4. 1 3
To make a call during a conference:
(1) Depress HOLD button-all buttons restore.
(2) Select an idle line.
(3) Dial call.
(4) If it is desired to add this call to the
conference while holding this CO/PBX line
button down, depress the conferenced CO/PBX
line buttons.
(5) To reenter conference again after call is
completed, simultaneously depress conferenced
buttons again.
4. 1 4
I f i t i s desired to add another call to the
conference, while holding the conferenced
CO/PBX line buttons down, depress button of
CO/PBX line to be added.
4. 1 5
To prevent dropping one of the participants
when setting up a conference, ensure that
the conferenced CO/PBX line buttons are held down
when adding another station.
Remember:
The system may be disabled
if multiple buttons are left depressed at
an idle station after a conference.
4. 1 6
Conferencing is a mechanical function of
the telephone set and requires no wiring.
D. Pickup, Hold, and Illumination
4. 1 7
The system provides pickup on CO/PBX
and intercom lines and hold on CO/PBX
lines. Lamps provide the following information:
steady lamps are for line busy, flashing lamps for
incoming calls, -:tnd winking lamps for hold.
4. 1 8
The CO/PBX and intercom lines appear on
the same buttons at all stations. By observing
the lamps associated with the CO/PBX and intercom
line buttons, the station user can readily determine
the status of each line. Any station user can pick
up any idle line or place any CO/PBX line on hold.
E.
Tone and Voice Signaling
4. 1 9
All stations are alerted to a n incoming call
by a distinctive tone signal. CO/PBX ringing
is a frequency-shifting tone. Intercom ringing is
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5 1 8-450-1 00
a single tone followed by voice signaling. Voice
signaling is used in conjunction with tone signaling
when calling a station on the intercom. When a
station receives incoming CO/PBX tone signals and
is simultaneously signaled on the intercom, the
intercom signal is given preference.
F.
2-Path Intercom
4.20
The intercom has two separate talking paths.
A path is selected by depressing one of the
two intercom buttons on the telephone set. There
is no privacy on either path and any station may
break into an existing conversation.
4.2 1
When it is desirable for a station to pick
up only the two intercom lines and not have
access to the CO/PBX lines, a 575AM or a 2575AM
telephone set can be used. The 575AM and 2575AM
telephone sets are connected to the 570A KSU by
A25B connector cables (Fig. 30).
4.22
The selector, used to select and alert the
called stations, is shared between the two
paths. The alerting signal at the called station is
a tone burst followed by a voice signal from the
calling station. The lamp signals on the intercom
are as follows: When the selector has seized a
path, the lamp associated with that path will flash
on all telephone sets. This shows the called party
which path to answer.
When the called party
answers, the flashing intercom lamp lights steadily.
When an intercom path is idle, the associated
lamp is off.
4.23
To place an intercom call:
(1) Select idle intercom path and depress
associated button.
(2) Lift telephone handset.
Note:
If lamp is flashing on other intercom
path, dialing cannot take place until the selector
is released. While the selector is seized by
another station, no dial tone or other indication
is available.
(3) Dial selected station-tone burst signals
called station.
(4) Calling station makes announcement or waits
for called party to answer. When called
party picks up, intercom lamp will go steady.
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