Siemens SCALANCE W788

Connecting up
5.3 Power supply and Ethernet
SCALANCE W788-x / W748-1
Operating Instructions, 09/2017, A5E03678333-12
39
5.3
Power supply and Ethernet
Connecting the power supply
Models RJ-45 / degree of protection IP30
The four-pin connecting socket has the following pin assignment:
Pin
Signal
Description
1
L1+
24 VDC
2 M1 Ground
3
M2
Ground
4 L2+ 24 VDC
The M12 socket for the power supply has the following pin assignment:
Pin
Signal
Description
1
L1
24 VDC
-
-
-
3
M1
Ground
-
-
-
Power over Ethernet (PoE)
With the SCALANCE W7x8, power supply using Power over Ethernet (PoE) is also possible.
The devices support the standards 802.3at type 1 (IEEE 802.3af) and IEEE 802.3at type 2.
● Gigabit Ethernet
When you connect to gigabit Ethernet, the power supply is a phantom power supply over
data wires 1, 2, 3 and 6. This corresponds to alternative A according to IEEE 802.3af.
● Fast Ethernet
On an 8-wire Fast Ethernet cable, the power is supplied via the free data wires 4, 5, 7
and 8. This corresponds to alternative B according to IEEE 802.3af.
Note
Disabling the PoE power supply
Before you pull a plug via which the device is suppl
ied with power using PoE, disable the
relevant PoE power supply.
Note
No power sourcing equipment (PSE)
The W7x8 cannot be used as a PoE power supply for other devices.