Industrial communication networks - Fieldbus specifications - Part 5-24: Application layer service definition - Type 24 elements
工业通信网络.现场总线规范.第5-24部分:应用层服务定义.24型元件
IEC 61158-5-24:2023 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 24 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.