Home / Standards / GB/T 4728.9-2022 GB/T 4728.9-2022 Active Graphical symbols for electrical diagrams—Part 9: Telecommunications :Switching and peripheral equipment 电气简图用图形符号 第9部分:电信:交换和外围设备 Standard Type GBT ICS 29.020 CCS K04 Status 现行 Issue Date 2022-10-14 Implementation 2023-05-01 Responsible Dept 国家标准委 Drafting Unit N/A