分布式测试系统时间同步技术的研究

分布式测试系统是集计算机控制技术、网络通信技术与多传感器信息融合技术于一体的复杂测控系统;与独立测试系统不同,在网络化分布式测试系统中,各测试装置需按通信协议与网关节点通信以完成相应的测试;不同测试装置在接收网关节点发出的信号时,由于传输距离不同会引起时延差;如果系统中的各个测试装置不具备统一的时间基准,那么得到的测试数据因为时钟差异将无法反映出信息的真实情况;因此,整个网络中所有测试装置需要保持时间同步;针对分布式测试系统时间同步的需求,对信号传输过程中的时延问题进行了研究,提出了一种基于FPGA的时延测量方法,对这种软硬件结合时延测量方法的实现原理进行了详细阐述,并进行了功能仿真及试验验证。

Research on Time Synchronization Technology in Distributed Test System

The distributed test system is a complicated measuring and controlling system based on computer controlling technology, network communicating technology and sensor technology. Different from the independent test system, in the network distributed test system, every test device need to communicate with the gateway node according to the communicating treaty to fulfill corresponding test. Different transmission distances will lead to delay difference when the gateway node has sent signals to different test devices. The test data can not reflect the true information for the reason of clock difference unless the test devices of the system own a unified time base. So all the devices in the whole test network should keep time synchronization. In the view of the requirement of time synchronization, the delay of signal transmission in the test system is studied, and also, a time delay measuring method based on FPGA is presented. The realization principle of delay measuring method from software and hardware is expounded in detail, and the function simulation and experiment verification are carried out.