外文翻譯--可編程控制器-其他專業(yè)-全文預(yù)覽
【正文】 other IEC configuration s within the control system through defined interfaces, called access paths. The choice of the term configuration conflict with the historic use of this term in the controls industry. Generally, configuration refers to the process of specifying items such as the PLC processor model, munication interfaces, remote I/O connections, memory allocation, and so on. Therefore, the vendors producing IECpliant PLCs that use the term configuration in the historic sense refer to the entire body of software with some other term, such as projects. A resource provides the support functions for the execution of programs. One or more resources constitute a configuration. Normally, a resource exists within a PLC, but it may exist within a personal puter to support program testing. One of the main functions of a resource is to provide an interface between a program and the physical I/O of the PLC. A program generally consists of an interconnection of function blocks, each of which may be written in any of the IEC languages. A function block or program is also called a program anization unit. In addition to the function blocks, the program contains declarations of physical inputs/outputs and any variables local to the program. A program can read and write to I/O channels, global variables, and municate with other programs. Provide the means to transfer information between con?gurations. Tasks control the execution of the program or parts of a program. A task controls one or more programs and/or function blocks to execute. The execution of a
環(huán)評公示相關(guān)推薦
鄂ICP備17016276號-1