',
    'iot.MQTT_CLIENT_HOSTNAME': 'test.mosquitto.org', 
    'iot.MQTT_CLIENT_PORT': 1883,
}

kepconfig.iot.configure_iot_device('localhost', mqtt_client_properties)

#### Publishing Data Using MQTT
Once configured correctly, KEPServerEX acts as an intermediary collecting information from various sources then pushing them outwards towards subscribed clients listening at designated endpoints defined during initial configurations stages mentioned earlier[^3].

#### Subscribing To Topics And Handling Incoming Messages
Similarly, configuring subscription involves setting up desired topics along with specifying actions taken upon receipt of incoming payloads; whether storing locally against certain registers/tags or executing scripts/functions based off received instructions.

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--related questions--

1. How does KEPServerEX handle security concerns while communicating over MQTT?
2. What are some common troubleshooting steps if my KEPServerEX isn't connecting properly to the MQTT broker?
3. Can multiple instances of KEPServerEX publish/subscribe simultaneously without conflicts occurring?
4. Is there any performance impact associated with integrating large numbers of devices through MQTT in KEPServerEX environments?