Campbell GPS16X-HVS User manual

INSTRUCTION MANUAL
GPS16X-HVS GPS Receiver
Revision: 10/17
Copyright © 2003-2017
Campbell Scientific, Inc.

Limited Warranty
“Products manufactured by CSI are warranted by CSI to be free from defects in
materials and workmanship under normal use and service for twelve months
from the date of shipment unless otherwise specified in the corresponding
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www.campbellsci.com.) Products not manufactured by CSI, but that are resold
by CSI, are warranted only to the limits extended by the original manufacturer.
Batteries, fine-wire thermocouples, desiccant, and other consumables have no
warranty. CSI’s obligation under this warranty is limited to repairing or
replacing (at CSI’s option) defective Products, which shall be the sole and
exclusive remedy under this warranty. The Customer assumes all costs of
removing, reinstalling, and shipping defective Products to CSI. CSI will return
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Products which have been subjected to modification, misuse, neglect, improper
service, accidents of nature, or shipping damage. This warranty is in lieu of all
other warranties, expressed or implied. The warranty for installation services
performed by CSI such as programming to customer specifications, electrical
connections to Products manufactured by CSI, and Product specific training, is
part of CSI's product warranty. CSI EXPRESSLY DISCLAIMS AND
EXCLUDES ANY IMPLIED WARRANTIES OF MERCHANTABILITY
OR FITNESS FOR A PARTICULAR PURPOSE. CSI hereby disclaims,
to the fullest extent allowed by applicable law, any and all warranties and
conditions with respect to the Products, whether express, implied or
statutory, other than those expressly provided herein.”

Assistance
Products may not be returned without prior authorization. The following
contact information is for US and international customers residing in countries
served by Campbell Scientific, Inc. directly. Affiliate companies handle repairs
for customers within their territories. Please visit www.campbellsci.com to
determine which Campbell Scientific company serves your country.
To obtain a Returned Materials Authorization (RMA) number, contact
CAMPBELL SCIENTIFIC, INC., phone [phone]. Please write the
issued RMA number clearly on the outside of the shipping container. Campbell
Scientific’s shipping address is:
CAMPBELL SCIENTIFIC, INC.
RMA#_____
815 West 1800 North
Logan, Utah 84321-1784
For all returns, the customer must fill out a “Statement of Product Cleanliness
and Decontamination” form and comply with the requirements specified in it.
The form is available from our website at www.campbellsci.com/repair. A
completed form must be either emailed to [e-mail] or faxed to
[phone]. Campbell Scientific is unable to process any returns until we
receive this form. If the form is not received within three days of product
receipt or is incomplete, the product will be returned to the customer at the
customer’s expense. Campbell Scientific reserves the right to refuse service on
products that were exposed to contaminants that may cause health or safety
concerns for our employees.

