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Hydrogen Technologies Standards form the basic framework for market ramp-up
More information
Climate change Standards and specifications support climate targets
More information
Smart Farming Standards and specifications are drivers for the digitalization of agriculture
More information

Standards [CURRENT]

BS 8521
Specification for dual-tone multi-frequency (DTMF) signalling protocol for social alarm systems

Edition 2009-04-30

Original language English

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Hydrogen Technologies Standards form the basic framework for market ramp-up

Climate change Standards and specifications support climate targets

Smart Farming Standards and specifications are drivers for the digitalization of agriculture

BS 8521 Specification for dual-tone multi-frequency (DTMF) signalling protocol for social alarm systems

Want to learn more?

BS 8521
Specification for dual-tone multi-frequency (DTMF) signalling protocol for social alarm systems