| High-precision synchronous system is the key part of ICF diagnostic system,it can be used to make the diferent diagnostic equipments triggered at the sametime. General synchronous devices are always with the disadvantages of largeoutput jitter and low delay resolution, so they can’t meet the requirements ofdiagnostic experiment. The synchronous system that presented in this paper,not only provides multi-channel signal pulses simultaneously, but also has goodstability and high delay resolution. In order to realize the remote control of thesystem, the dynamic control page is designed.The high-precision synchronous system consists of three parts: the design ofdigital delay, the research of analog delay in high resolution and the realization ofremote control. In the digital delay part, FPGA is used as the intelligent controlchip to complete the programming of delay logic. After the timing analysis ofthe simulation software, the logic circuit is improved, the5ns delay resolution isrealized, and the16synchronous trigger signals and16command control signalscan be provided simultaneously, the adjustable range of pulse width is from0to21s. The research of analog delay is based on the technology of current integra-tion. In this part, the constant current source is used to charge the capacitance,and the charging rate will change with the diferent charging current. The OTAis used to control the preset voltage of the capacitance, which determines thecapacitance charge time. In this way, the precision delay pulse is generated. Theremote control of the system consists of the host computer communication andthe slave computer communication. The host computer communication is basedon the TCP/IP protocol of internet, and the program is developed at the plat-form of IntraWeb, which is realized in the way of B/S. The slave computer isused to receive the system parameters that set by the host computer, and thensends them to the FPGA. All this process is controlled by the MCU. The significance and innovations of this thesis are as follows:1.The high-precision synchronous system that researched in this thesis canbe used in the control of ICF diagnosis, and the diferent diagnostic equipmentstriggered simultaneously are realized. So this system has great significance inresearching the phenomenon of ICF.2.The design of digital delay is completed by the technology of FPGA. Be-cause of the deep analysis of timing limitation, the system can work stably atthe clock of200MHz high frequency, which is designed by the low cost FPGA.Not only the5ns delay resolution is realized, but also multiple functions areintegrated in the system.3.The traditional control method is instead by the remote control system.The dynamic control page is designed in the way of B/S, so the control of thesystem becomes more easily. It provides a new idea to the complex integratedremote control. |
