采用可编程I/O接口的多路串行通讯模拟器设计

The design of multi-channel serial communication simulator based on programmable I/O interface

摘要:

某航天器闭式贮箱增压控制系统的测试中,需要设计具有多路串行通讯接口的模拟器,用于模拟数字式压力传感器的输出信号。对于72路串行发送和10路串行接收功能,若采用传统商用的标准串行通讯接口板,则整个模拟器需要十多套板卡,系统复杂,体积大,且多个通道之间难以实现同步与实时控制。为此提出了一种采用多路可编程I/O接口板实现485通讯功能的方案,借助于LabVIEW软件开发平台,由FPGA编程实现通讯协议；并配置信号调理板以实现信号的隔离传输和驱动。最终仅用一台小型便携式设备和三块板卡就实现了模拟器的所有功能,可以灵活地根据系统设置的工作模式模拟传感器的输出,在增压系统的测试中表现优异。试验结果表明,此种设计方案具有较强的通用性和适应性,可以广泛推广到多种通讯应用场合。

Abstract:

The purpose of this paper is to design a simulator with multi-channel serial communication interfaces to simulate the outputs of pressure sensors, which would be used for the test of closed-loop pressure control system. For the requirement of 72 transmission interfaces and 10 receiving interfaces, it would be more than 10 boards with the application of standard commercial communication cards, and the simulator would be large, complex, and difficult to achieve real-time and synchronous control among those channels. So, a multi-channel programmable I/O interface board is applied for RS-485 communication, whose protocol is programmed on the FPGA supported by LabVIEW platform; and regulation boards are deployed for signal’s isolated transmission and driving. All functions are implemented within a miniaturized portable device, which is flexible to simulate the signals based on the patterns set up by users,and has excellent performance during the test. The result shows the approach has strong versatility and adaptability for a variety of communication applications.