Lightweight Node.js & EJsS-based Web Server for Remote Control Laboratories*

This paper presents a new approach to develop a web server for remote Systems Engineering and Automatic Control laboratories based on Node.js and Easy JavaScript Simulations (EJsS). On one hand, Node.js, a JavaScript development and runtime platform to distribute non-blocking data-intensive event-driven real-time applications across different devices, is used 1) as the server that hosts the laboratory web-pages and 2) to support the real-time communication between the controller back-end (application that closes the control loop over the plant) and front-end (graphical user interface that lets students parametrize and observe the behavior of the controllers/systems under study from any web-browser). On the other one, EJsS, a powerful intuitive graphical tool to develop graphical/interactive interfaces and simulations, is used to generate the JavaScript and HTML5 controller front-end. The new strategy, deployable over different operating system (Linux, Mac OS and Windows) and against different controller back-ends (e.g. an application developed in C, a TwinCAT Programable Logic Controller, and a LabVIEW Virtual Instrument), is a lightweight versatile solution to set up a friendly remote control laboratory whose experiments can be accessed by the students from different types of devices (PCs, laptops, tablets and smartphones).