现场总线应用层（FAL）为用户程序提供访问现场总线通信环境的方法。在这方面，FAL可以被视为“相应应用程序之间的窗口” 本国际标准提供了基本时间关键型和非时间关键型的通用元素 自动化环境中的应用程序和25型现场总线专用材料之间的消息传递通信。术语“时间关键型”用于表示存在一个时间窗口，在该时间窗口内，一个或多个指定动作需要以某种确定的水平完成。 如果未能在时间窗口内完成指定的操作，则可能会导致请求操作的应用程序失败，并对设备、工厂以及可能的人身安全造成风险。交叉引用:ISO/IEC 8824-1IEC 61158-6-25:2019ISO/IEC 7498-1ISO/IEC 9545ISO/IEC 8822ISO/IEC 10731IEC 61158-3-25:2019ISO/IEC 8822ISO/IEC 8824-1ISO/IEC 7498-1ISO/IEC 9545IEC 61158-6-25:2019ISO/IEC 10731IEC 61158-1:2019购买本文件时可提供的所有现行修订版。

The fieldbus Application Layer (FAL) provides user programs with a means to access the fieldbus communication environment. In this respect, the FAL can be viewed as a "window between corresponding application programs." This International Standard provides common elements for basic time-critical and non-time-critical messaging communications between application programs in an automation environment and material specific to Type 25 fieldbus. The term "time-critical" is used to represent the presence of a time-window, within which one or more specified actions are required to be completed with some defined level of certainty. Failure to complete specified actions within the time window risks failure of the applications requesting the actions, with attendant risk to equipment, plant and possibly human life.Cross References:ISO/IEC 8824-1IEC 61158-6-25:2019ISO/IEC 7498-1ISO/IEC 9545ISO/IEC 8822ISO/IEC 10731IEC 61158-3-25:2019ISO/IEC 8822ISO/IEC 8824-1ISO/IEC 7498-1ISO/IEC 9545IEC 61158-6-25:2019ISO/IEC 10731IEC 61158-1:2019All current amendments available at time of purchase are included with the purchase of this document.