ABSTRACT: The objective of this program is to develop event-triggered methods for message passing in the optimization, estimation, and control of networked dynamical systems. Prior work has demonstrated experimentally that event-triggering can greatly reduce communication usage while maintaining high levels of networked system performance. The main goal of this project is to develop formalisms that better explain the reason for these benefits and to develop a more systematic approach to designing event-triggered networked systems. Event-triggering provides a novel approach to the discretization of networked dynamical systems. This approach is based on the simple idea that messages between subsystems should only exchanged when there is novel information relevant to the performance of the overall system. This event-triggered approach therefore has subsystems transmit information when some internal measure of that information's novelty exceeds a time-varying and state-dependent threshold. The design of these thresholds is accomplished by enforcing stability concepts (such as input-to-state stability or input-output stability) subject to constraints on the frequency with which information can be passed within the overall system. The project's impact will be broadened through interactions with industrial partners EmNet LLC and Odyssian LLC. EmNet LLC is interested in using event-triggered message passing on the CSOnet system, a wireless sensor-actuator network being used to control the frequency of combined sewer overflow (CSO) events. Odyssian LLC is interested in using event-triggered methods for the intelligent control of event-triggered microgrids.