Interfaces and Connectible Terminals
109
Internal S
0
Ports
Up to eight ISDN terminals per bus can be connected to the internal S
0
ports
by means of four-wire cables. Three of these terminals can be supplied with
power from the bus; any additional terminals will require their own power
supply. The internal S
0
buses can be used for point-to-multipoint
connections in accordance with the DSS1 protocol (Euro ISDN).
ISDN terminals can be connected to internal S
0
ports by means of a crossed
ISDN cable. For the pin assignment of crossed ISDN cables, refer to the
illustration
on page 108. If the terminal did not
come with a suitable ISDN cable, contact your Proximus service centre.
The length of an internal S
0
bus cable must not exceed 150 m. Each internal
S
0
bus has a power feed of approx. 3 W. The feed voltage is –42 V.
U
pn
Ports
Terminals Connected to U
pn
Ports
System telephones and Forum Base DECT v2 base stations can be connected
to and U
pn
port. The older Forum Base DECT base station cannot be
connected.
The Forum Base DECT v2 base station can be used to connect the Forum Free
DECT handsets. Note that handsets such as the Forum Free 567/577/587
can also be used in conjunction with base stations operating with the GAP/
CAP standard.
Technical Information
The U
pn
ports have been implemented as RJ45 sockets.
Each of the devices listed above can be connected to the U
pn
interface by
means of a two-wire 1:1 cable. System terminals come with a suitable cable
for connection to the RJ45 socket of the interface.
A two-wire cable connected to a U
pn
port can be up to 1000 m long,
provided it is a 0.6 mm twisted-pair cable.
Each U
pn
port has a power feed of approx. 2.1 W. The short-circuit-proof feed
voltage is –42 V.
