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CCS-IP2 CALL STATION
User Manual
page 46/52
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APPENDIX B (REFERENCE)
POE FUNCTION IN CCS-IP2
Power over Ethernet (PoE) – technology which enables to transmit electrical power to
a remote device along with data, via a twisted pair on an Ethernet network according to
the IEEE 802.3af standard. The technology is advantageously used where power cable
installation is difficult, undesirable or economically unviable.
IEEE 802.3af standard – active PoE, describes two types of PoE devices:
–
power device or injector (Power Sourcing Equipment – PSE), which is designed
to supply power to the Ethernet network;
–
device which is powered via Ethernet (Powered Device – PD).
DC voltage from the power devices is applied to the powered devices.
The IEEE 802.3af standard provides for remote power supply via free pairs of Ethernet
cable according to Figure B.1:
A) Using high frequency transformers at both ends of the line with the center tap of
the windings. DC voltage supplied to the center tap of the secondary windings of
these transformers, and also a central tap is removed on the reception side.
B) Using free pairs to connect power.
Figure B.1 –
Remote power supply setup according to the
IEEE 802.3af standard
CCS-IP2 satisfies requirements of the IEEE 802.3af standard on automatic
determination of power rating. When using a load detection procedure in an active PoE
power device (injector), supply voltage in the line will be turned on only after confirmation
that the load class matches power supply capabilities. CCS-IP2 satisfies Class 0 load
parameters, the characteristics of this class are given in Table B.1.