Safety
DANGER — MANY HAZARDS ARE ASSOCIATED WITH INSTALLING, USING, MAINTAINING, AND WORKING ON OR AROUND
TRIPODS, TOWERS, AND ANY ATTACHMENTS TO TRIPODS AND TOWERS SUCH AS SENSORS, CROSSARMS, ENCLOSURES,
ANTENNAS, ETC. FAILURE TO PROPERLY AND COMPLETELY ASSEMBLE, INSTALL, OPERATE, USE, AND MAINTAIN TRIPODS,
TOWERS, AND ATTACHMENTS, AND FAILURE TO HEED WARNINGS, INCREASES THE RISK OF DEATH, ACCIDENT, SERIOUS
INJURY, PROPERTY DAMAGE, AND PRODUCT FAILURE. TAKE ALL REASONABLE PRECAUTIONS TO AVOID THESE HAZARDS.
CHECK WITH YOUR ORGANIZATION'S SAFETY COORDINATOR (OR POLICY) FOR PROCEDURES AND REQUIRED PROTECTIVE
EQUIPMENT PRIOR TO PERFORMING ANY WORK.
Use tripods, towers, and attachments to tripods and towers only for purposes for which they are designed. Do not exceed design limits.
Be familiar and comply with all instructions provided in product manuals. Manuals are available at www.campbellsci.com or by
telephoning [phone] (USA). You are responsible for conformance with governing codes and regulations, including safety
regulations, and the integrity and location of structures or land to which towers, tripods, and any attachments are attached. Installation
sites should be evaluated and approved by a qualified engineer. If questions or concerns arise regarding installation, use, or
maintenance of tripods, towers, attachments, or electrical connections, consult with a licensed and qualified engineer or electrician.
General
•Prior to performing site or installation work, obtain required approvals and permits. Comply
with all governing structure-height regulations, such as those of the FAA in the USA.
•Use only qualified personnel for installation, use, and maintenance of tripods and towers, and
any attachments to tripods and towers. The use of licensed and qualified contractors is highly
recommended.
•Read all applicable instructions carefully and understand procedures thoroughly before
beginning work.
•Wear a hardhat and eye protection, and take other appropriate safety precautions while
working on or around tripods and towers.
•Do not climb tripods or towers at any time, and prohibit climbing by other persons. Take
reasonable precautions to secure tripod and tower sites from trespassers.
•Use only manufacturer recommended parts, materials, and tools.
Utility and Electrical
•You can be killed or sustain serious bodily injury if the tripod, tower, or attachments you are
installing, constructing, using, or maintaining, or a tool, stake, or anchor, come in contact with
overhead or underground utility lines.
•Maintain a distance of at least one-and-one-half times structure height, 20 feet, or the distance
required by applicable law, whichever is greater, between overhead utility lines and the
structure (tripod, tower, attachments, or tools).
•Prior to performing site or installation work, inform all utility companies and have all
underground utilities marked.
•Comply with all electrical codes. Electrical equipment and related grounding devices should be
installed by a licensed and qualified electrician.
Elevated Work and Weather
•Exercise extreme caution when performing elevated work.
•Use appropriate equipment and safety practices.
•During installation and maintenance, keep tower and tripod sites clear of un-trained or non-
essential personnel. Take precautions to prevent elevated tools and objects from dropping.
•Do not perform any work in inclement weather, including wind, rain, snow, lightning, etc.
Maintenance
•Periodically (at least yearly) check for wear and damage, including corrosion, stress cracks,
frayed cables, loose cable clamps, cable tightness, etc. and take necessary corrective actions.
•Periodically (at least yearly) check electrical ground connections.
WHILE EVERY ATTEMPT IS MADE TO EMBODY THE HIGHEST DEGREE OF SAFETY IN ALL CAMPBELL SCIENTIFIC PRODUCTS,
THE CUSTOMER ASSUMES ALL RISK FROM ANY INJURY RESULTING FROM IMPROPER INSTALLATION, USE, OR
MAINTENANCE OF TRIPODS, TOWERS, OR ATTACHMENTS TO TRIPODS AND TOWERS SUCH AS SENSORS, CROSSARMS,
ENCLOSURES, ANTENNAS, ETC.

i
Table of Contents
PDF viewers: These page numbers refer to the printed version of this document. Use the
PDF reader bookmarks tab for links to specific sections.
1. Overview.....................................................................1
1.1 Default Settings....................................................................................1
1.2 Compatible Dataloggers.......................................................................2
1.3Common Accessories...........................................................................2
2. Precautions ................................................................2
3. Initial Inspection.........................................................3
4. QuickStart...................................................................3
5. Specifications.............................................................4
6. Installation ..................................................................6
6.1 Wiring ..................................................................................................6
6.1.1 Using with an A300 ......................................................................8
6.2 Mounting..............................................................................................8
7. GPS Data ....................................................................9
7.1 $GPGGA Sentence (Position and Time)..............................................9
7.2 $GPRMC Sentence (Position and Time) ...........................................11
8. CRBasic Programming ............................................11
8.1 GPS() Instruction ...............................................................................11
8.2 Example Program Using GPS() Instruction .......................................13
9. Troubleshooting.......................................................14
9.1 Testing and Evaluating Serial Communications ................................15
9.1.1 Through a Direct Connection to the GPS16X-HVS ...................15
9.1.2 Through a Datalogger Connected to the GPS16X-HVS .............15
9.2 NMEAStrings Variable Populated, but Clock Not Setting ................16
Appendices
A. Changing GPS16X-HVS Settings .......................... A-1
A.1 Computer Connections.................................................................... A-1
A.1.1 Using the A200 ........................................................................ A-1
A.1.1.1Driver Installation ......................................................... A-1
A.1.1.2 Wiring ........................................................................... A-2
A.1.1.3 Powering the Sensor...................................................... A-3

