Ruijie RG-S2900G-E Series, Руководство по настройке

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Configuration Guide Configuring PoE Configuration
PoE Configuration
Overview
Introduction
Basic Concepts
Power over Ethernet (PoE) is a technology for transmitting electric power and data over twisted pairs to devices on an
Ethernet. It enables numerous devices such as Internet phones, WiFi Access Points (APs), Internet cameras, hubs, and
PCs to directly obtain power supply from twisted pairs.
In a PoE system composed of PoE switches, a PoE switch plays the roles of both PoE power supply and Power Sourcing
Equipment (PSE). Users' power consumption devices such as WLAN APs and Voice over IP (VoIP) phones can all be
called Power Devices (PDs). The longest power supply distance of a PoE switch is 100 m according to related standards
and specifications. The PoE switch supports statistics about the power supply of each port and statistics about the power
supply of the entire switch. The statistics can be displayed using related query commands.

If the working environment temperature is not higher than 35

C and the current power consumption of the PoE
switch is not higher than 50% of the rated power of the PoE switch, the cooling fans of the PoE switch will not run
and the entire switch will be in mute state.

If the working environment temperature is above 35

C or the current power consumption of the PoE switch is higher
than 50% of the rated power of the PoE switch, the cooling fans of the PoE switch will start running with automatic
speed control to quicken heat dissipation inside the PoE switch.

In this document, the voltage is expressed in volts (V for short), current in milliampere (mA for short), and power in
watts (W for short).
The PoE system consists of the following three components:
PoE Power Supply
The PoE power supply will supply power to the entire PoE system. It is classified into external power supply and internal
power supply. Of Ruijie products, box-type PoE switches generally contain internal power modules and some may also
support external power supply. The external power supply is called Remote Power Supply (RPS).
PSE
The PSE searches and detects PDs on the line of its PoE interface, classifies PDs, and supplies power to PDs. The PSE
stops supplying power to a PD once detecting that the PD is unplugged.
PD
PDs receive power supply from the PSE. PDs are classified into standard PDs and non-standard PDs. Standard PDs are
PDs in compliance with IEEE 802.3af and 802.3at. A PD can be connected to other power supply sources while receiving
power supply from the PoE so as to implement power redundancy.