This manuscript deals with the tuning of event-based controllers. By suitably constraining in a coordinated manner the controller discretisation and the event triggering rule, stability of the closed loop system is ensured, through an analysis that evidences and exploits its switching nature as induced by the event-based controller realisation. Such a sufficient condition, simple to enforce in practice, allows to take standard tuning rules, conceived for continuous-time controllers, and apply them to event-based realisations in a straightforward manner. The manuscript refers to the PI(D) controller structure, but extensions can be envisaged. Both simulation examples and an experimental test are reported. (C) 2013 Elsevier Ltd. All rights reserved.