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

Abstract

The ALMA Observatory was inaugurated in 2013; after almost ten years of successful operation, obsolescence emerged in different areas. One of the most critical areas is the real-time controller, there are around 80 of this kind of controller distributed across the observatory. They monitor and control hardware devices through a customized protocol built on top of the CAN bus. Similarly, other observatories are facing the obsolescence problem in this area. In collaboration with Universidad de la Frontera, initial studies were performed to explore alternatives to provide state-of-the-art solutions for the next decades. One of the candidate solutions explored is based on the EtherCAT technology. This project takes the ALMA control system as a challenge, and evaluated a new design that is not only compatible with the existing hardware devices framework of ALMA but also provides the foundation for the new subsystems associated with ALMA 2030 initiatives. In this paper, 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 and using EtherCAT as the primary communication protocol to monitor and control hardware devices of ALMA telescope subsystems.