MQTT Publisher

The MQTT Communication Driver Publisher enables you to publish data from the Application Server to the MQTT broker. You can publish payloads encoded as either Sparkplug or JSON using the MQTT publisher.

Note: Tags in the Application Server with data types ElapsedTime and CustomStruct are not supported in the MQTT Communication Driver Publisher.

Important:

The user who launches the OCMC must be part of the oiAdministrators Windows Local Users and Groups to access the MQTT Publisher. Otherwise, an error message is displayed saying the user or the user group is not part of oiAdministrators group. If the user is not a part of the oiAdministrators group, you must add the user to the oiAdministrators group manually and re-login your computer. The user who installs the Communication Drivers Pack will be added to the oiAdministrators group automatically.

If you make any changes to the configuration of the System Management Server (SMS), you must restart the AVEVA Communications Backend Service in the Services console of your machine. In the Advanced Configuration of the System Management Server (SMS), if you change the HTTP Port or the HTTPS Port then you must run the following command as an administrator in the command prompt:

If you change the HTTP Port field

netsh http add urlacl url=http://localhost:<https port configured in SMS>/oi/ user="NT Authority\Network Service"

If you change the HTTPS Port field

netsh http add urlacl url=https://localhost:<https port configured in SMS>/oi/ user="NT Authority\Network Service"

If you do not run the above commands after changing the ports and try to access the MQTT Publisher functionality, you will get an HTTP 503 error saying the service is unavailable.

The MQTT Publisher provides an easy-to-configure topology to publisher data. Logical devices can be created which bind appropriate data points from the data source. The logical devices, simply called Devices in this document, are organized underneath an Edge Gateway (EON) which defines the publishing parameters and publishes the data defined in each Device.