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Document 15949 Rev. E 4/12/95 P/N 15949:E
Backup Alarm Bus
- The interconnection of alarm bus cables between each AIM-200
provides backup general alarm capability in the event of communications failure with the
CPU. Under this condition, the following events will take place.
When an alarm occurs on an AIM-200, output modules mapped to the alarmed zone will be
activated. The AIM-200, unable to communicate with the CPU, will assume general alarm
responsibility and will close its own alarm bus cable connection. This has the same effect as
a signal from the alarm relay--all AIM-200s receive an alarm bus cable closure and enter a
general alarm condition.
Figure A-1: Alarm Bus Activity
Signal Silence Function - Signal Silence will only function for those CMX-2s that have
been programmed as notification appliance modules (software type
C
) and have been pro-
grammed for general alarm service (see the
General Alarm Service section of this docu-
ment).
The Signal Silence function is exercised by first closing, then opening, the alarm bus cable
connection. The closure occurs after initiation of an alarm—when the alarm relay changes
state. The opening occurs when the SIGNAL SILENCE switch is pressed—the Alarm Relay
is silenced, opening the alarm bus connection. This signals the AIM-200(s) to silence all
general alarm CMX-2 modules.
Signal Silence has no effect on CMX-2 Control Modules that are Form-C
(
Type
CO
)
, ad-
dress 60 or higher, or that are mapped to any AIM-200 zone. These modules can only be
silenced by the RESET switch on the CPU.
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