4.15.2 System Configuration. Planet WGS-804HPT, WGS-4215-8T, WGS-4215-8T2S

User’s Manual of WGS Managed Series

4.15.2 System Configuration

In a power over Ethernet system, operating power is applied from a power source (PSU-power supply unit) over the LAN infrastructure to powered devices (PDs), which are connected to ports. Under some conditions, the total output power required by PDs can exceed the maximum available power provided by the PSU. The system with a PSU is capable of supplying less power than the total potential power consumption of all the PoE ports in the system. In order to maintain the function of the majority of the ports, power management is implemented.

The PSU input power consumption is monitored by measuring voltage and current .The input power consumption is equal to the system’s aggregated power consumption .The power management concept allows all ports to be active and activates additional ports, as long as the aggregated power of the system is lower than the power level at which additional PDs cannot be connected .When this value is exceeded, ports will be deactivated, according to user-defined priorities. The power budget is managed according to the following user-definable parameters: maximum available power, ports priority and maximum allowable power per port.

Reserved Power

There are five modes for configuring how the ports/PDs may reserve power and when to shut down ports.



Classification mode

In this mode each port automatic determines how much power to reserve according to the class the connected PD belongs to, and reserves the power accordingly. Four different port classes exist and one for 4, 7, 15.4 and 30.8 watts.

Class

0

1

2

3

4

Usage

Default

Optional

Optional

Optional

Optional

Range of maximum power used by the PD

0.44 to 12.95 watts

0.44 to 3.84 watts

3.84 to 6.49 watts

6.49 to 12.95 watts (or to 15.4 watts)

12.95 to 25.50 watts (or to 30.8 watts)

Class Description

Classification unimplement

Very low power

Low power

Mid power

High power

Table 4-16-1: Standard PoE Parameters and Comparison

1. In this mode the Maximum Power fields have no effect.

2. The PoE chip of PD69004 designed to that Class level 0 will be assigned to 15.4 watts in

AF mode and 30.8 watts in AT mode under classification power limit mode. It is hardware limited.



Allocation mode

In this mode, the user allocates the amount of power that each port may reserve. The allocated/reserved power for each port/PD is specified in the Maximum Power fields. The ports are shut down when total reserved power exceeds the amount of power that the power supply can deliver.

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