IEC 60839-7-20 Ed. 1.0 b:2001, Alarm systems - Part 7-20: Message formats and protocols for serial data interfaces in alarm transmission systems - ... ITU-T Recommendation V.24/V.28 signalling

Specifies the requirements for standard interfaces between the terminal transceiver of an alarm transmission system and the annunciation equipment. Employs signalling in accordance with ITU-T Recommendation V.24/V.28. This title may contain less than 24 pages of technical content.