MQTT payload includes ALL Tags of view, want to create one topic for each Tag

Forum / Questions & Answers

kullmann
5 mths ago
6replies

Hi. When i publish data coming from a view, using jsonmqtt, via publisher, i am getting one topic on the MQTT Server including all datapoints.

Is there a configuration possibility to publish datapoints to single topics?

I want to get 500 topics when the view have 500 datapoints listed

- smason
- 5 mths ago
- Reported - view
Hi ,

You can drill all the way down the tagpath excluding the tag name. In that case, each tag would need to have a unique branch above it in order to publish a single tag on a single topic. Now, having said that, we've never tested this many publisher sessions. I don't know how it would handle 500 sessions. Can I ask what the use case is for having a single tag per topic?
- kullmann
  
  5 mths ago
  
  Reported - view
  Of course. We're trying to get Nodered connected to Canary to get some more calcpower to canary. Using MQTT, Nodered get new triggers every time a value changes. As of now, we're receiving a big structure and then? Need to build some ugly solution within Nodered to distribute messages between Flows :-(
  
  Honestly, i like more the idea to have a node connecting direktly via webapi, like the free Osi-Webapi Nodes. maybe some of the experts here have already invented that wheel :-)
  
  Btw: We're talking about 20.000 tags. I guess that will kill the publisher when we setup that amount of sessions, and it is super ugly as well :-)
- smason
  
  5 mths ago
  
  Reported - view
  Thanks for the info. 20k tags would be rough for sure and probably not feasible. If you want, you could leave a feature request: https://helpcenter.canarylabs.com/category/data-connectivity. That way we have it documented.
- travishunt23
- 1 mth ago
- Reported - view
I would add that this would benefit publishing into an existing MQTT topic space. If I already have a structure like "enterprise/site/line1/“ it would be useful to publish asset tags such as "line1.boiler.temperature" and "line1.production_counter" into that same hierarchy.
- smason
  
  1 mth ago
  
  Reported - view
  Hi ,
  You could publish data to a topic that already exists, but there is a potential to create a loop if you are already subscribed to the topic for logging data into the Historian. You would need to create some sort of logic within your script if using the JSON payload in the MQTT Collector if you don't want to log the tags you are trying to publish back to the topic.
- hmatuse
- 4 days ago
- Reported - view
i saw this post the other day and made this.
https://github.com/huntermatuse/simple-canary-mqtt-forwarder/tree/main

in my limited testing i was able to consistently push around 300 tags per 1 second cycles with bursts up to 5000 tags. my suggestion would be to make a new view with the tags you wanted to push to the MQTT broker and point this at that view specifically. this will use the exact tag paths for the topic.

it uses live data endpoints from Canary's read api but, requires anonymous access enabled right now.