  Event-triggered approach to networked control systems is used to reduce the
workload of the communication network. For the static output-feedback
continuous event-trigger may generate an infinite number of sampling instants
in finite time (Zeno phenomenon) what makes it inapplicable to the real-world
systems. Periodic event-trigger avoids this behavior but does not use all the
available information. In the present paper we aim to exploit the advantage of
the continuous-time measurements and guarantee a positive lower bound on the
inter-event times by introducing a switching approach for finding a waiting
time in the event-triggered mechanism. Namely, our idea is to present the
closed-loop system as a switching between the system under periodic sampling
and the one under continuous event-trigger and take the maximum sampling
preserving the stability as the waiting time. We extend this idea to the
$L_2$-gain and ISS analysis of perturbed networked control systems with
network-induced delays. By examples we demonstrate that the switching approach
to event-triggered control can essentially reduce the amount of measurements to
be sent through a communication network compared to the existing methods.
