ABSTRACT
Due to the COVID-19 pandemic, teaching has had to move from face-to-face to online models. In the context of the subject 'Home and Building Control' taught in the Electronic Engineering Bachelor Degree, an online Modbus device simulator has been developed to conduct online laboratory sessions. The simulator stablishes a Modbus TCP endpoint and a web interface for each student where they can send orders and visualize the behavior of the virtual devices under the configuration given by Modbus. The simulator was developed and used for the first time during the second half of the 2019/2020 academic year where quarantine restrictions were imposed. The simulator proved to work as expected, allowing to move all laboratory sessions to the online model. © 2022 IEEE.