Research On Remote Measurement And Control System For LHAASO

The LHAASO's(Large High-Altitude Air Shower Observatory)key scientific objective is to explore the origins of the high-energy cosmic rays,related cosmic evolution,and high-energy celestial bodies.It provides a basic experimental environment and platform for conducting cross-cutting research on the various forms of frontier science in the atmosphere,meteorology and space environment,and it also provides a strong technical support for China and the world of related technology development.In this paper,a remote measurement and control system based on OPC(Object Linking and Embedding for Process Control)technology is designed to meet the functional requirements of LHAASO WCDA(Wide Field of view Cerenkov/fluorescence Telescope Array)and WFCTA(Wide Field of view Cerenkov/fluorescence Telescope Array)slow control system,which can achieve the common functions of WCDA and WFCTA,controls the experimental process of cosmic rays detection,and ensures the operations of detectors are safe and reliable.The LHAASO remote measurement and control system consists of the environmental detection module,the gates control module,the power supply module and the control and communication module.The environmental detection module is mainly used to get parameters of temperature,humidity and water level of the enviorment,which ensures the operations of detectors are safty and reliable.The gates control module is used to detect the switch status of the detectors' doors and to control the switch.The power supply module provides about 1300 V high voltage to the photomultiplier array of detectors.The control and communication module is used to communicate between remote computers and field devices.This paper introduces the testing experiment contents,the testing methods and the testing results of monitoring system for LHAASO.In terms of communication tests of this system,a mature OPC client is used to test of the OPC server.The testing experiment of client monitoring software is based on the function of OPC sever is good.The environmental detection module,the gate control module,and the power supply module are tested in this paper.The temperature and humidity are continuously measured by the environmental detection module for 12 hours.The range of liquid level measurement experiment is 110 mm to 300 mm,the accuracy error is less than ±1mm.The openning degree of two doors is about 270.5° in the switch door repeated experiments,and the resolution is 0.088°.The design and test results of this system will provide a theoretical basis for the development of the LHAASO slow control system in the future.