Connecting
7.2 Power over Ethernet (PoE)
Only connect safety extra-low voltage (SELV) to IEC 60950/EN 60950/VDE 0805
The device is designed for operation with safety extralow voltage (SELV). This means that
only safety extra-low voltages (SELV) complying with EC 60950/EN 60950/VDE 0805 can
be connected to the power supply terminals.
The power unit for supplying the device must comply with NEC Class 2 as described by the
National Electrical Code(r) (ANSI/NFPA 70).
The power of all connected power supply units must total the equivalent of a power source
with limited power (LPS limited power source).
7.2
Power over Ethernet (PoE)
"Power over Ethernet" (PoE) is a power supply technology for network components
complying with 802.3af.
● The power is supplied over the Ethernet cables that connect the individual network
components together. This makes an additional power cable unnecessary.
● PoE can be used with all PoE-compliant network components that require little power
(max. 12.95 W).
Restriction of the power supply type
The IEEE standard 802.3af specifies two types of power supply:
● Power via pairs of wires that are not used for data transmission (redundant wires).
● Power via pairs of wires that are used for data transmission (phantom power).
The Ethernet connector of the SIMATIC MV440 reader is four-wire. Power can only be
suppled via these four wires with phantom power. The device supplying the power must
provide the phantom power.
The following Siemens switches with PoE provide phantom power:
● SCALANCE X108POE
● SCALANCE X308-2M POE
● SCALANCE XR324-12M POE
● SCALANCE XR324-4M POE
120
WARNING
SIMATIC MV420 / SIMATIC MV440
Operating Instructions, 04/2013, A5E02371045-06