BS G 242:1989

Foreword
Committees responsible
Specification
1. Scope
2. Definitions
3. Cable
4. Coupling
5. Couplers
6. Connectors
7. Terminators
8. Splices
Appendices
A. Surface transfer impedance measurement
B. Data bus cable, dimensions and performance
C. Transformer waveform integrity: droop test
D. Concentric trinax removable contacts:
     intermateability dimensions
Figures
1. Data bus interface using direct coupling for type
     A or type B systems
2. Data bus interface using transformer coupling for
     type B systems
3. Surface transfer impedance test fixture for testing
     cable screens and cables containing splices
4. Ancillary test fixture for measuring surface
     transfer impedance of mated connectors
5. Ancillary test fixture for measuring surface
     transfer impedance of coupler housing
6. Typical construction details for data bus cable
     optimized single screen, multiplex, for type A
     systems
7. Typical construction details for data bus cable
     optimized double screen, multiplex, for type B
     systems
8. Typical construction details for data bus cable
     superscreened, multiplex, for type B systems
9. Coupling transformer
10. Intermateability dimensions for size 8 male
     contacts
11. Intermateability dimensions for size 8 female
     contacts
12. Intermateability dimensions for size 10 male
     contacts
13. Intermateability dimensions for size 10 female
     contacts

Defines the characteristics of the data bus line and components up to the interface with electronic components of the system.

This British Standard establishes requirements for data bus interconnecting systems for aerospace applications. It defines the characteristics of the data bus line and components up to the interface with electronic components of the system.

Digital data transmission systems fall basically into two categories working at data rates either above or below 100 kilobits/second. The electrical requirements of the components of the transmission systems in these categories are different and the categories are classified in this standard as follows:

type A systems, operating at rates of 100 kilobits/second or less;

type B systems, operating at rates greater than 100 kilobits/second.

NOTE The titles of the publications referred to in this standard are listed on the inside back cover.