Garmin GPS 35 LP Manual

GPS 35/36 TracPakTM
GPS SMART ANTENNA
TECHNICAL SPECIFICATION
GARMIN · 1200 E. 151st Street · Olathe, Kansas 66062 ·
[phone] · [phone] FAX

©1999GARMINCorporation,1200E.151stStreet,Olathe,
KS 66062
Allrightsreserved. Nopartofthismanualmaybereproduced
or transmitted in any form or by any means, electronic or
mechanical,includingphotocopyingandrecording,forany
purposewithouttheexpresswrittenpermissionofGARMIN.
Information in this document is subject to change without
notice. GARMIN reserves the right to change or improve
their products and to make changes in the content without
obligation to notify any person or organization of such
changes or improvements.
January, 1999 190-00104-00 Rev. D

CAUTION
The GPS system is operated by the government of the
United States which is solely responsible for its accuracy
and maintenance. Although the GPS 35/36 is a precision
electronic NAVigation AID (NAVAID), any NAVAID can be
misused or misinterpreted, and therefore become unsafe.
Use the GPS 35/36 at your own risk. To reduce the risk,
carefullyreviewandunderstandallaspectsofthisTechnical
Manual before using the GPS 35/36. When in actual use,
carefully compare indications from the GPS 35/36 to all
availablenavigationsourcesincludingtheinformationfrom
other NAVAIDs, visual sightings, charts, etc. For safety,
always resolve any discrepancies before continuing
navigation.
NOTE
This device has been tested and found to comply with the
limits for a Class B digital device, pursuant to Part 15 of the
FCC Rules. Operation is subject to the following two
conditions: (1) This device may not cause harmful
interference,and(2)thisdevicemustacceptanyinterference
received, including interference that may cause undesired
operation.
Thisdevicegenerates,usesandcanradiateradiofrequency
energyand,ifnotinstalledandusedinaccordancewiththe
instructions, may cause harmful interference to radio
communications. However, there is no guarantee that
interference will not occur in a particular installation. If this
devicedoescauseharmfulinterferencetoradioortelevision
reception, which can be determined by turning the device
off and on, you are encouraged to try to correct the
interference by one or more of the following measures:
· Reorient or relocate the receiving antenna.
· Increase the separation between this device and the
receiver.

· Connect this device to an outlet on a different circuit
than that to which the receiver is connected.
· Consult the dealer or an experienced radio/TV
technician for help.
This device contains no user-serviceable parts. Repairs
shouldonlybeperformedbyanauthorizedGARMINservice
center. Unauthorizedrepairsormodificationstothisdevice
could void your warranty and your authority to operate this
device under Part 15 regulations.

TABLE OF CONTENTS
1. Introduction 1
1.1 Overview 1
1.2 Features 2
1.3 Technical Specifications 2
1.4 Application 4
2. Operational Characteristics 5
2.1 Self Test 5
2.2 Initialization 5
2.3 Navigation 6
2.4 Satellite Data Collection 7
3. Hardware Interface 9
3.1 Mechanical Dimensions 9
3.2 Mounting Configurations and Options 11
3.3 Connection Wiring Description 15
4. Software Interface 17
4.1 NMEA Received Sentences 17
4.2 NMEA Transmitted Sentences 21
4.3 Baud Rate Selection 28
4.4 RTCM Received Data 29
A. Earth Datums A-1

SECTION 1
INTRODUCTION
1.1 OVERVIEW
The GARMIN GPS 35/36 is a complete GPS receiver,
including an embedded antenna, designed for a broad
spectrumofOEM(OriginalEquipmentManufacturer)system
applications. Based on the proven technology found in
other GARMIN 12 channel GPS receivers, the GPS 35/36
will track up to 12 satellites at a time while providing fast
time-to-first-fix, one second navigation updates and low
power consumption. Its far reaching capability meets the
sensitivity requirements of land navigation as well as the
dynamics requirements of high performance aircraft.
The GPS 35/36design utilizes the latest technology and
highlevelcircuitintegrationtoachievesuperiorperformance
whileminimizingspaceandpowerrequirements. Allcritical
components of the system including the RF/IF receiver
hardware and the digital baseband are designed and
manufactured by GARMIN to ensure the quality and
capability of the GPS 35/36. This hardware capability
combinedwithsoftwareintelligencemakes theGPS 35/36
easy to integrate and use.
The GPS 35/36 is designed to withstand rugged operating
conditionsand iscompletelywater resistant. TheGPS35/
36 is a complete GPS receiver that requires minimal
additional components be supplied by an OEM or system
integrator. AminimumsystemmustprovidetheGPS35/36
with a source of power and a clear view of the GPS
satellites. ThesystemmaycommunicatewiththeGPS35/
36 via a choice of two RS-232 compatible full duplex
communicationchannels. Internalmemorybackupallows
theGPS35/36toretaincriticaldatasuchassatelliteorbital
parameters,lastposition,dateandtime. Enduserinterfaces
1

