2 - 6 ONline Ethernet 10BASE-FL Installation and Operation Guide
Determining Maximum 10BASE-FL Link Distances
This section describes how to calculate the maximum allowable link
distances between two 10BASE-FL ports.
To do this, you must know the following information:
❑ 10BASE-FL Module optical (link) power budget
❑ Fiber cable diameter (for example, 50 micron, 62.5 micron)
❑ Fiber cable light loss/km (for example, 3 dB loss/km)
❑ Number of patch panel connections between ports
❑ Number of splices on the link
The following tables assist you in obtaining this information:
❑ Table 2-3 - Outlines the optical power budget for the 10BASE-FL
Module.
❑ Table 2-4 - Lists typical losses for various connector types.
❑ Table 2-5 - Lists typical losses for various fiber cables.
Calculating Maximum Link Distance
To calculate the maximum link distance allowed:
1. Determine the optical power budget for the 10BASE-FL port
(Table 2-3).
2. Subtract the optical power loss due to patch panels and splices
(Table 2-4) from the optical power budget for the 10BASE-FL port.
3. Subtract the dB loss/km rating of the fiber cable (Table 2-5) from the
remainder of Step 2. If the result is greater than 0 dbm, the link
distance is valid.
