Power Over Ethernet (Poe) - Siemens SIMATIC NET SCALANCE XM-400 Operating Instructions Manual

Description of the device

4.6 Power over Ethernet (PoE)

4.6 Power over Ethernet (PoE)
Function
The "Power over Ethernet" function supplies connected devices with power via the Ethernet
cable. Devices supplied with power via an Ethernet cable do not require a separate voltage
source.
PoE-compliant devices can be divided into the following groups:
• Power source (PSE - Power Sourcing Equipment)
These inject power onto the Ethernet cable.
• Power consumer (PD - Powered Device)
These are supplied with power via the Ethernet cable.
Port extender PE408PoE
Without connected PoE power supply
If no PoE power supply is connected, the PE408PoE functions like a PE408. It expands the basic
device by 8 RJ-45 ports.
With connected PoE power supply
If a PoE power supply is connected, the PE408PoE port extender is a power source. The PE408PoE
can supply devices capable of PoE with power via the Ethernet cable.
You will find suitable PoE power supplies in the section "Accessories (Page 24)".
You will find notes on connecting the PoE power supply in the section "PoE power supply of the
PE408PoE (Page 45)".
Note
Even when a PoE power supply is connected, you can connect devices without PoE functionality.
A voltage is applied only after the port extender has detected an end device capable of PoE at the
port. With devices not capable of PoE, only the data connection is used.
PoE ports of the PE408PoE
• The PoE ports of the PE408PoE comply with the standard IEEE 802.3at (type 2).
• Ports P1 to P4 are not isolated from each other. This means that they meet the conditions
named in Environment A: Power supply over Ethernet within a power supply system. The
same applies in the port group P5 to P8.
• Any port of the port group P1 to P4 is isolated from any port in port group P5 to P8 and
therefore meets the conditions named in Environment B.
The requirement for this is the supply via two separate power supply units.
• Ports P1 to P4 are supplied with power via the PoE power supply L1+/M1. Ports P5 to P8 are
supplied with power via the PoE power supply L2+/M2.
28
Extender for SCALANCE XM-400
Operating Instructions, 03/2021, C79000-G8976-C332-10