Table of Contents
ii
A.1.1.4 Determining which COM Port the A200 has been
Assigned .................................................................... A-3
A.1.2 Using the 28840 Interface ........................................................ A-3
B. Serial Programming ............................................... B-1
Figures
1-1. The GPS16X-HVS terminates in pigtails for direct connection to
our dataloggers................................................................................. 1
6-1. CR1000 to GPS16X-HVS connection................................................. 7
6-2. GPS16X-HVS mounted using a CM235 Magnetic Mounting
Stand ................................................................................................ 9
A-1. A200 Sensor-to-PC Interface .......................................................... A-2
Tables
1-1. Default Settings ................................................................................... 1
6-1. Datalogger Wiring............................................................................... 6
6-2. CR9000X Wiring ................................................................................ 7
6-3. GPS16X-HVS Wiring to A300 Terminals and Datalogger
Terminals ......................................................................................... 8
6-4. A300 Cable Wiring to Datalogger Terminals...................................... 8
7-1. NMEA $GPGGA String Definition .................................................. 10
A-1. A200 Wiring.................................................................................... A-2
A-2. 28840 Interface Wiring ................................................................... A-3
CRBasic Examples
8-1. Reading the GPS Using the GPS() Instruction.................................. 14
B-1. Reading the GPS Using Serial Programming .................................. B-1

1
GPS16X-HVS GPS Receiver
1. Overview
FIGURE 1-1. The GPS16X-HVS terminates in pigtails for direct
connection to our dataloggers
The GPS16X-HVS is a complete GPS receiver manufactured by Garmin
International, Inc. Campbell Scientific configures the GPS16X-HVS to work
with our dataloggers and modifies its cable so that the cable terminates in
pigtails. The pigtails connect directly to the control ports of our dataloggers or
with the aid of an A300.
The GPS16X-HVS includes the GPS receiver and antenna in the same housing
with one cable for the power supply and communications. The GPS antenna
must have a clear view of the sky. Generally, the GPS antenna will not work
indoors.
The GPS16X-HVS is a 12-channel GPS receiver that supports FAA Wide Area
Augmentation System (WAAS) or RTCM differential GPS. Also supported is
the 1 Pulse Per Second (PPS) timing signal. The cable connections provided
with the GPS16X-HVS do not support differential GPS correction. The cable
can be modified by the user if differential correction is required.
1.1 Default Settings
TABLE 1-1 shows the default settings of the GPSX16-HVS.
TABLE 1-1. Default Settings
Baud Rate 38400 bps
Parity N (no parity)
Stop Bit 1
Sentences Output GPGGA, GPRMC
PPS 100 ms

