scope:

Scope and purpose

This supplement is to enable users and potential users of the Def Stan 00-18 (Part 2) to implement the Standard using a fibre optic single transmissive star.

The approach taken defines the fibre optic transmission issues in this supplement which must be appended to the Part 2 of the Def Stan 00-18 Standard. The main advantage of this approach compared with a stand-alone fibre optic standard is that the supplement does not have to be amended each time the specific Def Stan 00-18 Standard is changed.

The format of all supplements is identical in that the same parameters are defined in the same units producing commonality to ease the task of implementation by the systems designer. This approach allows efficient use of the interface standard by enabling the optimum interconnect configurations to be used for specific applications.

A number of other classes of supplement have already been identified. These include Point to Point, Star, Tee and Ring type interconnect topologies. The way these apply to the Def Stan 00-18 series of avionics interface standards is shown in figure B.l.

To enable the most flexible use of hardware (through interoperability) the fibre optic interface is defined at the Line Replaceable Unit (LRU) as shown in figure B.2. A minimum set of optical parameters have been identified that allows adequate definition of this interface. The values of the characteristics detailed in the supplement are subject to improvement as technology develops.

All parameter specifications and technical details are contained within the supplement for completeness rather than including references component standards and specifications. However, such documents should be called up at the system or project level specification according to normal practice.

A summary of the structure and content of the supplement is given in clause 3.