The Decoupled Digital Architecture for Manufacturing is a high performance, low cost, standards-based, superior alternative to tightly coupled systems that are prevalent in manufacturing. The benefits are gained through the use of an extremely scalable publish and subscribe message broker technology which dramatically reduces the number of unique point-to-point communication paths.
The architecture can accommodate a wide variety of devices, protocols and applications. It is very secure, easy to maintain, simple to install and built upon prevalent IoT standards which makes it well suited for workcell or enterprise implementations. A conceptual representation of the architecture is shown in figure 1.
Figure 1. A decoupled digital architecture for manufacturing.
Data exchange is accomplished via a publish and subscribe message broker that transfers messages bi-directionally among clients using MQTT. The architecture exchanges standardized messages (based upon the IPC CAMX Standards) which contain manufacturing parameter data and are represented in Javascript Object Notation (JSON). Definitions of the messages can be found in the Messages section of this site. Routing of messages is accomplished through broker topics which are described in the Topics section of this site.
Gateways (as shown in figure 1) are used to convert client communication protocols into the standardized and holistic protocol defined by the architecture. Gateways receive data from machines in various ways (e.g. IPC CAMX, Modbus, MTConnect, OPC-UA) convert the data into standard JSON messages and publish them to the broker using MQTT. Gateways can also receive data from the broker and place it into a database or a format required by an application.
MQTT brokers can be implemented using open-source, leased, purchased or hosted software provided by a variety of vendors.