GAI-Tronics CB193-001 Call Boxes - Manual (Page 17)

Pub.: 43004-031E
Model CB193-xxx, CB194-xxx, and CB195-xxx RF Call Boxes Page 16 of 52
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Functional Description
Each GAI-Tronics RF Call Box is typically in a low-power sleep mode when not in use (factory default
setting). In this state, the radio is powered down and all audio circuitry is disabled. The processor is in a
low-power sleep mode, waking periodically to check the battery voltage. The sleep mode can be disabled
via the CARD Suite Software to provide receive capability at all times (call box-to-radio or call box-to-
call box operation only.) In this mode, the Call Box must be connected to a constant 13.8 V dc supply
(or 12 V dc if battery is not used.) When used for call box-to-telephone operation, there is no need to
disable the sleep mode as all calls must be initiated by the RF Call Box.
RF Call Box-to-Radio Operation
Pressing the PTT button or the handset pressbar removes the Call Box from the low-power sleep mode
and enables the radio and the audio circuitry. The front panel status lamp lights red, while the Call Box
momentarily monitors the transmit channel for activity, and (when ANI is enabled) broadcasts its
programmed ANI code if there is no other radio traffic.
When the radio traffic is clear and after transmitting the ANI code, a “go-ahead” splash tone is generated
over the speaker or handset receiver and the front panel status lamp turns green. Speak in a normal voice
at arm’s length distance from the push button models or into the handset microphone while holding the
pressbar. When finished, release the button or pressbar. The radio ceases transmission and waits for
receive audio. The front panel status lamp lights red whenever receive audio is present.
Continue conversation in this push-to-talk, release-to-listen manner. After conversation has ended, the
RF Call Box returns to sleep mode with the absence of carrier activity after a preprogrammed amount of
time (factory set at 10 seconds).
Call Box-to-Call Box Operation
In this operation application, the RF Call Box will function similarly to the RF Call Box-to-Radio
operation, as each Call Box is actually a radio. Operation is push-to-talk/release-to-listen and the
transmitting Call Box first monitors the transmit channel and provides a busy signal (if busy) or “go-
ahead” splash tone if the channel is clear. In this mode of operation, the ANI feature is not used, and the
RF Call Box will not “go to sleep” to conserve power (must be programmed for “Standby Forever”
operation). A constant external power source is required.
RF Call Box-to-Telephone Line Operation
In the call box-to-telephone line operational mode, a phone call is initiated by momentarily pressing and
releasing the PTT button or handset pressbar. The front panel status lamp flashes red indicating a wait
signal. During this time period, the RF Call Box is interfacing with the Model PL1877A Telephone
Interconnect. When the telephone interconnect is accessed, the RF Call Box dials a pre-programmed
telephone number. When the phone line is accessed, the front panel status lamp changes to a steady red.
A ringing or a busy signal will be heard on the speaker or handset receiver.