Shortwave Gigabit Models
The two 1000BASE-SX (shortwave gigabit) MDA models are:
•450-1SR MDA -- single MAC MDA with a separate redundant Phy (backup Phy port). Only one Phy port can be active at any time. If the active Phy port fails, the redundant Phy port automatically becomes the active port.
•450-1SX MDA -- single PHY MDA.
Both models conform to the IEEE 802.3z 1000BASE-SX standard and use shortwave 850 nm fiber optic connectors to connect devices over multimode (550 m/1805 ft) fiber optic cable.
Figure 7 shows the 450-1SR MDA and the 450-1SX MDA.