ASCOM Ascotel 2025 System Manual page 804

AD2 Interface
Never install the Y bus by interrupting it at the storey distribution board. Only use
commercial adapters to connect e.g. two Office system terminals to the same ter-
minal socket-outlet.
The max. length of an AD2 connection via secondary, tertiary and patch cables
must not exceed 100 m in compliance with UGV guidelines. Both patch cables
together can be a max. 10 m.
S-bus Crossover
On the S-bus user-network interface the pairs c/d and e/f are wired in a different
sequence on an RJ45 connector than on the UBC / ISDN network side.
Observe the following installation rules:
• Always terminate the bus extremity with 2 x 100 W (0.25 W, 5%)!
• Carry out the necessary crossover on the subscriber side of the PBX.
• If the subscriber cabling is integrated into the installation of a universal building
cable installation (UBC), cross over the S bus as shown in Fig. 4.26.
NT RJ45
f
c
d
e
UBC / ISDN network cabling
Fig. 4.26: S-bus crossover in the universal building cable installation
HBT_20321104_04/B0_en
UBC
f c d e
3
4
5
6
f
c
d
e
haz0317aaenb0
ascom
PBX
T S
f c d e
c
f
e
d
S-bus cabling
Ascotel 2025/2045/2065
UBC RJ45 Terminal
3
c
4
f
5
e
6
d
Connecting the PBX 4.33