IEC TR 63194:2019 pdf download

IEC TR 63194:2019 pdf download.Guidance on colour coding of optical fibre cables
1 Scope
This document examines the need for and intent of colour coding of optical fibre cables. Further, this document lists the major colour codes in various regions throughout the world. Noting that decades of discussion of a universal recommended colour coding scheme has failed to bring about an agreement, this document does not intend to promote any listed colour code above any other. This document includes regional information on the colour coding of units when different from the fibre code, and of jackets to convey information about the types of fibres within, or the types of performance expected. It also includes information on colours beyond the basic 1 2 set out in IEC 60304. This document is not a normative document, but, rather, a guide to the subject of colour coding of cables.
4 Rationale
The need to uniquely identify a particular fibre within a cable is a common and rational requirement for cable standards. The determination of which fibre is which – without having to resort to “ringing it out” – is a key criteria in cable system management. A definition of an agreed cable colour coding scheme has been discussed in past years. But it has not been possible to reach agreement within the IEC because several embedded regional coding schemes exist that are part and parcel of the fibre system architecture.
The rationale of a colour coding scheme is that each fibre within a cable be uniquely identified. This concept requires that each fibre in a unit be identified by colour or position or both, and that each unit also be identified – again, by colour or position or both. The combination of the two will uniquely identify any particular fibre within a cable. The scheme for the fibre and for the unit may or may not be the same. Note that IEC 60304 defines the 1 2 colours for fibre identification, but does not specify which colour is for which fibre number. Also note that IEC 60794-3-1 1 :201 0 [7], 6.1 .3.1 , lists the 1 2 colours, but specifically leaves the coding to being “as agreed”. The only definition of a colour code in the IEC 60794 system to date appears in IEC 60794-2:201 7, 5.1 3. IEC 60794-2:2002, and earlier, contained a colour code for fibre identification; edition 4.0 (201 7) does not contain that code. That code has been anecdotally described as having been “made up” to specifically not conform to any existing code, in hopes that it might become an agreed default. That agreement never occurred, therefore, it was dropped from edition 4.0. The stated colour codes stated in IEC 60794-2:201 7 [6] are for fibre, buffered fibre, ribbons, unit, ruggedized fibre elements and jacket colours, based on fibre type. The current work to restructure the IEC 60794-1 series – especially the revision of IEC 60794-1 -1 – would suggest that the colour code should be a basic criterion addressed in the general specification.Contemporary proposals with regards to the latest edition of IEC 60794-1 -1 seek to move these criteria to IEC 60794-1 -1 [4] and to this document, presuming some future revision of IEC 60794- 2:201 7. They present the necessary changes to IEC 60794-1 -1 to standardize the “as agreed” approach and refer to this document for details. In view of current and future revisions, it may be that IEC 60794-1 -1 will be normative regarding these requirements. In addition, a jacket, sub-cable jackets, tube, or buffer colour may be used to identify the type of fibre within the cable. This type of coding may or may not conflict with the unique identification rationale of the coding scheme, depending on the cable type.