GPS16X-HVS GPS Receiver
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1.2 Compatible Dataloggers
Compatible Contemporary Dataloggers
CR300
Series
CR200(X)
Series
CR800
Series CR6 Series
CR1000X
Series CR1000 CR3000 CR9000X
* * * **
*If PPS is required, the A300 Power and Signal Converter is needed.
**CPU Card RS-232 port only.
This manual provides information only for CRBasic dataloggers.
It is also compatible with some of our retired Edlog dataloggers.
For Edlog datalogger support, see an older manual at
www.campbellsci.com/old-manuals.
Our CR1000X-series, CR6-series, CR300-series, CR800-series, CR1000, and
CR3000 dataloggers typically use the CRBasic GPS() instruction to read the
GPS16X-HVS. To use the PPS functionality, some dataloggers need an
updated clock chip. The clock chip is factory replaced (requires an RMA).
Dataloggers with the following serial numbers need an updated chip:
Datalogger Serial Number
CR1000M < 20409
CR800 Series < 7920
CR3000 < 3168
In August 2014, Garmin changed the GPS16X-HVS PPS output signal from
5 V to 3 V. Units with serial numbers greater than 1A4189318 have a 3 V PPS
output signal. When this new design is used with a CR800-series, CR1000, or
CR3000 datalogger, a 3 V to 5 V voltage shifter is required for use with the
PPS signal output. The A300 can be used for this purpose. This level shifter is
NOT required for the CR6-series datalogger.
1.3 Common Accessories
CSI part number Description
17212 GPS16X-HVS magnetic mount
CM235 Magnetic mounting stand
A200 Sensor to PC interface
A300 Power and signal converter
28840 DB9 female to terminal block with hood and hardware kit
2. Precautions
•READ AND UNDERSTAND the Safety section at the front of this
manual.
•When wiring the GPS16X-HVS, connect Ground before connecting 12V.
NOTE

GPS16X-HVS GPS Receiver
3
3. Initial Inspection
Upon receipt of the GPS16X-HVS, inspect the packaging and contents for
damage. File damage claims with the shipping company.
4. QuickStart
Short Cut is an easy way to program your datalogger to measure the
GPS16X-HVS and assign datalogger wiring terminals. Short Cut is available as
a download on www.campbellsci.com. It is included in installations of
LoggerNet, PC200W, PC400, or RTDAQ.
The following procedure shows using Short Cut to measure the GPS16X-HVS.
1. Open Short Cut and select to create a new program.
2. Double-click the datalogger model.
3. Under the Available Sensors and Devices list, select the Sensors |
Miscellaneous Sensors folder and double-click GPS16X-HVS. Specify
the Local time offset, whether to synchronize datalogger clock to GPS
clock, and the Maximum time difference allowed between datalogger
clock and GPS clock. You may also change any of the default labels for
the returned GPS values. Press OK.

GPS16X-HVS GPS Receiver
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4. After completing the sensor form, click Wiring Diagram to see how the
GPS16X-HVS is to be wired to the datalogger. The wiring diagram can be
printed now or after more sensors are added.
5. Select any other sensors you have, then finish the remaining Short Cut
steps to complete the program. The remaining steps are outlined in Short
Cut Help, which is accessed by clicking on Help | Short Cut Help |
Contents | Programming Steps.
6. If LoggerNet, PC400, RTDAQ, or PC200W is running on your PC, and the
PC to datalogger connection is active, you can click Finish in Short Cut
and you will be prompted to send the program just created to the
datalogger.
7. If the GPS16X-HVS is connected to the datalogger, as shown in the wiring
diagram in step 4, check the output of the GPS16X-HVS in the datalogger
support software data display to make sure it is making reasonable
measurements.
5. Specifications
Physical
Size: 86 mm (3.39 in) diameter, 42 mm (1.65 in) high
Weight: 181 g (6.4 oz) without cable, 332 g (11.7 oz) with 5 m
cable
Cable: PVC-jacketed, 5 m, foil-shielded, 8-conductor, 28 AWG
Electrical Characteristics
Input Voltage: 8.0 Vdc to 40 Vdc unregulated
Current Drain: 65 mA @ 12 Vdc

