Siemens SIMATIC NET SCALANCE W774-1 RJ-45 - Page 26

Connection
5.2 Power supply
SCALANCE W774-1/W734-1
26 Operating Instructions, 09/2015, C79000-G8976-C325-06
SCALANCE W774 M12 EEC
For the power supply, there are two options with the SCALANCE W774 M12 EEC:
● Direct feed in via the four-pin M12 socket (position
①)
● Power over Ethernet via the M12 Ethernet interface P2 (position
②). The other Ethernet
interface P1 is not capable of PoE.
The four-pin M12 socket has the following pin assignment:
Pin
Signal
Assignment
1 L1+ 24 VDC
2
L2+
24 VDC
3
M
Ground
4
M
Ground
Power over Ethernet
The two following variants are available for power supply via an Ethernet cable:
●
IEEE 802.3at type 1 (IEEE 802.3af)
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.
●
IEEE 802.3 at type 2
The power supply is known as phantom power via the wire pairs carrying signals (1/2 and
3/6).