This paper is focused on the tuning of an event-based PI controller for first-order plus time delay systems (FOPTD). In this work, a novel design and combination of a controller and event generator with an easy-to-use tuning methodology is presented. The event generator combines the Smith predictor structure with the symmetric send-on-delta (SSOD) sampling scheme to compensate the delay and trigger the events. The controller has an adaptive structure with the purpose of improving the set-point tracking and guaranteeing stability under conditions of uncertainty. The approach is focused on FOPTD systems but can be easily extended to higher order systems. Stability and robustness analyses are conducted, and the experimental results verify the effectiveness of the approach. (C) 2013 Elsevier Ltd. All rights reserved.