Event-based control is a means to restrict the feedback in control loops to event time instants that are determined by a well-defined triggering mechanism. The aim of this control strategy is to adapt the communication over the feedback link to the system behavior. In this thesis, a state-feedback approach to event-based control is extended to systems that are composed of physically interconnected subsystems. The main concern of this thesis is disturbance rejection in interconnected systems, which is supposed to be best accomplished by a continuous state feedback. This consideration leads to the idea that the event-based state-feedback system should approximate the disturbance rejection behavior of a continuous state-feedback system with adjustable precision. Various methods for the event-based control of physically interconnected systems are investigated. In particular, decentralized, distributed and centralized state feedback is studied, which differ with respect to the effort for the communication between the components of the event-based controller over the communication network. The main results concern the design and analysis of event-based state-feedback control methods for physically interconnected systems. For all approaches the disturbance behavior of a continuous state-feedback system is shown to be approximated with adjustable accuracy by the event-based state-feedback system. The novel event-based control methods are tested and evaluated in experiments on a continuous flow process implemented on a large-scale pilot plant.