This is a container for the set of controllers in the system.

A controller can represent an entity that can control an aspect of the joining process. A controller can also be any kind of supervisory instance, which manages multiple tools. So, controller can be any kind of computation device which controls specific parts of the joining system and communicates to another system. A joining system may consist of multiple controller instances. The first controller in the list is intended to harbor the OPC UA communication for the Joining System information model.