This paper proposes a control architecture that employs event-triggered control techniques to achieve out-

put synchronization of a group of heterogeneous linear time-invariant agents. We associate with each

agent an event-triggered output regulation controller and an event-triggered reference generator. The event-

triggered output regulation controller is designed such that the regulated output of the agent approximately

tracks a reference signal provided by the reference generator in the presence of unknown disturbances.

The event-triggered reference generator is responsible for synchronizing its internal state across all agents

by exchanging information through a communication network linking the agents. We first address the out-

put regulation problem for a single agent where we analyze two event-triggered scenarios. In the first

one, the output and input event detectors operate synchronously, meaning that resets are made at the same

time instants, while in the second one, they operate asynchronously and independently of each other. It is

shown that the tracking error is globally bounded for all bounded reference trajectories and all bounded

disturbances. We then merge the results on event-triggered output regulation with previous results on event-

triggered communication protocols for synchronization of the reference generators to demonstrate that the

regulated output of each agent converges to and remains in a neighborhood of the desired reference tra-

jectory and that the closed-loop system does not exhibit Zeno solutions. Several examples are provided to

illustrate the advantages and issues of every component of the proposed control architecture.