Saturday, February 14, 2009

Fiber-Optics cable color-code



Color code, used in fiber optics, resembles that of copper. The major difference is 12-color sequence as oppose to 10-color for copper. The sequence of colors is the same, with addition of two colors - Rose (11-th) and Aqua (12-th).

In the high fiber count cables fibers are grouped in 6 or 12, and then the groups themselves are numbered. Therefore, the individual fiber's number equals the number of the group times 6 or 12 plus the number of the fiber in the group. The group size (6 fibers or 12) depends on the cable design and the total fiber count. Be aware that in cables with fiber count that is not a multiple of 12, especially those with more than 24 fibers, you can encounter both 6- and 12-fiber groups at the same time.

Groups of fibers can be designated in several different ways:
Fibers are housed inside of colored plastic tubes, all under the same outer jacket. In this case, colors of the tubes go in the same sequence as colors of the fibers: tube #1 - blue; tube #2 - orange and so on.
Fibers are helix-wrapped in colored threads or plastic ribbons. Same coloring scheme as above applies to the wraps.
Fibers have black stripes, one, two, three or even four. This is by far the most complicated tecnique. The stripes (or stripes pairs, triples etc.) are usually located about a foot (approx. 30 cm) from each other. So, you can't immediately tell what group the individual fiber belongs to. You would have to find the stripes, count them, and then decide what group number it is. If you can't find ANY stripes, it means that this fiber belongs to group one

There are also colors that designate the type of the optical fibers. It is not always followed by all manufacturers, and also, this code only applies to indoor cables: multimode fiber cables have orange jacket, and singlemode fiber cables have yellow.

Thursday, February 12, 2009

8P8C Wiring


The most talked about EIA/TIA standard in data, voice is structured wiring. Here is the EIA568B standard, an ethernet cabling. The EIA568A standard is obselete.