Phoenix Contact 1708 M12 POE, Руководство пользователя, Страница: 18 / 34

FL SWITCH 1708 M12 POE
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PHOENIX CONTACT 105648_en_01
at a time, starting with port 8, until the resulting system load is below 200 W again. The PoE
status LEDs of the PDs deactivated by the management system flash twice every 2 sec-
onds.
Another reason why the contact may be opened is the overload of one or more connected
PDs. This happens, for example, in the event of an error (e.g., short circuit) at a PD. The PoE
port where the error occurred is disconnected by the power management system. The PoE
status LED of the corresponding port indicates this state by flashing at 5 Hz. The port can
only be supplied again when the cause of the overload has been removed and the PD has
been reconnected to the device.
In addition, both overload responses are also indicated by the activation of the FAIL LED,
which remains active, regardless of whether the PoE port has been reset, until the signal is
reset by a High signal at the digital input (e.g., by using a key switch). Provided there is no
other error state at the PoE ports at that time, the N/O contact closes again and the FAIL
LED goes out.
3.3.1 Method of operation of the PSE system
The maximum total PoE power of the system that can be managed is 200 W.
A newly connected powered device (PD) is only supplied with power if the currently calcu-
lated power consumption of all devices plus the worst case power consumption of the new
PD (4 W, 7 W, 15 W or 30 W depending on the classification) allows a power reserve of at
least 15%.
As soon as the power consumption of the connected PDs exceeds the total power during
operation, low-priority ports are switched off in order of priority until the resulting total power
is no longer exceeded.
If the current power consumption exceeds the available total power by 10% or more, all low-
priority ports are instantly switched off.