1.5 BLOCK DIAGRAM DESCRIPTION
1.5.1
System Block Diagram
This shows the main items of the system and their interconnection.
LOCAL
P B X L I N E S
S T A T I O N
M A I N
U I P M E N T
M E - A N
RING GEN.
UNIT
RGU -AN.
E X T .
- -
TIE LINE INTER-
FACE UNIT
TIE LINES
Fig. 1.5.1
SYSTEM BLOCK DIAGRAM
Incoming Local Exchange Lines or PBX Lines are connected to the main equipment. A Call Metering Unit
may be used to record meter pulses sent from the local exchange. Tie Lines are connected via a tie line
interface unit
Powerfail bells, if used, are automatically connected across incoming exchange lines when the power fails.
Stations and standard telephone extensions are connected to the ME ports. Handsfree, on-hook and basic
stations are connected to ME by 4 wires, one pair is the speech pair and the other is for data transmission
and power feed to the station.
Standard decadic telephones, standard telephone stations, are connected to the ME by a single pair of
wires. Audio communication and decadic signalling are performed on this pair. A special interface and Ring
Generator Unit are provided if standard telephones are used.
The Two-Wire Extender Unit increases the maximum allowed loop resistance for standard telephone
stations to 1500 ohms (8.5 km of
cable).
1.5.2
Main Equipment Block Diagram
C R O S S P O I N
- I N T E R F A C E
M A T R I X
R
I
B-PAIR
INTERFACE
L
GFNFRATOR
VOICE
S W I T C H E S
C P U C O N T R O L
EXTERNAL
PAGE
AUDIO PATH
DATA PATH
PB-AN
Fig. 1.5.2
MAIN EQUIPMENT BLOCK DIAGRAM
25
AN-61 6
ISSUE
1
