EtherCAT as an alternative for the next generation real-time control system for telescopes

Abstract

The ALMA Observatory was inaugurated in 2013; after the first 8 years of successful operation, obsolescence emerged in different areas. One of the most critical areas is the control bus of the hardware devices located in antennas, which is based on a customized protocol built on top of the controller area network bus. Similarly, other observatories are facing the same problem. In collaboration with the Universidad de la Frontera, initial studies were performed to explore alternatives to provide state-of-the-art solutions for the next decades, and one of the candidate solutions can be based on the EtherCAT technology. Our study takes the ALMA control system as an example; it compares the current architecture with the new design that is not only compatible with the existing hardware devices of ALMA but also provides the foundation for the new subsystems associated with ALMA 2030 initiatives. The progress of a proof of concept is reported, which explores the possibility of embedding the existing ALMA monitor and control data structure into EtherCAT frames, using EtherCAT as the primary communication protocol to monitor and control hardware devices of ALMA telescope subsystems.