GPS16X-HVS GPS Receiver
5
GPS Receiver
Sensitivity: –185 dbW minimum
GPS Performance
Receiver: WAAS enabled; 12 parallel channel GPS receiver
continuously tracks and uses up to 12 satellites, 11 if
PPS is active
Acquisition Times (Approximate)
Reacquisition: Less than 2 s
Hot: 1 s (all data known)
Warm: ~38 s (initial position, time and almanac known,
ephemeris unknown)
Cold: ~45 s
SkySearch: 5 min (no data known)
Sentence Rate: 1 s default; NMEA 0183 output interval configurable
from 1 to 900 s in one second increments
Accuracy: GPS Standard Positioning Service (SPS)
Position: Less than 15 m, 95% typical (100 m with selective
availability on)
Velocity: 0.1 knot RMS steady state
DGPS (USCG/RTCM)
Position: 3-5 m, 95% typical
Velocity: 0.1 knot RMS steady state
DGPS (WAAS)
Position: Less than 3 m
Velocity: 0.1 knot RMS steady state
PPS Time: ±1 microsecond at rising edge of PPS pulse (subject to
selective availability)
Dynamics: 999 knots velocity (limited above 60,000 ft, 6g
dynamics)
Interfaces: True RS-232 output, asynchronous serial input
compatible with RS-232 or TTL voltage levels, RS-232
polarity. Selectable baud rates (4800, 9600, 19200,
38400)
PPS: 1 Hz pulse, programmable width, 1 microsecond
accuracy
Power Control
Off: Open circuit
On: Ground or pull to low logic level < 0.3 volts

GPS16X-HVS GPS Receiver
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Environmental Characteristics
Temperature: –30 to 80 °C operational, –40 to 80 °C storage
6. Installation
6.1 Wiring
The GPS16X-HVS connects directly to a CR300-series, CR1000X-series,
CR6-series, CR800-series, CR1000, or CR3000 datalogger (see TABLE 6-1).
However, if PPS is required, the A300 Power and Signal Converter may be
required for use with the CR800 series, CR1000, and CR3000. See Section
6.1.1, Using with an A300 (p. 8). The CR6 series, CR1000X series, and CR300
series do not require the use of an A300.
The CR9000X only supports the GPS16X-HVS on the RS-232 port of the CPU
card. The recommended interface is pn 28841. See TABLE 6-2.
If the GPS16X-HVS is to be connected to a computer to change the default
settings, an A200 or pn 28840 interface is needed (see Appendix A, Changing
GPS16X-HVS Settings (p. A-1)).
TABLE 6-1. Datalogger Wiring
GPS16X-HVS Datalogger Function
Red 12V Power In
Black Ground Power Ground
Yellow Ground or Control Port for
On/Off control Power Switch
White Control Port (Rx) TXD
Gray Control Port (Tx) PPS
Blue Ground or Control Port (Tx) for
datalogger-based configuration Rxdata
Shield Ground Shield

GPS16X-HVS GPS Receiver
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FIGURE 6-1. CR1000 to GPS16X-HVS connection
TABLE 6-2. CR9000X Wiring
GPS16X-HVS CR9000X Function
Red 12 V (SDM or 9011
connector) Power In
Black Ground (SDM or 9011
connector)* Power Ground
Yellow Ground (SDM or 9011
connector)* Power Switch
White RS-232 pin 3 (using
28841) TXD
Gray RS-232 pin 9 (using
28841) PPS
Blue No Connection RxData
Shield Ground (SDM or 9011
connector)* Shield
*All of the grounds should also be tied to the RS-232 pin 5 (using pn 28841). A pn
27373 terminal connector can be used to facilitate connecting all of the wires into the
same terminal.

