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Accessing $SYS topics from MQTT broker

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  • Accessing $SYS topics from MQTT broker

    I'm having a problem accessing the $SYS topics from the mcsMQTT plugin. If I'm on the broker I can sub and see the payload of let's say "$SYS/broker/clients/total". But I can't figure out the syntax of manually subscribing to it via the 'Edit/Add' tab of mcsMQTT.

    Any of the $SYS topics I try to subscribe to will not show any payload.

    I've tried a couple different methods of escaping out the $SYS, including not escaping it, but I can't figure out what syntax I should be using to get that data.

    Can anyone show me the proper method? Thanks.

  • #2
    This is from the manual. Does it answer your question? These manual topics may not be subscribed until mcsMQTT disconnects form broker and then reconnects. This can be done from General Tab or from HS Plugins menu to stop and start the plugin.

    I want to subscribe to a Topic, but the Topic has not yet been published through the broker

    The Edit/Add tab is used add any subscription topic. Enter the new subscription Topic “MQTT Subscribe Topic” row in the green table. Other properties of the subscription can be set at the same time in this table. A common use for this is to subscribe to the special case broker $SYS topics that are otherwise not visible. Edit/Add Tab

    The Edit tab is the place where edits are made to existing MQTT-HS associations or where subscriptions are manually defined. Manual entry is for case of the broker topics that start with “$SYS” as these are not normally subscribed by mcsMQTT, if topic discovery is turned off on General tab, or if a message has not yet been published but a HS relationship setup when it does get published.


    • #3
      Ah.... it only takes affect after reconnecting... OK I had it configured right I just didn't know about the reconnecting bit. Thanks for the quick help. All is good again.