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3.4.5 PoE indicators
The PoE A indicator is ON when power is supplied over data (pairs 1, 2 and 3,
6). The PoE B indicator is ON when power is supplied via free pairs (pairs 4, 5
and 7, 8).
3.4.6 LINK indicators
A blinking LINK indicator shows that data are transmitted via the corresponding
port.
3.4.7 Power indicators
Power indicators show the presence of power supply on the switch boards.
3.5 Tamper sensor
The optical tamper sensor is located inside the switch (Figure 3.5.1). The optical
tamper sensor is more reliable than sealed and limit switches, because it does
not get stuck and does not chatter. Its operating principle is simple. When the
power supply unit is closed, a curtain (Figure 3.5.2) installed on its cover
discontinues the optical flow. When the power supply unit is opened, the curtain
moves out of the sensor and triggers it.
Figure 3.5.1 Tamper sensor on the switch board
