Description
2.8 Power over Ethernet (PoE)
SCALANCE W780/W740 to IEEE 802.11n Web Based Management
34
Configuration Manual, 03/2015, C79000-G8976-C267-08
Midspan
Midspan is used when the switch is not PoE-compliant. The power is supplied by an
additional device between the switch and end device. In this case, only data rates of 10/100
Mbps can be achieved because the power is supplied on redundant wires.
A Siemens power insert can also be used as the interface for the power input. Since a power
insert supports a power supply of 24 VDC, it does not conform with 802.3af or IEEE 802.3at.
The following restrictions relating to the use of power inserts should be noted:
WARNING
Operate the power insert only when the following conditions apply:
•
with extra low voltages SELV, PELV complying with IEC 60364-4-41
•
in USA/CAN with power supplies complying with NEC class 2
•
in USA/CAN, the cabling must meet the requirements of NEC/CEC
•
Power load maximum 0.5 A.
Cable lengths
Table 2- 1
Permitted cable lengths (copper cable - Fast Ethernet)
Cable type
Accessory (plug, outlet,
TP cord)
Permitted cable length
IE TP torsion cable
with IE FC Outlet RJ-45
+ 10 m TP cord
0 to 45 m
+ 10 m TP cord
with IE FC RJ-45 Plug 180
0 to 55 m
IE FC TP Marine Cable
IE FC TP Trailing Cable
IE FC TP Flexible Cable
with IE FC Outlet RJ-45
+ 10 m TP cord
0 to 75 m
+ 10 m TP cord
with IE FC RJ-45 Plug 180
0 to 85 m
IE FC TP standard cable
with IE FC Outlet RJ-45
+ 10 m TP cord
0 to 90 m
+ 10 m TP cord
with IE FC RJ-45 Plug 180
0 to 100 m
Table 2- 2
Permitted cable lengths (copper cable - gigabit Ethernet)
Cable type
Accessory (plug, outlet,
TP cord)
Permitted cable length
IE FC standard cable, 4×2, 24
AWG
with IE FC RJ-45 Plug 180, 4x2 0 to 90 m
IE FC flexible cable, 4×2, 24
AWG
with IE FC RJ-45 Plug 180, 4x2 0 to 60 m
IE FC standard cable, 4×2, 22
AWG
with IE FC Outlet RJ-45
+ 10 m TP cord
0 to 100 m
+ 10 m TP cord