Mitel Aastra 470 System Manual page 138

Installation
Connection
Tab. 62 Connection of BRI-S terminal interfaces
Communication server
Socket Pin
1
2
3
4
5
6
7
8
S bus configuration
The S bus is a four-wire, serial ISDN bus based on the DSS1 protocol (ETSI standard).
It starts in each case at an BRI-S interface of the communication server. Four bus
configurations are possible, depending on the line length and the number of ter-
minals:
Tab. 63 S bus configurations depending on line length and the number of terminals.
S bus
Length (max.)
Server  terminal
Terminal 1  Terminal 4
Number of terminals (max.)
Note
The maximum number of terminals per S bus depends on the power
requirements of the terminals (see
Communica-
tion server
Fig. 50 S bus, short
138
Cable cores
BRI-S sig-
nal
–
–
c
f
e
d
–
–
Short Short, V-shaped Long
2  150 m
150 m
– –
8 8
1.
max. 150 m
Connection socket
BRI-S sig-
nal
–
–
c
f
e
d
–
–
500 m
20 m
4
"Restrictions", page
8. Connection
2. 3. point
Pin Socket
1
2
3
4
5
6
7
8
Point-to-point
1'000 m
–
1
139).
2 x 100 Ω
Aastra 470 as of R3.2
syd-0337/1.6 – R3.2 – 09.2014