T-Home Comfort Pro S, Installation Manual

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43
Port assignment, Termination, Cable Length Installation
IAE = ISDN wall socket (German ISDN „Anschluss Einheit“ )
If the S0 bus is coming from the Comfort Pro S leading to one or
more IAE sockets, the terminating resistors (“TR”) in the
Comfort Pro S and in the most distant IAE socket needs to be
switched on.
If the cabling of the S
0
bus is realized with two lines, outgoing from
the Comfort Pro S and leading to several IAE sockets, the termi-
nating resistors (“TR”) in both most distant IAE sockets needs to be
switched on. The terminating resistors in the Comfort Pro S must be
switched off. The S
0
bus should not be installed as star topology.
Sub-distributions are not allowed either.
Termination on an IAE socket: IAE sockets with built-in resistors are
recommended, because the terminating resistor can be switched
on or off with a mechanical switch. The figure shows how to mount
resistors in an IAE socket without switchable resistors.
You can add S
0
ports by installing appropriate S
0
interface cards in a slot. These S
0
ports can be switched
between internal and external operating modes.
Pressure terminals are used for internal and external S
0
ports. The
connection assignment of the pressure terminals changes when
switched from internal to external, as shown in the diagram above.
Line termination:
Enabled
IAE IAE IAE
Line termination:
Disabled
IAE IAE IAE
1a
1b
2a
2b
TR
TR
S
0
int
2a 2b 1a 1b
1 2 3 4 5 6 7 8
S
0
ext
1a 1b 2a 2b
1 2 3 4 5 6 7 8