MQTT Transmission - Set "Refresh" on "Discover Edge Nodes Required" rising edge?

Ignition
1

I haven't done much with MQTT, and I have a question about using MQTT Transmission.
I've noticed that whenever I change the structure of my Ignition tags (e.g. add/remove tags), the [MQTT Transmission]Transmission Control/Discover Edge Nodes Required tag changes to True. Setting [MQTT Transmission]Transmission Control/Refresh to True then sends the new structure on to the broker and the Required tag then clears.
Edit: The "Required" tag sometimes changes to True when the tag structure changes... sometimes it doesn't :confused:

Two questions:

  1. Is there any reason not to auto-refresh if the structure changes?
  2. I'm thinking I should add an on-change script on the "Required" tag to write True to the "Refresh" tag if "Required" goes True. Any issues with this?

It seems to my MQTT-inexperienced mind, that there should be a setting on the transmission module to check to refresh this automatically if there are structure changes (instead of having to add the on-change script).. But maybe I'm missing something

1 Like
2

I am not sure if maybe there is a shallow change detection where is the tag changes are minimal it does some magic versus doing a full birth message maybe? I don't believe there is any harm in refreshing on tagStructureChange as this will make sure you get a proper birth to the broker whenever you get changes. This is good when you have an application that generates UDT instances for you because it makes sure the instances will be reflected.