网络化测控设备间的时间同步

Time synchronization in the network equipments of measurement & control

为使广域网络范围内的测控设备同步工作，必须准确的计算出网络数据传输的时延。依据排队论，本文提出并证明了准确的网络节点模型和数据延时分布统计模型，以此为基础计算出数据报在互联网上传输的精确时延并给出时延修正方法。实验数据论证了模型的正确性。最后提出了广域自动测试系统内设备的同步解决方案，时间同步精度在10～50μs范围内。

The time-delay of data transmission must be precisely calculated for equipment in network to work synchronously. The accurate model of network node and data time-delay was proposed and proved according to QT （Queuing Theory）. Based on this model, the datagram transmission time-delay on network was calculated accurately and the time-delay correction method was given. Experimental data demonstrate the correctness of the model. Lastly the synchronous scheme in wide automatic test system was put forward. The accuracy of the time synchronization is in 10～50 microsecond.