Mitel SMB Controller - Page 139

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C
ABLING INTERFACES
CHAPTER 4 INSTALLATION
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 terminals:
NOTE: The maximum number of terminals per S bus depends on the power requirements of the termi-nals
(see Restrictions
).
Figure 4.35: S bus, short
1 – – 1
2 – – 2
3 c c 3
4 f f 4
5 e e 5
6 d d 6
7 – – 7
8 – – 8
Table 4.25:S bus configurations depending on line length and the number of terminals.
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
Table 4.24:Connection of BRI-S terminal interfaces (Continued) (Sheet 2 of 2)