Transmitting Tags with UDTs

I am attempting to send tags from one Ignition gateway to another using the Transmission module. I am able to send tag folders under the default tag provider when the tags in those folders don’t contain UDT instances.

All the folders which have UDT definitions don’t ever get populated in the Gateway with the Engine Module.

Any suggestions?

Hello Jacob,

Yes, the first thing to check is that the MQTT Transmission Settings for that particular Transmitter is configured to pass the UDT definitions to Engine. There is a box for Convert UDTs which must be unchecked and the Publish UDT Definitions in Birth checked.

And Depending on how fast your Tags are updating it may be advisable to Disable that Transmitter while taking this next step but you’ll need to delete the Tags and UDT Definitions at Engine so a fresh copy can be sent from Edge to the Server. Then reenable the Transmitter and Refresh Transmission.


That is how I have it configured, Convert UDTs is unchecked and Publish UDT Definitions in Birth is checked.

The tags have never populated in Engine yet, so there’s nothing to delete.

What versions of Ignition (both Gateways) and what version of our modules at each side?


Ignition Gateway A - Version: 8.1.10 (b2021090812)
MQTT Distributor - Version: 4.0.8 (b2021071520)
MQTT Engine - Version: 4.0.8 (b2021071520)

Ignition Gateway B - Version: 8.1.10 (b2021090812)
MQTT Transmission - Version 4.0.8 (b2021071520)


Can you send us the system-name.idb log from each Gateway to support @, please?
We’ll dig through and see what’s happening. You will need to send these compressed and if that file is larger than about 10MB you’ll have to send separately. Send the Edge first and I’ll reply for the second.


I have sent the edge gateway file.