The Design And Implementation Of The External Systeequivalent Device Based On PCI Bus

The measurement system plays a crucial role in the whole aircraft system, the main roleof which is to monitor all states and parameters of air vehicles in real time when air vehiclesare tested and work to ensure that the entire aircraft system could work properly. Theperformance of the measurement system has a direct impact on the working performance ofthe entire aircraft system. Therefore, the measurement system itself can be seen as asubsystem of aircraft systems. At present, national competitions in the military and defenseare becoming increasingly fierce. In such a context, the production of our national securitysystem must be finished in high efficiency and high quality. Therefore, in the course of thedevelopment and production of the entire aircraft system, the development of each subsystemmust proceed simultaneously. If not, it affects both the quality of production and extension ofthe production cycle. So, to ensure the stability and reliability of the working performance ofthe measurement system, the external system equivalent device that can simulate thetested-system interfaces can check itself in the development of the measurement system.Based on the project-some type measuring system external system equivalent device of avehicle and on the basis of scientific research experience the research team has obtained, thispaper studies and realizes the external system equivalent device that both can achieve thebasic requirements of this project and has the scalability to support similar projects.In accordance with the modular, universal design thought and combined with the actualrequirements of the project, this paper proposes the overall design scheme of the externalsystem equivalent device based on PCI bus. According to the practical needs of the project,the whole design of the external system equivalent device is divided into PCI bus interfacemodule, data transfer module, analog module, digital module and switch module. Amongthem, PCI bus interface module is responsible for data communication between host computer and data transfer module. Data transfer module is responsible for the interaction ofinstructions and data between PCI bus interface module and the rest of the functional modules.Analog module can generate48straight flow and can also generate the DC analog, such assquare wave, triangle wave, according to the specific needs of the follow-up projects. Digitalmodule can have up to24-way RS422serial data in-out channels,6-way opto-coupler inputchannels,8-way digital output channels and2-way pulse signal channels. Switch module cangenerate up to64-way binary signals. The whole workflow of the external system equivalentdevice is that: PC software sends orders to function modules; the logical device FPGA on thefunction module controls the specific devices on the modules to output the signals as theorders they have received. At last, through the test of the authentication system builded bytheir own and the joint-test of the real measurement system, it is proved that this system cansatisfy the requirements of the subject mandate and has the backward compatible scalability.