现场设备是智能交通系统（ITS）的关键部件。现场设备包括交通信号、信息标志、气象站、交通传感器、用于连接ITS（C-ITS）环境的路边设备等。 现场设备通常需要与其他外部实体（管理者）交换信息。现场设备可能非常复杂，需要对许多数据概念进行标准化以进行交换。因此，ISO20684系列分为几个单独的部分。 本文档规定了用户需求、要求和设计元素，用于在日志中记录带时间戳的信息，以供以后检索。这允许管理器在触发动作发生时几乎同时确定特定对象实例的状态，而无需频繁轮询。 注释1NTCIP 1103的某些部分之间存在相似性。 注2ISO 20684-1提供了关于ISO20684系列涉及整个ITS架构。

Field devices are a key component in intelligent transport systems (ITS). Field devices include traffic signals, message signs, weather stations, traffic sensors, roadside equipment for connected ITS (C-ITS) environments, etc. Field devices often need to exchange information with other external entities (managers). Field devices can be quite complex, necessitating the standardization of many data concepts for exchange. As such, the ISO？20684 series is divided several individual parts. This document specifies the user needs, requirements and design elements that are used to record timestamped information in a log for later retrieval. This allows a manager to determine the state of a particular object instance nearly simultaneously when the trigger action occurs without frequent polling. NOTE 1？There are similarities between certain portions of NTCIP 1103. NOTE 2？ISO 20684-1 provides additional details about how the ISO？20684 series relates to the overall ITS architecture.