Software Design Of Wireless Adaptive Terminal Server In Distributed Test System

Traditional automatic test systems are mainly based on wired connections,which are bound by cables and suffer from wiring difficulties,incompatible interfaces,long development cycles and poor scalability in multi-scene,long-distance and distributed test applications.The extension of wired to wireless is the general trend.It is a meaningful research and innovation to develop a wireless distributed test system with wide versatility for all kinds of wired interfaces and wireless protocols.The project team developed a universal hardware(wireless adaptation terminal)for various test instruments as the terminal equipment of the distributed test system,which can wirelessly adapt the test instrument terminals with different interfaces,extend the wireless communication capability for them,and be compatible with various wireless communication protocols.In this paper,the overall architecture of the wireless distributed test system is designed from the perspective of versatility and scalability,and an edge server(wireless adapter terminal server)software system in the middle layer is developed to provide network access services for the wireless adapter terminal group in the lower layer,and interact with the upper layer application platform(including test cloud platform and test application software)to provide reliable wireless data transmission and nodes for the test application from the upper layer to the instrument terminals in the lower layer.Provide reliable wireless data transmission and node management services.The main research contents are as follows:1.Analyze the basic functional requirements and communication interaction logic of the software system,and design the data structure with clear behavioral hierarchy and logic according to the software engineering principles of high cohesion and low coupling.2.Research the interaction technology between the middle layer server and the upper layer application platform.On the one hand,based on the Message Queue Telemetry Transport Protocol(MQTT)publish/subscribe mechanism,design a multi-type test channel for information interaction with the private cloud application software platform to achieve microservice control and system decoupling;on the other hand,based on the "virtual LXI bus device" proposed in this paper,realize the heterogeneous bus instrument terminals in the On the other hand,based on the "virtual LXI bus device" proposed in this paper,we can realize the unified application interface of instrument terminals with heterogeneous buses on the server and extend LXI bus to wireless.3.Study the high concurrency model and data management methods of the server,design and implement concurrency models and algorithms to improve service performance,and data encryption algorithms to prevent wireless data security problems.4.Research on the interaction technology between the middle layer server and the lower layer wireless adaptation terminal group.Including six wireless communication technologies such as Wi-Fi,Bluetooth,ZigBee,LoRa,Wi-FiHaLow,LTE-M,etc.,design targeted methods for different wireless subnets to access the core network,as well as multi-protocol application communication protocols for wireless adaptation terminals to access the middle layer server,and realize reliable test data transmission,automatic network entry of terminal nodes based on this application protocol,and Online testing and other functions.After comprehensive testing and application scenario verification,the middle layer server(wireless adapter terminal server)software system developed in this paper meets all functional requirements,and also lays the foundation for building a new generation of wireless distributed automatic test system.