MQTT Version issue

Previously, the ignition gateway was running on V8.1.7, the MQTT module was V4.0.8. At the site edge side, ignition was V8.1.7, MQTT module was V4.0.8. The communication was great.

Now I have upgraded the ignition gateway to V8.1.19, the Gateway MQTT module is still V4.0.8. At the existing running edge side, ignition version is still V8.1.7 and MQTT module is V4.0.8. Everything works fine after the gateway upgrade.

I am currently now adding a new edge, I have installed, ignition V8.1.21, the MQTT module is V4.0.13.
The new edge says connected to the MQTT server, but I cannot see this node on the MQTT node list on the gateway.
Then I tried to uninstall MQTT transmission module V4.0.13 on the edge and install with MQTT transmission module V4.0.8, it does not even connect to the gateway MQTT engine.

Here’s my questions:

  1. is it because the MQTT version difference which caused the issue?
  2. can I upgrade the gateway MQTT module to V4.0.13? Will it cause issue to existing site connection? the existing site is still on MQTT V4.0.8, should they be upgraded as well?
  3. option 2 will generate a lot of extra. Maybe I just downgrade the new edge to Ignition V8.1.19 and use MQTT module V4.0.8.

Appreciate if anyone can help out.

Cheers
Chaoliang

I have downgraded the new edge to Ignition V8.1.18 and the MQTT module to V4.0.8, the comms is back to normal.

But the question still remains:

  1. whether I can use MQTT transmission V4.0.8 on Ignition V8.1.21?
  2. If to upgrade the MQTT engine from V4.0.8 to V4.0.13 on the gateway, should the MQTT transmission module to be upgraded to V4.0.13 on all of the edge unit?

Our version compatibility matrix is here: Ignition Compatibility with Cirrus Link Modules - MQTT Modules for Ignition 8.x - Confluence

So, v4.0.13 Cirrus Link modules will run on the Ignition versions you are trying. It appears you may be hitting something else but I’m not quite sure what without more details. There were some changes in subscriptions between those versions. Maybe you’re hitting an issue with MQTT Server ACLs?

The quickest way to get to the bottom of it would be to open a support ticket here: Contact Support - Cirrus Link Solutions - Worldwide - United States

Including logs should help us get to the bottom of it quickly.