GAI-Tronics 69253-001 Audio Generator Interface PCBA - Manual (Page 2)

Pub. 42004-601L2
69253-001 Audio Generator Interface PCBA Page 2 of 7
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The MCU monitors the output of the Primary Alarm Generator to detect the presence of this tone. Note
that during this test, this tone is not connected to any backplane page resources. The Primary Alarm
Generator may be connected to one of the two backplane page resources on MCU command. The Primary
Alarm Generator can generate tones or playback digitally recorded and stored speech/audio messages with
the optional flash card memory.
Backup Tone Generator
In the event that the Primary Alarm Generator fails to respond to an MCU command, the MCU switches
the backplane page resource from the Primary Alarm Generator to the Backup Tone Generator. The
Backup Tone Generator then assumes operation. This event is reported by a printer attached to the control
unit or by an access panel containing a vacuum fluorescent display attached to the control unit. During
normal conditions, the MCU regularly activates the Backup Tone Generator to test the communication link
and ensure proper working order. However, during this test, the Backup Tone Generator audio is not
switched to any backplane page resources.
Fail-safe Tone Generator
The Fail-safe Tone Generator can be activated by the AGI if communication with the MCU is disrupted.
This occurs if the MCU is malfunctioning. The Fail-safe Tone Generator remains active until
communication with the MCU is restored. This alerts personnel that a trouble condition exists between the
MCU and the AGI. The Fail-safe Tone Generator is linked directly to the 10457 Series backplane,
allowing the Fail-safe Tone Generator to operate without interference from the MCU.
Supervisory Tone Generator
The Supervisory Tone Generator produces a tone that is used by the MCU to survey central amplifiers and
associated speaker runs. This health check is performed periodically at the command of the MCU. If this
health check fails at any point, a message is reported by a printer attached to the control unit or by an
access panel containing a vacuum fluorescent display attached to the control unit. The message identifies
the speaker loop at which the failure was detected.
Additional Features
In addition to providing the tones above, the audio generator also provides the following features:
Feature Benefit
One 600-ohm, 0-dBm (line-level)
balanced input (transformer isolated) Allows an additional input to the system from such devices as
telephone interfaces, (e.g. TI984), radio interfaces and other
600
Ω, 0-dBm devices.
One 33-ohm/600-ohm (jumper
selectable), 0-dBm (line-level) balanced
input (transformer isolated) Allows an additional input to the system from such devices as
telephone interfaces (e.g. TI984), radio interfaces and other 600
Ω, 0-dBm devices or from a 33-ohm Page/Party
®
line.
One 600-ohm 0-dBm output
(transformer isolated, adjustable volume) Allows an output to other 600-ohm devices such as a logging
recorder.
Three dry-contact closure inputs Provides for control signals from such devices as radio
interfaces or telephone interfaces (e.g. TI984).
Four relay contact outputs To control auxiliary devices such as radio interfaces or
telephone interfaces (e.g. TI984).