Industrial communication networks - Fieldbus specifications - Part 5-21: Application layer service definition - Type 21 elements (IEC 61158-5-21:2019); English version EN IEC 61158-5-21:2019, only on CD-ROM
工业通信网络.现场总线规范.第5-21部分:应用层服务定义.21型元件(IEC 61158-5-21-2019);英文版EN IEC 61158-5-21:2019 仅CD-ROM