APPLICATION NOTES:
PoE for ROAMEO Access Points
ROAMEO is a wireless matrix system from RTS. In this Application Note, we will look at a way of connecting the
ROAMEO Access Points using Power over Ethernet, PoE.
Power over Ethernet is a way of simplifying wiring for devices that connect to Ethernet. With PoE, there is no
need for a separate power supply. There is an upper limit on the amount of power that can be supplied using
PoE, and the limit is dependent on the type of PoE switch used. In general, PoE is intended for devices that
require little power, up to about 13 Watts. (There is another standard called PoE Plus, which allows up to 25
Watts of power, but we will not get into that here.) With PoE, the data signal is superimposed on the power.
On the receiving end, filters are used to pick out the data from the power. When a PoE device is turned on, it
communicates with the PoE switch to “negotiate” the right electrical parameters. For this reason, PoE devices
can never be connected in cascade.
The ROAMEO Access Point, AP-1800, is designed to
be tolerant to PoE, but it is not designed to use PoE
directly. Expressed differently, it is PoE tolerant but
not PoE enabled. RTS does supply a PoE adapter kit, to
allow the AP-1800 to work with a PoE enabled switch.
The PoE kit is shown in Figure 1.
The PoE adapter is designed to support three different
voltages. The AP-1800 expects 12 V. The setting on the
PoE adapter (TP-Link) must be set to 12 V before it is
connected to the Access Point. This is shown in Figure
2. To set it to 12 V, slide the little selector to the left.
Note if the selector is in the wrong position, nothing will
break. The AP simply will not power up.
The kit can be ordered as any other part. The part
number is F.01U.335.167 (POE ADAPTER 12V) and it
contains the following parts:
• The PoE adapter
• A barrel adapter
• A short DC-cable
• Two Ethernet-cables
Figure 1. The PoE kit for AP-1800
INTRODUCTION
Figure 2. The voltage selector should
be in the left-most position for 12V
SETTING THE VOLTAGE ON THE PoE ADAPTER
WHAT IS PoE?
THE ROAMEO AP
