Development Of A Monitoring System For Saturation Diving Gases Supply Station Based On PLC

Saturation diving is a way of diving which is suitable for large depth condition to carry out a job for a long time, and it is an important means to support submarine rescue, marine engineering and seabed resources development work. In recent years as increasingly expanding of ocean development scale, scope and depth, saturation diving has become increasingly important.The gases supply station is an important component part of the 300 meters saturation diving training system, it provides compressed air, oxygen, nitrogen, helium and other gases for saturation diving divers. In order to use various gases safely and effectively, and ensure the safety of divers' life and diving smoothly, a monitoring system for gases supply station must be established to monitor the process of gases' production, storage, preparation and delivery. In this paper, aiming at the saturation diving gases supply station, a monitoring system based on Siemens PLC and configuration software has been developed to guarantee the stable and reliable operation of the gases supply station.Based on Siemens S7 300 PLC, touch-screen and configuration software, this paper has developed the monitoring system for saturation diving gases supply station based of upper and lower structure. Firstly, according to the functional requirements of the monitoring system for gases supply station, combining with the process flow of the gases supply station, the monitoring system for gases supply station has been designed, the reliability and security of the monitoring system have been studied. Secondly, the hardware of the system has been designed, including the design of hardware structure, key equipments and sensors have been selected, and the design of control board has been studied. Thirdly, the paper has designed and written PLC control programs and touch-screen monitoring programs, to achieve the goal of digital acquisition and processing, analog acquisition and processing, Modbus communications, electric valves' controlling and so on, and it has designed the security mechanism of PLC control software. Fourthly, the papaer has used Kingview to develop PC monitor interface, to achieve the goal of real-time monitoring of process and the equipments' operating status, data reporting, trend of curve and other functions. In the end, the paper has conducted hardware-in-the-loop simulation test, to test the function and performance of the monitoring system.The monitoring system for the gases supply station which has been developed in this paper can realize acquisition of datas of field sensors and gases producing equipments' running state,real time displaying, electric valves controlling, alarm and event logging, trend curves and other functions, it meets the functional needs of the gases supply station monitoring system,and provides protection for the gases supply station and intelligent management of safe production, and it can provide a reference for the future development of similar systems.