Accton Technology SwitcHub-2se Installation Manual page 19

For a sample calculation, assume the following values:
• cable gauge - 62.5/125 m, which means a 13 dB power budget,
• 2 patch panels between the switches, each with 0.5 dB power loss, and
1 splice with 0.4 dB power loss (i.e., 2 * 0.5 + 0.4 = 1.4 dB power loss for
intervening devices), and
• inherent power loss in the cable is 4.5 dB/km
The maximum cable length is therefore:
m ≤ 13 dB - 1.4 dB ≤ 2.58 km
4.5 dB/km
When the 100BASE-FX link is used for a dedicated connection (i.e.,
full-duplex communications), cable length should not exceed 2
kilometers. However, when the link is used for a shared collision
domain (i.e., half-duplex communications), cable length should not
exceed 412 meters (IEEE 802.3u).
Note: Even though your calculations for power loss may indicate a longer permissible
length based on signal strength (as seen in the preceding example), we advise remaining
within the recommended limits.
3. Set the communication mode via the Configure button to full-duplex or
half-duplex mode to match the connected device. (Refer to
Communication Mode in Chapter 3.)
2-4
Fast SwitcHub-2se User's Guide
Setup and Configuration
Setting t h e