GPS16X-HVS GPS Receiver
8
6.1.1 Using with an A300
In 2014, Garmin changed the pulse-per-second (PPS) output of the
GPS16X-HVS from 5 V to 3 V. Units with a serial number 1A4189318 or
greater have a PPS output of 0 to 3 V. For those units, an A300 is needed to
connect the PPS output to a CR800-series, CR1000, or CR3000 datalogger.
Those dataloggers require the PPS line to have a voltage of 3.8 V or greater.
TABLE 6-3. GPS16X-HVS Wiring to A300 Terminals
and Datalogger Terminals
GPS16X-HVS
Wire Color
GPS16X-HVS
Wire Function
A300
Terminal Datalogger
Red 12 V 12V
Black Ground G
Yellow Enable Ground (or
Control Port)
White TXD (Output) Control Port (Rx)
Gray PPS 3.3V IN
Blue RXD (Input) Ground
Shield Shield Ground
TABLE 6-4. A300 Cable Wiring to Datalogger Terminals
A300 Wire Color A300 Wire Function Datalogger
Red 12 V 12V
Black Ground Ground
Green 5 V Signal Input Ground
White 5 V Signal Output Control Port (Tx)
6.2 Mounting
The GPS16X-HVS mounts to a mast or crossarm using the CM235 Magnetic
Mounting Stand. Typically, the GPS16X-HVS mounts to the CM235
magnetically with the addition of the 17212 Magnetic Mount. Alternatively,
the GPS16X-HVS can be mounted directly to the CM235 using three M4
screws supplied with the 17212 or by the customer.

GPS16X-HVS GPS Receiver
9
FIGURE 6-2. GPS16X-HVS mounted using a CM235 Magnetic
Mounting Stand
7. GPS Data
The GPS16X-HVS has several data formats available. The GPS16X-HVS is
configured to output the NMEA $GPGGA and $GPRMC time and position
string. It is possible to configure the GPS16X-HVS to output other NMEA
strings including the $GPVTG track made good and ground speed string. See
Appendix A, Changing GPS16X-HVS Settings (p. A-1), for details.
7.1 $GPGGA Sentence (Position and Time)
Sample NMEA $GPGGA data string:
$GPGGA,hhmmss,llll.lll,a,nnnnn.nnn,b,t,uu,v.v,w.w,M,x.x,M,y.y,zzzz*hh<CR><LF>

GPS16X-HVS GPS Receiver
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TABLE 7-1. NMEA $GPGGA String Definition
Field Description
0 $GPGGA NMEA string identifier
1 hhmmss UTC of Position: Hours, minutes, seconds
2 1111.111 Latitude: Degrees, minutes, thousandths of minutes
3 a N (North) or S (South)
4 nnnnn.nnn Longitude: Degrees, minutes, thousandths of minutes
5 b E (East) or W (West)
6 t GPS Quality Indicator: 0 = No GPS, 1 = GPS, 2 =
DGPS
7 uu Number of Satellites in Use
8 v.v Horizontal Dilution of Precision (HDOP)
9 w.w Antenna Altitude in Meters
10 M M = Meters
11 x.x Geoidal Separation in Meters
12 M
M = Meters. Geoidal separation is the difference
between the WGS-84 earth ellipsoid and mean-sea-
level.
13 y.y Age of Differential GPS Data. Time in seconds since
the last Type 1 or 9 Update
14 zzzz Differential Reference Station ID (0000 to 1023)
15 * Asterisk, generally used as the termination character
16 hh Checksum
17 <CR><LF> Carriage return, line feed characters.
Sample $GPGGA output strings:
Cold Start
No satellites acquired, Real Time Clock and Almanac invalid:
$GPGGA,,,,,,0,00,,,,,,,*66
Warm Start
No satellites acquired, time from Real Time Clock, almanac valid:
$GPGGA,235032.0,,,,,0,00,,,,,,,*7D
Warm Start
One satellite in use, time from GPS Real Time Clock (not GPS), no position:
$GPGGA,183806.0,,,,,0,01,,,,,,,*7D
Valid GPS Fix
Three satellites acquired, time and position valid:
$GPGGA,005322.0,4147.603,N,11150.978,W,1,03,11.9,00016,M,-016,M,,*6E

