Aastra 470 System Manual

Installation
142
Aastra 470 ab R3.0
syd-0337/1.5 – R3.0 – 05.2013
Connection
Tab. 60 Connection of BRI-S terminal interfaces
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. 61 S bus configurations depending on line length and the number of terminals.
Note
The maximum number of terminals per S bus depends on the power
requirements of the terminals (see "Restrictions", page 143).
Fig. 49 S bus, short
Communication server Cable cores Connection socket
Socket Pin
BRI-S sig-
nal
BRI-S sig-
nal
Pin Socket
1– –1
2– –2
3c c3
4f f4
5e e5
6d d6
7– –7
8– –8
S bus Short Short, V-shaped Long Point-to-point
Length (max.)
Server  Terminal
Terminal 1  Terminal 4
150 m
–
2  150 m
–
500 m
20 m
1’000 m
–
Number of terminals (max.) 8 8 4 1
















1.
2.
3.
max. 150 m
2 x 100 Ω
Communica-
tion server
8. Connection
point

Aastra 470 Specifications

General

Brand	Aastra
Model	470
Category	Telephone
Language	English