suchaskeyboardsanddisplaysareaddedbytheapplication
designer.
1.2 FEATURES
TheGPS35/36providesahostoffeaturesthatmakeiteasy
to integrate and use.
1) Full navigation accuracy provided by Standard
Positioning Service (SPS)
2) Compact design ideal for applications with minimal
space
3) High performance receiver tracks up to 12 satellites
whileprovidingfastfirstfixandlowpowerconsumption
4) Differential capability utilizes real-time RTCM
corrections producing 3-10 meter position accuracy
5) Internalclockandmemoryaresustainedbyamemory
backup battery or optional external standby power
6) User initialization is not required
7) Navigation mode (2D or 3D) may be configured by
the user
8) Two communication channels and user selectable
baud rates allow maximum interface capability and
flexibility
1.3 TECHNICAL SPECIFICATIONS
Specifications are subject to change without notice.
1.3.1 PhysicalCharacteristics
1) Single construction integrated antenna/receiver.
2) Weight: 4.4 oz, (124.5 g), not including cable
3) Size: 2.230"(w)x 3.796" (l)x1.047" (h), (56.64mm
x 96.42 mm x 26.60 mm)
2

1.3.2 EnvironmentalCharacteristics
1) Operating temperature: -30°C to +85°C (internal
temperature)
2) Storage temperature: -40°C to +90°C
1.3.3 ElectricalCharacteristics
1) Input voltage: 10 to 30 VDC, unregulated.
2) Typically draws 150 mA @ 12 VDC
3) Backup power: Internal 3V Lithium coin cell battery,
up to 10 year life
1.3.4 Performance
1) Tracks up to 12 satellites
2) Update rate: 1 second
3) Acquisition time
- 15 seconds warm (all data known)
- 45 seconds cold (initial position, time and
almanac known, ephemeris unknown)
- 5.0 minutes AutoLocateTM (almanac known, initial
position and time unknown)
- 5 minutes search the sky (no data known)
4) Position accuracy:
Differential GPS (DGPS): 5 meters RMS
Non-differentialGPS: 15metersRMS(100meters
with Selective Availability on)
5) Velocityaccuracy: 0.2m/sRMSsteadystate(subject
to Selective Availability)
6) Dynamics: 999 knots velocity, 6g dynamics
3

1.3.5 Interfaces
1) DualchannelRS-232compatiblewithuserselectable
baud rate (1200, 2400, 4800, 9600)
2) NMEA 0183 Version 2.0 ASCII output (GPALM,
GPGGA, GPGSA, GPGSV, GPRMC, GPVTG,
PGRME, PGRMT, PGRMV, PGRMF, LCGLL,
LCVTG)
Inputs
- Initial position, date and time (not required)
- Earth datum and differential mode configuration
command, almanac.
Outputs
- Position, velocity and time
- Receiver and satellite status
- Differential Reference Station ID and RTCM Data
age
- Geometry and error estimates
3) Real-timeDifferentialCorrectioninput(RTCMformat)
1.4 APPLICATION
4
TYPICAL APPLICATION ARCHITECTURE

SECTION 2
OPERATIONAL CHARACTERISTICS
Thissectiondescribesthebasicoperationalcharacteristics
of the GPS 35/36. Additional information regarding input
and output specifications are contained in Section 4.
2.1 SELF TEST
After input power has been applied to the GPS 35/36 and
periodically thereafter, the unit will perform critical self test
functionsandreporttheresultsovertheoutputchannel(s).
The following tests will be performed:
1) RAM check
2) ROM test
3) Receiver test
4) Real-time clock test
5) Oscillator check
In addition to the results of the above tests, the GPS 35/36
will report software version information.
2.2 INITIALIZATION
Aftertheinitialselftestiscomplete,theGPS35/36willbegin
the process of satellite acquisition and tracking. The
acquisition process is fully automatic and, under normal
circumstances, will take approximately 45 seconds to
achieve a position fix (15 seconds if ephemeris data is
known). After a position fix has been calculated, valid
position, velocity and time information will be transmitted
over the output channel(s).
5