Over the last week, I’ve been working with MQTT–Node Red, Raspberry Pi3, Ignition by Inductive Automation, Cirrus Link MQTT modules and MQTT Spy to build an OEE simulator. This is for a client based in Europe, with operations all over the world. We are implementing a hybrid of our OEE template and the goal is to integrate hundreds of lines, globally, in the next 18 months.
With MQTT, all topics (tags) are published to a central broker, which then publishes the topic updates to all agents who are subscribing to those topics (tags). When subscribing we have a couple of options.
I can say subscribe to topic hello/world, hello/mom, hello/dad or I can say subscribe to topic hello/#. This will subscribe us to any current topics under the hello directory and any future ones. Of course, if we say subscribe to topic # then we will subscribe to all current and future topics, no matter what directories they sit in.
For the project we are currently working on, our plants only want to subscribe to topics (tags) that fall under their plant.
In the video below, I show you how to use Custom Name Spaces in Cirrus Link’s MQTT Engine module to filter to only the topics (tags) we want to see in our gateway. In this example, a Raspberry Pi3 is our Broker and Ignition is an Agent.