120 20110-003 PRELIMINARY
Gemini/PD Technical Manual
1
1. PRODUCT OVERVIEW
This document provides the information
required for the operation and maintenance
of the
DATARADIO
Gemini/PD mobile radio-
modem.
1.1 Intended
Audience
This document is designed for use by engi-
neering design, installation, and mainte-
nance personnel.
1.2 General
Description
Gemini/PD is a mobile radio-modem aimed
at the public safety and public utility markets
to meet demand for high speed and high
throughput. It integrates all the necessary
hardware for data-only vehicular installations
up to but not including the laptop PC and its
application software. Example of
applications are:
1.
Database inquiry systems.
Small number of brief messages, (usu-
ally from the mobile station) with fairly
long responses.
2.
Computer-aided dispatch (CAD).
Large number of messages, (usually
from the base station) with very brief
responses.
3.
Automatic Vehicle Location (AVL).
Using a GPS receiver, determines posi-
tion, speed and direction of fleet mem-
bers.
The Gemini/PD is made-up of a main
transceiver and a auxiliary receiver for
Parallel Decode (PD), a 40 Watt power
amplifier, a Gemini Control Unit (GCU) with
DSP driven modem and an integrated OEM
GPS receiver.
Features:
•
Rugged water-proof die-cast aluminum
chassis.
•
Data speeds of 9600 to 19200 b/s
(9600 b/s maximum in half channels)
•
3 available user ports using standard
RS-232 interface
•
Built–in 16-channel synthesized radio
transceiver.
•
Power output of 10W to 40W (software
controlled).
•
Half duplex or simplex operation.
1.3 Configuration
Operating characteristics of the Gemini/PD
are configured by Dataradio System
Engineering for communication protocols
and network settings.
A R
adio Service Software (RSS
) is provided
for radio/modem maintenance, adjustments
and frequency programming. The RSS is
MSDOS based and will run on any 486 or
higher PC (2 Megabytes memory required).
WARNING
: The frequency band 406 to
406.1 MHz is reserved for use by distress
beacons and cannot not be programmed into
the unit.
