operating voltage, maximum supported current, overcurrent protection, effective distance and other
parameters. The table below summarizes all key parameters of both IEEE standards relevant for
RAy units.
Tab. 4.1: PoE standards according IEEE802.3at/bt and their relevance for RAy units
PoE++
PoE+
IEEE 802.3bt
IEEE 802.3at
Standard*
Type 3 (Type 4)
Type 2
PoE Sub-Type
60 W (100 W)
30 W
PoE Max. Power
50 (52) - 57 V
50 - 57 V
PoE Voltage Range
51 (71) W
25.5 W
Device Max. Power
42.5 (41.1) - 57 V
42.5 - 57 V
Device Voltage Range
Cat5 or better
Cat5 or better
Supported Cables
4-pairs, 2**-pairs
2-pairs
Twisted Pairs Used
RAy3-10, RAy3-11, RAy3-18,
RAy3-80
RAy3-17, RAy3-24, all RAy2 and RAy1
Suitable RAy units
*Most of IEEE 802.3bt power supplies support also IEEE 802.3at standard. Those are marked as
'IEEE 802.3at/bt compatible'.
**2-pairs are not recommended, but allowed for 'PoE Type 3' (for low power devices only)
•
Passive PoE power supply
(called sometime PoE injector) is an equipment pushing input DC power
into the pins of Ethernet connector without recognition of RAy unit. It can operate in whole extended
voltage ranges
. Internal RJ45 pins wiring are identical with Active PoE
(mentioned above). Typically, the current is sourced from a DC power with adequate parameters.
The only additional requirement is that non-grounded wire of DC power circuit to the PoE injector
has to be secured by a fuse disconnecting the power circuit in the case of over current (similar like
for DC power source connected directly to the RAy unit by a DC connector).
•
Note
Pasive PoE power supply has to ensure enough voltage and enough current to the RJ45
connector (ETH1+POE). For RAy3-10, RAy3-17 and RAy3-24 the power voltage has to be
at least 20 V, for booting 21 V (to prevent booting with discharged 24 V battery). For other
RAy3 models the minimum power voltage has to be at least 37 V. For all models both polar-
ities of DC are supported. More details can be found in
Section 1.3.1, “RJ45 connector
.
PoE with 8-wires is strongly recommended for RAy3-10, RAy3-18 and RAy3-80 due to their
power consumption bigger than 25 W. PoE with 8-wires is an advantage also for other RAy3
models with low power consumption to minimize the energy lost in the Eth cable (it lowers
the resistance of the Eth cable to half compared with 4-wires PoE).
Quality connectors (like
40
) are recommend to be used on both ends of
Ethernet cable to ensure long-term reliability of the connection. Such connectors have better
resistance against oxidation and also against scorching contacts due to spikes during power-
on and power-off the unit by plug / unplug Ethernet cable. Anyhow standard Eth cable with
standard Eth connectors should work as well.
40
https://www.racom.eu/eng/products/microwave-link.html#accessories_cable
RAy3 Microwave Link – © RACOM s.r.o.
70
Installation
Содержание RAy3-11
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