IEEE1588协议延时不对等问题的修正

IEEE1588同步协议在网络化测控系统中得到了广泛应用,其时钟同步精度直接影响测量仪器的准确度.详细分析了交换设备固有延时时间不对等和线路传输延时不对等问题对IEEE1588同步协议的影响,并针对性地提出了修正方法.采用能够记录报文时间戳的交换设备,修正了交换设备固有延时不对等引起的同步误差;测量线路传输延时时间差后,通过软件方法修正了线路传输延时不对等引起的同步误差;最后对从时钟频率进行了修正,提高了从时钟同步的稳定性.实验结果表明,所提出的修正方法行之有效,可将同步精度提高至50 ns.

Correction methods of unequal delay time based on IEEE1588

IEEE1588 precision time protocol is widely used in network test and control system,and the accuracy of clock synchronization directly affects the measurement results. The influences of inherent delay time of switch and unequal delay time of circuit are analyzed and the correction methods are proposed. The unequal inherent delay of switch was modified by using equipments which can record the time of message ; the unequal delay of line transmis- sion was modified by software; finally, the slave clock frequency was modified to improve the stability of clock syn- chronization. Experimental results show that these methods are useful and the precision can achieve 50ns.