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Gemini G3 - User Manual
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Appendix 1 - "Officer Requires Assistance" alarm function
Overview
The DTE Port Interface pin 9 (AUX) on DEV-2 is used for the
“Officer Requires Assistance”
alarm func-
tion.
Intended Audience
This appendix is designed for use by System Integrators.
Physical Connection
This auxiliary input may be activated by (normally open) dry contact pull-up to the port’s DSR output
(pin 6). It can also tolerate user pull-up resistor via an external (+10.8 to 16 volts DC power supply). An
isolated dry contact is preferred due to the risk of noise-related false alarms caused by the vehicle’s elec-
trical system.
Method 1:
Using a dry contact only
Figure 57 - Appendix 1 – Alarm Function, Dry Contact Connection
Method 2:
Using an external supply and pull-up resistor
Figure 58 - Appendix 1 – Alarm Function, External Power Supply & Pull-up Resistor
The GeminiG3 radiomodem polls the AUX2 line every 50 msecs. After the GeminiG3 unit debounces a
closed contact for approximately 1000 msecs, it triggers the alarm function.
Operation
When using Gemini
G3
product running firmware version 2.1 or later, activating the
“Officer Requires
Assistance”
alarm input starts emergency communications:
•
On systems using DMP-transition facilities, the modem sends a DMP
“x”
or
“y”
message through to
the MSC2 to the Host PC.
•
The alarm generates an SNMP trap. The trap report is repeated at a factory-set rate (default is 15 sec-
onds) for 1 minute.
Can also be manually cleared via the MIB Browser.
Dry Contact N.O.
DEV-2
DSR-Pin 6
AUX2- Pin 9
Dry Contact N.O.
DEV-2
DSR-Pin 6
AUX2- Pin 9
DTE
Dry Contact N.O.
DEV-2
AUX2- Pin 9
Pull-up Resistor
10 Ohm 1/4watt 5%
External Voltage
Source
10.8 to 16 volts dc