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Standards GB are Chinese national standards, which are issued by China's Standardization Administration Office (SAC).
Chinese national standards are used all over China commonly labeled as GB standards. They determine the united production requirements regarding product safety and quality .
GB standards are often modified or created according to the international standards of ISO, IEC or any other international level.
Although, they are largely harmonized, GB standards may differ from international standards .
Approximately 15% of all GB standards are obligatory and they can be identified according to the prefix GB, after which the code of the standards follows:
GB – Obligatory national standards
GB/T – Optional national standards
GB/Z – National steering technical document
Characteristic of the electrical interface at hierarchical bit rate for digital network
Standard published on 25.4.2016
Selected format:Electrical characteristics for unbalanced double-current interchange circuits for general use with inte-grated circuit equipment in the field of data communications
Standard published on 3.4.1987
Selected format:Electrical characteristics for balanced double-current interchange circuits for general use with integrated circuit equipment in the field of datacommunications
Standard published on 3.4.1987
Selected format:Standard current ratings
Standard published on 26.3.2002
Selected format:300 bits per second duplex modem standardized for use in the general switched telephone network
Standard published on 3.4.1987
Selected format:1200 bits per second duplex modem standardized for use in the general switched telephone network and on point-to-point 2-wire leased telephonecircuits
Standard published on 3.4.1987
Selected format:600/1200 bauds modem standardized for use in the general switched telephone network
Standard published on 3.4.1987
Selected format:Automatic answering equipment and/or parallel automatic calling equipment on the general switched telephone network including procedures for bling of echo control devices for both manually and automatically established calls
Standard published on 3.4.1987
Selected format:2400 bits persecond modem standardized for use on 4-wire leased telephone type circuits
Standard published on 3.4.1987
Selected format:2400/1200 bits per second modem standardized for use in the general switched telephone network
Standard published on 3.4.1987
Selected format:Latest update: 2026-08-02 (Number of items: 2 290 553)
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