跳到主要内容

MQTT 操作-向主题发布消息

向主题发布消息

本示例复用 MQTT 操作-连接MQTT Broker 中的示例，向 sensors/livingroom/temp 主题发布消息。

问题背景​

向指定MQTT主题发布消息

解决方案​

使用 写入 MQTT 节点将消息发布到主题。

示例​

mqtt-publish-message-to-topic

配置​

mqtt-publish-message-to-topic-config

示例JSON​

[{"id":"9c138886.116928","type":"mqtt out","z":"09f64d8a7f751be5","name":"","topic":"sensors/livingroom/temp","qos":"","retain":"","respTopic":"","contentType":"","userProps":"","correl":"","expiry":"","broker":"407a01e4.6b637","x":510,"y":560,"wires":[]},{"id":"ff654e7f.32e9e","type":"inject","z":"09f64d8a7f751be5","name":"temperature","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":"","topic":"","payload":"22","payloadType":"num","x":250,"y":560,"wires":[["9c138886.116928"]]},{"id":"407a01e4.6b637","type":"mqtt-broker","name":"数字工厂","broker":"172.16.0.3","port":"1883","clientid":"ocs_controller_sensors_example","autoConnect":true,"usetls":false,"protocolVersion":"5","keepalive":"60","cleansession":true,"birthTopic":"","birthQos":"0","birthPayload":"","birthMsg":{},"closeTopic":"","closePayload":"","closeMsg":{},"willTopic":"","willQos":"0","willPayload":"","willMsg":{},"userProps":"","sessionExpiry":""}]

运行结果​

点击注入，在调试窗口将会看到 sensors/livingroom/temp 主题收到了消息 22。

mqtt-publish-message-to-topic-result