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1.4.3
System Components
The system is made up of the following items; main equipment (ME-AN), stations and powerfail bells. In
addition the following items are available; call metering unit
two-wire extender unit
tie
line unit
and the ring generator unit
Main Equipment
The main equipment consists of a one shelf rack which houses a removable power supply and a number of
polarised plug-in printed circuit boards. Refer to table
for details of the printed circuit boards
housed in the main equipment rack.
BOARD
BOARD DESCRIPTION
MAXIMUM
CODE
QUANTITY
CPB-AN
CENTRAL PROCESSOR BOARD (ESSENTIAL)
1
This board has the main CPU, ROM containing the operational programme, RAM
containing site dependent data and abbreviated dial numbers, the dialling
circuits and station-to-main CPU interface circuits.
SLB-AN
EXCHANGE LINE STATION BOARD
4
This board contains interface circuitry for 2 exchange lines and 4 stations, the
crosspoint matrix and powerfail relays.
TMB-AN
OPTIONAL FACILITIES BOARD
1
This board contains voice switch circuits, real time clock data, internal
music-on-hold generator and interface circuits for external music source and
external paging.
TWO-WIRE STATION LINE BOARD
3
This board contains interface circuitry for two exchange lines and four standard
telephone stations, the crosspoint matrix and powerfail relays.
CDRB-AN
CALL DETAILS RECORDER BOARD
1
This board contains circuitry to interface with a printer to print a record of
outside line calls.
S t a t i o n s
Table
BOARDS USED WITH ME-AN
There are three types of stations; basic, on-hook and handsfree stations.
Basic stations contain a telephone network including handset, a dial key pad, non locking function keys,
status lamps and electronics to control the station’s operation.
On-hook stations contain, in addition to the above, a microphone, a speaker and a volume control.
Handsfree stations also contain additional function keys, a handsfree board and a display capable of
displaying a large variety of information.
(iii) Powerfail Dial
A powerfail dial, either decadic or VF, can be installed into an on-hook or a handsfree station to provide
dialling facility during power failure. The dial contains an electronic buzzer to indicate the incoming calls
during power failure.
(iv)
Call Metering Unit
The call metering unit may be connected to exchange lines to provide an indication of the number of meter
pulses sent from the local exchange.
23
AN-61 6
ISSUE
1