The Graphical Symbols for Diagrams (GB / T 4728) are divided into 13 parts:
——Part 1: General Information
——Part 2: Symbol Elements, Definitive Signs and Other Conventional Signs;
——Part 3: Conductors and Connecting Pieces;
——Part 4: Elementary Passive Element;
——Part 5: Semiconductors and Electron Tubes
——Part 6: Production and Conversion of the Electrical Energy;
——Part 7: Switchgear, Control Gear and Protective Devices;
——Part 8: Measuring Instruments, Lamps and Signaling Devices;
——Part 9: Telecommunications: Switching and Peripheral Equipment;
——Part 10: Telecommunications: Transmission;
——Part 11: Architectural and Topographical Installation Plans and Diagrams;
——Part 12: Binary Logic Elements;
——Part 13: Analogue Elements
This section is part 9 of GB/T 4728 and identical to IEC 60617 database Graphical Symbols for Diagrams data base standard (IEC 60617 _Snapshot_ 2007-08-03 English edition).
This part will replace Graphical Symbols for Diagrams-Part 9: Telecommunications: Switching and Peripheral Equipment (GB/T 4728.9- 1999).
Compared with GB / T 4728.9- 1999, changes are listed as following:
——21 signs are abolished:S00992 (09-01-12), S00993 (09-01-13), S01003 (09-03-09), S01020 (09-05-04), S01021 (09-05-05), S01022 (09-05-06), S01024 (09-05-08), S01026 (09-05-10), S01027 (09-05-11), S01031 (09-06-03), S01032 (09-06-04), S01034 (09-06-06), S01035 (09-06-07), S01036 (09-06-08), S01037 (09-06-09), S01038 (09-07-01), S01040 (09-07-03), S01041 (09-07-04), S01054 (09-09-02), S01057 (09-09-05), S01058 (09-09-06) ;
——According to IEC 60617 data base standard, more information is listed for each sign compared with the old edition.
The "replaced symbol" of this standard is the symbol replaced by present symbol which is the standard symbol. "replacing symbol" of this standard is the symbol replacing the present symbol, which is abolished.
