The Design and Implementation of the Remote Control and Visualization System for Pulse Application Experiments

In order to meet the needs of pulse experiments in different environments, a remote control and visualization system (RCVS) is designed and implemented based on the conceptual design of COntrol, Data Access and Communication (CODAC). RCVS works on the web server and adopts the website deployment mode of LAMP (Linux + Apache + MySQL + PHP/Python) and the working mode of B/S architecture. It includes a remote data acquisition module, a remote real-time visualization module, a monitoring module, and a remote data access module. In the first one, to avoid system deadlock and other problems caused by concurrent operations between local and remote users and concurrent scheduling conflicts between remote users, we have improved the previous solution and adopted the Deterministic Finite Automaton (DFA) and the Two-Phase Locking (2PL) protocol to unify the state of RCVS and that of the overall system and to ensure the serializability of concurrent operations. With regard to real-time data visualization, RCVS adopts the technology of server push to obtain the needed data to minimize the pressure on the server and shun some problems such as server paralysis caused by network congestion in the case of large-scale concurrent request. In addition, RCVS provides a monitoring method based on a heartbeat mechanism and an Application Programming Interface (API) of the web end of the MDSplus database for system status monitoring and remote data retrieval and analysis. Moreover, thanks to the responsive design and the deployment model of B/S architecture, the system can be accessed on any terminal device. This system as part of the overall experimental system will be integrated into the Experimental Advanced Superconducting Tokamak (EAST) neutral beam injection master control system in the future and provide services of remote control and visualization for its long-pulse experiments.