A topic-based publish-subscribe message broker for SCADA system using hierarchical subscription handling

The SCADA system, i.e. Supervisory Control and Data Acquisition System is used to control the industrial processes by monitoring and controlling field devices remotely. It allows to carry out industrial processes smoothly with minimal human intervention. The SCADA system collects information from the devices in the field using PLCs/RTUs and provides it to the SCADA software to take the appropriate actions independently depending upon the current parameters collected from the field devices. The SCADA system also provides HMI to also allow a human operator to take actions in case of alarm conditions. To enable the message transfer between the components of SCADA system a message broker is required. The aim of this study is to understand the various messaging models and implement a message broker for SCADA systems to handle data transfer between the SCADA components. We implement publish-subscribe based model and aim to handle subscriber connections in an optimized manner.