Development Of Coaxial Cable And Fiber Optic Cable Simulation System For Scientific Research Ship

With the increasing number of marine equipment,the requirements for the function and stability of the equipment have gradually raised.Some countries with developed marine technologies had made much effort and devoted much money to build test sites.However,in our country the test sites were built relatively later,resulted in simple system functions and small service areas.Therefore,the realization and development of a more complete marine equipment test system,a more efficient conversion of marine high-tech achievements as well as a related system about measurement and control platform are of great significance.The coaxial cable parameter simulation system and optical cable parameter simulation system developed in the paper are important parts of the underwater detection and sampling equipment monitoring control platform.At present,China's test-control platform site and underwater detection sampling equipment testing system is still in the construction and development,such as communication performance and bandwidth testing system.In order to solve the problem that the underwater detection system frequently encounters anomalies in the sea trials,two simulation systems were developed in this paper which enabled to test the communication performance and the communication bandwidth in the underwater detection system before use.Coaxial cable parameter simulation system is divided into software part and hardware part.The hardware part has adjustable parameters and suits for 23 varieties of coaxial cable simulation.The software part is mainly used to assist users to use the system.It enabled users to select the relevant parameters according to the demand,and then provides the system parameter adjustment mode and displays the corresponding frequency characteristic curve.Fiber optic cable parameters simulation system is used to analog all-optical attenuation,provides a wide range of optical power attenuation value adjustment,and has good characteristic.The main work in this paper: research for transmission line theory and model,selection for devices,comparison of various scheme designs,designfor hardware and software,commissioning in laboratory and test site.For coaxial cable parameter simulation system,,the paper firstly used Multisim simulation software to simulatethe hardware design,and latter the physical part was built in the laboratory.SP1641 D signal generator and Tektronix TDS2022 B oscilloscope were both used during testing.Software design realized functional interface design and parameter processing design,so Qt software platform with C++ language was used.For fiber optic cable parameter simulation system,the hardware design was based on STM32F103ZET6,together with AD5732 voltage control module adjustable dimmer.Embedded C language was used to design the software part.It had made an efficient human-machine interface design,multi-functionbuttons and voltage control.Finally,the system was debugged.In this paper,a coaxial cable parameter simulation system and an optical cable simulation system are developed.Debugging processwas carried out at Zhoushan Shallow Water Experimental Station.Two sets of simulation system both successfully realize the communication performance and capability test of underwater monitoring and sampling equipment by the monitoring and control platform,which will be put into formal use soon.