Powerfail Bell
A powerfail bell may be connected to the systems to provide incoming audible signalling
when a power failure occurs.
When the power fails the powerfail bell will be connected in parallel with the powerfail
station.
The powerfail bell consists of a capacitor, a bell and a lamp that flashes with the incoming
ring (fig. 25).
Handsfree Console
A handsfree console
may be connected to a station to provide full handsfree
capability for all types of calls (fig. 24).
(vii)
Call Metering Unit
The call metering unit may be connected to exchange lines to provide an indication of the
cost of calls. The call metering unit records meter pulses sent from the local exchange (fig.
26).
(viii)
Remote Extension and Tie Line Interface Unit
The
is a small sub rack which provides the possibility to interface with remote
extensions or tie lines with a maximum capacity of two interfaces per sub rack and a
standard card.
The
is equipped with its own power supply
The components which can be
used with the
are shown in Table 2 (fig. 27).
Ring Generator Unit
The ring generator unit (figure
generates ring voltage for Internal Extensions. The RGU
is used in conjunction with the
The RGU is capable of providing ring voltage for
up to two
boards.
1.4.2.2
Customer Provided Optional Equipment
Standard
RTB-A
Options
RRB-A
LRB-A
RXB-A
Table 2 :
BOARDS
Ring and Tone Source
Ring-in, Ring-out Tie Line Interface
Loop-in, Ring-out Tie Line Interface
Remote Extension Interface
616.1236. 2260 Interface Circuit for RXB-A
Note:
For a remote extension a pair of cards are required, the RXB-A card and the
card which is a main equipment interface card. For each remote
extension both cards must be provided.
Loudspeakers or a public address system with 8 ohm input impedance for external zone paging
options.
A music source for background music and hold music.
An alarm detector or supervisory system for alarm signalling
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