ISO/IEC 9549:1990 PDF

Scope: 1 This International Standard specifies galvanic isolation of balanced interchange circuits using optocoupler integrated circuit technology and is provided for data transmission in the two-condition code (e.g. NRZ). The electrical characteristics are compatible with both ISO 8482 and CCITT Recommendation V.11. NOTE — Compatible means to allow interoperation with devices having interchange circuits conforming to the electrical characteristics specified in the referenced standards. Annex A shows interoperation with CCITT Recommendation V. 11 interchange circuits in a point-to-point environment. 2 The specifications are given in terms of parameters and measurements for an isolated generator and an isolated receiver. These components may be used in twisted pair 2-wire or 4-wire point-to-point connections up to 1 000 m or multipoint connections up to 500 m for speeds up to 2 Mbit/s for point-to-point connections and 1 Mbit/s for multipoint connections. For data signalling rates up to 20 kbit/s, device manufacturers may optimize their component design. 3 Options are provided to meet special application requirements, such as - isolated generator high impedance control; - isolated receiver circuit failure detection capability; - line termination in point-to-point configuration. 4 This International Standard does not describe a complete equipment interface in terms of mechanical, electrical and functional /procedural specifications.

ISO/IEC 9549:1990 history

1990 ISO/IEC 9549:1990 Information technology; galvanic isolation of balanced interchange circuits