MQTT Publishing

ACM supports MQTT in two ways. First, it provides the functionality to publish real-time data gathered by ACM to an MQTT 3.1.1 compliant broker using the industry standard Sparkplug B specification. Second, AUTOSOL Bridge allows subscription to external MQTT data & publishing of that data via OPC. The two are independent. Either can be used alone, or both can be used simultaneously.

While MQTT Publishing can occur without using a secure connection, AUTOSOL suggests using TLS certificates for MQTT publishing in all production environments. It is highly advisable to take these steps before continuing ACM Monitor TLS setup:

Work with a qualified security professional to determine the best means of securing MQTT communications for your use case.
Configure the MQTT broker according to your needs.
Test using a third party MQTT client with support for certificates and Sparkplug B. AUTOSOL used Node-RED during testing, among others.

Certificate configuration in particular tends to be the most problematic area of MQTT setup. Taking these steps, with the help of a qualified security professional, will greatly simplify ACM configuration.

Setup of real-time data publishing from ACM requires configuration in five major areas:

An external MQTT broker transmits data between ACM and MQTT clients.
A certificate secures communication between ACM & the MQTT broker.
ACM Monitor provides settings controlling how ACM connects to the broker(s) and in what format it publishes data.
ACM Configuration allows creation of Alias Groups which control which data is published.
An external MQTT client consumes data, writes data values back to ACM, and if it is acting as a SCADA Host, notifies ACM of its ONLINE/OFFLINE status.