GAI-Tronics CB193-001 Call Boxes - Manual (Page 29)

Pub.: 43004-031E
Model CB193-xxx, CB194-xxx, and CB195-xxx RF Call Boxes Page 28 of 52
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Phone Line Connection Not Made - Busy Signal or No Answer
Step Action Response
1 User presses and releases
PTT button Call Box wakes from low power sleep mode, checks transmit
channel activity and status lamp slowly flashes red to
indicate unit is operating.
2 No transmit channel activity
detected Call Box keys radio and initiates communication with
PL1877A. Status lamp slowly flashes red to indicate unit is
operating.
3 PL1877A detected and dials
phone number Call Box dials preprogrammed number. Status lamp slowly
flashes red to indicate unit is operating.
4 Phone number has been
dialed Status lamp stops flashing red. Ring or busy signal is
broadcast over speaker.
5 Call not answered or busy
signal PL1877A time out occurs (defined in PL1877A manual) and
PL1877A discontinues transmission to Call Box.
6 Call Box detects a lack of
PTT or carrier detect activity
for the programmed duration The status lamp flashes red, the Call Box terminates the call
with the PL1877A, and emits three tones to the speaker. Call
Box terminates the call by powering down the radio and
audio circuitry. The status light is off and the unit returns to
its low-power sleep mode.