Description of the device
4.3 Interfaces and signaling contact of the switches
SCALANCE X-300
82 Operating Instructions, 10/2010, A5E01113043-10
Transmission medium
Data is transmitted over an eight-wire twisted pair cable.
NOTICE
For data transmission at 1 Gbps, at least a Cat 5e twisted-pair cable with 4 x 2 wires is
necessary. With a four-wire cable (2 x 2 wires), a maximum data transmission rate of 100
Mbps is possible.
Transmission range
The maximum transmission range (segment length) is 100 m.
Connectors
The connectors used are 8-pin RJ-45 jacks.
4.3.1.3 Power over Ethernet (PoE)
Power over Ethernet (PoE)
With PoE, the power for networked devices is carried via Ethernet. Here, there are two
methods of supplying power:
● Over spare pairs
Power is transferred on the free wires 4, 5, 7 and 8 of the Ethernet cable. This method is
used with Fast Ethernet (10Base-T / 100Base-TX) since only the two wire pairs 1-2 and
3-6 of the Ethernet cable are used for data transmission.
● Phantom power
Here, the power is transferred on data wires 1, 2, 3 and 6 of the Ethernet cable
(alternative A according to IEEE 802.3af/802.3at (type 1)).
PoE-compliant devices can be divided into the following groups:
● PSE - power sourcing equipment
These inject power onto the Ethernet cable.
● PD - powered devices
These are supplied with power via Ethernet.
4.3.1.4 Ports of the X308-2M PoE
The PoE ports of the switch
As a PSE, the X308-2M PoE supplies PoE-compliant devices with power over Ethernet. The
48 V power required to supply the powered devices is generated internally on the switch, no
extra power supply unit is necessary.