DeWalt SV12 User Manual

SV12 GPS Receiver

User’s Manual

CTI06-117

May 2006

Prepared by:

Coleman Technologies, Inc.

20 North Orange Avenue, Suite 300

Orlando, Florida 32801

[phone]

Table of Contents

1.0

PREFACE......................................................................................................................................... 1

2.0 SV12 GPS RECEIVER OVERVIEW............................................................................................. 1

2.1 Interface Protocols..................................................................................................................... 2

2.1.1 SV12 GPS Serial Port Interface ............................................................................................. 3

2.2 Antenna....................................................................................................................................... 3

2.3 Power.......................................................................................................................................... 4

2.4 Hardware Setup.......................................................................................................................... 4

3.0 INTEGRATION OF THE SV12 GPS RECEIVER ...................................................................... 5

3.1 Hardware Integration................................................................................................................. 5

3.1.1 Power Requirement ................................................................................................................ 5

3.1.2 Pulse Per Second.................................................................................................................... 6

3.1.3 Mounting ................................................................................................................................ 6

3.2 Software Interface ...................................................................................................................... 7

3.2.1 Start-up................................................................................................................................... 7

3.2.2 Communicating with the SV12 GPS Receiver........................................................................ 7

3.2.3 Protocol Summary.................................................................................................................. 8

APPENDIX A – SPECIFICATIONS .....................................................................................................A-1

1.0 PREFACE

The Global Positioning System (GPS) is a satellite based navigation system operated and
maintained by the U.S. Government. The GPS consists of a constellation of 24 satellites
providing world-wide, 24 hour, three dimensional (3-D) coverage. GPS applications
include military, surveying, marine, land, aviation, and vehicle navigation. GPS is the
most accurate technology available for vehicle navigation/location.

Since GPS is a satellite based system, it is immune to the limitations of land-based
systems such as Loran. Loran is limited in coverage and can be adversely affected by
weather. In addition, the accuracy of Loran is significantly worse than GPS. By
computing the distance to GPS satellites orbiting the earth, a GPS receiver can calculate
an accurate position. To determine a 2-D position calculation (latitude/longitude), 3 GPS
satellites must be in range. A 3-D position calculation (which includes altitude), requires
a minimum of 4 GPS satellites to be in range. GPS receivers can also provide precise
time, speed and course measurements.

Differential GPS (DGPS) is a form of GPS navigation which provides even greater
accuracy than standard GPS. Differential GPS requires error corrections transmitted
from a GPS receiver placed in a known location, referred to as a reference station. The
reference station calculates the error in the satellite range data and outputs corrections for
use by other GPS receivers. These GPS receivers are designated as mobile units and can
be dispersed as far as 100 KM form the reference station. Differential GPS eliminates
virtually all the measurement error in the satellite ranges and enables a highly accurate
position calculation. The SV12 GPS receiver is differential-ready for applications
requiring DGPS accuracy.

The SV12 GPS Receiver is an upgrade to CTI’s SV8 GPS Receiver (which was a
replacement for the Trimble SVeeEight Plus GPS Receiver). The SV12 GPS Receiver is
manufactured by Coleman Technologies, Inc., located at 20 North Orange Avenue, Suite
300; Orlando, FL 32801.

2.0 SV12 GPS RECEIVER OVERVIEW

The SV12 GPS Receiver delivers an unmatched level of performance for your GPS
applications. The device uses the Trimble’s Lassen® iQ12-channel GPS module. The
iQ GPS module has improved immunity to in-band jammers over it’s predecessors and is
designed to track weak signals improving position availability in environments with
obscured coverage.

The SV12 GPS Receiver includes a complete 12-channel parallel tracking GPS receiver
designed to operate with the L1 frequency, Standard Position Service, Coarse Acquisition
code, using Trimble custom integrated circuits. The receiver is housed in a rugged metal
enclosure especially suited for plug and play applications. The SV12 GPS receiver

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acquires a position fix with minimal delay after power cycling. The following
information is necessary to help decrease the time to track satellites after power-up and is
stored in RAM when backup power is provided:

• Almanac

• Ephemeris

• Real-time clock

• Last position

User settings, including port parameters and receiver processing options, can be stored in
non-volatile electrically erasable (EEPROM) that does not require power.

The SV12 GPS Receiver has two independently configurable serial I/O communication
ports. The dual data I/O port characteristics and other options are user programmable
and can be stored in non-volatile memory.

Warning – When customizing port assignments or characteristics, confirm that your
changes do not affect the ability to communicate with the receiver.

2.1 Interface Protocols

The SV12 GPS Receiver operates using either of three protocols – Trimble Standard
Interface Protocol (TSIP), Trimble ASCII Interface Protocol (TAIP) and NMEA 0183
(Version 3.0). The SV12 GPS Receiver also supports RTCM SC-104 for DGPS. The
factory default settings for the different factory default configurations are listed in Table

2.1-1 and Table 2.1-2.

Table 2.1-1 TSIP and NMEA Receiver Interface Protocols

Port Setting

Port 1 NMEA 0183 out/RTCM SC-104 V2.1 in
Port 2 TSIP bi-directional

Table 2.1-2 TAIP Receiver Interface Protocols

Port Setting

Port 1 NMEA 0183 out/ RTCM SC-104 V2.1 in
Port 2 TAIP bi-directional

TSIP

TSIP is a binary packet protocol that allows the system designer maximum configuration
control over the GPS receiver for optimum performance in any number of applications.
TSIP supports over 40 commands and their associated response packets for use in
configuring the SV12 GPS Receiver to meet user requirements.

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