Cirrus Link Website
Contact Us (Sales/Support)
Forum
Chariot MQTT Server Documentation
Cirrus Link Modules Docs for Ignition 8.x
Ignition User Manual
Knowledge Base Articles
Inductive University
Forum
...
It is important to note that the configuration of the transmitters in conjunction with the tag tree determines what MQTT topics data is published on. The MQTT topics are essentially the 'addresses' of the different components in the distributed system. In the topics, per the Sparkplug specification, there are three important identifiers to note. These are shown below.
...
These identifiers then become components of the MQTT topics. There is also a 'verb' in Sparkplug messages which denotes whether the message is a birth certificate, death certificate, data message, command message, etc. Sparkplug topics are of the following form using all of these different parameters.
It is also important to note that the combination of any GROUP_ID and EDGE_NODE_ID must be unique within the distributed system. Because these are used as 'addresses' in the system you should never have two that conflict with each other. It is a bit like having two houses with the same postal address. It isn't possible for other MQTT clients in the system to tell where messages are coming from and when sending messages to them they will both receive the messages. This is why the combination of these two identifiers must be unique. For example, you can have two or more Edge Nodes with the same GROUP_ID as long as each EDGE_NODE_ID is unique.
...
Note because these was no Device ID specified in the Custom Transmitter configuration the Device IDs still get picked up from the tag tree. Alternatively the Device ID could be specified in the Custom Transmitter configuration and they would not be picked up from the tag tree.