Much of the current research in human-robot interaction is concerned with single systems and single or few users. These systems and their interfaces are generally tightlycoupled and well-defined. For large-scale human-robot interactions, it may not be possible to know the systems in advance of designing the interface for potential human interaction. This presents a difficult goal for allowing multiple users to interact with many possibly unknown systems. In this paper, we present an interaction infrastructure aligned with providing this interface. It operates in two phases accommodating both many-to-many interactions and allowing for generalized and more personal one-to-one interaction between users and robotic systems. Our previous research has demonstrated the infrastructure to scale to a large number of users and several systems in simulation. The experiments in this paper substantiate these results in a smaller-scale real robotic environment.