SNTP时间同步技术在农产品质量安全追溯系统中的应用

Application of SNTP time synchronization technique in agricultural products quality and safety traceability system

农产品质量安全追溯系统中各计算机设备间必须保持精确的时间同步,才能保证对农产品各种相关信息的记录准确可靠。基于简单网络时间协议(SNTP),结合农产品质量安全追溯系统的网络结构特点,设计了一种低成本、低负载、较为可靠的时间同步方案,选用GPS作为整个系统的时钟源,构建了中心服务器级、分区服务器级以及生产、销售企业或组织级三个级别构成的时间同步网络,并可以根据实际情况灵活调整。将时间同步的服务端和客户端的实现封装成为单独的类库,采取动态链接库的形式,便于与现有的追溯系统集成。系统各设备间时间同步的精度可以达到数十毫秒,满足农产品质量追溯的要求。

Equipments in Agricultural products quality and safety traceability systems should maintain accurate time synchronization to ensure the records of agricultural products are valid and reliable.Based on Simple Network Time Protocol (SNTP)and characteristics of traceability system,a low cost,small load and more reliable time synchronous network was designed.The GPS was chosen as clock source and this time synchronization network consist of three layers including central servers,regional time servers and production and sale companies or organizations.The structure of this network can be adjusted flexibly according to the actual situation.The implementation codes of time synchronization server and client were encapsulated as the standalone class library in the form of Dynamic Linking Library,which was combined with available traceability system conveniently.Utilizing this network,the time synchronization precision among equipments in traceability system can reach several tens of millisecond,which meet the requirements of agricultural products quality traceability.