optical fiber (fiber optics) (OF)
Following the link classes for copper cables, a link classification has also been introduced for optical fib ers in the EN-50173(-1) standard: the OF classes. There are several OF classes: OF-300, OF-500 and OF-2000.
Due to the increased requirements for industrial communication systems, the following additional optical transmission classes have been specified: OF-25, OF-50, OF-100, OF-200, OF-5000 and OF-10,000. The number in each case represents the link length in meters.
The channel attenuation for multimode and monomode fibers in the various optical windows was specified. These attenuation values are particularly important for critical applications such as 10 Gigabit Ethernet or 100 Gigabit Ethernet for determining the attenuation budget.
The extended OF classes OF-25 and OF-50 are operated exclusively at a wavelength of 650 nm. Their attenuation values are 7.5 dB (OF-25) and 12 dB (OF-50). OF-100 and OF-200, on the other hand, can be used at 650 nm , 850 nm and 1,300 nm . At 650 nm, the attenuation values are highest: at 13 dB (OF-100) and 23 dB (OF-200); at 850 nm and 1,300 nm, they are 6.3 dB (OF-100) and 9.6 dB, respectively. OF-5000 and OF-10000 are used only at 1,550 nm and have attenuation values of 4.0 dB (OF-5000) and 6.0 dB.