GPS16X-HVS GPS Receiver
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7.2 $GPRMC Sentence (Position and Time)
Example (signal not acquired):
$GPRMC,235947.000,V,0000.0000,N,00000.0000,E,,,041299,,*1D
Example (signal acquired):
$GPRMC,092204.999,A,4250.5589,S,14718.5084,E,0.00,89.68,211200,,*25
Field Example Comments
Sentence ID $GPRMC
UTC Time 092204.999 hhmmss.sss
Status A A = Valid, V = Invalid
Latitude 4250.5589 ddmm.mmmm
N/S Indicator S N = North, S = South
Longitude 14718.5084 dddmm.mmmm
E/W Indicator E E = East, W = West
Speed over ground 0.00 Knots
Course over ground 0.00 Degrees
UTC Date 211200 DDMMYY
Magnetic variation Degrees
Magnetic variation E = East, W = West
Checksum *25
Terminator CR/LF
8. CRBasic Programming
This section describes programming a CR1000X-series, CR300-series,
CR6-series, CR800-series, CR1000, CR3000, or CR9000X datalogger.
This manual provides information only for CRBasic dataloggers.
It is also compatible with some of our retired Edlog dataloggers.
For Edlog datalogger support, see an older manual at
www.campbellsci.com/old-manuals.
8.1 GPS() Instruction
The GPS() instruction is available for our CR6-series, CR800-series, CR1000,
and CR3000 dataloggers. It is used along with a GPS device to set the
datalogger's clock. This instruction will also provide information such as
location (latitude/longitude) and speed, and store NMEA sentences from the
GPS device.
NOTE

GPS16X-HVS GPS Receiver
12
To use the GPS() instruction, the datalogger operating system
(OS) should be OS17 or higher for the CR1000; OS10 or higher
for the CR3000; or OS08 or higher for the CR800 series. Go to
www.campbellsci.com/downloads to upgrade the datalogger OS.
The resolution of accuracy for the clock set is 10 microseconds if the
datalogger has a hardware revision number greater than 007 (RevBoard field in
the datalogger's Status table). Otherwise, resolution is 10 milliseconds. The
clock set relies on information from the GPRMC sentence. If this sentence is
not returned, a clock set will not occur.
By default, the instruction expects the GPS unit to be set up at 38400 baud,
outputting the GPRMC and GPGGA sentences once per second. The
datalogger expects the start of the second to coincide with the rising edge of the
PPS signal. If there is no PPS signal or if the required sentences come out at
less than once per second, the datalogger will not update its clock.
GPS units with lower baud rates can be used with the GPS() instruction but the
baud rate has to be set for the relevant Com port it is to be connected to either
in the datalogger settings or by including a SetStatus() command after the
BeginProg() instruction in the program (e.g.,
SetStatus("BaudrateCOM4",19200)).
Baud rates of 2400 bps or lower will not work as the GPS unit will not transmit
the two GPS sentences once per second reliably. Similar problems can be
encountered even at higher baud rates if too many optional GPS strings are
selected to be output.
The GPS() instruction has the following syntax:
GPS(GPSArray,ComPort,TimeOffset,MaxTimeDiff,NMEAStrings)
Description of the parameters follows:
GPSArray The GPSArray parameter is the variable in which to store the
information returned by the GPS. Fifteen values are returned.
If this array is not dimensioned to 15, values will be stored to
fill the array and no error will be returned. If no values are
available, NAN will be returned. The following values are
returned by the GPS:
Array(1) = Latitude, degrees
Array(2) = Latitude, minutes
Array(3) = Longitude, degrees
Array(4) = Longitude, minutes
Array(5) = Speed over ground, knots
Array(6) = Course over ground, degrees
Array(7) = Magnetic variation (positive = East, negative =
West)
Array(8) = Fix Quality (0 = invalid, 1 = GPS, 2 = differential
GPS, 6 = estimated)
Array(9) = Number of Satellites
Array(10) = Altitude, meters
Array(11) = Pulse per second (PPS) length, microseconds
Array(12) = Seconds since last GPRMC sentence
NOTE