We’re using the MQTT Transmission modules to publish to a HiveMQ broker cluster. We have some Ignition tags that rarely change values. We’ve added new subscriber clients that are not able to get the current tag values and won’t get them until they change, which may be never. I was thinking we could start publishing Retained Messages, but I don’t see a configuration setting in the MQTT Transmission page of the Ignition gateway to do that. We’re using MQTT Transmission module version 4.0.12. Am I missing something?
After further research, I’ve found that Retained Messages can be sent from Ignition using the scripting function “system.cirruslink.transmission.publish()”, but that just using the gateway-configured Transmitters to publish tags in a specified folder of a specified tag provider does not provide that option. Instead, the Transmission module publishes some retained messages as defined in the Sparkplug B specification.