Above configuration (Fig 3-2) is particularly useful in a lab/shop environment where DOCSIS is
available but without power. A power injector
2
fed with 24 VDC with at least 1 amp capacity
powers the SMC8511 through the Ethernet port.
Note: Do not exceed 28VDC into the power
injector (no 48 VDC injectors), and do not use a power injector which places DC voltage on the
data leads. See Section 3.4 for connections.
3.3 Power Output to PoE
When the SMC8511 Outdoor Cable Modem is powered from the CATV system through its F-
connector interface, it can optionally
provide 24 VDC at 0.5 amps from the Ethernet port to
power the external Ethernet device. The wiring /pin connections are given in Figure 3-3, below.
3.4 PoE Wiring
When the SMC8511 Outdoor Cable Modem is powered by means of PoE the connections are
given in Figure 3-3, below.
When the SMC8511 Outdoor Cable Modem is powered by 60-90 VAC CATV system power it can
optionally provide 24 VDC output to an attached Ethernet device. The connections for this
application are also as given in Figure 3-3, below.
Pin Input /
Output
1
Tx (+)
2
Tx (-)
3
Rx (+)
4
+V
5
+V
6
Rx (-)
7
GND
8
GND
Figure 3-3 PoE Wiring
Note that this PoE implementation differs from both the IEEE 802.3-2005 and draft IEEE 802.3af
standards.
Do not exceed 28VDC into the power injector (no 48 VDC injectors), and do not
use a power injector which places DC voltage on the data leads.
2
such as the SENAO PoE injector readily available on the Internet
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