Phoenix Contact 1708 M12 POE, User Manual, Page: 17 / 34

Startup and function
105648_en_01 PHOENIX CONTACT
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3 Startup and function
3.1 Basic settings
3.1.1 Delivery state/default settings
The following functions and properties are available by default:
– The available M12 ports are set to auto negotiation and autocrossing
– The alarm contacts only open in the event of a PoE system or PD (powered device)
overload
– The MAC address table does not contain any entries
3.2 Special notes regarding the use of PoE
For easy configuration, the complete performance framework of PoE/PoE+ is available at
all eight ports, provided the combined total power consumption of all connected powered
devices (PDs) does not exceed 200 W. Otherwise, the internal PSE management system
for the PoE switch makes sure that, starting with the port with the highest number (x8), the
ports are deactivated by the system one at a time until the resulting total load falls below this
threshold value again.
Maximum freedom and flexibility is ensured as it is possible to connect PoE as well as PoE+
loads at all eight ports. Thanks to the power status display, i.e., the power bar, you can de-
termine at a glance how high the current power consumption is in relation to the maximum
power provided. The last red LED on the bar starts to light up as soon as insufficient system
power is available to connect a new class 1 PD (max. 4 W) to the system, since otherwise
a safety margin of 15% of 200 W can no longer be maintained for the continued safe oper-
ation of the PoE loads already connected.
If at some point during operation there is an overload situation in the form of the total per-
missible PoE load of 200 W being exceeded or an overload of a connected PD, this is indi-
cated by a FAIL LED being activated and by a signal contact being opened. Even after the
system has independently removed these overload situations by switching off low-priority
ports or by deactivating the overloaded PD, the FAIL LED is still active and the signal con-
tact is still open. The signal contact can be reset manually via a digital input.
The PSE system of the PoE switch is designed so that it is possible, in principle, to use
PoE/PoE+-capable powered devices (PDs) with a power consumption of up to 30 W each
on all eight ports, provided the total PoE load of the switch does not exceed 200 W.
3.3 Overload response and reset
The diagnostic socket has a standard digital input (DI) and a relay output (N/O contact). The
input and output are in the M12 connector integrated in the housing.
The relay opens the contact on the one hand as soon as the PoE power management sys-
tem of the module finds itself in a PoE overload situation, i.e., as soon as the current total
power consumption of all PDs rises above 200 W. In this case, the PDs are switched off one