本标准定义了一种协议，该协议能够在使用网络通信、本地计算和分布式对象等技术实现的测量和控制系统中实现时钟的精确同步。该协议适用于通过支持多播消息的局域网进行通信的系统，包括但不限于以太网。该协议使包含各种固有精度、分辨率和稳定性的时钟的异构系统能够与主时钟同步。该协议支持亚微秒范围内的系统范围内的同步精度，并且具有最小的延迟 网络和本地时钟计算资源。协议的默认行为允许简单的系统 安装和运行时无需用户的管理注意。 标准包括 映射到用户数据报协议（UDP）/互联网协议（IP）、DeviceNet和第二层以太网 实施它包括消息扩展的正式机制、更高的采样率和更正 对于不对称性，一种时钟类型，用于减少大型拓扑中的错误积累，以及如何 将生成的附加数据合并到同步协议中。标准允许 同步精度优于1ns。该协议具有一些功能，可以解决以下应用: 冗余和安全是一项要求。该标准定义了合规性和管理能力。 提供了支持单播和多播消息的功能。本标准包括一个关于 建议的做法。定义特定于通信介质的实施细节的附件 本标准的未来版本预计将提供其他网络实现。

This standard defines a protocol enabling precise synchronization of clocks in measurement and control systems implemented with technologies such as network communication, local computing, and distributed objects. The protocol is applicable to systems communicating by local area networks supporting multicast messaging including, but not limited to, Ethernet. The protocol enables heterogeneous systems that include clocks of various inherent precision, resolution, and stability to synchronize to a grandmaster clock. The protocol supports system-wide synchronization accuracy in the sub-microsecond range with minimal network and local clock computing resources. The default behavior of the protocol allows simple systems to be installed and operated without requiring the administrative attention of users. The standard includes mappings to User Datagram Protocol (UDP)/Internet Protocol (IP), DeviceNet, and a layer-2 Ethernet implementation. It includes formal mechanisms for message extensions, higher sampling rates, correction for asymmetry, a clock type to reduce error accumulation in large topologies, and specifications on how to incorporate the resulting additional data into the synchronization protocol. The standard permits synchronization accuracies better than 1 ns. The protocol has features to address applications where redundancy and security are a requirement. The standard defines conformance and management capability. There is provision to support unicast as well as multicast messaging. The standard includes an annex on recommended practices. Annexes defining communication-medium-specific implementation details for additional network implementations are expected to be provided in future versions of this standard.