No modifications to the default parameters are required. However, it is important to make sure the Operation System allows inbound connections on port 1883 and there are no firewalls blocking inbound connections on this port from the remote edge nodes.
Ignition Primary - MQTT Engine
The only change from defaults is to set a Primary Host ID. MQTT uses Quality of Service (QOS) levels to ensure messages get delivered. However, this only ensures delivery between a single MQTT client and the MQTT server. In other words, it doesn't ensure delivery from one MQTT client to another MQTT client. Sparkplug introduces the notion of a Primary Host ID which is used to ensure client to client communications. The only requirement is that it match exactly on both the MQTT Engine and MQTT Transmission configurations.
Ignition Edge 1 and Ignition Edge 2 - MQTT Transmission (Configure the same on both Ignition instances)
As with the MQTT Engine configuration, the Primary Host ID must be set on the General tab as shown below.
Delete the existing default MQTT Transmission Server.
Create a new MQTT Server configuration by clicking the link below. Image RemovedImage Added
Configure MQTT Transmission to point to the Primary Ignition. Configure as shown below making sure to change the URL to reflect your network settings. For example, if you Ignition Primary is at 192.168.1.100 the MQTT Server URL would be: tcp://192.168.1.100:1883. After setting the parameters as shown below. Click the 'Save Changes' button at the bottom.
Verify the MQTT Server has been created and is shown in the list of MQTT Servers as shown below.
Repeat the process of creating a MQTT Server but instead point it to the Ignition Primary Backup MQTT Server. These are the parameters to use: