86
en | Installation wiring
PRAESENSA
2021.12.21 | V0.15b | F.01U.402.882
Underwriters Laboratories Listing Document (ULLD)
Bosch Security Systems B.V.
3.8.5
Power over Ethernet
The call station has two Ethernet connection ports with a built‑in Ethernet switch, supporting
RSTP for Class N pathway realization. The call station is an PoE Powered Device (PD). It
provides the correct signature and classification to power sourcing equipment (PSE), so that a
PSE sources the right amount of power to a PD over the Ethernet cables. Although it is
sufficient to provide PoE power to only one port, both Ethernet ports take PoE power for
cable redundancy and supply redundancy. For best availability it is advised to connect each
port to a different, independent PSE, such as a PRA-MPS3 multifunction power supply (ports
1 and 2) or a PRA-ES8P2S Ethernet switch (ports 1‑8). In case one of the connections fail, or
one of the PSE sources fail, the operation of the call station is not affected. With both
connections to the same PSE, there is still connection redundancy but no PSE redundancy.
The ports of the call station can be looped through to another PRAESENSA device, but at least
one port must be connected to a PSE to power the call station and its extensions. With only
one port connected to a PSE, there is no connection redundancy.
The call station ports cannot source PoE power to subsequent devices, such as another call
station.
To connect the call station, follow the procedure below:
1.
Remove the cable cover at the bottom of the call station using a TX10 screwdriver.
–
Get access to the two screws via the holes in the table stand bracket.
2.
Use one or two Gb‑Ethernet cables with RJ45 connectors to connect the call station to a
PSE port, with PoE enabled.
3.
Put back the cable cover with the two TX10 screws.
